IN THIS STUDY, probiotic nutritive beverages were formulated by mixing fermented milk permeate with pumpkin or strawberry pulps at a ratio of (1:1), and stored at 4±1ºC for 30 days. Milk permeate was fermented with the use of a 2% mixed starter culture (1:1:1) containing Lactobacillus delbrueckii subsp bulgaricus, an exopolysccharide (EPS) strain of Streptococcus thermophilus, and a probiotic organism Bifidobacterium longum. Changes in antioxidant activity and bioactive compounds as well as the chemical, rheological, microbiological and organoleptical characteristics of the resulting functional beverages were studied. The total solid, ash, fat, protein, fiber and acidity contents were slightly increased, while the total carbohydrate, antioxidant activity, total phenols, total flavonoids, ascorbic acid, anthocyanin and carotenoids contents and pH value were decreased during cold storage. The addition of pumpkin and strawberry pulps greatly improved but variably the Ca, P, Na, K, Mg, Fe, Cu and Zn contents in the prepared beverage. Lactic acid bacteria (LAB), Str. thermophilus, Lb. delbrueckii subsp. bulgaricus or Bif. longum counts were not detected in prepared beverages from heated fermented permeate during cold storage, while the total viable bacteria, LAB, Str. thermophilus, Lb. delbrueckii subsp. bulgaricus and Bif. longum counts gradually decreased in beverages produced from unheated fermented milk permeate during cold storage. |
