ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF POMEGRANATE (Punica granatum L.) FRUIT PEELS EXTRACT ON SOME CHEMICAL, MICROBIOLOGICAL AND ORGANOLEPTICAL PROPERTIES OF YOGHURT DURING STORAGE.

Pomegranate (Punica granatum) fruit peels was investigated for its phenolic compounds, antioxidant and antoxidative activity on L.A.B in yoghurt during cold storage. Results of chemical composition being 7.15 %, 1.22 % 0.65 % and 85.04 % for moisture, protein, crude fat and carbohydrates respectively. Total phenolic compounds were 42.62 mg gallic acid / g. Data of HPLC revealed that ten compounds were identified namely catechin, gallic and - chlorogenic acid being 138.71, 111.68 and 92.39%, Moreover catechol and caffein were 84.36 and 44.47 % and other trace compounds namely coumarin, cinnamic, chrysin, caffeic and ferulic. Radical scavenging activity DPPH for the aqueous extract was 90.97 %,compared with TBHQ 94.1% as synthetic one. Pomegranate peel extract explored considerable inhibitory effect of each of lactic acid bacteria, coliform group and Staph. Sp. The increase aqueous extract of pomegranate peel from 1to 5 % lead to an inhibitory effect on LAB and other tested pathogenic bacteria. 1 % of extract was appropriate for the viability of Lactic acid bacteria which was above 30 × 10P 6 P c.f.u ⁄ ml. In addition, using of 1 %, 0.75, 0.5 and 0.25% on yoghurt processing was acceptable for the chemical, microbiological and organoleptical properties of the resultant yoghurt. Moreover, the ratio of 0.75 % was more acceptable, comparing with other added doses.