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Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG A scale-up process was carried out to obtain potent bioactive peptides from whey protein through a simple hydrolysis process. The scale-up was satisfactory, with results similar to those obtained at lab scale: a fraction of peptides < 1 kDa with ACE inhibitory activity of 18.44 ± 2.47 μg/mL, a DPPH value of 69.40 ± 0.44%, and an ORAC value of 3.37 ± 0.03 μmol TE/mg protein. The peptide sequences responsible for the ACE inhibitory activity were also similar to those identified at lab scale: PM, LL, LF, HFKG and PT. The hydrolysate was used as a functional ingredient in a low-fat yoghurt. The consumer sensory taste panel found no significant difference (p > 0.05) between the bitterness of the control and the functional yoghurt, and about 50% of consumers would buy it. The hydrolysate maintained its bioactivities for 4 months at −20 ◦C (after thawing and pasteurisation), and for 1 week in yoghurt at 4 ◦C.

The functional properties α-LA nanotubes and the gels formed during their synthesis were studied to evaluate their potential applications. The bioactivity of α-LA was improved by the synthesis of nanotubes, with significantly (p < 0.05) higher ACE-inhibitory (IACE) and antioxidant activity (μmol TE/mg protein). The IC50 (protein concentration to inhibit 50% of ACE activity) of α-LA nanotubes was 281 ± 21 μg mL−1 and the antioxidant activity 1.28 ± 0.01 μmol TE mg−1 protein. Besides, the IACE-value was significantly higher (p < 0.05) when the α-LA fragments incorporated into the nanotube’ structure were considered, and not only the low MW peptides formed during the nanotube synthesis (not incorporated into the nanotube’ structure).This study also analysed how different ion ratios in the synthesis of α-LA nanotubes changed their functionality. Thus, gels formed by long and regular α-LA nanotubes (2 mol of Mn2+/mol of α-LA) showed fluid−gel characteristics, with some time-dependent shear-thinning flow (thixotropy). At fixed recovery time, a less thixotropic behaviour was found in these fluid gels (high percentage −71.6 ± 7.4%− of structural regeneration). Additionally, they stayed in gel form at high temperatures and even increased their stiffness up to 65 °C. The increase in the ion ratio (3 mol of Mn2+/mol of α-LA) during nanotube synthesis modified the α-LA nanotubes' microstructure nanotubes resulting in short and branched nanotubes. These gels showed a higher level of pseudo-plasticity, higher consistency and thixotropy. These are characteristics of a more complex and dense network with greater time dependence and lower structural regeneration (18.6 ± 2.0%) Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Xunta de Galicia | Ref. ED431E 2018/07

Okara oil is a by-product remaining from defatting okara, the solid residue generated after extracting the aqueous fraction of grounded soybeans in the elaboration of soy beverages. The goal of this work was to encapsulate the probiotic Lactobacillus plantarum CIDCA 83114 into W/O emulsions composed of a block-copolymer constituted of pluronic® and acrylic acid (PPP12) and okara oil, prepared in microfluidic devices. For comparative purposes, alginate was also included as a second dispersed phase. Lactobacillus plantarum CIDCA 83114 was suspended in PPP12 or alginate giving rise to dispersed phases with different compositions, named I, II, III and IV. Controls were prepared by suspending microorganisms in water as dispersed phase. 6-carboxyfluorescein was added as bacterial marker in all the emulsions. The presence of green dyed bacteria in the dispersed phases, inside the droplets of the emulsions and the absence of fluorescence outside them, confirmed the complete encapsulation of bacteria in the dispersed phases. After being prepared, emulsions were freeze-dried. The exposure to gastric conditions did not lead to significant differences among the emulsions containing polymers. However, in all cases bacterial counts were significantly lower than those of the control. After exposing emulsions to the simulated intestinal environment, bacterial counts in assays I, II and III (emulsions composed of only one dispersed phase or of two dispersed phases with bacteria resuspended in the PPP12 one) were significantly greater than those of the control (p < 0.05) and no detectable microorganisms were observed for assay IV (emulsions composed of two dispersed phases with bacteria resuspended in the alginate one). In particular, bacterial cultivability in emulsions corresponding to assay I (only PPP12 as dispersed phase) exposed to the intestinal environment was 8.22 ± 0.02 log CFU/mL (2 log CFU higher than the values obtained after gastric digestion). These results support the role of PPP12 as an adequate co-polymer to protect probiotics from the gastric environment, enabling their release in the gut, with great potential for food or nutraceutical applications. Fil: Quintana, Gabriel Sebastian. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Gerbino, Oscar Esteban. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Alves, Patricia. Universidad de Coimbra. Facultad de Ciencias e Tecnología. Department of Chemistry; Portugal Fil: Nuno Simões, Pedro. Universidad de Coimbra. Facultad de Ciencias e Tecnología. Department of Chemistry; Portugal Fil: Rúa, María Luisa. Universidad de Vigo. Facultad de Ciencias de Ourense; España Fil: Fuciños, Clara. Universidad de Vigo. Facultad de Ciencias de Ourense; España Fil: Gomez Zavaglia, Andrea. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina

