Influência da contagem de células somáticas no perfil e teores de aminasbioativas e na qualidade de leite cru e de queijo mussarela

Abstract

The aims of this work were to optimize the extraction of amines from milk for HPLC determination; to investigate the influence of somatic cellcounts on the quality and profile of amines in raw milk; to determine the profile and levels of amines in Mozzarella cheese from the market of Belo Horizonte, MG, Brazil; and to investigate the influence of somatic cell counts on the quality and levels ofamines in Mozzarella cheeses during 60 storage days. The extraction method was optimized as follows: 40 sec of vortexing, 4 successive extractions, 1.5% sulfosalicylic acid and centrifugation at 14.000 x g for 5 min. This condition provided amines recoveries . 92.8% and coefficient of variation . 5.8%. No bioactive amine was detected in the raw milk samples (< 0.05 mg/L). The somatic cell counts did not influence the profile and levels of the amines examined. In relation to the physicochemical quality, SCC affected significantly (p < 0.05) only lactose levels. Mozzarella cheese from the market of Belo Horizonte, MG, Brazil contained all ten amines investigates (total levels from < 0.5 to 84.0 mg/kg). The cheese samples were of good quality in relation to bioactive amines. One day Mozzarella cheese was not affected by somatic cell counts with respect to quality and bioactive amines. During storage of thecheese made from milk with different SCC there was a linear increase in the extent and depth of proteolysis indexes and pH values; however no significant interaction was observed. Tyramine, serotonin, spermidine, spermine and tryptamine were detected in the cheese samples at levels ranging from < 0.5 to 156.3 mg/kg. No significant effect of somatic cell counts was observed on the formation of these amines in cheese during 60 days storage.