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Microscopy techniques are essential for understanding the structure of materials of interest in agriculture, food, and the environment. These techniques can be classified according to their operating principles, such as fluorescence, electron, and probe scanning. Their complementary techniques provide specific advantages in the characterization of materials in the above mentioned fields. These approaches facilitate the characterization of the structure and morphology at nanometric and atomic scales of different materials through high-resolution images, as well as the analysis of important characteristics related to the composition and distribution of specific components. In this work, detailed descriptions are given of the operation principles of light microscopy (LM), confocal laser scanning microscopy (CLSM), superresolution microscopy (SRM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). A compilation of operating principles is presented along with examples obtained with advanced microscopy techniques applied to the afore mentioned areas. In addition, the preparation of the samples to obtain the final images is described in order to explain the interaction of the sample with the modes of operation for each technique. This review provides an overview of microscopy techniques used in various fields of nanotechnology, including agriculture, food, and the environment.

This study aimed to evaluate the influence of pH changes on morphometric parameters of casein micelles and a general overview of their conformational structure through microscopy techniques, Raman spectroscopy and multivariate analysis. It was found that casein micelles morphology and protein secondary structure depend strongly upon pH. The changes of arithmetic average roughness (Ra), size, and shape of casein micelles at different pH are properly characterized by atomic force and cryo-transmission electron microscopy. Morphometric changes of casein micelles were correlated correctly with folding and unfolding of casein molecules as evaluated by Raman spectroscopy when the pH was varied. The novelty of this contribution consists in demonstrating that there is a close structure-functionality relationship between the morphometric parameters of proteins and their secondary structure. Knowledge about casein micelles can help improve their use of its diverse applications.

Currently, the use of high-resolution microscopic techniques has become popular due to their accessibility and accuracy in the information obtained from a micrograph. Transmission Electron Microscopy (TEM) can achieve nanometric spatial resolution, and further, elucidate the crystalline structure of a material such as cellulose nanoparticles (CNP). The objective of this work was the molecular characterization of the crystalline structure of CNP obtained from garlic and agave residues. Gatan microscopy (GM3), ImageJ, and CrystalOgraph software were used to analyze TEM images, measure distances (d1, d2, d3), angles (α, β, γ) and simulate their respective cellulose allotropes. CNP sizes were smaller for garlic than agave, and a triclinic structure (Iα) exists for garlic CNP but a monoclinic (Iβ) one for agave CNP. The crystallographic study by TEM allows the elucidation of crystal structures with enough precision using only an image, and it provides insight into molecular arrangements in biological material that are rarely studied.

Fluorescence techniques have been widely used by scientists to reveal valuable information from biological samples, but in food science, small progress is known due to the complexity of the samples. In this study, two different biological samples, garlic skin (GS) and agave fibers (AF), were used to evaluate the techniques of confocal laser scanning microscopy (CLSM) and total internal reflection fluorescence (TIRF) microscopy, to obtain valuable information on the fiber size of the samples. A compositional characterization with calcofluor white in CLSM was achieved, but a superficial characterization of the samples with TIRF was made, evidencing fiber sizes of 398.67 ± 48.47 nm and 677.38 ± 76.88 nm for GS and AF, respectively. This work reveals that only an untreated sample can be used with the two techniques in the same microscope. In addition, it is possible to characterize the sample only using a spatial field of research and which valuable information about the structure of the material is found. This work provides the opportunity to use advanced fluorescence techniques for elucidation of structures shortly before studied with these techniques.

The cuajilote (Parmentiera edulis D.C.) tree produces fibrous fruits with a high content of lignocellulosic compounds. However, this fruit and their fibers have been scarcely studied. For this reason, an integral study of their cellular architecture, physicochemical, micromechanical, and structural properties in two maturity stages were carried out. Physicochemical tests, light, confocal and electron microscopy, microindentation, and X-ray diffraction were used for the characterization of fruit and their fibers. Chemical analysis showed that the unripe fruits have the highest cellulose content (42.17%), but in ripe fruit the cellulose content decreases (32.76%) while lignin content increases from 35.26 to 40.79%, caused by the lignification of the sclerenchyma fibers. Microstructural and micromechanical studies in the different regions of the fruit provided relevant information about its cellular architecture, distribution of lignocellulosic compounds and its role in the micromechanical properties of their fibers. The thickening cell wall of sclerenchyma fibers was caused by the cellular lignification of the ripe fruits. According to the physicochemical and structural studies, cuajilote fibers are comparable to other fibers obtained from crops rich in lignocellulosic compounds. The current study provided new knowledge about the cellular architecture of fruit and criteria for selecting the ripening stage adequate for the extraction of cellulose or lignin. Furthermore, information regarding the micromechanical properties of their fibers and which structural arrangement could be more convenient for mechanical reinforcement of biodegradable materials was obtained.

