[Fatty acid composition and content in 33 commercial dairy products in Chongqing].

OBJECTIVE

The fatty acid composition and content of different commercial dairy products were analyzed.

METHODS

A total of 33 representative dairy products were purchased in the supermarket of Chongqing, which were divided into three types: pure milk, milk powder and yogurt. The composition and content of fatty acids were analyzed by gas chromatography.

RESULTS

A total of 26 fatty acids were detected in this study, including 15 SFAs, 6 MUFAs, 3 n-6 PUFAs and 2 n-3 PUFAs. The composition and content of fatty acids in each sample were quite different. The total SFA content of milk powder((58.94±1.40)g/100 g) was significantly lower than that of pure milk((69.40±5.93)g/100 g) and yogurt((72.89±0.93)g/100 g)(F=12.485, P<0.05), and there was no significant difference in MUFA content except for myristoleic acid(P>0.05). The content of linoleic acid in milk powder((15.78±0.54)g/100 g) was 7.74 times and 8.92 times that of pure milk((2.04±0.86)g/100 g) and yogurt((1.77±0.22)g/100 g). The α-linolenic acid content((2.83±2.22)g/100 g) was 4.56 times and 5.87 times that of pure milk((0.62±0.25)g/100 g) and yogurt((0.49±0.08)g/100 g). The content of n-6 PUFA in milk powder((21.03±4.78)g/100 g) was significantly higher than that in pure milk((2.33±0.92)g/100 g) and yogurt((2.03±0.22)g/100 g)(F=44.904, P<0.05). The content of n-3 PUFA in milk powder((3.26±0.88)g/100 g) was significantly higher than that in pure milk((0.56±0.16)g/100 g) and yogurt((0.49±0.08)g/100 g)(F=27.842, P<0.05). The SFA: MUFA: PUFA value in milk powder(1∶0.44∶0.41) was closer to the recommended value in the Reference Intake of Dietary Nutrients for Chinese Residents(1∶1∶1) than that in pure milk(1∶0.37∶0.04) and yogurt(1∶0.34∶0.03).

CONCLUSION

There are differences in the composition and content of fatty acids among various dairy products on the market, especially in saturated fatty acids and polyunsaturated fatty acids, and the proportion of SFA, MUFA, and PUFA in various dairy products is also significantly different.