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13 C nuclear magnetic resonance monitoring of free fatty acid release after fish thermal processing
Author(s) -
Medina Isabel,
Sacchi Raffaele,
Aubourg Santiago
Publication year - 1994
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02540657
Subject(s) - chemistry , fatty acid , docosahexaenoic acid , hydrolysis , food science , biochemistry , polyunsaturated fatty acid
13 C Nuclear magnetic resonance spectroscopy was applied to the study of lipid hydrolysis occurring during industrial canning of tuna ( Thunnus alalunga ). An increase in the free fatty acid (FFA) level was observed after cooking and sterilization, and a different FFA pattern was found when storage of the frozen raw material and thermal steps (cooking and can sterilization) were compared. Lipolysis in raw muscle occurs preferentially in the sn ‐1 and sn ‐3 acyl positions of triacylglycerols, with a consequent cleavage of saturated and monounsaturated fatty acids. After thermal processing, an increase of docosahexaenoic acid (DHA) was found in the FFA fraction, as well as a relative decrease of the peak intensity of DHA in the sn ‐2 position of triacylglycerols. This finding indicates a different mechanism of FFA release during the frozen storage and thermal processing of raw fish.