Background Cervical Cancer (CC) is a worldwide public health concern associated with genetic alterations, among these the gain of the 19q chromosome harboring the Pregnancy Specific Glycoproteins (PSG) gene family. These proteins play a critical role in pregnancy, with participation in immunotolerance, angiogenesis, and invasion processes, which are also observed in carcinogenesis. The aim of this study was to determine the molecular alterations of PSG1 and its relationship with CC. Methods PSG1 Copy Number Variation (CNV) was evaluated in 31 CC and eight normal cervical tissues by qPCR. PSG1 expression was correlated with HPV detection and IL-10 and TGF-β expression in CC samples. Finally, PSG1 protein expression was evaluated by immunofluorescence in CC cell lines, by immunohistochemistry in a tissue microarray, and by immunoblotting in the sera of women with normal cervix, pre-invasive lesions, and CC. Results PSG1 showed a gain of 25.6% in CNV and gene expression in CC. There was a lack of PSG1 expression in normal cervical epithelium and positive immunostaining in 57% of CC tissues, while all CC cell lines expressed PSG1. Finally, PSG1 was immunodetected in 90% of pre-invasive lesions and in all CC serum samples, but not in healthy women. PSG1 expression correlates with the expression of IL-10 and TGF-β in CC tissues, but not with the presence of HPV. Conclusion These data show evidence of the differential expression of PSG1 in CC that could explain its participation in tumor-biology and immunotolerance mechanisms. Further, its immunodetection could provide early detection of this cancer.

Microplastics (MPs) alone may endanger the health and fitness of aquatic species through different mechanisms. However, the harmful effects of these when mixed with other emerging contaminants require additional research. Herein, we aimed to determine whether a mixture of MPs with metformin (MET) or guanylurea (GUA) might induce embryotoxicity and oxidative stress in Danio rerio. Upon exposure to mixtures, our results showed MPs reduced the mortality rate of MET and GUA in embryos. Moreover, the severity and the rate of malformations were also decreased in all mixtures with MPs. Concerning oxidative stress, our findings indicated MET, GUA, MPs, and the mixtures increased the levels of lipoperoxidation, hydroperoxide content, and protein carbonyl content in D. rerio larvae. However, the oxidative damage induced in all mixtures was lower than that produced by both drugs alone. Thus, it is likely that the accumulation of MPs avoided the entrance of MET and GUA into the embryos. Once the embryo hatched, MPs did only remain accumulated in the yolk sac of larvae and did not translocate to other organs. Our risk assessment analysis confirmed that MPs shrunk the damage produced by MET and GUA. In a nutshell, MPs mitigate the embryotoxic damage of metformin and guanylurea in D. rerio by blocking their entrance.

This study presents a nanocomposite developed with PVA, multiwall carbon nanotubes (CNTs) doped with nitrogen, and NaDDBS, which change the electrical properties of the polymer and its viscosity to be used in electrospinning process for obtaining mats of nano/macro fibers. The proposed nanocomposite was characterized using Fourier transform-infrared and Raman spectroscopy techniques, confirming the presence of the CNxs immersed in the polymer. High-resolution transmission electron microscopy was used to obtain the micrographs that showed the characteristic interplanar distances of the multiwall CNT in the polymeric matrix, with values of 3.63 Å. Finally, the CNx mats were exposed to various aqueous solutions in a potentiostat to demonstrate the effectiveness of the nanofibers for electrochemical analysis. The CNx-induced changes in the electrical properties of the polymer were identified using cyclic voltammograms, while the electrochemical analysis revealed supercapacitor behavior.

