مطالعه تأثير عصاره مالت بر افزايش رشد باكتري هاي پروبيوتيك لاكتوباسيلوس اسيدوفيلوس و بيفيدوباكتريوم بيفيدوم

The Effects of Malt Extract on the Increasing Growth of Probiotic Bacteria Lactobacillus acidophilus and Bifidobacterium bifidum in probiotic Milk and Yoghurt

Introduction: Probiotic products are useful for human health. Probiotic bacteria grow slowly in the basic cultures of fermented products. In this study, the effects of Malt extract as a growth factor on the bioability and fermentation rate was investigated. Materials and Methods: In order to determine the effect of different doses of malt extract (0, 2, 4 and 6%) on the increasing growth of probiotic bacteria; Lactobacillus acidophilus and Bifidobacterium bifidum in probiotic milk and yoghurt, first lyophilized bacteria Lactobacillus acidophilus was added to 1 liter of low fat sterilized milk and was considered as control. Malt extract at the concentrations of 2, 4 and 6% were added to the samples and incubated at 38 °C until reached the acidity at 40 degree Dornic and then left in refrigerator. Similar procedure was applied to the bacteria Bifidobacterium bifidum. Lactobacillus acidophilus and Bifidobacterium bifidum yoghurts were made from the respective milks. Results: The shelf lives of the products were evaluated after 5, 10 and 20 days. This study 9 showed that the growth rate of bacteria was increased by increasing the concentration of malt extract and reached the desired acidity at shorter period. Conclusion: By increasing the concentration of malt extract, the acidity is increased and firmer yoghurt is produced. The increasing rate of acidity in Lactobacillus acidophilus yoghurt was higher but the shelf life was shorter.