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Functional meat products are necessary to improve the health of consumers without detrimental effects on high biological value protein consumption. The incorporation of natural antioxidants and dietary fibre from agro-industrial coproducts is a good alternative to improve the nutritional characteristics of meat products. Pomegranate peel flour was employed as a functional ingredient to replace part of the fat, in a raw meat product like chorizo, determining changes in instrumental colour and texture, sensory acceptation, and neophobia. Pomegranate peel flour presented high content of polyphenols with considerable antioxidant activity, and high content of dietary fibre as well. Fibre retained moisture, decreasing water activity of the chorizos, decreasing pH during storage. Pomegranate peel flour increased the colour tone of the chorizos and decreased colour intensity, with a tough but easy to crumble texture. Sensory acceptation of chorizos with pomegranate peel flour was higher than control, although taste and texture were scored lower than the control sample. Results show that incorporation of pomegranate peel flour decreased Aw and pH, besides increased the samples luminosity and tone. Chorizo with pomegranate peel flour were harder than control. Nonetheless, as a functional ingredient improved health benefits with a positive consumers’ acceptance, non-neophobic, particularly in older consumers (40-50 years old). Pomegranate peel flour is a viable ingredient in the formulation of functional meat products.

Pork is the most consumed meat in the world but can also be a source of foodborne diseases. The objective of this study was to analyze the prevalence of pathogen microorganisms in pork loin muscle from six retail markets in six different demarcations in Mexico City with more than 500 000 inhabitants, analyzing Listeria, Staphylococcus and, Salmonella. The results showed that the prevalence of Listeria monocitogenes was 33.33%. Staphylococcus was detected in 42% of the samples analyzed with an average count of 770 CFU/g. Biochemical identification showed that 20% of isolates corresponded to Staphylococcus aureus. Salmonella sp. had the lowest prevalence with 2.77% of the total samples analyzed. The presence of pathogens in pork meat is an important problem because of their impact on consumer health.

Moonlighting proteins are those capable of performing more than one biochemical or biophysical function within the same polypeptide chain. They have been a recent focus of research due to their potential applications in the health, pharmacological, and nutritional sciences. Among them, some ribosomal proteins involved in assembly and protein translation have also shown other functionalities, including inhibiting infectious bacteria, viruses, parasites, fungi, and tumor cells. Therefore, they may be considered antimicrobial peptides (AMPs). However, information regarding the mechanism of action of ribosomal proteins as AMPs is not yet fully understood. Researchers have suggested that the antimicrobial activity of ribosomal proteins may be associated with an increase in intracellular reactive oxidative species (ROS) in target cells, which, in turn, could affect membrane integrity and cause their inactivation and death. Moreover, the global overuse of antibiotics has resulted in an increase in pathogenic bacteria resistant to common antibiotics. Therefore, AMPs such as ribosomal proteins may have potential applications in the pharmaceutical and food industries in the place of antibiotics. This article provides an overview of the potential roles of ribosomes and AMP ribosomal proteins in conjunction with their potential applications.

The gene encoding N-acetylmuramoyl-L-alanine amidase in Latilactobacillus sakei isolated from a fermented meat product was cloned in two forms: its complete sequence (AmiC) and a truncated sequence without one of its anchoring LysM domains (AmiLysM4). The objective of this work was to evaluate the effect of LysM domain deletion on antibacterial activity as well the biochemical characterization of each recombinant protein. AmiC and AmiLysM4 were expressed in Escherichia coli BL21. Using a zymography method, two bands with lytic activity were observed, which were confirmed by LC-MS/MS analysis, with molecular masses of 71 kDa (AmiC) and 66 kDa (AmiLysM4). The recombinant proteins were active against Listeria innocua and Staphylococcus aureus strains. The inhibitory spectrum of AmiLysM4 was broader than AmiC as it showed inhibition of Leuconostoc mesenteroides and Weissella viridescens, both microorganisms associated with food decomposition. Optimal temperature and pH values were determined for both proteins using L-alanine-p-nitroanilide hydrochloride as a substrate for N-acetylmuramoyl-L-alanine amidase activity. Both proteins showed similar maximum activity values for pH (8) and temperature (50 °C). Furthermore, structural predictions did not show differences for the catalytic region, but differences were found for the region called 2dom-AmiLysM4, which includes 4 of the 5 LysM domains. Therefore, modification of the LysM domain offers new tools for the development of novel food biopreservatives.

