58-5 |
Mechanisms for reversion flavor formation in soybean oil |
A. L. CALLISON, Dept. of Food Science and Technology, The Ohio State University, 110 Parker Food Science and Technology Building, 2015 Fyffe Ct., Columbus, OH 43210 and D. B. Min. Food manufacturers use soybean oil due to its high nutritional quality, availability and low price. However, soybean oil produces reversion flavor, which makes it unacceptable. Reversion flavor of soybean oil has been investigated extensively for fifty years. The isomers of 2-pentenylfuran have been reported to contribute to reversion flavor. However, the mechanisms of 2-pentenylfuran formation in soybean oil have not been reported unequivocally due to the unique reactivity of singlet oxygen that has only been studied during the last twenty years. The objectives were to study (1) whether singlet oxygen oxidation is responsible for the formation of 2-pentenylfurans in soybean oil during storage under light and (2) the mechanisms for the formation of 2-pentenylfuran. This lab previously demonstrated that chlorophyll produces singlet oxygen in the presence of light. Therefore, soybean oil was purified to remove chlorophyll. Purified oil, with and without added chlorophyll, was stored under light and dark. The volatiles produced were analyzed by SPME-GC-MS. Headspace oxygen depletion gas chromatography and peroxide value tests were used to verify oxidation of the samples. 2-Pentenylfuran was not formed in soybean oil without chlorophyll, even when exposed to light for thirteen days. Also, 2-penteylfuran was not present in soybean oil samples with added chlorophyll that were stored in the dark. However, 2-pentenylfuran was produced in samples with chlorophyll stored under light. This indicates that singlet oxygen is responsible for the formation of 2-pentenylfuran in soybean oil during storage under light. The amount of 2-pentenylfuran increased as the light exposure time and added chlorophyll content increased. Additionally, the amount of headspace oxygen decreased while peroxide value increased as light exposure time increased. A singlet oxygen oxidation mechanism for the formation of 2-pentenylfuran has also been proposed. Overall, this research suggests that removing chlorophyll from soybean oil during processing will reduce reversion flavor formation.
Session 58, Food Chemistry: Lipids, Emulsions and Antioxidants
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