29B-35 |
Thermal degradation of menhaden oil from different purification steps |
S. SATHIVEL1, W. Prinyawiwatkul2, I. I. Negulescu3, J. M. King2, and B. F. A. Basnayake4. (1) Fishery Industrial Technology Center, Univ. of Alaska, Fairbanks, School of Fisheries & Ocean Sciences, 118 Trident Way, Kodiak, AK 99615-7401, (2) Dept. of Food Science, Louisiana State Univ. Agricultural Center, 111 Food Science Bldg., Baton Rouge, LA 70803-4200, (3) School of Human Ecology, Louisiana State Univ. Agricultural Center, 125 Human Ecology Bldg., Baton Rouge, LA 70803-4200, (4) Dept. of Agricultural Engineering, Univ. of Peradeniya, Faculty of Agriculture, Peradeniya, Sri Lanka Fish oil production for human consumption includes extraction of crude oil, degumming, neutralizing, bleaching, and deodorizing. It is important to understand the stability of fish oil during purification process in order to produce high quality purified oil. The thermogravimetric (TG) analysis can be used to evaluate the stability of fish oil at different purification steps. This study investigated the effects of temperature on weight loss of menhaden oil at each purification step. Menhaden oil samples including crude, degummed, neutralized, bleached, and deodorized oils were subjected to the TG analyzer. Samples (0.5-1 mg) was placed in the furnace and heated up to 600 C at the rate of 5 C/min. Duplicate experiments were conducted. Between 200-550 C, weight loss of Menhaden oils increased with increased temperature, regardless of the purification steps. Deodorized oil showed greater weight loss (88%) at 400 C, whereas lower weight loss (63%) was observed in crude oil. There was, however, no distinct weight loss of all oils at below 300 C. Oils with less impurity had greater weight loss especially at 400-500 C. At 550 C, crude, degummed, and neutralized oil samples were completely decomposed, whereas bleached and deodorized oils were completely decomposed at 500 C. Knowledge of thermal stability or degradation (weight loss through evaporation or decomposition) of menhaden oils during purification is useful for defining the quality of oils at each purification step.
Session 29B, Food Chemistry: Lipids, antioxidants and emulsifiers
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