Bovine whey protein was hydrolysed using cardosins A and B purified from dried flowers of Cynara cardunculus by combining diafiltration, anion-exchange chromatography and ultrafiltration. The proteolysis experiments were performed using different whey protein concentrations and enzyme/substrate (E/S) ratios. Complete hydrolysis of the main whey proteins, β-Lactoglobulin (β-Lg) and α-lactalbumin (α-La), was achieved after 4 h, at E/S ratios of 1/150 U/mg, regardless the initial protein concentration. In previous reports, the authors suggested that cardosins could not hydrolyse β-lactoblogulin. However, our promising results open up new possibilities to further explore the action of cardosins on whey proteins for the production of bioactive peptides.

Most of the studies related to the susceptibility of the main bovine whey proteins to the action of cardosins of Cynara cardunculus have underestimated the potential of these proteases to hydrolyse β-Lactoglobulin (β-Lg). These works used the one-factor-at-a-time methodology, which ignores the interactions and can lead to misleading conclusions. In this work, the hydrolysis of bovine whey protein, exploiting the joint action of cardosins A and B of C. cardunculus, was optimised. For that purpose, a second-order rotatable design (with two variables at five levels) was used to study the combined effect of pH and temperature on the degree of hydrolysis (DH), the number of peptides generated and the angiotensin I-converting enzyme (ACE)-inhibitory activity. The complete hydrolysis of α-Lactalbumin (α-La) was achieved at pH 6.99/35.86 °C and pH 5.01/64.14 °C, and contrary to the previous studies, cardosins were able to hydrolyse β-Lg (up to ~40%) at pH 6.29/50 °C. In addition, the statistical analysis revealed that the same pH and temperature values that led to a minimum DH for α-La also provide a maximum DH for β-Lg. At pH 5.3 and 60 °C, we have obtained abundant peptides with high angiotensin I-converting enzyme (ACE)-inhibitory activity, but also a non-hydrolysed β-Lg. So, the purification and identification of the bioactive peptides, produced under these hydrolysis conditions, was performed. Moreover, the biotechnological potential of the β-Lg obtained was successfully proved for 3 promising applications: heat-induced gels, nanofibrils (self-assembly) and microparticles (spray-dryer).

The development of protocols for efficient gluten elimination is one of the most critical aspects of any allergen management strategy in the industry. The suitability of different proteolytic enzymes to be included in a cleaning formulation that allows the effective elimination of gluten residues was studied. Alcalase (ALC), neutrase (NEUT) and flavourzyme (FLAV) were selected from in silico analysis. The presence of 1% (v/v) of linear alkylbenzene sulphonate (LAS), a common anionic detergent, improved the gluten solubility, which may favour its elimination. Chromatographic analysis showed that the three enzymes studied were able to hydrolyse gluten in the presence of LAS. The highest percentage of short peptides (< 5 kDa) was achieved with ALC, what increases the probability of reducing the gluten antigenicity. Besides, in the presence of ALC and detergent LAS have detected the lowest levels of gluten with ELISA kits. So, effective amounts of ALC and LAS were added to a cleaning formulation, where its proteolytic activity was maintained above 90% after 37 days at 4 °C and 25 °C (under dark). Preliminary validation of the effectiveness enzymatic cleaning formulation to hydrolyse gluten was performed in a ready-to-eat/frozen food company, in which previous episodes of cross-contamination with gluten have been detected. The gluten content decreased to values below 0.125 μg/100 cm2 when the cleaning formulation was tested on different surfaces with different cleaning protocols, demonstrating the high suitability of the enzymatic cleaning formulation developed.

