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Background: Rice plants generate a large amount of straw after harvesting, which is currently managed mainly by incineration or used as animal bedding, animal fodder or wrapping of materials during transport. Other technological uses, such as the production of energy and biofuels, pulp and paper production or construction materials have also been described. However, due to the current European Union (EU) restrictions, alternatives for waste management must be sought. Valorisation of rice straw is aligned with the Sustainable Development Goals agenda set by the EU, since interesting biocompounds have been described in their composition and, after a successful extraction and purification, they can be used in various sectors. Scope and approach: This review gathers the most relevant works related to the valorisation of rice straw. It focuses on polyphenolic extracts and cellulose derivatives obtained by different extraction techniques, either conventional or innovative. In addition, the different applications that these compounds have in the field of food and nutrition sciences are summarized. Key findings and conclusions: Polyphenols and cellulose fractions have shown their viability to be extracted from rice straw, showing great potential as antioxidants in the food sector or as nutritional components in the development of new food or packaging materials, respectively. In conclusion, the valorisation of rice straw as a rich source of valuable compounds has been demonstrated, which currently generates serious environmental and human problems due to difficulties in its management and incineration, adding value to these underutilized residues and contributing to the circular bioeconomy concept. This study was supported by the Spanish Ministry of Science Innovation and Universities, [PID2020-116496RB-C21 and PDC2021-121345-C21].

Seventeen extra virgin olive oil samples from Valencian Community (Spain) were submitted to a domestic-frying process (180 °C) during different degradation times (5, 10, 30, 60, 120 min). A dispersive liquid–liquid aerosol phase extraction by using a methanol/water (50:50) extracting solution was used to isolate the polyphenol fraction. Total phenolic content (TPC) was determined, whereas the determination of seven individual target polyphenolic compounds (hydroxytyrosol, tyrosol, oleuropein, vanillic acid, p-coumaric acid, ferulic acid, and vanillin) was carried out by using ultrahigh-performance liquid chromatography coupled to a tandem mass spectrometer. Statistically significant differences in the TPC values were found for Blanqueta and Manzanilla samples from different harvesting years. The domestic-frying process impacted the TPC and the individual phenolic compounds content. Thermal treatment for 2 h gave rise to a 94% decrease in the TPC. A first-order kinetic model was suitable to accurately describe the degradation of the individual phenolic compounds. The authors wish to thank the Spanish Ministry of Science, Innovation, and Universities for the financial support (project ref. PID2021-127566NB-I00).

Analysis of the oxidative stability of novel avocado chips with added natural extracts was carried out with the aim of reducing the chemical additive content in their formulation. Two different natural extracts were initially evaluated and characterized: one obtained from olive pomace (OE) and other from pomegranate seed waste. OE was selected due to its better antioxidant potential according to FRAP, ABTS, and DPPH assays as well as its higher total phenolic content. The formulations used were 0, 1.5 wt.%, and 3 wt.% of OE. A gradual disappearance of the band found around 3009 cm−1 and related to unsaturated fatty acids was observed in the control sample in contrast to formulations with added OE. The band observed near 3299 cm−1 widened and intensified with time due to the oxidation degree of samples, with this effect being higher in the control chips. The observed changes in fatty acid and hexanal content with storage time underlined the higher extent of oxidation in the control samples. This fact could suggest an antioxidant protectant action of OE in avocado chips during thermal treatment, which was attributed to the presence of phenolic compounds. The obtained chips incorporating OE represent a viable option for the development of a natural, healthy, and clean-label avocado snack at competitive cost and with low environmental impacts.

In the present study, thirteen elements (Ag, Al, Ba, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Ni, Pb) have been extracted from used cooking oils, olive oils and animal fat. Either inductively coupled plasma optical emission spectrometry (ICP-OES) or tandem mass spectrometry (ICP-MS/MS) have been chosen as detection techniques. Due to the difficulty of directly introducing highly viscous organic samples into the spectrometer, a fast dispersive liquid – liquid aerosol phase extraction (DLLAPE) method has been selected to isolate the analytes from the sample matrix. The DLLAPE is based on the generation of an aerosol from the extracting phase with the help of a pneumatic nebulizer. This high velocity aerosol impacts and penetrates in the liquid sample. Consequently, the liquid – liquid exchange surface area becomes high, thus leading to high extraction yields. A hydrophilic deep eutectic solvent (DES) consisting of choline chloride and ethylene glycol (1:2 mass ratio) has been selected as the extracting solvent. Prior to undertaking the experiments, the extraction method has been evaluated in terms of precision under suitable conditions. In comparison with conventional methods based on sample digestion, sample dilution and shot analysis or extraction assisted by vortex agitation, the DLLAPE shows several advantages, because it is faster, and it provides lower limits of detection than the reference methodologies. The procedural limits of quantification for the determined elements with the DLLAPE in ICP-OES were 0.046 (Ag), 0.396 (Al), 0.013 (Cd), 0.033 (Cr), 0.040 (Cu), 0.20 (Fe), 0.026 (K), 0.026 (Li), 0.33 (Mg), 0.013 (Mn), 2.64 (Ni) and 0.53 (Pb) mg kg−1. Meanwhile, pLOQ in ICP-MS/MS lowered by roughly one order of magnitude. The accuracy of the aerosol phase extraction method has been evaluated through the determination of the recoveries for four representative analytes (Ca, Cu, Mg and Ni) from spiked real samples. For these elements, recovery has taken values of (100 ± 20)%. Moreover, a comparison of the multielemental concentration obtained with conventional methods (c.a., sample dilution and shot ICP analysis and liquid-liquid extraction using a vortex agitator) against that measured with the DLLAPE has been carried out. Multiemelemental concentrations have been obtained for real samples and the found levels have been similar to those encountered in previously published works. The authors wish to thank to the Spanish Ministry of Science, Innovation and Universities for the financial support (Projects Ref. PID2021-127566NB-I00 and PID2021-127322NB-100).

Toxic metals found in the environment have been linked to female infertility and gynecological illnesses. Reliable analytical methods, such as inductively coupled plasma tandem mass spectrometry (ICP-MS/MS), are necessary to determine the elemental composition of biological samples. Currently, the multielemental profile of peritoneal fluid (PF) samples has not yet been established. Due to the complexity of the PF matrix, an ICP-MS/MS-based method has been optimized to mitigate matrix effects and spectral interferences. A dilution factor of 1:4 was the best option to mitigate matrix effects while keeping sensitivity at an appropriate level. A collision gas (He) was useful to lower the extent of spectral interferences for 56Fe, 52Cr, 63Cu, and 68Zn. An intermediate validation test was performed to evaluate accuracy, achieving recoveries ranging from 90 to 110%. The method was validated in terms of intermediate precision, reproducibility, and trueness, with an expanded uncertainty lower than 15%. Afterward, it was applied to perform the multielemental analysis of 20 PF samples. The concentrations for major analytes were up to 151 µg L−1. Meanwhile,209Bi, 111Cd, 52Cr, 55Mn, 95Mo, 60Ni, 208Pb, 118Sn, and 51V were present at concentrations included within the 1–10 µg L−1 range, while 59Co and 139La were found at concentrations below 1 µg L−1. This study was funded by the Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (UGP-19-042 and UGP-20-039). A.L.-B. is supported by the European Social Fund and the Generalitat Valenciana under a Ph.D. contract (ACIF–2021/243).

Elemental analysis of (bio)fuels and their feedstock is performed for the first time through ICP-MS/MS using a high temperature torch integrated sample introduction system (hTISIS). The system has been operated in continuous sample aspiration mode at a 30 μL min−1 liquid flow rate. An oxygen additional gas stream has been used in order to avoid soot deposit formation either in the torch or the ICP-MS/MS interface. Temperature and collision/reaction gas type and flow rate were varied in order to obtain the highest signal to background ratio. Compared with a conventional sample introduction system, the hTISIS operated at 300 °C yielded lower limits of detection. This parameter was included within the 0.005 (60Ni) to 6 μg kg−1 (28Si and 66Zn) range. An in-house method validation and uncertainty estimation were performed and it was verified that 80–90% of the uncertainty corresponded to the trueness assessment (i.e., bias, sample preparation and multielemental stock solution uncertainty). For most of the elements, the expanded uncertainty took values in between 7 and 24%. The hTISIS accounted for non-spectroscopic interferences, whereas ICP-MS/MS mitigated spectroscopic ones. This allowed the implementation of an accurate quantification method based on external calibration from a set of xylene-based standards. Thus, working with the hTISIS at 300 °C it was possible to perform the analysis of 36 samples including light petroleum cuts, diesel oil, kerosene, pyrolysis oils, vegetal oils and grease. The authors wish to thank to Total Raffinage Chimie, S. A., Gonfreville, France for financial support of the present study and for providing the samples analyzed.

