The content of L-carnitine in meat after different methods of heat treatment

摘要

Purpose - The objective of this study is to examine the effects of pan-frying, boiling and cooking in a microwave on the amount of L-carnitine in meat and to look at its distribution in the surrounding fluid after food processing. Design/methodology/approach - Total carnitine, free carnitine and acylcarnitines were determined in meat samples from beef, pork and poultry (including ostrich) and in a liver sample from beef. The measurements were carried out before and after the specimens were subjected to different heat treatments. A radio-enzymatic assay was used for measurement of L-carnitine. Results are expressed per 100 gram dry matter and per 100 gram wet weight. Findings - Except for pan-frying, virtually no losses of carnitine occurred during the different procedures of heat treatment. During boiling and microwaving, however, a considerable portion of the tissue carnitine escaped into the water fraction. With pan-frying, carnitine losses from meat amounted to from 3 to 36 per cent. In all animal species, tissue losses of L-carnitine increased with increase of boiling time. When expressed as a percentage of total carnitine, the proportion of carnitine present as esters differed somewhat between different heating procedures but showed no typical pattern. Originality/value - The findings of this study show the important role that meat products play for providing an adequate amount of L-carnitine in humans who are suffering from carnitine deficiency and an exogenous supplementation is needed.