A one-step anion-exchange chromatography method (NaCl gradient elution on a DEAE Sepharose Fast Flow gel column) was developed to purify -lactalbumin (-LA) from whey protein isolate. -LA nearly 100% pure (based on the total protein content) was obtained with a yield of about 39%. Besides pure -LA, which was the main objective of this work, highly pure -lactoglobulin was also obtained with a yield of about 59%. The high purity of the obtained -LA samples allowed its use to synthesise protein nanotubes with excellent gelation properties for their use as food thickeners and bioactive carriers. The samples purity degree obtained (based on the total protein content) was critical in the formation of proper nanotubes instead of random aggregates, which produced opaque and weak gels, less useful for food applications., Clara Fuciños gratefully acknowledge her Postdoctoral grant (I2C 2014) from Consellería de Cultura, Educación e Ordenación Universitaria(XuntadeGalicia,Spain).Thisstudywassupportedbythe Portuguese Foundation for Science and Technology (FCT, Portugal) under the scope of the strategic funding of UID/BIO/04469/2013 unit and the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER027462)., info:eu-repo/semantics/publishedVersion

The potential application of polysaccharide-based films containing smart nanohydrogels for the controlled release of food preservatives is demonstrated here. Smart active packaging is the most promising alternative to traditional packaging as it provides a controlled antimicrobial effect, which allows reducing the amount of preservatives in the food bulk, releasing them only on demand. This work evaluates the usefulness of smart thermosensitive poly(N-isopropylacrylamide) (PNIPA) nanohydrogels with or without acrylic acid (AA) incorporated into polysaccharide-based films (GA) to transport natamycin and release it as a response to environmental triggers. Release kinetics in liquid medium from GA films containing PNIPA/AA nanohydrogels (GA-PNIPA(5) and GA-PNIPA-20AA(5)) presented a characteristic feature regarding the films without nanohydrogels that was the appearance of a lag time in natamycin release, able to reach values of around 35 h. Another important feature of natamycin release kinetics was the fact that the release from GA-PNIPA/AA films only occurred when temperature was increased, so that the natamycin release was restricted to when there is a risk of growth of microorganisms that cause food spoilage or the development of pathogenic microorganisms. Additionally, it could be observed that the relative fraction of natamycin released from GA-PNIPA/AA films was significantly (p, Clara Fucinos and Miguel A. Cerqueira are recipients of a fellowship (SFRH/BPD/87910/2012 and SFRH/BPD/72753/2010, respectively) from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN, and FSE Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", Ref. NORTE-07-0124-FEDER-000028 co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER and the project from the "Ministerio de Educacion y Ciencia" (Spain) "Nanohidrogeles inteligentes sensibles a cambios de pH y Temperatura: Diseno, sintesis y aplicacion en terapia del cancer y el envasado activo de alimentos", Ref. MAT2010-21509-C03-01.

This work evaluated the stability and functionality of nanotubes obtained from α-lactalbumin (α-LA). α-LA nanotubes' structure was highly stable during a freeze-drying process but not after grinding. The ability of α-LA nanotubes to encapsulate caffeine, used as a model molecule, was evaluated. α-La nanotubes were highly effective for this purpose as encapsulation efficiency (%EE) was near 100% and loading capacity (%LC) near 10% at 1.5/20 and 2/20 ratios (caffeine/α-LA, w/w). α-LA nanotubes' structure was not affected by the presence of caffeine. Also, in general, refrigeration temperatures and neutral or alkaline conditions, under which the adverse effect of chelating agents was prevented, helped to stabilise α-LA nanotubes' structure and maintain caffeine encapsulated. At 8 °C and pH 7.5, in the presence of 75 μg mL− 1 of EDTA, > 50% of the caffeine remained encapsulated into α-LA nanotubes., Clara Fuciños gratefully acknowledge her Post-Doctoral grant (I2C 2014) from Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia, Spain). Pablo Fuciños gratefully acknowledges his Marie Curie COFUND Postdoctoral Research Fellowship (Project No: 600375. NanoTRAINforGrowth - INL Fellowship programme in nanotechnologies for biomedical, environment and food applications). This study was supported by the Fundação para a Ciência e a Tecnologia (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462).

Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.foodcont.2016.10.028., Pimaricin is a fungicide commonly used on the cheese surface. In this work poly(N-isopropylacrylamide) nanohydrogels copolymerized with acrylic acid (PNIPA-20AA(5)) were proposed to encapsulate pimaricin and release it in a controlled manner to prevent a real food product, Arzúa-Ulloa DOP cheese, from food spoilage. The results reflect that the nanohydrogel coating neither impart any adverse effects (compared to the control) nor influence the natural ripening process of Arzúa-Ulloa DOP cheese. In the bioassay with artificial contamination, the total fungal counts in cheeses with the pimaricin-loaded nanohydrogel coating (NP) were lower than those of all the other treatments, during all the assay (30 days). Despite significant (p, Clara Fuciños and Isabel R. Amado gratefully acknowledge their Pos-Doctoral grants (I2C 2014 and 2012, respectively) from Consellería de Cultura, Educaci on e Ordenaci on Universitaria (Xunta de Galicia, Spain). Pablo Fuciños gratefully acknowledges his Marie Curie COFUND Postdoctoral Research Fellowship (Project No: 600375. NanoTRAINforGrowth - INL Fellowship programme in nanotechnologies for biomedical, environment and food applications). The authors want to thank Benigno Pereira, Queizúar S. L. Manager, for providing us with the cheeses for the assays.

Whey proteins are widely used as nutritional and functional ingredients in formulated foods because they are relative inexpensive, generally recognized as safe (GRAS) ingredient and possess important biological, physical and chemical functionalities. Denaturation and aggregation behavior of these proteins is of particular relevance toward manufacture of novel nanostructures with a number of potential uses. When these processes are properly engineered and controlled, whey proteins may be formed into nanohydrogels, nanofibrils or nanotubes and be used as carrier of bioactive compounds. This review intends to discuss the latest understandings of nanoscale phenomena of whey protein denaturation and aggregation that may contribute for the design of protein nanostructures. Whey protein aggregation and gelation pathways under different processing and environmental conditions such as microwave heating, high voltage and moderate electrical fields, high pressure, temperature, pH and ionic strength were critically assessed. Moreover, several potential applications of nanohydrogels, nanofibrils and nanotubes for controlled release of nutraceutical compounds (e.g. probiotics, vitamins, antioxidants and peptides) were also included. Controlling the size of protein networks at nanoscale through application of different processing and environmental conditions can open perspectives for development of nanostructures with new or improved functionalities for incorporation and release of nutraceuticals in food matrices., Oscar L. Ramos, Ricardo N. Pereira and Clara Fuci~nos gratefully acknowledge their Post-Doctoral grants (SFRH/BPD/80766/2011, SFRH/BPD/ 81887/2011, and SFRH/BPD/87910/2012, respectively) to the Fundação para a Ciência e Tecnologia (FCT, Portugal). All authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project “BioEnv— Biotechnology and Bioengineering for a sustainable world”, REF. NORTE07-0124-FEDER-000048, co-funded by Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER.

Functional foods or ingredients (nutrients and nonnutrients) are a wide variety of products that have beneficial physiological effects when consumed because they affect a wide range of body functions relevant to a state of well-being and health and/or to the reduction of the risk of a particular disease. In this article the beneficial physiological effects in humans of the intake of dietary fiber including nondigestible prebiotics such as inulin, fructooligosaccharides, and galactooligosaccharides; ?3 and ?6 polyunsaturated fatty acids (particularly conjugated linoleic acid and docosahexaenoic acid); and bioactive peptides, polyphenols, and carotenoids, as well as probiotic microorganisms, are critically presented. To clarify the roles of these compounds in promoting health, a wide range of positive effects are discussed, including laxation, lower cholesterol and glucose levels in the blood, better immune response, lower risk of obesity and cardiovascular and gastrointestinal diseases, and antiarrhythmic, antiinflammatory, antihypertensive, antioxidant, opioid, hypocholesterolemic, antimicrobial, immunomodulatory, antithrombotic, antiobesity, and anticancer properties, as well as their being mineral carriers., (undefined), info:eu-repo/semantics/publishedVersion

