摘要：Background: The current study was designed to raise the antioxidant activity of low fat stirred yoghurt by supplementing with natural sources of antioxidant (pomegranate peel and milk thistle seeds) and to raise its nutritive value by addition Whey Protein Concentrate (WPC) to milk. Material and Methods: The whole Pomegranate Peels (PPs) were dried by using oven (40°C/48 h.) and aqueous extract was prepared from the dried peels. Low fat stirred yoghurt supplemented with 25% Pomegranate Peel Extract (PPE), 0.5 (g/100 mL) WPC and MTSE (1, 1.5, 2, 2.5, 3, 3.5 and 4%) was manufactured. Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and antioxidant activities (DPPH and ABTS) were evaluated in extract and product. Total counts of S. thermophilus , L. delbrueckii subsp., bulgaricus , mold and yeast, chemical composition and physical properties were evaluated of the products. Results: Increasing the concentration of MTSE from 1-4% increased TPC from 17.241-20.225 (equivalent mg gallic acid g1), TFC from 3.545-6.996 (mg rutin g1), RSA from 94.085-94.887% and ABTS from 83.694-98.905%. During cold storage the TPC, TFC and antioxidant activity showed a gradually decrease for all yoghurt samples. Increasing the concentration of MTSE in yoghurt samples led to slight increase in total solids, lactose, fat and protein percentage, while these contents were slightly decreased during storage and there wasnt significantly difference during storage in fat percentage. Acidity percentage was decreased with increasing MSTE percentage and increased during storage. With increasing the MTSE concentration, the counts of S. thermophilus , L. delbrueckii subsp., bulgaricus , molds and yeast were decreased and this also observed during storage at 5±1°C for 15 days. Conclusion: Yoghurt samples with the different concentration of MTSE were accepted when fresh. While along the cold storage at 5°C for 15 days the sensory scores were decreased. The product was contained 25% PPE, 0.5% WPC and 4% MTSE can be recommended of meet health continues consumer demanded and has multihealthy benefits.
