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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 ɑW 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. [ABSTRACT FROM AUTHOR]

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 [ABSTRACT FROM AUTHOR]

Giant squid (Dosidicus gigas ) is abundant along the Pacific Coast of Mexico. It possesses a high proteolytic activity that makes it a low-quality food material. Squid mantle endogenous proteases were partially characterized; physicochemical and structural changes during storage at 4C were also examined. High proteolytic activity was observed at acidic and alkaline pH values. Proteases were strongly inhibited by leupeptine and pepstatin A, as well as by phenyl methyl sulfonyl fluoride, indicating the possible presence of serine, cysteine and metal proteases. Myosin heavy chain was degraded during storage, as shown on sodium dodecyl sulfate–polyacrylamide gel electrophoresis patterns, resulting in a significant decrease (P < 0.001) in muscle water-holding capacity, texture and gelling capacity. Muscle deterioration was evident in scanning electron micrographs, where the initial compact structure loosened during storage. [ABSTRACT FROM AUTHOR]

The article discusses a study on the incorporation of antilisterial bacteriocin-like inhibitory substance (BLIS) from Pediococcus parvulus VKMX100 into film-forming protein matrices of ethanol-soluble corn zein (CZ) and water-soluble whey protein isolate (WPI). Inhibition zones against Listeria innocua ATCC 33090 were measured to determine antimicrobial activity. Results show that high bacteriocin concentration in films does not necessarily improve their effectiveness against Listeria innocua.