Blending Poly(lactic acid) (PLA) and Poly(ε-caprolactone) (PCL) is a promising strategy to enhance the properties of biodegradable materials. However, these compounds are thermodynamically immiscible and, consequently, compatibilization is required during polymer blending. Reinforced biocomposites can be obtained by adding agricultural wastes generated by industries which are forced to consider waste treatment methods to prevent environmental concerns. Novel PCL/PLA blends were proposed based on the addition of 10 wt.% almond shell (AS) waste combined with 3 wt.% glycidyl methacrylate (GMA) as a compatibilizer. Different PCL-, PLA-, and PCL/PLA-based blends at different percentages (75:25, 50:50, 25:75, 15:85) added with GMA and AS were obtained. The color results highlighted the lower transparency and brownish tone of the studied formulations after the addition of AS. The addition of PCL provided a positive effect on PLA’s ductility due to its intrinsically higher flexibility. The combination of GMA and AS improved the mechanical properties of PCL, PLA, and 50:50 controls by reducing yield strength, yield strength at break, and elongation at break values. The 75:25_GMA_AS formulation showed a homogeneous visual appearance, low transparency, and desirable mechanical properties for rigid food packaging applications, reducing the final material cost through the revalorization of AS. This research was funded by Conselleria de Educación (Spain), ACIF/2010/172 Predoctoral Research Training Grant.

The high temperature torch integrated sample introduction system (hTISIS) is coupled to microwave plasma optical emission spectrometry (MIP-OES) for the first time. The goal of this work is to develop an accurate analysis of digested samples under continuous sample aspiration mode by coupling the hTISIS to a MIP-OES instrument. To achieve this, different operating conditions such as, nebulization flow rate, liquid flow rate and the spray chamber temperature were optimized in terms of sensitivity, limits of quantification (LOQs) and background equivalent concentration (BECs) for the determination of Ca, Cr, Cu Fe, K, Mg, Mn, Na, Pb and Zn, and these values were compared with those reported with a conventional sample introduction system. Under optimum conditions (0.8–1 L min−1, 100 μL min−1 and 400 ᵒC, respectively), the hTISIS improved MIP-OES analytical figures of merit and shortened 4-times wash out times with respect to a conventional cyclonic spray chamber, reporting an enhancement factor in the sensitivity among 2–47 times and LOQs from 0.9 to 360 μg kg−1. Once the best operating conditions were set, the magnitude of the interference caused by 15 different acid matrices (2, 5 and 10% w/w of HNO3, H2SO4, HCl and mixtures of HNO3 with H2SO4 and HNO3 with HCl) was significantly lower for the former device. Finally, 6 different digested oily samples (used cooking oil, animal fat, corn oil and the same samples after a filtration step) were analyzed by means of an external calibration approach based on the use of multielemental standards prepared in 3% (w/w) HCl solution. The obtained results were compared against those supplied by a conventional methodology employing an inductively coupled plasma optical emission spectrometry, ICP-OES, instrument. It was clearly concluded that the hTISIS coupled to MIP-OES afforded similar concentrations as compared to the conventional methodology.

Almond (Prunus amygdalus) is one of the most common tree nuts on a worldwide basis. This nut is highly regarded in the food and cosmetic industries. However, for all these applications, almonds are used without their shell protection, which is industrially removed contributing approximately 35-75% of the total fruit weight. This residue is normally incinerated or dumped, causing several environmental problems. In this study, a novel cellulose nanocrystal (CNCs) extraction procedure from almond shell (AS) waste by using microwave-assisted extraction was developed and compared with the conventional approach. A three-factor, three-level Box-Behnken design with five central points was used to evaluate the influence of extraction temperature, irradiation time, and NaOH concentration during the alkalization stage in crystallinity index (CI) values. A similar CI value (55.9 +/- 0.7%) was obtained for the MAE process, comprising only three stages, compared with the conventional optimized procedure (55.5 +/- 1.0%) with five stages. As a result, a greener and more environmentally friendly CNC extraction protocol was developed with a reduction in time, solvent, and energy consumption. Fourier transform infrared (FTIR) spectra, X-ray diffractogram (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) images, and thermal stability studies of samples confirmed the removal of non-cellulosic components after the chemical treatments. TEM images revealed a spherical shape of CNCs with an average size of 21 +/- 6 nm, showing great potential to be used in food packaging, biological, medical, and photoelectric materials. This study successfully applied MAE for the extraction of spherical-shaped CNCs from AS with several advantages compared with the conventional procedure, reducing costs for industry. This work was supported by Conselleria de Educacion (Spain) (APOSTD/2016/093 Postdoctoral Research Training Grant), the Spanish Ministry of Economy, Industry and Competitiveness (MAT2017-84909-C2-1-R), and the University of the Basque Country (UPV/EHU) (GIU18-216).

This work proposes the revalorization of almond shell (AS) wastes as an active additive for food packaging applications. A new microwave-assisted extraction (MAE) method to obtain extracts rich in polyphenolic compounds with high antioxidant capacity was optimized. An experimental design to optimize the MAE procedure through response surface methodology (RSM) using a Box–Behnken design was proposed. The effects of extraction temperature, irradiation time, ethanol:water concentration, and solvent pH at three levels were evaluated in terms of total phenolic content (TPC) and antioxidant activity (DPPH (2,2-diphenyl-1-picrylhydrazyl) and ferric reducing antioxidant power (FRAP) assays). The optimal conditions found were 57 min, 80 °C, pH 8, and 70% (v/v) ethanol. Optimized MAE extracts showed low soluble protein content (0.43 mg BSA g−1) and were rich in TPC (5.64 mg GAE g−1), flavonoids (1.42 mg CE g−1), and polysaccharides (1.59 mg glucose g−1), with good antioxidant capacity (2.82 mg AAE acid g−1). These results suggest the potential application of these extracts in the food industry as active additives. This strategy opens new pathways to valorize almond shell residues, contributing to the circular economy. A. Valdés acknowledges Conselleria de Educación (Spain) for APOSTD/2016/093 Postdoctoral Research Training Grant.

The use of agro-industrial wastes to obtain compounds with a high added-value is increasing in the last few years in accordance with the circular economy concept. In this work, a cascade extraction approach was developed based on ultrasound-assisted extraction (UAE) for tomato, watermelon, and apple peel wastes. The protein and antioxidant compounds were obtained during the first extraction step (NaOH 3 wt.%, 98.6 W, 100% amplitude, 6.48 W/cm2, 6 min). The watermelon peels (WP) showed higher proteins and total phenolic contents (857 ± 1 mg BSA/g extract and 107.2 ± 0.2 mg GAE/100 g dm, respectively), whereas the highest antioxidant activity was obtained for apple peels (1559 ± 20 µmol TE/100 g dm, 1767 ± 5 µmol TE/100 g dm, and 902 ± 16 µmol TE/100 g dm for ABTS, FRAP and DPPH assays, respectively). The remaining residue obtained from the first extraction was subsequently extracted to obtain cutin (ethanol 40 wt.%, 58 W, 100% amplitude, 2 W/cm2, 17 min, 1/80 g/mL, pH 2.5). The morphological studies confirmed the great efficiency of UAE in damaging the vegetal cell walls. WP showed a higher non-hydrolysable cutin content (55 wt.% of the initial cutin). A different monomers’ profile was obtained for the cutin composition by GC-MS, with the cutin from tomato and apple peels being rich in polyhydroxy fatty acids whereas the cutin extracted from WP was mainly based on unsaturated fatty acids. All of the cutin samples showed an initial degradation temperature higher than 200 °C, presenting an excellent thermal stability. The strategy followed in this work has proved to be an effective valorization methodology with a high scaling-up potential for applications in the food, pharmaceutical, nutraceutical, cosmetics and biopolymer sectors. This research was funded by the Bio-Based Industries Joint Undertaking under the European Union Horizon 2020 research program (BBI-H2020), ECOFUNCO project, grant number G.A 837863.