This study evaluated the incorporation of microcapsules containing nisin and avocado peel extract on the shelf life of ground beef. Ten treatments were studied and divided into two groups: one packaged under vacuum and the other in permeable packaging. Each group contained: (a) control, (b) extract, (c) nisin, (d) empty microcapsules (only wall microcapsule system), and (e) microcapsules with extract and nisin. The samples containing the microcapsules presented lower bacterial growth and less oxidation. On day 10, the vacuum‐packaged samples with microencapsulated preservative presented a reduction in the oxidation of proteins of approximately 45%, of 30% in the growth of mesophiles, and of 38% in the growth of coliforms, as well as a reduction in the changes in the pH and ɑ W that occur during storage, compared with the permeable control. The combination of microcapsules with vacuum packaging reduced the physicochemical and microbiological changes that occur in the controls., Microcapsules with natural preservatives prevent deterioration changes in meat. Encapsulation improved the preservatives properties of nisin and avocado peel. Microencapsulation improves microbial and oxidation stability of minced meat.

Paprika is the main spice used in the elaboration of chorizo contributing to both color and flavor, but until now there have not been studies evaluating its role in the sausage quality parameters. Therefore, our aims were: to know the effect of paprika on the quality parameters during ripening of chorizo, estimating an optimal time, and to simultaneously explore the evolution of biogenic amines during this operation. Two types of chorizo, one with paprika (CH) and the other without paprika (CWS), ripened for 33 days, were prepared for this study. Physico-chemical, texture and microbiological analyses were carried out. Additionally, the biogenic amines: tyramine, cadaverine and putrescine were analyzed by high-performance thin-layer chromatography (HPTLC) at 0, 12, 19 and 33 days. At day 19, the sample with paprika obtained the pH and aw values of 4.9 and 0.90, respectively, the highest growth of lactic acid bacteria, and a decrease in the coliform bacteria group and Enterobacteriaceae family. The total content of biogenic amines also decreased, mainly cadaverine, while tyramine content was lower than 100 mg/kg. In general, paprika favored the development and quality parameters of chorizo after 19 days of ripening and preserved the product for a longer time.

Spanish-type chorizo is a fermented meat product that is highly appreciated by consumers. The physicochemical properties (pH, water activity (aw), total acidity (TA), and malonaldehyde content) were evaluated in the initial meat batter and at different ripening stages. Bacterial diversity and dynamics were also examined using high-throughput sequencing. A decrease in pH and aw was observed during ripening, while the TA and malonaldehyde contents increased significantly. This data correlated with the changes in lactic acid bacteria and enterobacteria populations. Total bacterial diversity in the initial samples was represented by Proteobacteria (44%) and Firmicutes (55%) phyla, where Pseudomonas (23%), Streptococcus (21%), Acinetobacter (14%), Bacillus (13%), and Brochothrix (11%) were the most abundant genera. In contrast, Firmicutes reached the highest frequency (~89%), with Lactobacillus and Streptococcus being the most represented at the end of ripening. Lactobacillus sakei, Pediococcus acidilactici, and Weissella thailandensis were identified by 16S rRNA gene analysis and were considered potentially responsible for the stability, microbiological safety, and sensory characteristics of this product.

The production of beauvericin (BEA) by Fusarium oxysporum AB2 in liquid medium (SmF) was compared to that on solid medium (SSF) on inert support (polyurethane foam or PUF), using a previously optimised medium. The analysis included two different concentrations of the medium (1 × and 3 ×). Under SSF, the production of BEA (22.8 mg·L

