Mandarin peel antioxidants and their application in enhanced probiotic ultra-filtration soft cheese

Abstract Mandarin peel powder (MPP), which has a higher polyphenol concentration than edible parts, is the most major source of bioactive ingredients. The total phenolic (TPC) and antioxidant content of several mandarin peel extracts were evaluated. A starter containing Lactobacillus acidophilus LA5 and Streptococcus thermophilus as a mixed strain (1:1) with the addition of 1, 3 and 5% of MPP and a control without MPP, was used to make UF soft cheese. The total solid content, pH values, acidity, protein and fat contents, and organoleptic properties during storage at 5±2°C for 21 days of soft cheeses were evaluated. The results revealed that the total phenolic contents in methanol extract were the highest and the lowest recorded in acetone extraction, the same trend found in antioxidant activity. The inclusion of both probiotic strains and MPP improved cheese quality; symbiotic cheese had considerably higher relative degrees of titratable acidity and total solids than control cheese. The sensory examination revealed that adding the MPP at a ratio of 1% increased the score. Finally, it is proposed that probiotic-fortified cheese and MPP oriented functional food have acceptable composition and sensory features.