In most active packaging systems for food applications, the preservative release is uncontrolled and frequently ineffective due to excessive or insufficient preservative concentration in the food matrix at a particular time. This work was aimed to evaluate the usefulness of pH- and temperature-sensitive poly(N-isopropylacrylamide) nanohydrogels for developing smart delivery systems to release preservatives as a response to environmental triggers. Pimaricin was used as a model preservative. Loading and release efficiencies were studied as a function of incorporation time and nanohydrogels composition, that differed in the cross-linker and acrylic acid content. Pimaricin loading efficiency was not affected by the acrylic acid. However, the cross-linking degree and incorporation time had a great influence. The lower the cross-linker content, the higher the loading efficiency, which in all cases exceeded 70 % at 12 h, approaching 100 % after 60 h of incorporation. No significant differences were observed between loading efficiencies obtained using water or methanol for pimaricin solubilisation. On the other hand, pimaricin release was dependent on the gel collapse, determined by the gel composition. Increasing the cross-linker content enhanced the nanoparticles' rigidity, and inclusion of acrylic acid as comonomer promoted strong electrostatic repulsions among the polymer chains. In both cases, the collapse was hampered, leading to a more hydrated collapsed state that favoured a sustained release of pimaricin. A mathematical model was also developed to predict the pimaricin release as a function of pH, temperature and storage time, allowing to select the most suitable nanohydrogel for a specific food application., This work was funded by grant (MAT 2006-11662-CO3-CO2-C01/MAT 2010-21509-C03-01/EUI 2008-00115) from the "Ministerio de Educacion y Ciencia" (Spain). Clara Fucinos gratefully acknowledge her Pos-Doctoral grant (SFRH/BPD/87910/2012) to the Fundacao para a Ciencia e Tecnologia (FCT, Portugal).

In this study, we assessed the potential as silage additive of a bacteriocin produced by Pediococcus acidilactici Northern Regional Research Laboratory (NRRL) B-5627 (pediocin SA-1). Maize was inoculated either with a bacterial starter alone (I) or in combination with the bacteriocin (IP), and untreated silage served as control. We monitored the products of fermentation (ethanol, and lactic and acetic acids), the microbial population, and the presence of the indicator strain Listeria monocytogenes Colección Española de Cultivos Tipo (CECT) 4032 (1 × 105 cfu/g) after 1, 2, 5, 8, 16, and 30 d of ensiling. Our results indicated antilisterial activity of the bacteriocin, anticipating the disappearance of L. monocytogenes in IP compared with I and control silages. The PCR-denaturing gradient gel electrophoresis analysis revealed the addition of the bacteriocin did not affect the bacterial communities of the spontaneous fermentation, and the inoculant-containing bacteria (Lactobacillus plantarum, Lactobacillus buchneri, and Enterococcus faecium) were found in addition to the bacterial communities of untreated maize silages in I and IP silages. Both treatments increased the concentration of antimicrobial compounds (acetic acid, ethanol, and 1,2-propanodiol) and led to lower residual sugar contents compared with the control, which would provide enhanced aerobic stability. The fact that the identified species L. plantarum, L. buchneri, and E. faecium produce some of these inhibitory compounds, together with their persistence throughout the 30 d of fermentation, suggest these bacteria could actively participate in the ensiling process. According to these results, pediocin SA-1 could be used as an additive to control the presence of L. monocytogenes in maize silages selectively, while improving their fermentative quality and eventually their aerobic stability., Isabel Rodríguez and Clara Fuciños were funded by a postdoctoral contract from the Xunta de Galicia, Spain (Plan I2C in 2012 and 2014, respectively). This research was financially supported by FP7 Project BiValBi (Biotechnologies to Valorise the regional food Biodiversity in Latin America; PIRSES-GA-2013-611493). We thank the Centro de Investigaciones Agrarias de Mabegondo for providing the maize used in this research. We also thank Pioneer Hi-Bred International Inc. for the inoculants and information supplied.

Antimicrobial edible packaging allows preserving food quality by avoiding or reducing the growth of food spoilage pathogen microorganism. Biopolymers used for this purpose include polysaccharides, proteins, and lipids. The mechanical and antimicrobial properties of biopolymers can be improved, respectively, by blending with other polymers or adding antimicrobial compounds (such as plant extracts and their essential oils) that are delivered from the matrix. Chitosan has by itself antimicrobial activity depending on pH, deacetylation degree, and molecular weight. The main applications to extend the shelf life are meat, poultry, fish and cheese products, and fruits and vegetables. In all cases, the protective effect of antimicrobial edible coating is complemented by the reduction of water loss and prevention of maturation and senescence or protection against oxidation., info:eu-repo/semantics/publishedVersion