Campylobacter jejuni is a pathogen bacterium that causes foodborne gastroenteritis in humans. However, phenolic compounds extracted from natural sources such as capsicum pepper plant (Capsicum annuum L. var. aviculare) could inhibit the growth of C. jejuni. Therefore, different extracts were prepared using ultrasonic extraction (USE), conventional extraction (CE) and thermosonic extraction (TSE). C. jejuni was then exposed to chili extracts to examine the antimicrobial effect and their growth/death bacterial kinetics were studied using different mathematical models. Atomic force microscopy was applied to investigate the microstructural and nanomechanical changes in the bacteria. Extracts obtained by TSE had the highest phenolic content (4.59 ± 0.03 mg/g of chili fresh weight [FW]) in comparison to USE (4.12 ± 0.05 mg/g of chili FW) and CE (4.28 ± 0.07 mg/g of chili FW). The inactivation of C. jejuni was more efficient when thermosonic extract was used. The Gompertz model was the most suitable mathematical model to describe the inactivation kinetics of C. jejuni. Roughness and nanomechanical analysis performed by atomic force microscopy (AFM) provided evidence that the chili extracts had significant effects on morphology, surface, and the reduced Young's modulus of C. jejuni. The novelty of this work was integrating growth/death bacterial kinetics of C. jejuni using different mathematical models and chili extracts, and its relationship with the morphological, topographic and nanomechanical changes estimated by AFM.

[Abstract] Lead (Pb2+) and copper (Cu2+) are polluting metals due to their toxicity; however, the extraction of these metals is essential for economic development, so it is important to look for efficient and low-cost alternatives that can remove heavy metals from the various bodies of water. One of the alternatives used in this work is biosorption, for which an agroindustrial waste (epidermis from Agave atrovirens) was used to evaluate the affinity of removal of lead and copper in aqueous solutions; in addition, spectroscopy and microscopy techniques were used to elucidate and corroborate the removal and affinity capacity of the agave epidermis for both metals studied. The optimal pH value for the removal of both metals was 3. The adsorption isotherms yielded a qmax of 25.7 and 8.6 mg/g for lead and copper, respectively. Adjusting to the Langmuir-Freundlich model, the adsorption kinetics were pseudo-second order, and it was found that the equilibrium time was at 140 min. The spectroscopy and microscopy analyses corroborated the affinity between metals and functional groups of the agave, as well as with the elemental analysis, which reported 17.38% of lead and 4.25% of copper. [Resumen] El plomo (Pb2+) y el cobre (Cu2+) son metales contaminantes debido a su toxicidad; sin embargo, la extracción de estos metales es indispensable para el desarrollo económico, por lo que es importante buscar alternativas eficientes y de bajo costo que puedan remover metales pesados de los diversos cuerpos de agua. Una de las alternativas utilizadas en este trabajo es la biosorción, para la cual se utilizó un residuo agroindustrial (epidermis de Agave atrovirens), para evaluar la afinidad de remoción del plomo y cobre en soluciones acuosas; adicionalmente, se emplearon técnicas de espesctroscopía y microscopía que permitieron elucidar y corroborar la capacidad de remoción y afinidad que tuvo la epidermis de A. atrovirens para ambos metales estudiados. El valor óptimo de pH para la remoción de ambos metales fue 3. Las isotermas de adsorción arrojaron una qmax de 25.7 y 8.6 mg/g para el plomo y cobre, respectivamente. Ajustando al modelo de Langmuir-Freundlich, las cinéticas de adsorción resultaron de pseudo-segundo orden, se encontró que el tiempo de equilibrio es a los 140 min. El análisis espectroscópico y microscópico, corroboró la afinidad entre metales y grupos funcionales del agave, así como con el análisis elemental, el cual reportó 17.38% de plomo y 4.25% de cobre.

Here, different tissue surfaces of tomato root were characterized employing atomic force microscopy on day 7 and day 21 of growth through Young's modulus and plasticity index. These parameters provide quantitative information regarding the mechanical behavior of the tomato root under fresh conditions in different locations of the cross-section of root [cell surface of the epidermis, parenchyma (Pa), and vascular bundles (Vb)]. The results show that the mechanical parameters depend on the indented region, tissue type, and growth time. Thereby, the stiffness increases in the cell surface of epidermal tissue with increasing growth time (from 9.19 ± 0.68 to 13.90 ± 1.68 MPa) and the cell surface of Pa tissue displays the opposite behavior (from 1.74 ± 0.49 to 0.48 ± 0.55); the stiffness of cell surfaces of Vb tissue changes from 10.60 ± 0.58 to 6.37 ± 0.53 MPa, all cases showed a statistical difference (p < 0.05). Viscoelastic behavior dominates the mechanical forces in the tomato root. The current study is a contribution to a better understanding of the cell mechanics behavior of different tomato root tissues during growth.