Nowadays, hemp farmers are facing an urgent problem related to plant stem disposal after seed harvesting. In this work, the commonly discarded epidermis and cuticle of hemp stems were valorized, turning them towards a sustainable recycling and reuse, contributing to the circular economy concept. Cellulose deprived of amorphous regions was obtained by a green process consisting of an ethanolic ultrasound-assisted maceration followed by mild bleaching/hydrolysis. The obtained hemp cellulose was esterified with citric acid resulting in a 1.2-fold higher crystallinity index and 34 ∘C lower Tg value compared to the non-functionalized hemp cellulose. Green innovative biocomposite films were developed by embedding the modified cellulose into PLA by means of an extrusion process. The structural and morphological characterization of the obtained biocomposites highlighted the functionalization and further embedment of cellulose into the PLA matrix. Attenuated Total Reflectance–Fourier Transform Infrared spectroscopy (ATR-FTIR) results suggested physical and chemical interactions between PLA and the organic filler in the biofilms, observing a homogeneous composition by Field Emission-Scanning Electron Microscopy (FESEM). Moreover, some increase in thermal stability was found for biocomposites added with 5%wt of the hemp cellulose filler. The obtained results highlighted the feasible recovery of cellulose from hemp stem parts of disposal concern, adding value to this agro-waste, and its potential application for the development of novel biocomposite films to be used in different applications.

Tiger nut is highly appreciated in the Mediterranean basin by the large number of nutritional advantages offered by a beverage, called “horchata,” which is directly obtained from the tuber of Cyperus esculentus L. However, the current tiger nut harvesting and processing practices generate a large number of residues, mainly a solid by-product after processing and the plant that remains spread out in the fields. In this work the plant residues have been fully characterized to get a clear picture of the possibilities for its valorization to generate products with high added value. Several analytical techniques have been applied to obtain data to assess the real possibilities of these residues in advanced applications in the food, packaging and nutrition sectors. Results on the compositional and elemental analysis, monosaccharide composition, phenolic concentration, and antioxidant capacity were obtained from the dry powder (DP). The high content of α-cellulose (47.2 ± 1.8%) in DP could open new possibilities for these residues as raw material in the production of cellulose nanoentities. Many essential minerals with nutritional interest (Na, Mg, Ca, Mn, Fe, Cu, and Zn) and free sugars (xylose, arabinose, glucose, and galacturonic acid) were identified in the DP making it an interesting source of valuable nutrients. The total carbohydrate content was 171 ± 31 mg gdm–1. In addition, microwave-assisted extraction (MAE) was used to obtain extracts rich in polyphenolic compounds. A Box–Behnken design (BBD) was used, and the optimal extraction conditions predicted by the model were 80°C, 18 min, ethanol concentration 40% (v/v), and solvent volume 77 mL, showing an extraction yield of 2.27 ± 0.09%, TPC value was 136 ± 3 mgGAE 100 gdm–1 and antioxidant capacity by the ABTS method was 8.41 ± 0.09 μmoltrolox gdm–1. Other assays (FRAP and DPPH) were also tested, confirming the high antioxidant capacity of DP extracts. Some polyphenols were identified and quantified: p-coumaric (7.67 ± 0.16 mg 100 gdm–1), ferulic (4.07 ± 0.01 mg 100 gdm–1), sinapinic (0.50 ± 0.01 mg 100 gdm–1) and cinnamic acids (1.10 ± 0.03 mg 100 gdm–1), 4-hydroxybenzaldehyde (1.28 ± 0.06 mg 100 gdm–1), luteolin (1.03 ± 0.01 mg 100 gdm–1), and naringenin (0.60 ± 0.01 mg 100 gdm–1). It can be concluded that C. esculentus L. residues obtained from the tiger nut harvesting and horchata processing could be an important source of high value compounds with potential uses in different industrial sectors, while limiting the environmental hazards associated with the current agricultural practices.

The paper tissue industry is a constantly evolving sector that supplies markets that require products with different specific properties. In order to meet the demand of functional properties, ensuring a green approach at the same time, research on bio-coatings has been very active in recent decades. The attention dedicated to research on functional properties has not been given to the study of the morphological and mechanical properties of the final products. This paper studied the effect of two representative bio-based coatings on paper tissue. Coatings based on chitin nanofibrils or polyphenols were sprayed on paper tissues to provide them, respectively, with antibacterial and antioxidant activity. The chemical structure of the obtained samples was preliminarily compared by ATR-FTIR before and after their application. Coatings were applied on paper tissues and, after drying, their homogeneity was investigated by ATR-FTIR on different surface areas. Antimicrobial and antioxidant properties were found for chitin nanofibrils- and polyphenols-treated paper tissues, respectively. The mechanical properties of treated and untreated paper tissues were studied, considering as a reference the same tissue paper sample treated only with water. Different mechanical tests were performed on tissues, including penetration, tensile, and tearing tests in two perpendicular directions, to consider the anisotropy of the produced tissues for industrial applications. The morphology of uncoated and coated paper tissues was analysed by field emission scanning electron microscopy. Results from mechanical properties evidenced a correlation between morphological and mechanical changes. The addition of polyphenols resulted in a reduction in mechanical resistance, while the addition of chitin enhanced this property. This study evidenced the different effects produced by two novel coatings on paper tissues for personal care in terms of properties and structure. This research was funded by the Bio-Based Industries Joint Undertaking under the European Union Horizon 2020 research program (BBI-H2020), ECOFUNCO project, grant number G.A 837863.

This report presents a study on the determination of total polyphenols together with metals in several samples of olive oil produced in Spain. The results provided by applying a conventional extraction method were compared against those encountered by means of the so-called Dispersive Liquid-Liquid Aerosol Phase Extraction method. The novel method is based on the dispersion of the extracting solution in the sample. To accomplish this, an aerosol is pneumatically generated and directed against the surface of the oil sample. The aerosol was generated in order to increase as much as possible the surface area of the interface between the two involved non-miscible phases. As a result, the partition equilibrium was quickly achieved. The critical variables dictating the characteristics of the obtained aerosols as well as those influencing the partition equilibrium state were studied. With the aerosol phase extraction method, the values corresponding to the total polyphenols and metals in real samples were not statistically different as compared to those obtained by the conventional liquid – liquid extraction method. The new method provided shorter extraction times and lower mass of consumed reagents than the conventional one, thus giving rise to a more environmentally friendly method. For polyphenols, calculated limits of detection and quantification were 0.48 and 1.5 mg of gallic acid kg−1, respectively. The absorbance linearity, in turn, was kept from 0 to 50 mg kg−1 (R2 = 0.998). In the case of metal and metalloid quantification, the limits of detection found with a sample digestion method ranged from 1.3 (Cu) to 291 (Na) ng mL−1. Meanwhile, because of the lower dilution factor, this parameter was one order of magnitude lower when these elements were extracted according to the new method. The new extraction method was applied to the analysis of 42 extra virgin olive oils both bottled and directly collected from the oil press, containing single cultivars or blends and produced from different areas. Fresh oils were analyzed and a preliminary study on the oil thermal degradation was also done. Dispersing the extracting solution as an aerosol into the sample can be considered a versatile method able to provide extensive oil chemical information in a rapid way what is especially important in the case of polyphenols. The authors wish to thank the Spanish Ministry of Science, Innovation and Universities for the financial support (Project Ref. PGC2018-100711-B-I00).

Silicon speciation in light petroleum products through the hyphenation of gas chromatography with ICP-tandem mass spectrometry (GC-ICP-MS/MS) is described in the present work. Eleven silicon compounds (nine siloxanes, trimethylsilanol and triethylsilane) have been taken as model molecules. The carrier and optional gas flow rates as well as the hydrogen gas flow rate in the octopole reaction cell (ORC) were critical variables. They precluded both the sensitivity and the extent of the effects caused by the sample matrix and silicon nature. The optimization of the latter variable mitigated the m/z 28 interference (14N14N+ and 12C16O+). Moreover, under the optimized conditions, a universal response was found irrespective of the silicon chemical form and sample matrix. The analytical performances of the method have been evaluated. Thus, the ICP-MS/MS response was linear between 0 and 500 μg kg−1 with correlation coefficients up to 0.999, whereas the limit of quantification (LOQ) ranged from 8 to 60 μg kg−1. Moreover, no drift was found for quality control samples analysed along a given analytical run. Only, the most volatile compound, i.e., trimethylsilanol (TMSOH), induced a drop in sensitivity caused by its partial evaporation from the GC vial. The method was validated by the analysis of real samples and the results were compared with those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence. No significant differences in Si total content provided by the three methods were found. These results demonstrated that all silicon species were taken into account using GC-ICP-MS/MS as the speciation method. Real light petroleum products, especially coker naphtha samples, were analyzed and it was verified that they only contained cyclic siloxanes (D3–D6), mainly hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4). The authors wish to thank the Spanish Ministry of Science, Innovation and Universities for the financial support (Project Ref. PGC2018-100711-B-I00).