This study evaluated the effectiveness as silage inoculants of two bacteriocin-producing lactic acid bacteria (LAB) with proven probiotic activity in post-weaned piglets, Lactococcus lactis CECT 539 and Pediococcus acidilactici NRRL B-5627, in combination with the ensiling strain Lactobacillus plantarum CECT 220. Four combinations of LAB were tested in grass and maize silages: L. plantarum (Lb), L. plantarum + L. lactis (LbL), L. plantarum + P. acidilactici (LbP), and the three species together (LbLP). Untreated silages and silages inoculated with commercial starters ( L. plantarum + Lactobacillus buchneri + Enterococcus faecium ) were prepared and used as controls. Since both bacteriocinogenic strains have shown antilisterial activity in vitro , this study also aimed to determinate their effectiveness for controlling Listeria monocytogenes in the silo. Therefore, silages were inoculated with the strain L. monocytogenes CECT 4032 (1.0 × 10 5 cfu/g), the evolution of which was monitored throughout fermentation using microbiological and DNA based methods. Each treatment was assayed in triplicate in lab-scale silos and sampled after 1, 2, 8, 16 and 30 days to extract DNA and determination of the pH, volume, organic acids (lactic, acetic, propionic and butyric), alcohols (ethanol and propane-1, 2-diol), water soluble reducing sugars (WSRS) and make LAB and L. monocytogenes counts. Our results showed that the silages treated with bacteriocin-producing LAB had a higher rate of pH decline (P L. monocytogenes colonies were found during ensilage; however, its DNA was present, which suggests that the adverse silage conditions (pH, anaerobiosis) might favour a viable but non-culturable state in the cells. In both forages, all treatments showed the anticipated disappearance of L. monocytogenes , unlike the control. It can be concluded that the bacteriocinogenic LAB tested in this study can be used as silage inoculants for controlling L. monocytogenes in the silo and also in the rumen of cattle due to their reported tolerance to acid.

An in-depth analysis of the kinetics of two lipases isoenzymes (Lip1 and Lip2) in triacetin hydrolysis in absence and in presence of hexane was carried out. The addition of hexane led to an increase in enzymatic activities of both enzymes for all triacetin concentrations, and the kinetic data described a hyperbola which was consistent with the classical Michaelis–Menten model. Without hexane, the time-course of the triacetin hydrolysis by Lip1 and Lip2 did not follow a Michaelian behaviour. In this case, a first phase of low enzymatic activity (at triacetin concentrations from 0 to 250 mM) was followed by a rapid increase in velocity at triacetin concentrations ≥250 mM. The Michaelis–Menten model was unable to describe the first phase due to the linear (nonhyperbolic) relationship between the velocity and the triacetin concentration, meanwhile the logistic model provided a satisfactory description of the experimental data corresponding to the second phase of activity. En este trabajo se llevo a cabo un pr...

The purpose of this study was to evaluate the effects of the application of chitosan coating containing natamycin on the physicochemical and microbial properties of semi-hard cheese. Three cheese groups were prepared: samples without coating, samples coated with chitosan and with chitosan containing 0.50 mg mL−1 of natamycin, whose minimum inhibitory concentration was previously determinated on cheese surface. Microbiological analyses showed that natamycin coated samples presented a decrease on moulds/yeasts of 1.1 log (CFU g−1) compared to control after 27 days of storage. Addition of natamycin also affected O2 and CO2 permeability, increasing from 7.12 to 7.68 × 10−15 g·(Pa s m)−1, and from 10.69 to 64.58 × 10−14 g·(Pa s m)−1, respectively. The diffusion coefficient values of natamycin from the film to phosphate buffered saline solution and to the cheese were 3.60 × 10−10 and 1.29 × 10−12 cm2 s−1, respectively. This study demonstrated that chitosan-based coating/films can be used as release system containing natamycin to create an additional hurdle for moulds/yeasts in cheese thus contributing to extend its shelf-life., Plan Galego de Investigación, Desenvolvemento e Innovación Tecnolóxica-Incite (Xunta de Galicia, Fundação para a Ciência e a Tecnologia (FCT)