The study aimed to evaluate the metabolism and resistance to the gastrointestinal tract conditions of Bacillus pumilus UAMX (BP-UAMX) isolated from overweight individuals using genomic tools. Specifically, we assessed its ability to metabolize various carbon sources, its resistance to low pH exposure, and its growth in the presence of bile salts. The genomic and bioinformatic analyses included the prediction of gene and protein metabolic functions, a pan-genome and phylogenomic analysis. BP-UAMX survived at pH 3, while bile salts (0.2–0.3% w/v) increased its growth rate. Moreover, it showed the ability to metabolize simple and complex carbon sources (glucose, starch, carboxymethyl-cellulose, inulin, and tributyrin), showing a differentiated electrophoretic profile. Genome was assembled into a single contig, with a high percentage of genes and proteins associated with the metabolism of amino acids, carbohydrates, and lipids. Antibiotic resistance genes were detected, but only one beta-Lactam resistance protein related to the inhibition of peptidoglycan biosynthesis was identified. The pan-genome of BP-UAMX is still open with phylogenetic similarities with other Bacillus of human origin. Therefore, BP-UAMX seems to be adapted to the intestinal environment, with physiological and genomic analyses demonstrating the ability to metabolize complex carbon sources, the strain has an open pan-genome with continuous evolution and adaptation.

The gene encoding N-acetylmuramoyl-L-alanine amidase in Latilactobacillus sakei isolated from a fermented meat product was cloned in two forms: its complete sequence (AmiC) and without one of its anchoring LysM domains (AmiLysM4). Deletion of the LysM domain is believed to affect the target microorganism’s affinity to the cell wall, which influences antimicrobial activity. To compare activity and inhibitory spectra, AmiC and AmiLysM4 were expressed in Escherichia coli BL21. Using the zymography technique, two bands with lytic activity were observed, which were confirmed by LC-MS/MS analysis, with molecular masses of 71 kDa (AmiC) and 66 kDa (AmiLysM4). The recombinant proteins were active against Listeria innocua and Staphylococcus aureus strains; however, the inhibitory spectrum of AmiLysM4 was broader because AmiLysM4 could inhibit Leuconostoc mesenteroides and Weissella viridescens, which are microorganisms associated with food deterioration. Optimal temperature and pH values were determined for both proteins using L-alanine-p-nitroanilide hydrochloride as a substrate for N-acetylmuramoyl-L-alanine amidase activity. Both proteins showed similar maximum activity values for pH (8) and temperature (50°C). Furthermore, in silico predictions did not show differences for the catalytic region, but differences were found for the region called 3dom, which includes 3 of the 5 LysM domains. Therefore, the modification of the LysM domain offers new tools for the development of novel food biopreservatives.

Lactic acid bacteria are the predominant group within meat products, whose metabolites such as bacteriocins and peptidoglycan hydrolases inhibit pathogenic or spoilage bacteria. Fermented meat products, as a salami, is a good source to analyze the viable microbiota, due to these products present a low risk to consumer health. The aim of this work was to identify the lactic acid bacteria with broad antibacterial activity present in salami, purify the protein responsible for this activity, achieve antagonistic spectrum and perform the biochemical characterization. Five strains from salami were selected, isolated and identified by 16S rRNA gene sequencing. The antimicrobial activity was evaluated by antagonism assay and zymography, using spoilage microorganisms commonly found in meat products. The strain that showed a broad antibacterial activity was Latilactobacillus sakei and the antibacterial activity was given by a protein with 75-kDa of molecular mass, identified by LC/MALDI-TOF/TOF. The sequence analysis showed 67% of identity with a N-acetylmuramoyl-l-alanine amidase protein with five non-identical LysM domains. The purified protein showed an optimal pH of 8.0 and heat resistance at 80 °C for 10 min. L. sakei strain displayed antibacterial activity against Gram-negative and Gram-positive spoilage microorganisms. The results of this study provide the information to use Latilactobacillus sakei as a starter culture which will provide the necessary metabolites to combat undesirable microorganisms. Additionally, the conditions and properties for the best application and use of the antibacterial protein produced by this strain. This protein may have a potential use in the food industry as a new antibacterial agent.