Uno de los puntos fundamentales de un título universitario es la empleabilidad de sus egresados. La viabilidad de estos proyectos educativos y el posicionamiento de estos en listas de prestigio nacionales e internacionales hacen necesaria trabajar en estructuras sólidas que garanticen la formación del alumnado, la empleabilidad de los egresados, y por tanto su inserción al mundo laboral. Por tanto, la inserción en el mercado laboral puede considerarse clave y de ahí que en las instituciones universitarias se impulsen iniciativas dirigidas a su logro. En este proyecto se planteó conocer el grado de implementación de la oferta de prácticas de diferentes grados tomando como evidencia los resultados académicos e indicadores de calidad con el objetivo de detectar punto débiles y posibles estrategias metodológicas que afiancen la empleabilidad del alumnado. Se considera que es necesario la evaluación y comparación de la visión que tiene el alumnado en relación con la oferta de prácticas para poder establecer nuevos planes de trabajo, nuevas estrategias de formación en empleabilidad o en competencias fundamentales que les ayuden a ser capaces de escoger la opción de prácticas que más de adapte a sus necesidades o sus metas.

En el marco de la Red Docente se ha propuesto el uso de píldoras formativas audiovisuales para la mejora de las habilidades relacionadas con el trabajo en los laboratorios de química analítica. Esta experiencia se ha desarrollado en el marco de la asignatura “Laboratorio de Análisis Químico de Alimentos y Análisis Quimiométrico”, asignatura optativa del máster en Nutrición y Alimentación. La mayoría de los estudiantes que han cursado esta asignatura no tienen un perfil formativo relacionado con el área de la química analítica. En esta asignatura los estudiantes deben realizar una actividad en la que abordan un tema relacionado con la actualidad, realizando una búsqueda bibliográfica que precede a los experimentos en el laboratorio. Finalmente, deben redactar un informe científico que resuma el trabajo realizado y los resultados obtenidos. La implementación de píldoras formativas puede considerarse como una herramienta útil. Las píldoras consistieron en pequeños vídeos didácticos en los que se introdujeron un concepto concreto centrado en el uso de técnicas experimentales complejas. Esta experiencia ha sido evaluada por los estudiantes mediante un cuestionario anónimo. Los estudiantes consideraron este tipo de material audiovisual como una herramienta motivadora de aprendizaje que les permite incrementar sus competencias relacionadas con el trabajo experimental.

Tomato seed (TS) wastes are obtained in large amounts from the tomato processing industry. In this work, microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) of antioxidant compounds from TS were optimized by using response surface methodology. The effect of MAE and UAE main extraction parameters was studied on total phenolic content (TPC) and antioxidant activity (DPPH) responses. Antioxidant, structural, morphological, and thermal properties of MAE and UAE extracts were evaluated. A great influence of ethanol concentration was observed in both extraction methods. Optimal MAE conditions were determined as 15 min, 80 °C, 63% ethanol and 80 mL, with a desirability value of 0.914, whereas 15 min, 61% ethanol and 85% amplitude (desirability = 0.952) were found as optimal conditions for UAE. MAE extracts exhibited higher TPC and antioxidant activity values compared to UAE (1.72 ± 0.04 and 1.61 ± 0.03 mg GAE g TS−1 for MAE and UAE, respectively). Thermogravimetric analysis (TGA) results suggested the presence of some high molecular weight compounds in UAE extracts. Chlorogenic acid, rutin and naringenin were identified and quantified by HPLC-DAD-MS as the main polyphenols found by MAE and UAE, showing MAE extracts higher individual phenolics content (1.11–2.99 mg 100 g TS−1). MAE and UAE have shown as effective green techniques for extracting bioactive molecules with high antioxidant activity from TS with high potential to be scaled-up for valorizing of TS industrial wastes. This research was funded by the Bio-Based Industries Joint Undertaking under the European Union Horizon 2020 research program (BBI-H2020), ECOFUNCO project, grant number G.A 837863.

Generalmente, se observa que en las sesiones prácticas de las asignaturas con una alta carga de experimentalidad son los docentes los que adquieren el máximo protagonismo, excediendo el rol de orientadores de los estudiantes llegando a convertirlas en una actividad expositiva y no inclusiva. Por ello, el objetivo de este trabajo de investigación ha sido la hibridación de diversas metodologías docentes inclusivas de forma que permitan que el protagonismo de las sesiones prácticas recaiga en el alumnado. Un total de 32 alumnos han participado en este proyecto educativo a través de la resolución de un caso práctico, simulando la escena de un crimen, enmarcado en la asignatura de Análisis Toxicológico y Forense (ATF). Los estudiantes realizaron una hipótesis inicial del caso propuesto que fue validad y/o refutada tras los análisis realizados en el laboratorio observándose un gran desarrollo de sus competencias transversales, así como sus conocimientos analíticos después de llevar a cabo la experiencia planteada. Entre las estrategias aplicadas se pueden resaltar los sistemas de Peer Instruction y Flipped Classroom que han facilitado la implicación del alumnado en el desarrollo de la parte experimental, tomando decisiones y aplicando sus conocimientos a medida que avanzaban las sesiones prácticas de la asignatura.

Se ha realizado una experiencia basada en la aplicación de actividades destinadas a fomentar el emprendimiento en la Universidad de Alicante con alumnos de primer curso del grado de Química. Los alumnos de primer curso debían desarrollar un proyecto de investigación sobre un tema de actualidad en Química, siendo cada grupo tutelado por un mentor que actuaba como figura de referencia complementaria pero más cercana que el profesor. Se aplicaron dinámicas de equipo que favorecieron el emprendimiento y fortalecieron la relación entre el mentor y el grupo de trabajo. Asimismo, se realizaron una serie de charlas por parte de estudiantes de doctorado y egresados de la Facultad de Ciencias con un marcado carácter emprendedor, con el objetivo de compartir su experiencia y sensibilizar al alumnado en el emprendimiento, y como éste puede generar un impacto positivo en su vida mediante la creación de un proyecto propio. Como resultado, los estudiantes desarrollaron habilidades relacionadas con el emprendimiento, que pueden ser útiles para su vida personal o su futuro profesional. El nivel de satisfacción de los estudiantes con este tipo de actividades fue evaluado mediante la cumplimentación de varias encuestas, mostrando respuestas muy positivas. Se puede concluir que generar competencias emprendedoras en el alumnado universitario es fundamental y necesario con tal de fomentar su iniciativa y cooperación.

In this work, poly(lactic acid) (PLA)/gelatin/PLA multilayer films supplemented with cellulose nanocrystals and antioxidant extract from almond shell (AS) by-products were developed by solvent casting technique for active food packaging. The almond shell antioxidant extract (ASE) was obtained by microwave-assisted extraction, while cellulose nanocrystals (CNCs) were extracted from AS by a sequential process of alkalization, acetylation and acid hydrolysis. Four formulations were obtained by adding 0 (control), 6 wt.% of ASE (FG/ASE), 4.5 wt.% of CNCs (FG/CNC) and 6 wt.% + 4.5 wt.% of ASE + CNCs, respectively, (FG/ASE + CNC) into fish gelatin (FG). PLA/FG/PLA multilayer films were prepared by stacking two outer PLA layers into a middle FG film. A surface modification of PLA by air atmospheric plasma treatment was optimized before multilayer development to improve PLA adhesion. Complete characterization of the multilayers underlined the FG/ASE + CNC formulation as a promising active reinforced packaging system for food preservation, with low values of transparency, lightness and whiteness index. A good adhesion and homogeneity of the multilayer system was obtained by SEM, and they also demonstrated low oxygen permeability (40.87 ± 5.20 cm3 mm m−2 day) and solubility (39.19 ± 0.16%) values, while mechanical properties were comparable with commercial plastic films. The developed multilayer films were applied to Hass avocado preservation. The initial degradation temperature (Tini), DSC parameters and in vitro antioxidant capacity of the films were in accordance with the low peroxide and anisidine values obtained from avocado pulp after packaging for 14 days at 4 °C. The developed PLA/FG/PLA films supplemented with 6 wt.% ASE+ 4.5 wt.% CNCs may be potential bioactive packaging systems for fat food preservation. This research was funded by Conselleria de Educación (Spain), APOSTD/2016/093 Postdoctoral Research Training Grant.

