The content of volatile free fatty acids in milk cultured with yoghurt bacteria
Baranowska, M.(University of Warmia and Mazury, Olsztyn (Poland). Inst. of Dairy Science and Technology)E-mail:[email protected]
The aim of the performed studies to determine the influence of fat content (0.05, 2 and 4 percent) incubation temperature (37, 43, 43/31 deg C), and storage period (7 and 14 days) on the concentration of volatile free fatty acids (VFFA) in milk cultured with: Str. thermophilus, L. delbrueckii ssp. bulgaricus, L. acidophilus, Bifidobacterium, traditional yoghurt culture as well as yoghurt cultures supplemented with bacteria: Str. thermophilus : L. delbrueckii ssp. bulgaricus : Bifidobacterium (SLB yoghurt) and Str. thermophilus : L. acidophilus : Bifidobacterium (SAB yoghurt ). The content of VFFA was determined with the chromatographic method using an internal standard (pelargonic acid). The results pointed to a significant influence of fat content and incubation temperature on VFFA level in all products tested. The highest content of VFFA was reported for the samples containing 4 percent of fat incubated at 37 deg C. In contrast, the storage period had no significant impact on the VFFA concentration in the products under study. Of the single cultures tested, the highest amount of VFFA was released and synthsised by L. acidophilus strain. In yoghurts, the contents of those compounds, at the applied incubation temperature and fat content, were not significantly different. The results confirm the observations of other scientists that the VFFA source is not only the fat but also other milk components
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