Analysis Of The Content And Stability Of Conjugated Linoleic Acid In The Muscles Of Sunite Sheep

Conjugated linoleic acid (CLA) is a group of geometric and positional isomers. As the product of rumen microorganism, conjugated linoleic acid naturally resides in the ruminant muscles and fat. The content of CLA contained in the ruminant meat products are related to the source type of the meat, but the processing condition in meat industry can also affect the content of CLA. So the purpose of this study was to find out the content of CLA in intercellular fat in muscle tissue and in abdomen of lamb meat and to find out the stability of CLA estimated with regular industrial technological parameters.In this research study, the sampled longissmus dorsi muscle and abdominal fat were selected from the 5-month-old Sunite sheep. GC-MS combination technique was used in the analysis of the data obtained from the sample. The study identified the content of CLA contained in the sample and examined how radiation sterilization, frozen preservation, heating, and curing had an effect on the stability of CLA. The research results showed that the mean of the relative percentage of CLA contained in the longissmus dorsi muscle was 0.83% and CLA contained in abdominal fat was 0.99%. Although 2 kGy y radiation sterilization could cause loss in the content of CLA, the content of CLA was still stable if it was in vacuum package and preserved at the temperature of-2℃ for 30 days. When sterilized with 2kGy y radiation and preserved at the temperature of -18℃, the content of CLA stayed stable for 45 days whether it was packaged in the air or in the vacuum. Conjugated linoleic acid demonstrated characteristic of UV absorbance. The regular 254 nm UV did not cause loss in the content of conjugated linoleic acid. Low temperature pasteurization (70-72℃, 82-86℃) could slightly reduce the content of conjugated linoleic acid. In the process of curing, the concentration of both sodium chloride and sodium nitrite affected the stability of conjugated linoleic acid. When the concentration of sodium chloride was high, the content of conjugated linoleic acid was stable; when the concentration of sodium nitrite was high, the content of conjugated linoleic acid tended to decrease.