Lactic acid bacteria are the predominant group within meat products, whose metabolites such as bacteriocins and peptidoglycan hydrolases inhibit pathogenic or spoilage bacteria. Fermented meat products, as a salami, is a good source to analyze the viable microbiota, due to these products present a low risk to consumer health. The aim of this work was to identify the lactic acid bacteria with broad antibacterial activity present in salami, purify the protein responsible for this activity, achieve antagonistic spectrum and perform the biochemical characterization. Five strains from salami were selected, isolated and identified by 16S rRNA gene sequencing. The antimicrobial activity was evaluated by antagonism assay and zymography, using spoilage microorganisms commonly found in meat products. The strain that showed a broad antibacterial activity was Latilactobacillus sakei and the antibacterial activity was given by a protein with 75-kDa of molecular mass, identified by LC/MALDI-TOF/TOF. The sequence analysis showed 67% of identity with a N-acetylmuramoyl-L-alanine amidase protein with five non-identical LysM domains. The purified protein showed an optimal pH of 8.0 and heat resistance at 80 °C for 10 min. L. sakei strain displayed antibacterial activity against Gram-negative and Gram-positive spoilage microorganisms. The results of this study provide the information to use Latilactobacillus sakei as a starter culture which will provide the necessary metabolites to combat undesirable microorganisms. Additionally, the conditions and properties for the best application and use of the antibacterial protein produced by this strain. This protein may have a potential use in the food industry as a new antibacterial agent.

The industrial processing of fruits and agricultural products produces a wide range of by-products which may constitute a source of contamination. However, today it has been recognized that the fruit and vegetable residues consisting mainly of leaves, shells and seeds, constitute an important source of fiber and antioxidants, which can be used as functional ingredients in the elaboration of different foods. In particular, peel of the pomegranate fruit is a very promising agro-industrial co-product to be used as a functional ingredient due to its high content of fiber and polyphenolic compounds. On the other hand, the meat industry faces new challenges due to the growing interest of consumers to acquire healthier meat products. Therefore, it is presented a review of the main components present in the shell of pomegranate fruit, as well as their inclusion in the formulation of emulsified cooked meat products, as an alternative to add value to an agro-industrial residue and to generate meat products that promote the consumers health.

This study was conducted in order to evaluate the effects of the incorporation of tamarind seed extract (TSE) into previously optimized biodegradable edible films made with native potato starch (NPS) and whey protein isolate (WPI). Variations on mechanical, antioxidant and colour properties were evaluated over storage. First, films were formulated using the response surface methodology, modifying three factors: pH, denaturation temperature of WPI, and the amount of glycerol (Gly) as a plasticizer. The combination of 6.2% Gly at pH of 7.9 and temperature of 76°C provided the optimal elongation (%ɛ), as well as, tensile strength (s) and Young’s elastic modulus (E). The TSE was added to the optimized edible films contained polyphenols (187±0.11 mg GAE/g) and antioxidant activity (62.5±0.04% DPPH• and 45.6±0.14% ABTS+• radicals).

Enterococcus faecium MXVK29 has the ability to produce an antimicrobial compound that belongs to Class IIa of the Klaenhammer classification, and could be used as part of a biopreservation technology through direct inoculation of the strain as a starter or protective culture. However, Enterococcus is considered as an opportunistic pathogen, hence, the purpose of this work was to study the food safety determinants of E. faecium MXVK29. The strain was sensitive to all of the antibiotics tested (penicillin, tetracycline, vancomycin, erythromycin, chloramphenicol, gentamicin, neomycin, kanamycin and netilmicin) and did not demonstrate histamine, cadaverine or putrescine formation. Furthermore, tyrosine-decarboxylase activity was detected by qualitative assays and PCR. Among the virulence factors analysed for the strain, only the genes encoding the sexual pheromone cCF10 precursor lipoprotein (ccf) and cell-wall adhesion (efaAfm ) were amplified. The presence of these genes has low impact on pathogenesis, as there are no other genes encoding for virulence factors, such as aggregation proteins. Therefore, Enterococcus faecium could be employed as part of a bioconservation method, because it does not produce risk factors for consumer's health; in addition, it could be used as part of the hurdle technology in foods. SIGNIFICANCE AND IMPACT OF THE STUDY The use of molecular techniques has allowed, in recent years, to detect pathogenicity genes present in the genome of starter cultures used in food processing and preservation. The presence of these genes is undesirable, because horizontal transfer may occur with the natural biota of consumers. For this reason, it is important to analyse the presence of pathogenicity genes in such cultures. In this work, virulence factors and antibiotic resistance of Enterococcus faecium strain MXVK29, producing an antimicrobial compound with high antilisterial activity, were analysed. The results indicate that the strain is safe to be used in food processing as starter culture.

