29B-11 |
Characterization of oil from roe and viscera of skipjack tuna (Katsuwonus pelamis) |
P. SOPHANODORA and J. Promnimit. Food Technology, Faculty of Agro-Industry, Prince of Songkla University, 15, Kanjanawanich, prince of Songkla University, Hat-Yai, Songkhla, 90112, Thailand Skipjack tuna (Katsuwonus pelamis) is commonly used for canned tuna production in Thailand. By-products such as roe and viscera are generated at 2.01 and 5.86 %(w/w), respectively. They were normally used to produce fishmeal or pet food with low value returns. Improving the utilization of those by-products into higher nutritive value fish oil is interested for potential better economic outcome. Our objectives were to recover oil from roe and viscera of skipjack tuna catching from different time of the year by different methods and then characterize the chemical composition as well as storage stability of oil. Oil from roe and viscera of skipjack tuna from Pacific ocean and Indian ocean caught over a year (April 1999-April 2000) were recovered by solvent and characterized for phospholipid content, fatty acid composition and chemical properties. Storage stability of crude oils was carried out at room temperature, 4 degree C and -20 degree C for 4 months. Roe and viscera contained different oil content, depending on catching period. Crude oils extracted using hexane and isopropanol (HIP) contained a higher amount of phospholipid than those extracted by chloroform and methanol (CM). Crude oil from roe and viscera had saturated fatty acid of 38.2 and 44.4%, monounsaturated fatty acid of 23.8 and 18.0% and polyunsaturated fatty acid of 37.4 and 35.2 %(w/w) of total fatty acid, respectively. The free fatty acid, peroxide value and TBARS value of oil stored at room temperature significantly increased. However no significant difference was found between samples stored at 4 degree C and -20 degree C. It was shown that the extraction of oil from tuna roe and viscera may upgrade the tuna by-products to high value application, especially EPA and DHA that have been very important for prevention of various human diseases and disorders.
Session 29B, Food Chemistry: Lipids, antioxidants and emulsifiers
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