ABSTRACT Sofi. F.R* , Raju.C.V, Lakshmisha.I.P, Singh.R.R ANTIOXIDANT AND ANTIMICROBIAL PROPERTIES OF GRAPE AND PAPAYA SEED EXTRACTS AND THEIR APPLICATION TO INDIAN MACKEREL PRESERVATION Sofi. F.R* , Raju.C.V, Lakshmisha.I.P, Singh.R.R Department of Fish Processing Technology Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar College of Fisheries,Mangalaru-575001,India. E mail : sofifaisal@gmail.com ABSTRACT Seeds from horticultural waste are rich in phenolic compounds that have wide range of biological functions including antioxidant and antimicrobial activities. In the present investigation our aim was to evaluate antioxidant and antimicrobial properties of ethanolic extract of grape and papaya seeds by cold extaction. Total phenolic content (TPC), total flavanoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2- azinobis-3 ethyl benxothiazoline-6-sulphonic acid (ABTS) cation decolorization activity, metal chelating activity, ferric reducing power and lipid peroxidation inhibition by linoleic acid model were conducted to determine the antioxidant activity. For the analysis of antimicrobial activity, the inhibitory effects of the extracts against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhium and Pseudomonas fluroscens were evaluated using disc diffusion method. Among the two extracts tested, grape seed extract (GSE) exhibited outstanding antioxidant and antimicrobial properties.The influence of these extracts was tested on the shelf life extension of Indian mackerel. The grape seed extract (GSE), papaya seed extract (PSE) and Butylated hydroxytoluene (BHT, a positive control) was individually used for dip treatment of Indian mackerel at concentration of 0.5, 1.0 and 0.1 mg/l respectively and was stored in iced condition after packing in polyethylene bags for 15 days. The shelf-life of the Indian mackerel was found to be 8-9 days for untreated group (control), 11-12 days for PSE treated group and 15 days for GSE treated group, according to sensory, biochemical and microbiological analysis. Hence the GSE could be used as potential preservatives to enhance the shelf-life of Indian mackerel during ice storage. Keywords: Grape seed extract, Papaya seed extract, Antioxidant, Antimicrobial, Indian mackerel, Ice storage HIGHLIGHTS RESULTS AND DISCUSSION We investigate combined effect of seed extracts from horticulture waste and ice storage preservation of Indian mackerel. Shelf life of Indian mackerel was increased by 3 and 6 days with treatment with grape and papaya seed respectively. Among the two extracts tested grape seed extract exhibiting higher antioxidant and antimicrobial activity than papaya seed extract and is comparable to synthetic ones. Antimicrobial activity of seed extracts from grape and papaya seeds were more prominent towards gram positive bacteria than gram negative bacteria. Fig. 1. Total phenolic & Total Flavanoid content of GSE & PSE Fig. 2. DPPH radical scavenging activity of GSE & PSE OBJECTIVES To study antioxidant and antimicrobial properties of Grape and Papaya seed extracts. To study the shelf life extension of Indian mackerel with dip treatment with seed extracts. Fig. 3. ABTS radical scavenging activity of GSE & PSE Fig. 4. Ferric reducing antioxidant power of GSE & PSE INTRODUCTION Fish is one of the most important sources of animal protein available in the tropics and has been widely accepted source of protein Apart from having superior quality of proteins, fish also consists of essential omega-3 polyunsaturated fatty acids (PUFA) such as Eicosapentaenoic acid (EPA, C20:5 n-3) and Docosahexaenoic acid (DHA, C22:6 n-3). The levels of the characteristic long chain polyunsaturated n-3 fatty acids (PUFA) make marine lipids unique compared to other lipid sources. Fish is easily perishable food. Spoilage prevention and shelf-life extension of fish products will always remain an important goal to the fish industry Fig. 5. Metal chelating activity of GSE & PSE Fig. 6. Linoleic acid lipid peroxidation inhibition of GSE & PSE METHODOLOGY Organoleptic failure Fig. 7. Antimicrobial activity of GSE & PSE against Styphlococcus aureus Fig. 8. Antimicrobial activity of GSE & PSE against Bacillus subtilis Fig. 9. Antimicrobial activity of GSE & PSE against Pseudomonas fluroscens Fig. 10. Antimicrobial activity of GSE & PSE against Eicherchia coli Comparative study on in vitro antioxidant activity of GSE and PSE PSE@ 1000 ppm Control GSE @500 ppm BHT@ 200 ppm CONCLUSION Storage in ice for 15days and analyses at 0,3,6,9, 12, 15 days The results obtained from this study showed that GSE having better antioxidative and antimicrobial activities both in -vitro and in-vivo conditions. Synthetic antioxidants and antimicrobial compounds having carcinogenic effects to human, so it is better to search antioxidant and antimicrobial compounds from natural sources. Sensory analysis Biochemical analysis Microbiological analysis ACKNOWLEDGEMENT The financial assistance from All India Coordinated Research Project on Post-Harvest Technology, CIPHET (ICAR) Ludhiana, India, in carrying out this study is gratefully acknowledged.