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Vacuum impregnation is a non-destructive method of introducing a solution with a specific composition to the porous matrices of fruit and vegetables. Mass transfer in this process is a result of mechanically induced differences in pressure. Vacuum impregnation makes it possible to fill large volumes of intercellular spaces in tissues of fruit and vegetables, thus modifying physico-chemical properties and sensory attributes of products. This method may be used, e.g., to reduce pH and water activity of the product, change its thermal properties, improve texture, color, taste and aroma. Additionally, bioactive compounds may be introduced together with impregnating solutions, thus improving health-promoting properties of the product or facilitating production of functional food.

Consumers around the world are choosing sustainable and unprocessed foods. Roe deer meat, due to the natural origin, is a source of organic and healthy meat. The selection of suitable storage conditions and times plays an important role in a deterioration of the meat's functional and nutritional values. The knowledge about oxidation processes in roe deer meat stored and packed deploying different methods is limited. The main aim of this study was therefore to investigate the effect of storage method on the physicochemical properties of musculuslongissimus thoracis et lumborum (LTL), musculus biceps femoris (BF), and musculus vastus lateralis (VL) of roe deer. The muscles were stored either dry (DRY-AGED), vacuum--packed (VAC), or packed under modified atmosphere (MAP) for 21 days. The quality of roe deer meat was assessed based on chemical composition, technological properties, pH values, water activity, colour, and oxidation processes of proteins and lipids. Roe deer meat had high protein (216.5-228.6 g/kg) and low fat content (17.1-25.8 g/kg). Both DRY-AGED and VAC contributed to improving meat tenderness during storage, while the Warner-Bratzler shear force of the MAP muscles increased. The high-oxygen conditions during MAP storage strongly induced the oxidation processes; an average increase of 1,263% for thiobarbituric acid reactive substance (TBARS) level and 155% for protein carbonyl content on day 21. Vacuum packaging and dry-ageing are recommended methods for storing roe deer meat. The high oxygen atmosphere negatively affected the quality of this game species. It carries the risk of increased oxidation of proteins and lipids which may promote the formation of potentially detrimental compounds. [ABSTRACT FROM AUTHOR]

BACKGROUND Knowledge regarding microaerophilic and anaerobic specific spoilage organisms (SSOs) is crucial for an appropriate evaluation of vacuum-packed ham. The objective of this study was to characterize the SSO community in vacuum-packed ham by a culture-dependent technique and MiSeq next-generation sequencing (NGS) platform. The relation between changes among the SSO group in the ham and changes in sensory characteristics of the product was also assessed. RESULTS In the study, conventional microbiological analyses were employed in order to establish the participation of several groups of microorganisms in the deterioration of vacuum-packed ham. The diversity of the SSO group in the product was further assessed with the use of MiSeq NGS technology. The bacteria identified in sliced cooked ham belonged mostly to four phyla, namely Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes. A temperature of 4 °C favoured the development of mesophilic and psychrophilic/psychrotrophic flora, mainly Lactobacillaceae, Enterobacteriaceae and Micrococcaceae families. A high ratio of Brochothrix thermosphacta species and new, cold-tolerant Clostridium spp. was also observed. The growth of these microorganisms facilitated changes in the pH value and organoleptic characteristics of the product. CONCLUSION This study confirms that the combination of culturing and MiSeq NGS technology improves the microbial evaluation of food. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]