Stability Profile of Fatty Acids in Yak (Bos grunniens) Kidney Fat During the Initial Stages of Autoxidation

摘要

Previously, we have shown that the fatty acid composition of yak kidney is of reasonable value and is suitable for further development of possible commercial products. Changes in the fatty acids of yak kidney fat during the initial stages of storage have been investigated. The full period of autoxidation was determined by peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) at 15 ± 1 °C for up to 70 days. The stability profile of the fatty acids identified by gas chromatography demonstrated that saturated fatty acids increased from 49.68 to 55.96% and that polyunsaturated fatty acids and monounsaturated fatty acids decreased from 10.73 to 6.95% and from 37.85 to 28.22%, respectively. Amounts of all the functional fatty acids except conjugated linoleic acid and linoleic acid, started to decrease after 10 days of storage. These results indicated that the initial stage of autoxidation occurred during the first 25 days of storage. It is suggested that development of potential commercial products should be accomplished within ten days, because the functional fatty acids started to decrease after this period of storage. In addition, the good correlation between PV/TBARS values and changes of individual fatty acids could be used as an indicator to monitor the changes of the functional fatty acid during the development process of yak kidney fat-related commercial products. Keywords Yak - Kidney fat - Fatty acids - Autoxidation - Storage - Stability H. Zhang and Q. Wang contributed equally to this work.