Fatty acid composition analysis and nutrition evaluation of milk and dairy products sold in Yinchuan City

Abstract

To analyze fatty acid composition of milk and dairy products sold in Yinchuan City, and to evaluate their nutritional value. Twenty-two types of milk and dairy products were collected in 2022-2023, including 14 types produced in Ningxia and 8 types not produced in Ningxia. Fatty acids were determined and analyzed according to the first method of National Standard for Food Safety Determination of fatty acids in Food(GB 5009.168-2016). The fatty acid polyunsaturated index(PI), atherogenic index(AI) and thrombosis index(TI) were used to evaluate the nutritional value of milk and dairy products. There were 25 kinds of fatty acids in milk and dairy products produced in Ningxia, which were more than those not produced in Ningxia. The main saturated fatty acids(SFA)were palmitic acid(30.14%-42.57%), the main monounsaturated fatty acids(MUFA)were oleic acid(15.45%-25.21%), the main polyunsaturated fatty acids(PUFA)were linoleic acid(1.79%-9.37%), the content of α-linolenic acid was 0.04%-0.95%, n-3 PUFA was 0.14%-0.95%. Oleic acid of adult milk powder, sheep milk powder, pure milk and Ningxia wolfberry milk were higher than others, linoleic acid of adult milk powder and walnut milk were higher than others. The value of oleic acid and linoleic acid of Ningxia pure milk was higher than that in imported pure milk, and the value of n-6 PUFA/n-3 PUFA was much lower than that in imported pure milk. The content of oleic acid and linoleic acid in Ningxia wolfberry milk was close to that of pure milk, higher than that of children's milk, and the total fat content was lower than that of children's milk. The n-6 PUFA/n-3 PUFA ratio of concentrated milk, walnut milk, sweet milk, pure milk, Ningxia wolfberry milk, adult milk powder 1, sheep milk powder was close to the ideal intake value of dietary fatty acids recommended by the Chinese Nutrition Society. Except for low-fat pure milk, ice cream yogurt, imported pure milk, children's milk 1, adult milk powder 1 and sheep milk powder, the n-6 PUFA/n-3 PUFA ratio of other milk and dairy products in Ningxia were close to the recommended value of the Food and Agriculture Organization of the United Nations and World Health Organization. SFA∶MUFA∶PUFA was(1.99-4.23) ∶1∶(0.08-0.38), PI range: 1.87-11.27, AI range: 1.67-4.32, TI range: 2.34-5.76. The fatty acid composition of 22 types of milk and dairy products in Yinchuan City was different, and the nutrition was slightly different.