Abstract: Five raw milk samples with different somatic cell counts (SCC) were analyzed for major chemical composition, fat decomposition degree (lipase activity, free fatty acid content and its ratio to total fat), and protein decomposition degree (water soluble nitrogen, ratio of non-protein nitrogen to total nitrogen, and casein profile) with the aim of understanding the effect of SCC on raw milk quality. The results showed that: 1) There was no significant difference (P ＞ 0.05) in major components and properties for raw milk with SCC lower than 4.0 × 105 cells/mL; 2) fat decomposition was positively related to SCC level and showed no significant difference between two raw milk samples with SCC lower than 4.0 × 105 cells/mL (P ＞ 0.05); 3) casein profile of raw milk varied with SCC, the ratios of water soluble nitrogen and none-protein nitrogen to total nitrogen, WAN/TN and NPN/TN, increased with increasing SCC, while no significant difference was observed between the raw milk samples with SCC lower than 4.0 × 105 cells/mL.

Key words: somatic cell count, raw milk, property