The objective of this study was to evaluate several conditions for complex coacervation to encapsulate a mixture of nisin, an antimicrobial peptide, and an antioxidant avocado peel extract. We evaluated the effects of three factors: two matrix-wall systems (collagen-alginate and collagen-pectin), two drying methods (freeze and spray drying) and two core dispersion systems (water in oil emulsion or in suspension). The final characteristics measured for each microencapsulation treatment were: encapsulation efficiency, encapsulation loading, encapsulation yield, Aw, and moisture. The core dispersion method (emulsified or not) and drying method (freeze or spray), as well as their interactions, were important factors in the final characteristics of the microencapsulation produced by complex coacervation. The interaction of the three factors only had an effect on moisture. The core dispersion factor had an effect on the encapsulation loading of both bioactives, whereas the drying method had an effect on Aw and encapsulation yield. Higher loading was obtained with non-emulsified core; higher encapsulation efficiency and yield were obtained through the combination of spray drying with emulsified core. Higher Aw, and moisture were obtained with the freeze drying method and emulsified core. The drying methods modified the final morphology, shape and structure of the microcapsules. The wide range of microcapsules produced by the combination of the three assessed factors may offer the food industry a wide range of option to deliver functional ingredients and meet various types of needs.

The study included fresh pork semimembranosus (SM, n=289) and triceps brachii (TB, n=283) muscles sourced from meat packers of Mexico and the USA. Samples were analyzed for moisture, protein, and fat content, pH, shear force (WBSF), cook loss, water holding capacity (WHC), instrumental color, emulsion capacity (EC) and stability (ES), and consumer sensory ratings. SM from the USA had lower WBSF (P0.05) than that from Mexico (26.7 vs. 29.7N), higher WHC (44.7 vs. 38.4%; P0.05) and a better appearance, as indicated by its lower h* (52.3 vs. 56.6; P0.05) and higher C* (23.1 vs. 21.3; P0.05). Consumer acceptance of SM was similar (P0.05) across countries. TB from Mexico had higher (P0.05) fat content (2.5 vs. 2.0%), lower (P0.05) WBSF values (32.0 vs. 36.9N), and received more positive ratings by Mexican consumers (87.1 vs. 81.7%) than its US equivalent. In general, US pork exhibits better technological properties, while country of origin has less effect on consumer acceptability.

This study focuses on the effect of a mineral supplementation on meat quality of pigs for slaughter; for these two groups of finishing pigs they were used; a control group that did not receive mineral supplement and other that consumed a mineral supplement three days before slaughter. In the slaughterhouse, were collected samples of Longissimus dorsi, which were vacuum packed, frozen and sent to the laboratory for evaluation later; in these samples shear force, color and pH was determined. After statistical analysis found that the performance variables, shear force and pH were not different (p>0.1); Only the color was significantly different (p

Background: Inhibition of carbohydrate hydrolyzing enzymes, such as α-amylase and α-glucosidase, is a key element in the regulation of diabetes mellitus (DM). The purpose of this work was to study the inhibition of carbohydrate hydrolyzing enzymes, and the antihyperglycemic activity of aqueous extract of Cladocolea (C . loniceroides ) in streptozotocin (STZ)- induced diabetic mice. Materials and Methods: The inhibitory activities of C. loniceroides aqueous extract on α-amylase and α-glucosidase were investigated in vitro . Glucose tolerance test was performed in normoglycemic (NG) mice which were fed with starch or sucrose. The effect of mistletoe aqueous extract (ME) was measured in (STZ)-induced diabetic mice. On day 35 of the treatment, the effect of decreasing oxidative stress (lipid peroxidation, glutathione redox state, GPx and GR specific activities, cytokines and aminotransferases analysis) was assessed. Results: ME showed a competitive mode of inhibition for the carbohydrate hydrolyzing enzymes (CHE). The maximum antihyperglycemic activity in mice was observed for the unripe fruit aqueous extract (UFAE) for α-amylase and stem aqueous extract (SAE); for α-glucosidase due to the glycemic response reduction by 23% or 35%, respectively. UFAE decreased malondialdehyde (MDA) 1.76 times; GSH/GSSG ratio was mantained (3.08 ± 0.66); GPx activity was reduced (24%); IL-6 was reduced (18%) and the concentration of TNF-α (37%) was leveled with respect to the (STZ)-induced diabetic mice; ALT and AST (liver transaminases) levels were nearly the same compared with those found in the NG mice. Conclusion: UFAE of C. loniceroides exhibited the highest antidiabetic activity in (STZ)-induced diabetic mice. Keywords: Diabetes mellitus, Cladocolea loniceroides , antihyperglycemic, antidiabetic, oxidative stress and α-glucosidase