The effects of sex, slaughtered age (9 vs. 12 months) and livestock production system (freedom extensive system vs. semi extensive system) of “Galician Mountain” foals breed on the fatty acid composition were studied. The sex and slaughtered age of the animals had no statistical significance in the intramuscular fatty acids. Furthermore, the livestock production system showed differences in the fatty acid profiles from the Longissimus dorsi. The feeding system showed significant differences in PUFA content (P

Pimaricin-loaded poly(N-isopropylacrylamide) nanohydrogels with and without acrylic acid, were evaluated as food-spoilage inhibitors in a model system and a real food product: grape juice. Pimaricin was proposed as a non-allergenic alternative to sulphites for protecting juices against recontamination. However, pimaricin may degrade under conditions and treatments (heating, acidification, lighting) commonly applied in producing fresh juices. Nanohydrogel encapsulation may be a feasible procedure to avoid pimaricin degradation, improving its antimicrobial activity. Pimaricin-free nanohydrogels did not affect the growth of the indicator yeast either in the food model system or in grape juice. Conversely, pimaricin-loaded nanohydrogels effectively inhibited the growth of the indicator yeast. In some cases, the inhibition was extended even further than using free pimaricin. For instance, in the food model system, pimaricin-loaded nanohydrogels with acrylic acid (NPPNIPA-20AA(5)) prevented the yeast growth for more than 81 h while free pimaricin was only effective for 12 h. Despite pimaricin-loaded nanohydrogels without acrylic acid (NPPNIPA(5)) were able to reduce maximum yeast growth, as in all treatments with pimaricin, the extent of the inhibitory effect was not significantly (p>0.05) different to that achieved with free pimaricin. In grape juice, both free pimaricin and NPPNIPA-20AA(5) treatment completely inhibited the growth of the indicator yeast until the end of the bioassay. However, the latter provided similar inhibition levels using a smaller amount of pimaricin due to PNIPA-20AA(5) protection and its controlled release from the nanohydrogel. Therefore, nanohydrogel encapsulation may help to optimise antifungal treatments and decrease the incidence of food allergies., Funded by grant (MAT 2006-11662-CO3-CO2-C01/MAT 2010-21509-C03-01/EUI 2008-00115) from the “Ministerio de Educación y Ciencia” (Spain). Grant (SFRH/BPD/87910/2012) from the Fundação para a Ciência e Tecnologia (FCT, Portugal). Marie Curie COFUND Postdoctoral Research Fellow.

This work aims at characterising polysaccharide-based films without (GA) and with the incorporation of free natamycin (GA-NA) and natamycin-loaded in a smart delivery device consisting in poly(N-isopropylacrylamide) nanohydrogels (GA-PNIPA). Transport properties (water vapour, oxygen and carbon dioxide permeabilities), mechanical properties (tensile strength and elongation-at-break), opacity, water sensitivity (moisture content and contact angle) and thermal properties (differential scanning calorimetry and thermogravimetric analyses) were evaluated. Chemical interactions were studied by means of Fourier transform infrared spectroscopy and scanning electron microscopy was used to verify the presence of natamycin and nanohydrogel particles in the film matrix. The results show that natamycin and natamycin-loaded poly(N-isopropylacrylamide) (PNIPA) nanohydrogels can be successfully added to edible films without changing their main packaging properties. However, tensile strength decreased (p, Miguel A. Cerqueira (SFRH/BPD/72753/2010) is a recipient of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN and FSE Portugal). The support of EU Cost Actions FA0904 and FA1001 is gratefully acknowledged.