Intensive black soldier fly (BSF) Hermetia illucens (Diptera: Stratiomyidae) rearing has a great importance for the feed industry. The objective of the present work was to perform a systematic study about the effect of the feeding media on the concentration and bioaccumulation factor (BAF) of Ca, K, Mg, Na, Cr, Cu, Fe, Mn, Ni and Zn in BSF fractions. Therefore, the evolution of the concentration of these elements has been studied along the stages of the BSF life cycle (larva, pupa and adult) as well as during its growth (exuviae) and metamorphosis (empty puparia). Two diets consisting of beer bagasse and commercial hen feed moistened with water have been chosen. An inductively coupled plasma optical emission spectrometer has been used to perform the elemental analyses. The obtained results demonstrated that the behaviour was generally, similar for all the elements studied, i.e. an accumulation in exuviae and puparia followed by their further elimination. Moreover, no significant differences in the results as a function of the feeding media have been found. This may be attributed to the fact that the chosen diets were equally favourable for this insect’s growth. The obtained concentrations have been expressed on a dry as well as a wet sample basis. BAF results also suggested that exuviae and puparia could be used as supplements or as bioactive compounds. The authors wish to thank the Spanish Ministry of Science, Innovation and Universities (Project Ref. PGC2018-100711-B-100) and Susinchain (SUStainable Insect CHAIN, Horizon H2020-SFS-2018-2020; Proposal ID: 861976) for the financial support and material used in this research.

Heavy metals are endocrine disruptors which interfere with processes mediated by endogenous hormones of the organism, negatively affecting endocrine functions. Some studies have correlated heavy metal exposure with male infertility. However, the number of studies conducted on humans are limited. Therefore, the aim of this study is to summarize the current knowledge on how heavy metals influence human male fertility. Hence, three distinct databases were consulted—PubMed, Scopus and Web of Science—using single keywords and combinations of them. The total number of identified articles was 636. Nevertheless, by using the inclusion and exclusion criteria, 144 articles were finally included in this work. Results display that the development of adequate instruments for heavy metal assessment may play an important function in human male fertility diagnosis and treatment. Furthermore, clinical trials could be useful to confirm the role of heavy metals in human male fertility diagnosis. Overall, further research is required to fully understand the molecular and cellular basis of the influence of environmental and occupational exposure to heavy metals on human male infertility and reproductive outcomes. This study was funded by Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (UGP-19-042 and UGP-20-039).

In the present work, anthocyanin (ACN) hybrid nanopigments were synthetized by using a natural pomegranate dye (PD) and calcined hydrotalcite (HT) and montmorillonite (MMT) nanoclays. A wide colour gamut was obtained with MMT-based nanopigments ranging from reddish to bluish hues caused by structural transformations of ACNs at different pH values. However, a buffer effect was observed with HT obtaining samples a similar final colour regardless of the synthesis conditions. Nanopigments added with a biomordant extracted from pomegranate peels showed a different colour compared to the incorporation of a commercial mordant due to the intrinsic colouring properties of the pomegranate bioadditive. The developed nanopigments were incorporated at 7 wt% loading to produce novel polyester-based bionanocomposites which were characterized in terms of thermal, mechanical and colour properties. The encapsulation of PD into the nanoclays improved its thermal stability, in particular for MMT-based nanopigments. The pH changes observed during the nanofillers synthesis affected the final colour of the MMT-based nanocomposites, inducing a general increase in ∆E* and a decrease in gloss values. Slight improvements were obtained in terms of elastic modulus for MMT-based polymer samples confirming the applicability of the developed bionanocomposites as colouring and reinforcement materials. A very similar environmental profile was obtained for MMT and HT-based nanofillers showing MMT-based nanopigments a slightly better general behaviour. The results of the LCA study evidenced the suitability of the processes used in this work to the circular bioeconomy approach through sustainable food waste management and the production of bioplastics using waste substrates. This project has received funding from the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 745578.

A novel method for the elemental analysis of undiluted wine samples was optimized and validated. The method was based on the use of a high-temperature torch integrated sample introduction system (hTISIS) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The operating conditions (hTISIS temperature and liquid flow rate) were optimized in terms of sensitivity and matrix effects. Low liquid flow rates allowed continuous introduction of organic samples into the plasma source with minimum soot as well as salt deposit formation at the ICP-MS interface and/or plasma thermal degradation. A double pass Scott-type spray chamber thermostated at 2 °C was taken as the reference sample introduction system. The results indicated that the hTISIS operated at 125 °C and a liquid flow rate of 30 µL min−1 improved the sensitivity and mitigated the extent of matrix effects compared to the conventional system. Once the optimum conditions were selected, the method was validated and applied to the determination of sixteen trace elements (Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Mo, Cd, Nd, Sm, Gd, Tb and Pb) in ten real wine samples. The sample was merely aspirated to the nebulizer with no additional preparation. For the sake of comparison, the samples were microwave digested and analyzed using a conventional setup. Method detection limits achieved by the hTISIS were 2 to 40 times lower than those found using the standard procedure and ranged from 0.002 to 6 µg kg−1. Furthermore, the accuracy of the quantification using the hTISIS was not significantly different as compared to that afforded by the conventional procedure and substantially improved in comparison with the direct analysis of wine using a Scott spray chamber. The sample throughput was close to 10 h−1, which was in clear contrast with 2 h−1, estimated when the digestion method was used. Finally, the suitability of the developed method for the routine analysis of wine samples was demonstrated by performing a 20 hour long analysis sequence. Good signal stability and accurate results were obtained for ten representative Italian and Spanish wines.

Nano-biocomposite films based on plasticized cellulose acetate/triethyl citrate (CA/TEC) were prepared with silver nanoparticles (AgNPs)/gelatin-modified montmorillonite nanofiller (AgM) and thymol (Th). AgNPs were biosynthesized in situ the clay using Curcuma longa (C. longa) tuber extract. Full characterization of clay and the formulated films was conducted including morphological, physical and functional properties. From the results, the AgNPs showed spherical shape, face centred cubic crystalline structure, and small average size with narrow distribution. Intercalated structure of films was achieved with some exfoliated platelets and clay aggregates. The glass transition temperature (Tg) of CA increased slightly by the added clay but decreased by Th due to its plasticizing effect. Also, the thermal stability of CA was enhanced only by the added clay. Increasing contents of both additives into films declined the optical clarity but enhanced greatly the UV barrier ability. The clay improved the tensile and oxygen barrier properties, while the Th initiated an antagonist effect. Besides, the radical 2,2‑diphenyl‑1‑picrylhydrazyl (DPPH) tests highlighted antioxidant activities of Th-included films. The films showed antimicrobial activities against bacteria and fungi, where Escherichia coli (E. coli) was the most sensitive, with an efficient growth inhibition in vapour-phase method. These materials with antimicrobial/antioxidant properties are promising active packaging.

In this work, lipids and bioactive compounds from tomato seed by-products were extracted and compared by using advanced extraction techniques, such as microwave-assisted extraction (MAE) and supercritical fluid extraction (SFE). The influence of different extraction parameters, including extraction temperature (T), time (t) and solvent volume (V) for MAE as well as extraction temperature (T), pressure (P) and flow rate (F) for SFE-CO2, was evaluated on tomato seed oil (TSO) yield and fatty acids composition using response surface methodology (RSM). Optimum extraction conditions for MAE were 56.2 °C, 29.0 min, and 67.6 mL, whereas conditions of 60.2 °C, 400.0 bar, and 64.6 g min−1 were found for SFE-CO2. Under these conditions, higher TSO extraction yields were obtained by MAE compared to SFE-CO2 (25.3 wt% and 16.9 wt%, respectively), while similar fatty acids profiles were found by GC in terms of FAMEs composition: methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate, accounting for around 80 wt% of unsaturated fatty acids. TSO MAE extracts showed high DPPH• radical scavenging activity which was related to the presence of tocopherols; in particular γ-tocopherol, which was found as the dominant homologue (260.3 ± 0.6 mg kgTS−1) followed by a lower amount of α-tocopherol (6.53 ± 0.12 mg kgTS−1) by HPLC-DAD. The obtained results suggested that tomato seeds are an interesting source of bioactive compounds with potential use in a wide range of nutritional and food applications, increasing the added value of this by-product, which is currently underexploited. This research was funded by the Bio-Based Industries Joint Undertaking under the European Union Horizon 2020 research program (BBI-H2020), ECOFUNCO project, grant number G.A 837863.

The effect of different cooking processes such as frying and roasting on the oxidative stability of sunflower seeds was evaluated under accelerated oxidation and normal storage conditions. The fatty acid composition by GC-MS showed a higher amount of linoleic acid in fried samples due to the replacement of the seed moisture by the frying oil. On the other hand, roasted samples presented a higher oleic acid content. DSC and TGA results showed some decrease in the thermal stability of sunflower seed samples, whereas PV and AV showed the formation of primary and secondary products, with increasing oxidation time. Roasted sunflower seeds showed seven main volatile compounds characteristic of the roasting process by HS-SPME-GC-MS: 2-pentylfuran, 2,3-dimethyl-pyrazine, methyl-pyrazine, 2-octanone, 2-ethyl-6-methylpyrazine, trimethyl-pyrazine, and trans,cis-2,4-decadienal, whereas fried samples showed six volatile characteristic compounds of the frying process: butanal, 2-methyl-butanal, 3-methyl-butanal, heptanal, 1-hexanol, and trans,trans-2,4-decadienal. The generation of hydroperoxides, their degradation, and the formation of secondary oxidation products were also investigated by ATR-FTIR analysis. The proposed methodologies in this work could be suitable for monitoring the quality and shelf-life of commercial processed sunflower seeds with storage time.