The beneficial effect of agave fructans on health has been demonstrated gaining popularity as a new prebiotic and functional food ingredient, however, their role as an ingredient and their technological properties is scarcely reported. This work studied the structural and quality features of doughs and cookies added with agave fructans “AF” and compared to systems added with chicory fructans “CF” or without fructans (“WF”) added, to analyse the effect of the chemical structure due to the fructan-type added. For doughs, it was found that AF lowered the water adsorption, causing a short development time and the highest stability during kneading. The texture profile analysis and rheological tests revealed that AF increased springiness and cohesiveness. For cookies, the crumb and lightness were evaluated using a computer vision system. Among the samples, AF promoted a darker and shiny crust and a more homogeneous and compact microstructure. X-ray diffraction analysis demonstrated that AF had the highest values of crystallinity. In order to provide more information about the distribution of carbohydrates (aldoses and ketoses) and gluten proteins in the cookies, a method was developed to specifically stain these molecules, and it successfully described the effect of the fructans incorporated into doughs and cookies. Results from confocal laser scanning microscopy illustrated differences in the distribution of the biopolymers stained. This research provided an improved understanding of the AF addition on the technological properties and the structure–functionally relationship of doughs and cookies, beyond the nutraceutical applications attributed to the AF.

Background Atomic force microscopy (AFM) has been used to study the molecular structure of biological materials. AFM has become a novel tool that allows measurement of nanomechanical properties of food materials. The importance of evaluating these properties in foods is that the biological functions are closely linked with physical phenomena that occur on the cell surfaces. Scope and approach The AFM is a technique that has already been used in the food research community as an efficient tool to evaluate cell mechanics occurring in food materials and it is possible to study the physical phenomena that occur in the cells and tissues of food during its processing and storage. This article presents an overview of the main issues that may arise during the evaluation of mechanical properties by AFM. It may be used as a guideline in order to apply these techniques for foods. A summary of the most recent studies in the nanomechanical properties of food is included. Key findings and conclusions AFM has been used to evaluate how nanomechanical phenomena on cell surfaces influence in the quality of food materials, as well as to evaluate the changes that occur at the nanometric scale in food materials due to its processing and storage. The methods to analyze nanomechanical properties in foods are not yet standardized since this is still a rarely used technique for foods. The development and application of techniques for measuring the nanomechanical properties in food materials is necessary. AFM and nanoindentation will be useful tools for the development of food nanotechnology.

Some physicochemical characteristics and antioxidant activity of extrudates made from corn grits and red potato flour were evaluated. The inclusion of red potato flour altered values of water absorption index, water solubility index, expansion index and fracturability of extrudates. Color analysis of extrudates showed a reduction of luminosity from 44.37 ± 0.87 to 25.06 ± 1.74. Likewise, extrudates made with red potato flour at 100% presented higher content of total phenols compared to the control extrudates (0.44 ± 0.02 and 2.88 ± 0.03 mg GA/g dry sample, respectively); consequently, an increase in antioxidant capacity was observed using DPPH, ABTS and FRAP assays. The images obtained by fluorescence microscopy provided information on the protein content. The proximal chemical analysis indicated that extrudates substituted with red potato flour at 10% showed higher protein content (7.78 g/100 g), compared to T5. This study concludes that when adding red potato flour, is possible to develop extrudates with good physicochemical characteristics and antioxidant properties.

The pollution caused by use of petroleum-derivate plastic materials is a major environmental problem. This has encouraged researchers to develop new compostable and environmental-friendly materials based on biopolymers and agro-industrial residues. The aim of this work was to study the addition of garlic skin (GS) particles and the changes in physicochemical, mechanical, and microstructural properties of films formulated with potato starch and gellan gum as well as the creation of an environmentally friendly dish. Different concentrations (1, 2 and 3% w/v) and sizes (1410-213 μm, 212-39 μm and 38-1 μm) of GS particles were used for the mechanical reinforcement of the films and as independent variables of the experimental design. Different response variables (phenolic content, color difference, thickness, film transparency, stress, strain, Young's modulus, water solubility, water adsorption capacity, fractal dimension and entropy of the images) were evaluated to select the optimal point using response surface methodology (RSM). Microscopy techniques and texture image analysis were used to explain the effect of adding GS particles to the microstructure and mechanical reinforcement of the films. Moreover, thermogravimetric analysis (TGA), principal component analysis (PCA) and RSM were used to select the best film for making a compostable dish using a low-cost molding process at laboratory level. A novelty of this study was proposing an alternative use of GS waste in a film with biopolymers, integrating different analytical tools to facilitate the selection of the suitable formulations to create compostable dishes in 60 days, which goes beyond the traditional studies of coatings and polymeric films reported.

