The Comparative of Fermentation Characteristics and Hypoglycemic Activity from Fermented Camel Milk and Cow Milk by Lactobacillus rhamnosus GG

Single bacteria Lactobacillus rhamnosus GG(L-GG)with strong acid,oxygen resistance,engraftment and rich function fermented camel milk and cow milk. The fermentation time was determined by growth curve of Lactobacillus rhamnosus GG,and the fermentation characteristics(pH,titratable acidity and bacterial counts),the proteolytic activity and hypoglycemic activity(α-amylase and α-glycosidase inhibition activity)of camel milk and cow milk under different fermentation time and storage time were evaluated. The results showed that pH,titratable acidity,bacterial counts and proteolytic activity were interrelated. With the increasing of fermentation time,the pH of the two fermented milk decreased,while the titratable acidity,bacterial counts and proteolytic activity increased. During the storage period,pH,titratable acidity,bacterial counts and proteolytic activity tended to be stable. The pH of fermented camel milk was lower than that of fermented cow milk,and the titratable acidity,bacterial counts and proteolytic activity were higher. It was superior to fermented cow milk in maintaining fermentation quality and extending shelf life. After fermentation,the hypoglycemic activity of raw milk was improved. During fermentation and storage,both camel milk and cow milk showed high α-amylase inhibitory activity,and higher α-glucosidase inhibitory activity during storage. Overall the hypoglycemic activity of fermented camel milk was better than that of fermented cow milk.