The properties of fermented beef products ripened as entire primal cuts of m. semitendinosus, m. semimembranosus and mm. psoas major and minor

Abstract

Abstract The physico-chemical, biochemical and microbiological changes in raw fermented beef products, manufactured from semitendinosus (ST), semimembranosus (SM), psoas major and minor (PM) muscles during ripening were evaluated. The accumulation of free fatty acids (1550, 2660, 1850 mg/kg) and the increase of lactobacilli (about 0.2 log cfu/g) had an effect on the pH. The low pH (4.9) reduced the coagulase-negative cocci population (0.2 log cfu/g) and affected the free amine groups content (185.2 and 25 μM Gly/kg) in the PM with the lowest fat content (2.9%). At the end of the ripening process the ST contained a similar quantity of water, protein, fat and proteolysis products as the SM, however small peptides were generated in all products. The release of volatile compounds could be affected by the drying mainly due to the increase of fat (free fatty acid transformations) and activity of bacterial cells (amino acid transformations, fermentation under aerobic or anaerobic conditions). The results of a two-way analysis of variance for physico-chemical, biochemical and microbiological attributes showed that all the analysed factors significantly influenced the level of the evaluated variables in the ST, SM and PM products (P<0.01) excluding the type of product and its effect on the fat, ash, 2-phenylethylamine and putrescine content, pH and the coagulase-negative cocci count in the ST and SM. The interactions between the type of product and the ripening period were highly significant, with the exception of the yeasts and the LAB, existing in the external and internal layer of the products.