Crystallinity (CI) and crystallite size (Dhkl) of cellulose nanoparticles obtained from commercial cellulose (cotton) have been evaluated after a ball milling by the deconvolution method. Ball milling was used to achieve cellulose nanoparticles based on the values of crystallite size previously reported. Variations in the CI were found in a range from 88% to 45%. Crystallite sizes were evaluated in an initial value from 4.99 nm that decrease until 1.41 nm by ball milling. A clear dependency of CI and Dhkl was found since ball milling decrease the CI until a re-agglomeration of the samples is found. Results for Dhkl reveals that cotton cellulose is a soft material easy to grind into nanoparticles in a heterogenous way as authors reported before. Cross-contamination due to higher quantities of silicon oxide was found after two-hour milling. This study presents an insight into the behavior of cellulose nanoparticles using ball milling and the selection of a time in which non-cross contamination or re-agglomerations have been found.

Background This study describes a promising method for understanding how halophytes adapt to extreme saline conditions and to identify populations with greater resistance. Image and colour analyses have the ability to obtain many image parameters and to discriminate between different aspects in plants, which makes them a suitable tool in combination with genetic analysis to study the plants salt tolerance. To the best of our knowledge, there are no publications about the monitoring of halophytic plants by non-destructive methods for identifying the differences between plants that belong to different maternal salinity environments. The aim is to evaluate the ability of image analysis as a non-destructive method and principal component analysis (PCA) to identify the multiple responses of two S. europaea populations, and to determine which population is most affected by different salinity treatments as a preliminary model of selection. Results Image analysis was beneficial for detecting the phenotypic variability of two S. europaea populations by morphometric and colour parameters, fractal dimension (FD), projected area (A), shoot height (H), number of branches (B), shoot diameter (S) and colour change (ΔE). S was found to strongly positively correlate with both proline content and ΔE, and negatively with chlorophyll content. These results suggest that proline and ΔE are strongly linked to plant succulence, while chlorophyll decreases with increased succulence. The negative correlation between FD and hydrogen peroxide (HP) suggests that when the plant is under salt stress, HP content increases in plants causing a reduction in plant complexity and foliage growth. The PCA results indicate that the greater the stress, the more marked the differences. At 400 mM a shorter distance between the factorial scores was observed. Genetic variability analysis provided evidence of the differences between these populations. Conclusions Our non-destructive method is beneficial for evaluating the halophyte development under salt stress. FD, S and ΔE were relevant indicators of plant architecture. PCA provided evidence that anthropogenic saline plants were more tolerant to saline stress. Furthermore, random amplified polymorphic DNA analysis provided a quick method for determining genetic variation patterns between the two populations and provided evidence of genetic differences between them.

The aim of this study was to obtain cellulose and cellulose nanoparticles (CNP) from garlic and agave wastes, as well as elucidating its structure at different scales using microscopy and spectroscopy techniques. Cellulose is isolated by using a sequential extractive process and monitored by CLSM and SEM, while CNP are produced in a high-energy planetary mill. FTIR and XRD confirmed the presence of cellulose type I and CI and Dhkl was used to evaluate the size of CNP. The corresponding crystalline structure, d-spacing and angles obtained from crystalline regions of CNP were estimated by TEM and computational simulation. It is shown that the triclinic phase is predominant in G, and a monoclinic conformation in CNP for A. The novelty of this contribution is to demonstrate that the crystalline structure of CNP, extracted from different agro-food wastes, depends on its initial microstructural arrangement (laminar or fibrillar).