The consumption of minimally processed fresh vegetables has increased by the consumer’s demand of natural products without synthetic preservatives and colorants. These new consumption behaviors have prompted research on the combination of emulsion techniques and coatings that have traditionally been used by the food industries. This combination brings great potential for improving the quality of fresh-cut fruits and vegetables by allowing the incorporation of natural and multifunctional additives directly into food formulations. These antioxidant, antibacterial, and/or antifungal additives are usually encapsulated at the nano- or micro-scale for their stabilization and protection to make them available by food through the coating. These nano- or micro-emulsions are responsible for the release of the active agents to bring them into direct contact with food to protect it from possible organoleptic degradation. Keeping in mind the widespread applications of micro and nanoemulsions for preserving the quality and safety of fresh vegetables, this review reports the latest works based on emulsion techniques and polysaccharide-based coatings as carriers of active compounds. The technical challenges of micro and nanoemulsion techniques, the potential benefits and drawbacks of their use, the development of polysaccharide-based coatings with natural active additives are considered, since these systems can be used as alternatives to conventional coatings in food formulations. This research was funded by the Spanish Ministry of Science, Innovation and Universities (MAT2017‐84909‐C2‐1‐R) and Generalitat Valenciana (IDIFEDER/2018/007).

El Grado de Gastronomía y Artes Culinarias de la Universidad de Alicante pretende dotar al alumno de conocimientos sobre la industria gastronómica y su relación con el entorno. El plan de estudios contempla asignaturas relacionadas con los alimentos, gestión de empresas alimentarias, marketing, turismo, habilidades sociales, recursos humanos, salud y nutrición. La presente investigación se contextualiza en la asignatura Bromatología (6 ECTS), impartida en primer curso. El objetivo de la presente actividad es detectar las necesidades formativas del alumnado con el fin de diseñar, implementar y evaluar las acciones educativas adecuadas para la mejora de su preparación inicial. La metodología de instauración de la acción docente ha consistido en el diseño e implementación de la actividad seguido del análisis y difusión de los resultados. Se confirmó que más del 60% del alumnado proviene del bachillerato de ciencias sociales y tiene conocimientos escasos sobre química, biología, etc. Además, se detectaron carencias en informática, en lectura y comprensión de idioma extranjero y en la redacción de trabajos académicos. Tras detectar las carencias, se desarrollaron diferentes materiales docentes incluyendo videos cortos sobre conceptos básicos de química, presentaciones sobre operaciones básicas de laboratorio, aula invertida sobre fórmulas, cálculos matemáticos y materiales de laboratorio. Una vez implementados los materiales docentes se observó una mejora significativa en la calificación final del alumnado.

Recommendations are given concerning the terminology of concepts and methods used in spectroscopy in analytical chemistry, covering nuclear magnetic resonance spectroscopy, atomic spectroscopy, and vibrational spectroscopy. © 2021 IUPAC and De Gruyter. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. For more information, please visit: http://creativecommons.org/licenses/by-nc-nd/4.0/ 2021.

En el marco de la asignatura de sumillería y mixología, que se imparte en el grado de gastronomía y artes culinarias en el segundo semestre, la imposibilidad de realizar las salidas de campo ha hecho que esta asignatura sufra una reestructuración de su programa docente e incluya la metodología de masterclass. Esta metodología está muy relacionada con el término e-learning y lo que se ha pretendido es aproximar al alumno al mundo laboral y ofrecer una nueva visión y reflexión sobre los conocimientos que van adquiriendo a lo largo de la asignatura. Para poner en práctica esta idea, se organizó una jornada en la que 5 profesionales del sector de la sumillería que aceptaron la invitación dieron una masterclass de 45 minutos cada uno. La Jornada se organizó de forma oficial, siendo publicitada y ofrecida al resto de alumnado. La particularidad con los alumnos de la asignatura es que debían entregar un informe ilustrado de lo que habían sido las jornadas para ellos. Los resultados mostraron que la jornada tuvo un éxito rotundo, por el grado de satisfacción obtenido.

A total sample consumption system (hTISIS) was used for the first time to evaluate the plasma spatial ion profile for ethanolic samples in ICP-MS. The effects of the extraction lens voltages, the inner diameter of the torch injector, the plasma sampled zone, spray chamber temperature and nebulizer and high matrix introduction gas flow rates on the plasma ion cloud distribution were systematically studied. Regarding the minimization of matrix effects caused by ethanolic matrices, it was found that extraction lenses voltages and the injector inner diameter played a key role when the hTISIS was set at 300 ⁰C. Under these conditions, the aerosol transport interferences were eliminated. The combination of the widest injector (2.5 mm id) with a 5V extra lens voltage allowed the mitigation of the matrix effects. Moreover, it was observed that for a 2.5 mm id injector, the interferences could be mitigated irrespectively of the plasma sampled volume. Meanwhile, for narrower injectors, it was necessary to carefully select the plasma sampled zone. Finally, the accurate determination of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Rb, Sr, V and Zn in bioethanol and beverages (wine, whisky, gyn, vodka, rum and apple liquor) was performed under optimum experimental conditions. The authors wish to thank the Spanish Ministry of Science, Innovation and Universities for the financial support (Project Ref. PGC2018-100711-B-I00). Authors would also like to thank IFPEn for the financial support. C. Sánchez thanks to the Ministry of Education, Spain for the contract FPU 13/01438.

El Grado de Gastronomía y Artes Culinarias pretende dotar al alumno de conocimiento sobre la industria gastronómica, y su relación con el entorno. El plan de estudios contempla asignaturas de diferentes ramas del conocimiento, gestión de empresas, marketing, turismo, habilidades sociales, recursos humanos, salud y nutrición humana. La presente investigación se contextualiza en la asignatura Bromatología. El objetivo de la presente actividad es detectar carencias formativas en el alumnado para diseñar, implementar y evaluar las acciones educativas necesarias. Para ello, se diseñó e implementó la actividad, se analizaron y difundieron los resultados y se desarrollaron nuevos materiales. Se confirmó que más del 60% del alumnado afirma tener ningún o muy escaso conocimiento sobre química, biología, etc. Además, se detectaron carencias en el alumnado en informática, lectura y comprensión de idioma extranjero y en la redacción de trabajos académicos. Se desarrollaron diferentes materiales docentes incluyendo la visualización de videos cortos con explicaciones sencillas, presentaciones con audio breves, aula invertida, cálculos matemáticos, así como juegos. Se llevó a cabo la evaluación de los resultados obtenidos a partir de cuestionarios al alumnado y se revisaron las calificaciones obtenidas observando una mejora significativa en la calificación final.

Uno de los objetivos de la acción tutorial universitaria, en particular en los primeros cursos, es el acompañamiento del estudiantado en su proceso de enseñanza-aprendizaje de forma que éste pueda desarrollar una mayor autonomía y motivación. Las competencias transversales son claves en la formación de un individuo, tanto a nivel personal y social como a nivel profesional; dado que integran conocimientos, destrezas, habilidades y capacidades que debe tener cualquier persona antes de su incorporación al mundo laboral. Aprender a aprender es una competencia básica de carácter transversal que implica la capacidad de iniciarse en el aprendizaje y continuar aprendiendo de forma cada vez más eficaz y autónoma, de manera individual o en grupo. En la acción tutorial desarrollada en alumnos de primer curso de biología se han elaborado materiales docentes específicos enfocados a trabajar competencias transversales, tales como la búsqueda de información bibliográfica a través de fuentes de calidad científica utilizando las TIC (incluyendo bases de datos), el trabajo en equipo y las habilidades de un buen comunicador. Asimismo, se ha recogido la opinión del estudiantado acerca de la importancia de las competencias transversales, su adquisición en la Universidad y posibles propuestas de mejora para el desarrollo de las mismas. En base a las respuestas obtenidas, se propone continuar con este tipo de actividades en próximos cursos dentro del PAT.