This study is focused on optimizing, by surface response methodology, the mixture of natural additives: nisin (an antimicrobial peptide) in combination with avocado seed or avocado peel extracts (both with antioxidant capacities) in order to maximize the antioxidant activity and antimicrobial response against some food-borne bacteria such as Listeria . The peel or seed extracts used in the mixture showed radical scavenging capacity and antioxidant activity due to their polyphenol composition, including kaempferide, epicatechin, chlorogenic acid, epicatechin gallate, among others. During optimization, the results showed that the major antioxidant response in the mixture was mainly provided by the peel extract compared with nisin, seed and their combinations in different proportions. In the antimicrobial response, a synergic effect was observed in the mixtures of each avocado byproduct extract with nisin. Maximum antioxidant and antimicrobial response were obtained with the mixture of 61% of peel extract with 39% of nisin ( p

Several fruits, such as strawberries, blueberries, cranberries, apples, mangos, grapes, citrus fruits, kiwi, and others, contain several compounds that provide health benefits. Among them, polyphenols are distinguished because of their chemical structure, that is, they are characterized by the presence of conjugated double bonds, hydroxyl, and carboxyl groups, and are capable of acting as antioxidants and antimicrobials. The antioxidant activity of polyphenols may prevent side effects of some diseases where oxidative stress is involved, such as diabetes, cardiovascular and inflammatory diseases, cancer, and metabolic syndrome alterations, among others. The most studied polyphenols include flavonoids, such as quercetin, present in berries and grapes, which have beneficial effects on diabetes, cancer, and metabolic diseases; another example is hesperidin in citrus, which has antiinflammatory and analgesic effects. Other groups of polyphenols are procyanidins, which are present in apples and have effects on cancer prevention, and anthocyanins, such as cyanidin and delphinidin, which have antiinflammatory effects. In addition, the resveratrol found in red grapes is effective in preventing cardiovascular diseases and cancer; while hydroxycinnamic acids, such as chlorogenic acid, which are present in plums, have a beneficial effect on diabetes.

The use of edible antimicrobial films has been reported as a means to improve food shelf life through gradual releasing of antimicrobial compounds on the food surface. This work reports the study on the incorporation of 2 antimicrobial agents, nisin (N), and/or glucose oxidase (GO), into the matrix of Whey protein isolate (WPI) films at pH 5.5 and 8.5. The antimicrobial activity of the edible films was evaluated against Listeria innocua (ATCC 33090), Brochothrix thermosphacta (NCIB10018), Escherichia coli (JMP101), and Enterococcus faecalis (MXVK22). In addition, the antimicrobial activity was related to the hydrophobicity and water solubility of the WPI films. The greatest antibacterial activity was observed in WPI films containing only GO. The combined addition of N and GO resulted in films with lower antimicrobial activity than films with N or GO alone. In most cases, a pH effect was observed as greater antimicrobial response at pH 5.5 as well as higher film matrix hydrophobicity. WPI films supplemented with GO can be used in coating systems suitable for food preservation.