The use of nanoparticles (NPs) in various industries has experienced significant growth due to the advantages they offer, so the increase in their use has generated the continuous discharge of these products in numerous water bodies, which can affect the organisms that inhabit them. Previous studies have shown that Al is capable of producing oxidative stress in aquatic organisms; however, so far the impact of AlNP on hydrobionts is limited. Therefore, the objective of this work was to determine the oxidative stress produced by AlNP in liver, gill and blood of Cyprinus carpio, as well as their bioconcentration factor (BCF) in various tissues. For this purpose, the organisms were exposed to 50 μg L−1 AlNP for 12–96 h. Subsequently, the tissues were obtained and the activity of antioxidant enzymes, oxidative damage to lipids and proteins were determined, and the BCF was calculated for liver, brain, gill and muscle. The results showed alterations in the activity of antioxidant enzymes and increased levels of lipoperoxidation, hydroperoxides and oxidized proteins. When establishing the integrated biomarker response, it was observed that the liver is the most affected organ and these effects are related to the Al content in the tissue. Finally, it was observed that muscle and gills presented a higher BCF, compared to brain and liver. These findings show that AlNP are capable of generating oxidative stress in carp, affecting tissue function and accumulating, which represents an important risk for the health of fish such as common carp.

The aim of this work was to study the microstructure and micromechanical properties of spines obtained from nopal waste. Spines were obtained by drying at 40 °C then sieving. Physical and chemical assays and microscopy techniques were used to determine the role of microstructural arrangement in local micromechanical properties. Transversal (TS) and longitudinal sections (LS) of the spines were studied by indentation and microscopy. Environmental scanning electron microscopy was helpful for characterizing the overall structure of spines. Confocal laser scanning microscopy was used for determining the distribution of cellulose and lignin in spines, which was associated with their micromechanical properties. Atomic force microscopy showed that TS is less rough (Ra = 3.08 ± 0.75 nm) and more hard (0.57 ± 0.31 GPa) than LS (Ra = 24.56 ± 1.60 nm, 0.57 ± 0.31 GPa). In accordance with these results, the elastic modulus of LS (8.65 ± 3.18 GPa) is lower than that of TS (14.94 ± 7.09 GPa). The hardness and elastic modulus of libriform fibers and sclerified epidermis are influenced by their microstructures and as well as the distribution of cellulose and lignin in the spines. The microstructural arrangement and the distribution of cellulose and lignin in the TS provide greater hardness values than those of woods. The current study presents a novel structural characterization of nopal spines and their local micromechanical properties. This waste product could be a cheap and non-wood alternative resource of cellulose with good mechanical properties useful for designing novel biomaterials with applications in the agricultural sector.

The morphology and micromechanical properties of the mineral crystals embedded in the pecan nutshell (Carya illinoinensis) were characterized. Qualitative and quantitative morphological analyses carried out revealed that the crystals were comprised of calcium oxalate (CaOx) and have a wide range of sizes, with prismatic shapes, distributed heterogeneously in the sclerenchyma tissue. From indentation tests, it was found that CaOx crystals are stiffer structures compared to stone cells (sclerenchyma tissue), showing hardness and elastic modulus values of 0.53 ± 0.19 GPa and 9.4 ± 1.80 GPa, respectively. Additionally, the values of fracture toughness (0.08 ± 0.02 MPa m0.5) and the brittleness index (9336 m−0.5) revealed that these types of structures are extremely brittle. The results obtained suggest that the main function of the CaOx crystals is to provide structural support to tissue. The presented methodology demonstrates the potential of the instrumented indentation technique (IIT) for in situ micromechanical characterization of mineral crystals located in plant tissues.

Mango is an important crop worldwide, with a postharvest loss that is huge due to its climacteric behaviour. This study evaluated the softening of Tommy Atkins mangos during the ripening process. Ripening index (RPI) shown a decrease from 9.18 ± 0.14 to 4.75 ± 0.47. The enzymatic activity agreed with physicochemical parameters and with the structural and mechanical changes. Three pectin fractions were isolated from the mango cell wall: water soluble (WSP), chelator soluble (CSP) and diluted alkali soluble (DASP) pectin. The Younǵs modulus (E) of the primary cell wall was evaluated, it decreased from 1.69 ± 1.02 to 0.39 ± 0.16 MPa, which could be attributed to the softening of the fruit. A linear fit correlation between E and RPI was found. X-ray and confocal laser scanning microscopy analysis showed the changes occurred in the mango cell wall structure during maturation. Novelties of current study can be helpful in the use of mango wastes to obtain cellulose.

