29B-10 |
Changes in chemical characteristics and fatty acid profile of salmon oil during refining |
P. Z. LIAN, Dept. of Nutrition and Food Science, University of Rhode Island, Kingston, RI 02881 and C. M. LEE, Dept. of Nutrition & Food Sciences, Univ. of Rhode Island, 530 Liberty Ln., West Kingston, RI 02892-1802. Fish oil has been considered as a good source of polyunsaturated fatty acids due to high content of EPA and DHA, whose levels vary with fish species. Crude fish oil requires refining to remove free fatty acids, pigments, odor, and high melting point lipids. However, there are no reports on changes in fatty acid profiles of salmon oil as a result of refining. The objective of this study was to analyze the changes in chemical characteristics and fatty acid profile of salmon oil after each refining step. Crude salmon oil (1000 g) was neutralized with NaOH, washed with NaCl solution to pH ~7, vacuum dehydrated, decolored with Fuller's earth, deodorized, and winterized at 10°C and –2°C for 24 h, respectively. Winterized oil was centrifuged at 0°C. The liquid and solid fractions were separated. Peroxide value, acid value, color, and fatty acid compositions were determined during refining. The free fatty acid content significantly decreased from 4.927 to 0.014 mg KOH/g oil after deacidification but slightly increased to 0.042 after decolored. There was no marked change in peroxide value. Decolorization significantly decreased redness (10.30 to –3.00) and yellowness (30.93 to 12.43). The contents of EPA and DHA did not greatly change in liquid and solid fractions after winterization. The results indicate that winterization at –2°C is not necessary in fish oil refining unless the improvement of the clarification is required.
Session 29B, Food Chemistry: Lipids, antioxidants and emulsifiers
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