El proceso de enseñanza-aprendizaje de los conceptos básicos de Análisis Instrumental que aparecen en el plan de estudios del Grado en Ingeniería Química en el marco de la asignatura Análisis Químico e Instrumental representa un desafío para los equipos docentes ya que los conocimientos previos del estudiantado en este campo son bastante limitados. Es por ello que, por la experiencia previa en la docencia de esta asignatura, se ha observado una alta exigencia al profesorado y un gran esfuerzo de adaptación a las necesidades de un alumnado de procedencia heterogénea y con un nivel de formación previa muy variable en el campo de la Química Analítica. La propia organización de la asignatura, así como la evaluación crítica y continuada de las nuevas competencias, metodologías y estrategias docentes hace necesario un planteamiento que permita superar la metodología clásica de acercamiento del alumnado a estos contenidos y competencias considerando la dualidad del proceso enseñanza-aprendizaje, desde el punto de vista del profesorado y del alumnado. En esta investigación, se han revisado de forma cuidadosa los conceptos básicos de la asignatura, comprendiendo las competencias necesarias en Análisis Instrumental que cualquier Graduado/a en Ingeniería Química debe manejar para el desarrollo de su carrera profesional.

The present work shows, for the first time, the application of laser ablation connected to inductively coupled plasma mass spectrometry (LA-ICP-MS) to the localized quantitative analysis of inclusions in polymeric industrial films. The multielemental mapping capabilities of LA-ICP-MS has allowed to chemically examine unique defects appeared during the plastic processing. This analytical tool is perfectly suited to detect elements such as Al, Mg, Zr, Ti, Cr, P, Pb, Sb, Zn, and Si in those inclusions. A method for multielemental quantitative analysis of these defects has been developed in the present work. The profiling for more than 100 different defects in three samples has demonstrated that more than 50% of these inclusions contain aggregates of some of the aforementioned elements. Therefore, the distribution of elements used as additives or present in catalysts must be carefully controlled during the production of polymeric films in order to avoid degradation in their performance. Funding acquisition M.B. and J.L.T. Authors wish to thank to Total Research and Technology and to the Spanish Ministry of Science, Innovation and Universities for the financial support (project ref. PGC2018-100711-B-I100).

En el contexto de reducción de la presencialidad que hemos vivido, el gran reto docente ha sido la realización de las prácticas de laboratorio. El objetivo de esta acción de innovación ha sido el desarrollo de actividades formativas dirigidas tanto a la virtualización, como a la propuesta de prácticas de laboratorio en casa. Esta acción se ha llevado a cabo en dos asignaturas obligatorias del Grado de Química. Debido a los contenidos trabajados en “Química Analítica” y las dificultades para su adaptación a un ambiente doméstico se decidió que serían estas prácticas las que se virtualizarían. Este proceso de virtualización se realizó mediante la plataforma Moodle. En el contexto de la asignatura de “Técnicas de Separación”, se les propuso a los estudiantes la realización de prácticas en casa utilizando sus propios medios. Una vez realizada la experiencia docente se emplearon encuestas para valorar la repercusión, en términos de mejora y desarrollo de competencias. Además, los resultados obtenidos por los estudiantes en la evaluación de las prácticas han proporcionado una visión global sobre la adquisición de las competencias trabajadas. Tomando como referencia las calificaciones obtenidas en cursos anteriores, se ha observado un incremento en las calificaciones obtenidas por los estudiantes.

Aloe vera skin (AVS) is a major by-product of Aloe processing plants all over the world. In this study, response surface methodology was used to optimize microwave-assisted extraction (MAE) of bioactive compounds from AVS. The influence of extraction parameters, such as ethanol concentration (%Et), extraction temperature (T), time (t) and solvent volume (V), on extraction yield (Y), total phenolic content (TPC), antioxidant activity (DPPH and FRAP methods) and aloin content, was studied. Optimum extraction conditions were determined as 80% ethanol, 80 °C, 36.6 min and 50 mL and optimized extracts showed interesting contents of polyphenols and antioxidant performance. The phenolic profile was determined by HPLC-DAD/MS and some major phenolic compounds, such as aloin A, aloin B, aloesin, aloe-emodin, aloeresin D, orientin, cinnamic acid and chlorogenic acid, were quantified while eight other compounds were tentatively identified. Moreover, structural and thermal properties were studied by FTIR and TGA analyses, respectively. The obtained results suggested the potential of AVS as a promising source of bioactive compounds, thus increasing the added value of this agricultural waste. Authors would like to acknowledge Consellería de Educación, Investigación, Cultura y Deporte de la Generalitat Valenciana (GRISOLIAP/2016/081) and Spanish Ministry of Science and Innovation (Refs. PID2020-116496RB-C21, PDC2021-121345-C21) for their financial support.

The use of oils and fats, mainly from non-edible or used sources, microalgae, plastic wastes, and lignocellulosic residues as feedstock to elaborate different kinds of renewable fuels (biodiesel, hydrotreated vegetable oils, pyrolysis oils, and bio-oils) is increasing with the aim of implementing a circular and dynamic economy. Quality control of these materials involves the quantification of trace elements. Their presence, even at trace levels, leads to environmental concerns, fuel instabilities and may impact the performance of combustion engines. Therefore, in order to circumvent these problems, accurate and sensitive analytical techniques are required to control the level of these elements with good precision. The present manuscript will review different analytical tools used to analyze these samples. Because of their high sensitivity, low limits of detection, wide dynamic range, and in some cases the capability of carrying out multi-elemental analyses, the review is mainly focused on inductively coupled plasma techniques. Furthermore, sample preparation procedures (e.g., direct dilution, emulsification, extraction, and matrix decomposition) are elaborated. At the end of the work, suggestions on procedures for multi-elemental determination in the aforementioned samples are provided. The authors wish to thank Total Research and Technology Gonfreville and the Spanish Ministry of Science, Innovation and Universities for the financial support (project ref. PGC2018-100711-B-I100).

In this work, pectin-based active films with a cocoa bean shell extract, obtained after waste valorisation of residues coming from the chocolate production process, and zinc oxide/zinc nanoparticles (ZnO/Zn-NPs) at different concentrations, were obtained by casting. The effect of the active additive incorporation on the thermal, barrier, structural, morphological and optical properties was investigated. Moreover, the photocatalytic properties of the obtained films based on the decomposition of methylene blue (MB) in aqueous solution at room temperature were also studied. A significant increase in thermal and oxidative stability was obtained with the incorporation of 3 wt% of ZnO/Zn-NPs compared to the control film. The addition of 5 wt% cocoa bean shell extract to pectin significantly affected the oxygen barrier properties due to a plasticizing effect. In contrast, the addition of ZnO/Zn-NPs at 1 wt% to pectin caused a decrease in oxygen transmission rate per film thickness (OTR.e) values of approximately 50% compared to the control film, resulting in an enhanced protection against oxidation for food preservation. The optical properties were highly influenced by the incorporation of the natural extract but this effect was mitigated when nanoparticles were also incorporated into pectin-based films. The addition of the extract and nanoparticles resulted in a clear improvement (by 98%) in UV barrier properties, which could be important for packaged food sensitive to UV radiation. Finally, the photocatalytic activity of the developed films containing nanoparticles was demonstrated, showing photodegradation efficiency values of nearly 90% after 60 min at 3 wt% of ZnO/Zn-NPs loading. In conclusion, the obtained pectin-based bionanocomposites with cocoa bean shell waste extract and zinc oxide/zinc nanoparticles showed great potential to be used as active packaging for food preservation. The authors would like to thank the Spanish Ministry of Science, Innovation and Universities (MAT2017-84909-C2-1-R) and Generalitat Valenciana (IDIFEDER/2018/007) for financially supporting this research.

Forty-one bioethanol real samples and related fractions, together with a biobutanol sample, have been analyzed with gas chromatography coupled to either mass spectrometry (GC–MS) or flame ionization detection (GC–FID). Bioethanol with different water contents, samples originated from several sources of biomass, first- as well as second-generation specimens, distillation fractions, samples stocked in containers made of four different materials, and, finally, a biobutanol sample have been analyzed. The number of the compounds found through GC–MS has been 130, including alcohols, aldehydes, ketones, esters, ethers, nitrogen compounds, organic acids, furane derivates as well as other species (e.g., limonene). Afterward, a quantitative determination of major components of bioethanol has been carried out. The achieved results have revealed that, besides ethanol and, in some cases, water, species such as acetaldehyde, methanol, and higher alcohols, as well as 1,1-diethoxyethane, may be present at concentrations above 500 mg L–1. While the source of bioethanol (nature of the raw material, ethanol generation, or water content) has a direct impact on its volatile organic compound (VOC) profile, the material of the container where the biofuel has been stored does not play a significant role. Finally, the results have demonstrated that, for a given production process, different distillation fractions contain unequal VOC profiles. Authors are grateful to the Spanish Ministry of Science, Innovation and Universities for the financial support (Project Ref. PGC2018-100711-B-I00). C.S. thanks to the Ministry of Education, Spain for the contract FPU 13/01438.