Jicama roots have been studied as an alternative starch source. However, reports about the extraction yield are scarce, as well as publications about the use of pretreatment techniques for this material. Hence, the aim of this study was to analyze the effect of sonication on the starch yield as well as on the granule structure. Ultrasound was observed to have a positive effect on the starch yield, with the largest value obtained at a sonication time of 10 min (24.76 ± 2.4%). This represents a 46.9% increase over a non-treated sample (16.86 ± 0.9%), and the starch granule structure was unaffected, as confirmed by microscopy and an X-ray diffraction analysis The imperviousness of the starch granule to the sonication process is attributed to the protective effect of soluble fiber and a change in viscosity caused by the material released from parenchyma cells. More studies are required in this area.

Salicornia is a genus of plants that are able to grow in saline conditions and that are known as “halophytes”. Moreover, this species has plenty of other industrial and ecological applications as a sustainable crop. Currently, there are many publications on plants with a high economic value, but few are related to the applications of high salt-tolerant plants as an important source for the food, pharmacy, bioenergy and ecology sectors. Aspects such as morphology, microstructure-composition, salt-adaptation mechanism are discussed to improve our understanding of these elements with regard to scale its production while its commercial exploitation depends on better knowledge of its structure and composition. A summary of its biomass, seeds, oil and ethanol yields is then presented to highlight its profitability as a sustainable crop. Furthermore, ecological applications in aquaculture and phytoremediation are also discussed, while applications in food, pharmacy, ecology, chemical and cosmetic sectors are also presented. In this review, Salicornia stands out in the fields of food and pharmacy due to its bioactive compounds which have been reported to have antioxidative and anti-inflammatory health benefits as well as immunomodulatory activities, and can also be used as secondary metabolites in pharmaceutics or as nutraceutics in food, with high commercial and culinary value as salt substitute due to its protective effect on vascular dysfunction and hypertension. The second aspect that is emphasized is its seed oil content, with a 30 % edible oil rich in linoleic, oleic, palmitic and stearic acids, along with a high protein content. It is also mentioned that Salicornia’s seed oil and biomass have been reported as good sources for biofuel and bioethanol production. Chemically, some studies have reported antipathogenic effects among others from Salicornia nanoparticles. Recommendations on how to increase its growth through the association of plant growth promoting bacteria, new application trends, the difficulties that need to be overcome with a proposal study cost and benefits of Salicornia farm associated with aquaculture as well as the main nutritional and/or productivity effects based on the cultivation methods, are discussed.

Nanomechanical properties of fruit determine macroscopic firmness. Young's modulus (YM) of apple tissue obtained by atomic force microscopy (AFM) at cellular level and its correlation with other macroscopic physical parameters are used to evaluate ripening when apples were stored at 25 °C during 40 days. The YM of the tissue decreased from 0.96 ± 0.42 MPa (first day) to 0.11 ± 0.06 MPa (last day). The best linear correlation of YM was obtained with firmness (F) which decreased from 21.15 ± 0.79 N to 12.74 ± 0.34 N. Also various physical parameters obtained as peel color difference (ΔE) from 57.80 ± 0.97 to 66.51 ± 0.71, environmental electron microscopy (ESEM) such as entropy: Ent (from 8.67 ± 0.12 to 9.60 ± 0.17) and fractal dimension: FD (from 2.67 ± 0.05 to 2.75 ± 0.03) changed as well. Significant correlations ( P 2 > 0.95 was found. Industrial relevance The study of the nanomechanical properties of fruit cells by AFM may provide insight into internally fruit properties and how changes in these properties over time influence the quality of the fruit. The determination of cell/tissue mechanics could be used to follow changes in the nanomechanical properties that occur during the processing and storage of climacteric fruits such as apples. The study of the nanomechanical properties of plant cells as well as their correlation with other useful food properties such as firmness, peel color and image texture could lead to a better understanding of the ripening process. Mathematical models to predict cell mechanical properties at the nanometric level through food quality parameters could be an innovation in food engineering and be a novel tool in evaluating the quality of apples. Benefits of the methods herein could be extended to address current issues, such as extending the storage life of other climacteric fruits and predicting nanostructural modifications to the cells when they are physically modified or chemically treated.