BACKGROUND The effect of storage time on sensory attributes and physicochemical characteristics (pH, L*, a*, b* color parameters, protein solubility, Warner–Bratzler shear force (WBSF), texture profile analysis (TPA), proteolytic activity, moisture and peptide changes) were evaluated as indicators of ovine meat quality changes during refrigeration. Meat samples were stored for 14 days at 2 ± 1 °C. The samples were divided into two sections: one was analyzed raw and the other was grilled to 72 ± 2 °C prior to analysis. The data were examined using multivariate data analysis (principal component analysis). RESULTS Tenderness showed a positive relationship with pH (0.55), and brightness presented a high correlation with sarcoplasmic protein solubility (−0.83) and L* (0.85) in raw ovine meat. Variations during storage were observed; for instance, textural parameters had a maximum value on the third day of storage for raw and grilled meat and decreased over the following days. Conversely, days 7 and 14 were distinguished by higher L* and b* values and by a greasy and bloody odor in the raw ovine meat. On day 14, grilled meat was characterized by chewiness on TPA, an intense grilled-meat odor and intense flavor, which had a positive relationship with cytochrome c equivalents (0.89). Likewise, sensory hardness was highly correlated with WBSF in grilled meat (0.89). CONCLUSION This information may be useful for describing and predicting ovine meat quality for both consumers and processors. Therefore, vacuum-packaged ovine meat can be stored for 14 days without disagreeable color to the consumer, and the raw meat texture is tender.© 2012 Society of Chemical Industry

The aim of this work was to assess the effects of temperature (T), time (t) and pH treatments and an in vitro digestion on the stability of the angiotensin I-converting-enzyme-inhibitory activity (ACEIA) and antithrombotic activity (ATA; assessed as inhibition of platelet aggregation) of selected protein hydrolysates of amaranth named Alb1H103 and GloH88 and GluH24 with dipeptidyl peptidase IV inhibitory activity (DPPIVIA). Heat treatment (40–100 °C) for 1 h showed no significant differences among ACEIA, DPPIVIA and ATA of the heated hydrolysates at pH 4 and 7. There was no statistically significant loss of any bioactivity under heat treatment for 3 h at pH 4.0. Alb1H103 and GluH24 maintained the inhibitory activity of ACE and ATA at pH 7.0 for 3 h, whereas GloH88 maintained ACEIA and ATA for 2.0 h at pH 7.0. The pH effect on hydrolysates bioactivity was assessed in the range of 2.0–12.0. This was negligible on ACEIA, ATA and DPPIVIA. The in vitro digestion was performed using pepsin, trypsin (T) and α-chymotrypsin (C). A previous treatment of hydrolysates with pepsin improved the proteolytic activities of T and C. The hydrolysates kept at 100 °C for 1 h at pH 4.0, showed a significant increase in bioactivity. Conversely, a treatment at pH 7.0 showed no significant difference (p

Cyclodextrin glycosyltransferase (CGTase) is an enzyme that produces cyclodextrins (CDs) from starch and related carbohydrates, producing a mixture of α-, β-, and γ-CDs in different amounts. CGTase production, mainly by Bacillus sp., depends on fermentation conditions such as pH, temperature, concentration of nutrients, carbon and nitrogen sources, among others. Bacillus megaterium CGTase produces those three types of CDs, however, β-CD should prevail. Although, waxy corn starch (CS) is used industrially to obtain CGTase and CDs because of its high amylopectin content, alternative sources such as amaranth starch (AS) could be used to accomplish those purposes. AS has high susceptibility to the amylolytic activity of CGTase because of its 80% amylopectin content. Therefore, the aim of this work was evaluate the AS as carbon source for CGTase production by B. megaterium in a submerged fermentation. Afterwards, the CGTase was purified partially and its activity to synthesize α-, β-, and γ-CDs was evaluated using 1% AS as substrate. B. megaterium produced a 66 kDa CGTase (Topt = 50°C; pHopt = 8.0), from the early exponential growth phase which lasted 36 h. The maximum CGTase specific activity (106.62 ± 8.33 U/mg protein) was obtained after 36 h of culture. CGTase obtained with a Km = 0.152 mM and a Vmax = 13.4 μM/min yielded 40.47% total CDs using AS which was roughly twice as much as that of corn starch (CS; 24.48%). High costs to produce CDs in the pharmaceutical and food industries might be reduced by using AS because of its higher α-, β- and γ-CDs production (12.81, 17.94, and 9.92%, respectively) in a shorter time than that needed for CS.