We propose here a delivery drug-polymer system using poly(N-isopropylacrylamide) (PNIPA) nanohydrogels that enables pimaricin to be protected from hostile environments and allows the controlled release of the antifungal through environmental stimuli. We synthesized 2 nanohydrogels, 1 with 100% N-isopropylacrylamide (PNIPA(5)) and 1 with 80% N-isopropylacrylamide copolymerized and 20% acrylic acid (PNIPA-20AA(5)). Both were then, loaded with a pimaricin aqueous solution. The pimaricin release profiles of these 2 nanohydrogels were considerably different: PNIPA(5) released 10% and PNIPA-20AA(5) released 30% with respect to the free pimaricin release. Moreover, the diffusion experiments showed that pimaricin was released from the PNIPA-20AA(5) nanohydrogel for up to 3 times longer than free pimaricin. Therefore, incorporating acrylic acid as comonomer into the PNIPA nanohydrogel resulted in a slower but more continuous release of pimaricin. The highest pimaricin levels were reached when the most hydrophilic nanohydrogel was used. The bioassay results showed that the pimaricin-nanohydrogel system was highly effective in inhibiting the growth of the indicator strain in conditions of thermal abuse. The spoilage in acidified samples stored under fluorescent lighting was reduced by 80.94%± 33.02% in samples treated with a pimaricin-loaded nanohydrogel, but only by 19.91%± 6.68% in samples treated with free pimaricin. Therefore, 2 conclusions emerge from this study. One is that the nanohydrogel delivery system could impede the degradation of pimaricin. The other is that the inhibitory effect of the antifungal on yeast growth is more pronounced when it is added included into the nanohydrogel to the food, especially in an acidic environment. Practical Application: This article presents relevant results on the use of nanohydrogels in food packaging. Nanohydrogels could provide protection so that the pimaricin remains active for a longer time. They also allow the controlled release of pimaricin, which thus regulates the unnecessary presence of the antifungal in the food.

The influence of initial pH on growth and nutrient (total sugars, nitrogen, and phosphorous) consumption byEnterococcus faeciumCECT 410 was studied during batch cultures in whey. With these data, two realkalized fed-batch fermentations were developed using different feeding substrates. The shift from homolactic to mixed acid fermentation, the biphasic kinetics observed for cell growth and nitrogen consumption and the increase in the concentrations of biomass and products (lactic acid, acetic acid, ethanol, and butane-2,3-diol) were the most noteworthy observations of these cultures. Modelling the fed-batch growth ofEnt. faeciumwith the Logistic and bi-Logistic models was not satisfactory. However, biomass production was best mathematically described with the use of a double Monod model, which was expressed in terms of biomass, product accumulation, and nitrogen utilization. Product formation was successfully modelled with a modified form of the Luedeking and Piret model developed in this study.

The effects of sex, slaughtered age (9 vs. 12 months) and livestock production system (freedom extensive system vs. semi extensive system) of "Galician Mountain" foals breed on the fatty acid composition were studied. The sex and slaughtered age of the animals had no statistical significance in the intramuscular fatty acids. Furthermore, the livestock production system showed differences in the fatty acid profiles from the Longissimus dorsi. The feeding system showed significant differences in PUFA content (P0.001) higher in freedom extensive production system that semi extensive system, whereas MUFA content was significantly (P0.001) higher in semi extensive system. This major PUFA content in freedom extensive production showed a significant (r=0.70, P0.01) correlation with C18:3n-3 content and can be attributed to their eaten only pasture until slaughtered. The higher MUFA contents (P0.001) observed for semi extensive production system foals were very significant (r=0.98, p0.01) correlated with C18:1cis-9 content and less significant (r=0.81, P0.01) correlated with C16:1cis-9 content. In addition, the data reinforced the evidence that foals from extensive production system on wood pasture have a higher nutritional quality (mainly due to the higher levels of n-3 PUFA) when compared to concentrate-fed foals, as a result of the beneficial effects of grass on meat fatty acid profiles.

The production of biomass and antibacterial extracellular products by Lactobacillus casei subsp. casei CECT 4043 was followed in both batch and in realkalized fed-batch cultures. Enhanced concentrations of biomass and antibacterial extracellular products were obtained with the use of the latter fermentation technique in comparison with the batch mode. The culture obtained by fed-batch fermentation was mixed with skim milk and used to prepare a probiotic feed for weaned piglets. To test the effect of the potentially probiotic culture of L. casei on body weight gain, feed intake, feed conversion efficiency, and on fecal coliform counts of piglets, two groups of animals received either feed supplemented with the probiotic preparation or avilamycin for 28 days. The control group was fed nonsupplemented feed. At the end of the administration period (day 28), the groups receiving probiotic and avilamycin exhibited the highest average body weight gain values, although the mean feed intake and feed conversion efficiency values were not different among the groups (P0.05). For the entire experimental period (42 days), the control group exhibited the lowest feed intake value, the probiotic group exhibited the highest feed conversion efficiency value, and the antibiotic group exhibited the highest body weight gain (P0.05). Interestingly, no significant difference in body weight gain was observed between the probiotic and the control groups by day 42 (P0.05). Fecal coliform values decreased (although not significantly) by day 28 in the three groups. However, the mean counts returned to pretreatment levels by day 42 in all groups.