Survival, growth characteristics and bioactive potential of Lactobacillus acidophilus in a soy-based cream cheese

BACKGROUND: Soy-based products have received much attention lately as dairyreplacers and carriers for probiotics, without the cholesterol and lactose intolerance factors. We have previously developed a soy cream cheese product and would like to evaluate its suitability as a carrier forprobiotic microorganisms. Soy cream cheese is commercially uncommon, while a probiotic soy cream cheese is yet to be available in the market. RESULTS: Five strains of probiotics were screened for their alpha-galactosidase activity. Lactobacillus acidophilus FTCC 0291 showed the highest alpha-galactosidase-specific activity and was incorporated into soy cream cheese for a storage study of 20 days at 25 and 4 degrees C. L. acidophilus FTCC 0291 in soy cream cheese at both storage temperatures maintained a viability exceeding 10(7) CFU g(-1) over storage. Oligosaccharide and reducing sugar analyses indicated that L. acidophilus FTCC 0291 was capable of utilizing the existing reducing sugars in soymilk and concurrently hydrolyzing the oligosaccharides into simpler sugars for growth. L. acidophilus FTCC 0291 also produced organicacids, leading to decreased pH. Under low pH and high organic acid concentration, the growth of total aerobes and anaerobes was significantly (P < 0.05) suppressed compared to the control. The hydrolysis of protein in soymilk produced essential growth factors such as peptides and amino acids that may have promoted the growth of L. acidophilus FTCC 0291 and the release of bioactive peptides with in vitro angiotensin I-converting enzyme inhibitory activity. CONCLUSION: This study showed that soy cream cheese could be used as a carrier for probiotic bacteria, with potential antihypertensive property. (C) 2009 Society of Chemical industry