Total polyphenols and flavonoids contents, as well as ferric reducing antioxidant power (FRAP), metal ions chelating activity, reducing power assay and scavenging activity of DPPH and ABTS radicals in aqueous and methanolic extracts obtained from mycelium, primordium and fruiting body of Pleurotus ostreatus in both fresh as dry, were evaluated. The total polyphenol content of dried samples was higher in aqueous extracts obtained both in room temperature and boiling. The total polyphenol content of the fresh samples obtained at room temperature and boiling was higher in aqueous extract of mycelium and in the methanolic extract of the fruiting body. In general, flavonoids represented a very small percentage of the total polyphenol content. The antioxidant activity measured by the FRAP method of extracts from fresh samples were higher with respect to the dried samples. The results of the metal ion chelating activity indicate that all extracts tested had acted. Reducing the power of all samples was concentration dependent. In general, the extracts of dried samples showed higher reducing power than the extracts of fresh samples and tend to show greater reducing power by aqueous than methanolic extracts. It was observed that the DPPH and ABTS radical scavenging activities were positively correlated to the concentration of the extract. The results suggested that antioxidant activity could be due to polyphenols, but mainly by different molecules or substances present in the extracts. Overall, the fruiting body of Pleurotus ostreatus showed the best results and the possibility of continuing to investigate its functional properties of this fungus is opened. This is the first report where the antioxidant activity of Pleurotus ostreatus in different growth stage was reported.

Biopreservation can be defined as the foods shelf life extension employing antibacterial products like bacteriocins. The objective of this work was to determinate the efficacy of E. faecium MXVK29 bacteriocin in combination with chemical preservatives against spoilage and pathogens microorganisms. Bacteriocin raw extrac antimicrobial activity was 46.34 UA/g of protein. Growth of Pseudomonas putida was not affected by the preservatives employed at the conditions employed. Antimicrobial response was different for other microorganisms since a synergetic effect of the preservatives combination inhibited Brochothrix thermosphacta and Escherichia coli growth. Sodium lactate had additive effect only against Listeria innocua.

BACKGROUND: Enterococci are lactic acid bacteria that can produce bacteriocins, which may offer an additional hurdle to control the growth of food-borne pathogens; moreover, these bacteriocins may have great potential as natural biopreservatives. The aim of this work was to characterize a bacteriocin-like inhibitory substance (BLIS) with antilisterial activity produced by an enterococcal strain. RESULTS: The bacteriogenic strain was isolated from Mexican fermented sausages and identified as Enterococcus faecium with 99% sequence similarity. Maximal activity was detected at 16 h, where bacterial growth was in middle of the stationary phase. The producer strain was not inhibited by its own antimicrobial peptide. BLIS showed a strong anti-Listeria activity and was inactivated by proteinase K. Heating (121 ◦ C for 15 min) induced some inactivation, but thermotolerance was higher at acid pH values. The yield obtained with a pH-mediated purification process was 32.7%, showing a band with an estimated molecular weight of 3.5 kDa. Automated N-terminal Edman degradation showed the following sequence: YYGNGVTCGSHHCSVD. CONCLUSION: Biochemical characteristics of BLIS produced by E. faecium MXVK29 suggested that it belongs to Class IIa of the Klaenhammer classification and could be considered as a natural food preservative, although further studies need to be performed. c � 2010 Society of Chemical Industry

Herbs and spices are traditional used as food ingredients as well as for their antioxidant properties. The objective of this work was to study the concentration of carnosol, rosmarinic and carnosic acids in rosemary (Rosmarinus officinalis L.) and oregano leaves (Origanum vulgare L.), and their effect on the oxidation and colour of model pork batters. Extracts were obtained by maceration with ethanol and reflux with chloroform. Rosemary extracts showed higher antioxidant activity, even more than the phenol compounds separately. These extracts also showed the highest antioxidant capacity, possibly due to the presence of high concentrations of carnosic acid and carnosol and unidentified active compounds. However, ethanol oregano extracts containing high concentrations of phenols, mainly rosmarinic acid, efficiently prevented colour deterioration. The antioxidant effect of the studied extracts depends, not only on the concentration of phenol compounds (rosmarinic acid, carnosol and carnosic acid), but also on the extraction method and solvent.