Nano-biocomposite films based on poly (lactic acid) (PLA) were prepared by adding thymol (8 wt.%) and a commercial montmorillonite (D43B) at different concentrations (2.5 and 5 wt.%). The antioxidant, antimicrobial, and disintegration properties of all films were determined. A kinetic study was carried out to evaluate the thymol release from the polymer matrix into ethanol 10% (v/v) as food simulant. The nanostructured networks formed in binary and ternary systems were of interest in controlling the release of thymol into the food simulant. The results indicated that the diffusion of thymol through the PLA matrix was influenced by the presence of the nanoclay. Disintegration tests demonstrated that the incorporation of both additives promoted the breakdown of the polymer matrix due to the presence of the reactive hydroxyl group in the thymol structure and ammonium groups in D43B. Active films containing thymol and D43B efficiently enhanced the antioxidant activity (inhibition values higher than 77%) of the nano-biocomposites. Finally, the addition of 8 wt.% thymol and 2.5 wt.% D43B significantly increased the antibacterial activity against Escherichia coli and Staphylococcus aureus 8325-4, resulting in a clear advantage to improve the shelf-life of perishable packaged food. Authors would like to thank Spanish Ministry of Economy and Competitiveness (MAT2017-84909-C2-1-R) and Generalitat Valenciana (IDIFEDER/2018/007) for their support of this research. Marina Ramos would like to thank University of Alicante (Spain) for the UAFPU2011-48539721S predoctoral research grant. AJMV thanks ´Coimbra Chemistry Center and Fundação para a Ciência e Tecnologia (FCT) for the financial support through the programmes UID/QUI/UI0313/2020 and COMPETE.

Antioxidant films based on poly(&epsilon, caprolactone) (PCL) containing almond skin extract (ASE) were developed for food packaging applications. The effect of ASE incorporation on the morphological, structural, colour, mechanical, thermal, barrier and antioxidant properties of the prepared films were evaluated. The structural, tensile and thermal properties of the films were not altered due to ASE addition. Although no significant differences were observed for the oxygen permeability of samples, some increase in water absorption and water vapour permeability was observed for active films due to the hydrophilic character of ASE phenolic compounds, suggesting the suitability of this novel packaging for fatty foods conservation. ASE conferred antioxidant properties to PCL films as determined by the DPPH radical scavenging activity. The efficiency of the developed films was evaluated by the real packaging application of fried almonds at different ASE contents (0, 3, 6 wt.%) up to 56 days at 40 &deg, C. The evolution of peroxide and p-anisidine values, hexanal content, fatty acid profile and characteristic spectroscopy bands showed that active films improved fried almonds stability. The results suggested the potential of PCL/ASE films as sustainable and antioxidant food packaging systems to offer protection against lipid oxidation in foods.

Fundamental aspects related to the analysis of nitric acid solutions by inductively coupled plasma mass spectrometry have been critically revisited in order to provide new insights into the possible sources of non-spectroscopic matrix effects and their correction by internal standardization. For elements having first ionization potential (IP) lower than 7.5 eV, the increase in the signal due to nitric acid was ascribed to a delay in the ionization process, which resulted in a reduction of the ion lateral diffusion in the plasma. In contrast, for non-easily ionisable elements, signal depression was correlated with their IP value and attributed to the cooling effect due to the energy required for nitric acid dissociation. Moreover, the atomic mass did not show any significant effect, thus precluding the application of the widely accepted criterion of choice of internal standards based on matching of masses. The extent and sign of the acid effect also depended on the applied operating conditions. For elements with low IP (e.g. Co, Cs, In, Li, Pb, Y), nitric acid caused signal enhancement at high RF power and nebulizer gas flow rate values (i.e., plasma robust conditions) and signal depression under non-robust conditions. For elements with high IP (e.g. As, Be, Cd and Sb), the decreasing acid effect became stronger with increasing the nebulizer gas flow rate and decreasing the RF power. The acid effect was also influenced by the ion lens voltage, that significantly interacted with the RF power effect. Finally, a procedure for the selection of optimal internal standards by principal component analysis has been successfully applied for the correction of the nitric acid effect. This work has been funded by the Italian National Program of Research in Antarctica (projects PNRA14_00091 and PNRA16_00252) and the Spanish Ministry of Science, Innovation and Universities for the financial support (Project Ref. PGC2018-100711-B-I00).

Aloe Vera is an ancient medicinal plant especially known for its beneficial properties for human health, due to its bioactive compounds. In this study, nanofibers with antioxidant activity were successfully obtained by electrospinning technique with the addition of a natural Aloe Vera skin extract (AVE) (at 0, 5, 10 and 20 wt% loadings) in poly(ethylene oxide) (PEO) solutions. The successful incorporation of AVE into PEO was evidenced by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH), 2,2&prime, azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging (ABTS) and ferric reducing power (FRAP) assays. The incorporation of AVE introduced some changes in the PEO/AVE nanofibers morphology showing bimodal diameter distributions for AVE contents in the range 10-20 wt%. Some decrease in thermal stability with AVE addition, in terms of decomposition onset temperature, was also observed and it was more evident at high loading AVE contents (10 and 20 wt%). High encapsulation efficiencies of 92%, 76% and 105% according to DPPH, FRAP and ABTS assays, respectively, were obtained at 5 wt% AVE content, retaining AVE its antioxidant capacity in the PEO/AVE electrospun nanofibers. The results suggested that the obtained nanofibers could be promising materials for their application in active food packaging to decrease oxidation of packaged food during storage.

Thymol and silver nanoparticles (Ag-NPs) were used to develop poly(lactic acid) (PLA)-based films with antioxidant and antibacterial performance. Different amounts of thymol (6 and 8 wt%) and 1 wt% Ag-NPs were added to PLA to produce the active films. Ag-NPs and thymol were successfully identified in the nanocomposite structures using spectroscopic techniques. A kinetic study was performed to evaluate the release of thymol and Ag-NPs from the nanocomposites to an aqueous food simulant (ethanol 10%, v/v) at 40 &deg, C. The diffusion of thymol from the polymer matrix was affected by the presence of non-migrating Ag-NPs, which showed non-Fickian release behavior. The ternary system including 1 wt% Ag-NPs and 8 wt% thymol showed clear antibacterial performance by reducing the cell viability of Escherichia coli and Staphylococcus aureus by around 40% after 3 and 24 h of storage at 4, 25, and 37 &deg, C compared to neat PLA. Significant antioxidant behavior of all active films was also confirmed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The obtained nanocomposite films based on PLA and the addition of Ag-NPs and thymol were proven to have combined antioxidant and antibacterial performance, with controlled release of thymol. These formulations have potential applications in the development of innovative and customized active packaging systems to increase the shelf-life of food products.

Cocoa bean shell (CBS) waste is obtained in large amounts in chocolate production. In this work, microwave-assisted extraction (MAE) of CBS was used and experimental parameters were optimised by using response surface methodology. Effects of pH, time, temperature and solid:liquid ratio were evaluated on the extraction yield, total uronic acid content, total phenolic content (TPC) and antioxidant performance. A great influence of pH on the CBS extraction was observed, since alkaline conditions resulted in higher extraction yields and antioxidant capacity. Optimal MAE conditions were determined as 5 min, pH 12, 97 °C and S/L 0.04 g/mL showing better outcome than conventional solvent extraction. Antioxidant performance was evaluated by using colorimetric methods (FRAP, ABTS) while structural (FTIR), physico-chemical and functional properties of the MAE extracts were also determined. MAE extracts obtained at pH 12 were rich in proteins (580.0 mg BSA/g), polysaccharides (370.4 mg Glu/g) and polyphenols (35.9 mg GAE/g), showing important antioxidant performance (35.5 mg TE/g). It can be concluded that MAE is an efficient technique for the release of bioactive molecules from CBS with antioxidant performance and potential applications in the food industry. Authors would like to express their appreciation to the Spanish Ministry of Science, Research and Universities in the project (Ref. MAT2017-84909-C2-1-R) and to Generalitat Valenciana (Ref. IDIFEDER/2018/007).

Regardless of the considerable progress in properties and versatility of synthetic polymers, their low biodegradability and lack of environmentally-friendly character remains a critical issue. Pectin is a natural-based polysaccharide contained in the cell walls of many plants allowing their growth and cell extension. This biopolymer can be extracted from plants and isolated as a bioplastic material with different applications, including food packaging. This review aims to present the latest research results regarding pectin, including the structure, different types, natural sources and potential use in several sectors, particularly in food packaging materials. Many researchers are currently working on a multitude of food and beverage industry applications related to pectin as well as combinations with other biopolymers to improve some key properties, such as antioxidant/antimicrobial performance and flexibility to obtain films. All these advances are covered in this review.