In Mexico, agave constitutes a natural waste that comes from many different industries. This situation creates an opportunity area for the research, exploitation, and use of these agro-industrial wastes. Present work compared color, mechanical, and functional properties of PVA/cellulose/Alginate, PVA/cellulose/chitosan, and PVA films. Milox process and high-energy ball milling were used to purify agave waste for the later obtaining of cellulose nanoparticles (CNP). Addition of CNP to the films reinforced and increased the tensile strength of them.

Environment care is currently a crucial priority due to the increase in worldwide pollution. Nanotechnology and recycled material could be used as a platform to know more easily some analytical ion concentrations. In this investigation, a recycled plastic-based ion-selective electrode (PB-ISE) to use as a potentiometric sensor was built using a transductor material as carbon nanotubes ink (CNT-ink) and a metalized polyester sheet (MPS) from packing residues. To make the electrode, CNT-ink is applied and spread onto the MPS surface adding cycles of 1 ml at 100°C until a maximal reduction in the electrical resistance and a stable roughness were observed. Once the conductive plastic is ready, it's covered with adherable plastic masks on both sides of MPS to protect it from liquids. The final step is the addition of the ion-selective membrane (ISM) for potassium determination on a circular orifice, which is located on the front mask. The results obtained were compared with a classical solid-contact ion-selective electrode (SC-ISE). Some analytical parameters as sensitivity, linear ranges, and limits of detection of the recycled plastic electrode were comparable with those obtained for the SC-ISE. The best performance was reported for the PB-ISE that afforded a near-N ernstian response $(\mathbf{52.08}\pm \mathbf{2.36}\ \mathbf{mV})$ with a linear range from 10−4 to 10−1M and a limit of detection of 0.0176 mM. The potentiometry technique presents advantages in comparison with other techniques as well as a reduction in the cost and instrumental equipment to measure a wide range of analytes. Also, the straightforward fabrication and robustness that embrace the ISE could create an advantage technique using residual material from food packaging.

In recent years the interest for the harvest of energy with micro thermoelectric generators ( &mu, TEG) has increased, due to its advantages compared to technologies that use fossil fuels. There are three ways to improve the performance of the device, by modifying its structure, type of material and operation control. In this study, the role of the load resistance R L on the performance of a &mu, TEG with nanostructured materials is investigated. The interaction of the load resistance with the thermoelements exhibits interesting features, arising from the coupling of the temperature-dependent electrical and thermal transport properties at different temperature ranges and the architecture of nanostructured thermoelectric materials. This coupling results in inflections on the efficiency, i.e., maximum and minimum values of the efficiency at higher temperatures, 600&ndash, 900 K. We show the explicit dependence of the performance of the &mu, TEG in terms of the load resistance and discuss the underlying physics. The unusual features of the efficiency of nanostructured thermoelectric materials are a result of the behavior of the power factor and the nonequilibrium properties of the system. We also analyze the effect of the geometric shape of the thermoelements on the device. We determine the performance of the &mu, TEG, evaluating the generation power and its efficiency. The results show that the efficiency of the device can decrease or increase depending on the value of R L , while the power decreases with an increase of the load resistance.

Nanotechnology is a developing field of research and has the potential to generate unique materials with notable properties. Elucidation of the functions of nanomaterials provides a deep framework for understanding the relationships between composites and their influences on the global structures of materials. Advances in the design of nanostructured materials have allowed us to obtain nanoparticles that have potential applications in the development of new smart packaging. The ability to control the way to assemble the material matrix is an advantage in designing products with better properties. This is the next step to achieve nanotechnological innovation: control of hierarchical structures to improve the functionality of polymers and smart packaging. This chapter reviews nanomaterial applications in the design of edible films, functional polymers, and smart packaging for use in the food sector.

Nanotechnology is a multidisciplinary science that is focused on characterization, production, and manipulation of materials at nanoscale, while nanoagriculture does to reference to three main fields: water, energy, and agro-food production, where the nanotechnology can be applied. The discovery of carbon nanotubes unleashed the revolution in the use and handling of nanomaterials. The most used nanomaterials in nanoagriculture are nanomembranes, nanoporous polymers, nanoporous zeolites, carbon nanotubes for nanosensors, and catalytic nanoparticles for the removal of pollutants of environment. Recently, an attractive application of nanotechnology is energy production based on the use of biological nanomaterials supported in carbon nanotubes and graphene. The understanding of nanotechnology is important to contribute significantly to improvement of growing crops, water quality, and sustainable energy.