关键词: 塞北兔, 脂肪酸, 脂肪酸甲酯化

Abstract:

The aim of this study was to develop an analytical method for the qualitative and quantitative determination of fatty
composition in subcutaneous connective tissue, mesenteric adipose tissue and muscle tissue of the meat rabbit breed Saibei. Lipid
extraction was performed by Soxhlet extraction or chloroform/methanol extraction, and the extracted lipids were methyl-esterified
under acidic or basic conditions before analysis by GC. Comparative evaluation suggested ultrasonic-assisted chloroform/
methanol extraction and methyl-esterification under basic conditions to be the best sample preparation procedure. The fatty acid
composition of rabbit meat was determined by GC-MS using this procedure. The results showed that intermuscular fat in rabbit
muscle consisted of 12 fatty acids including 4 saturated, among which the most abundant was C16:0 and its content was up to
27.30%; 4 monounsaturated, among which C18:1 showed the highest content, reaching 24.02%; and 4 polyunsaturated fatty acids
with 26.06% of C18:2 being the most abundant, and the polyunsaturated/saturated fatty acid ratio (P/S) was 0.88. A total of 13 fatty
acids were identified from the mesenteric adipose tissue, including 4 saturated with the greatest abundance in C16:0 (26.75%); 5
monounsaturated, among which C18:1 (29.07%) was the most abundant; and 4 polyunsaturated ones with C18:2 (21.99%) being
the most dominant, and the P/S ratio was 0.75. The mesenteric adipose tissue was found to be composed of 21 fatty acids with
a P/S ratio of 0.99, including 7 saturated, 7 monounsaturated and 7 polyunsaturated ones, among which the most abundant were
C16:0, C18:1 and C18:2 with contents of 25.47%, 26.25% and 27.52%, respectively. The number and relative contents of fatty acids
differed among the three tissues of rabbit meat. The mesenteric adipose tissue contained the largest number of fatty acids, while
only a smaller number of fatty acids were found in the intermuscular adipose tissue. The P/S ratio was the largest in the mesenteric
adipose tissue but smaller in the subcutaneous connective tissue.

Key words: Saibei rabbit, fatty acids, methyl-esterification of fatty acids