Effects of Lactic Fermentation of Milk on Milk Lipids

Fermentation of whole milk by Lactobacillus acidophilus, Lactobacillus bulguricus and Streptococcus thermophilus resulted in moderate but significant increase in the levels of saturated fatty acids and oleic acid with a concomitant decrease in the levels of linoleic and linolenic acids in the glyceride fraction. Similarly, the increase in the levels of free fatty acids was moderate. There were significant increases in the levels of stearic and oleic acids. Unusual fatty acids of bacterial origin were not detected, and monoglycerides disappeared completely upon fermentation. Changes in cholesterol levels were also not significant. Acid degree value and free fatty acid levels were correlated significantly (r = 0.711). Results indicate that previously reported hypocholestermic effect of fermented milk is not due to changes in the composition of lipid classes investigated.