Effect of permeate on growth and survival of lactobacillus acidophilus and bifidobacterium bifidum for production of probiotic nutritive beverages
Permeate is the by-product of the treatment of milk by using ultra filtration process. Permeate retains about 80% of the initial lactose of the treated milk that could cause a high BOD so it could be, a factor of environmental concern. This study was undertaken to determine the suitability of permeate for production of probiotic beverage by two lactic acid bacteria (Lactobacillus acidophilus and Bifidobacterium bifidum) that can be used in many formulation in food technology. In this Investigation, four Lactobacillus acidophilus and four Bifidobacterium bifidum permeate beverages were prepared containing permeate with concentrations of 0 (control), 5, 10 and 15%. Then the samples were incubated at 38°C for 6 hours and the products were put in the refrigerator. Changes in pH, acidity and viable cell counts during incubation and permanence period were measured. In all samples that contained Lactobacillus acidophilus and Bifidobacterium bifidum, it was observed that the increased permeate concentration has effect on increasing acidity, decreasing pH, good color and taste and microbial count. The shelf life of the products was evaluated after 1, 7, 14 and 21 days. After 21days of cool storage the bacterial count was higher than 10 8cfu.ml• 1. The results showed that permeate was a suitable support for these Intestinal bacteria. Lactobacillus acidophilus had the highest viability in all of the products investigated. In day seven, the products were sensory evaluated. The higher sensory scores were attained by beverage with lactobacillus acidophilus: 10%permeate and 20gram mixed date received the best scores after 7days of storage, but these scores decreased as storage time elapsed. © IDOSI Publications, 2012.