Chemical Composition, Probiotic Survivability and Shelf Life Studies of Symbiotic Buttermilk

Cultured buttermilk is becoming popular as an ingredient for bakery applications and for direct consumption in the U.S.. The objective of this study was to develop a symbiotic cultured buttermilk, containing inulin as a prebiotic and the probiotics Lactobacillus acidophilus and Bifidobacterium spp. The cultured buttermilk was prepared using a commercial mesophilic starter CHN22 (Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Leuconstoc mesenteorides subsp. cremoris, Lactococcus lactis subsp. lactis biovar diacetylactis) and the probiotics. The control buttermilk was prepared using CHN22 and the symbiotic buttermilk were analyzed for chemical composition, probiotics survivability, mold, yeast and coliform counts. Changes in pH, titratable acidity and proteolysis were also determined during storage at 4°C for 12 weeks. The chemical composition of the control and symbiotic buttermilk were: protein 3.29±0.05 and 3.30±0.02%; fat 3.28±0.04 and 3.26±0.06%; carbohydrate 4.55±0.05 and 5.16±0.06%; total solids 11.81±0.05 and 12.42±0.03%; ash 0.69±0.03 and 0.70±0.01%, respectively. The populations of both Lactobacillus acidophilus and Bifidobacterium spp. were initially above 10 cfu/ml and remained 10 cfu/ml during the 12-week study and no mold or yeast were detected. There were significant differences in pH and titratable acidity between the control and symbiotic buttermilk (p<0.05). There was no considerable difference in proteolysis between the two samples. Results indicated that the symbiotic buttermilk might be considered as a functional food as survival of probiotics was significantly higher compared to other fermented foods.