Lactational changes of fatty acids and fat-soluble antioxidants in human milk from healthy Chinese mothers.

Human milk fat is specially tailored to supply the developing infant with adequate and balanced nutrients. The present study aimed to quantify the composition of fatty acids, tocopherols and carotenoids in human milk, with special emphasis on the lactational changes. Colostrum, transitional and mature milk samples were collected longitudinally from the same forty-two healthy, well-nourished Chinese mothers. Fatty acids were quantified by GC with carotenoids (carotenes and xanthophylls) and tocopherols (α-, γ-tocopherol) determined by HPLC. Total fatty acid (TFA) content increased from 15·09 g/l in colostrum to 32·57 g/l in mature milk with the percentages of DHA and arachidonic acid (ARA) decreased. The ratio of n-6:n-3 PUFA and ARA:DHA remained constant during lactation at about 11:1 and 1·3:1, respectively. Both α-tocopherol and γ-tocopherol decreased over lactation with the ratio of α-:γ-tocopherol declined significantly from 7·21:1 to 4·21:1 (P < 0·001). Carotenoids all dropped from colostrum to mature milk as the less polar carotenes dropped by 88·67 %, while xanthophylls only dropped by 35·92 %. Lutein was predominated in both transitional and mature milk carotenoids (51·64-52·49 %), while colostrum carotenoids were mainly composed of lycopene (32·83 %) and ß-carotene (30·78 %). The concentrations of tocopherols and xanthophylls but not carotenes were positively associated with TFA content in milk. These results suggested that colostrum and mature milk contained divergent lipid profiles and selective transfer mechanisms related to polarity might be involved. The present outcomes provide new insights for future breast-feeding studies, which also add in scientific evidences for the design of both initial and follow-on infant formulas.

Fatty acid positional distribution (sn-2 fatty acids) and phospholipid composition in Chinese breast milk from colostrum to mature stage.

This study quantified the fatty acid profile with emphasis on the stereo-specifically numbered (sn) 2 positional distribution in TAG and the composition of main phospholipids at different lactation stages. Colostrum milk (n 70), transitional milk (n 96) and mature milk (n 82) were obtained longitudinally from healthy lactating women in Shanghai. During lactation, total fatty acid content increased, with SFA dominating in fatty acid profile. A high ratio of n-6:n-3 PUFA was observed as 11:1 over lactation due to the abundance of linoleic acid in Chinese human milk. As the main SFA, palmitic acid showed absolute sn-2 selectivity, while oleic acid, linoleic acid and α-linolenic acid, the main unsaturated fatty acids, were primarily esterified at the sn-1 and sn-3 positions. Nervonic acid and C22 PUFA including DHA were more enriched in colostrum with an sn-2 positional preference. A total of three dominant phospholipids (phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM)) were analysed in the collected samples, and each showed a decline in amount over lactation. PC was the dominant compound followed by SM and PE. With prolonged breast-feeding time, percentage of PE in total phospholipids remained constant, but PC decreased, and SM increased. Results from this study indicated a lipid profile different from Western reports and may aid the development of future infant formula more suitable for Chinese babies.

Food and Nutrients Intake in the School Lunch Program among School Children in Shanghai, China.

This study aimed to evaluate the intake of food and nutrients among primary, middle, and high schools students in Shanghai, and provide recommendations for possible amendments in new school lunch standards of Shanghai. Twenty schools were included in the school lunch menu survey. Of those, seven schools enrolled 5389 students and conducted physical measurement of plate waste and a questionnaire survey. The amount of food and nutrients was compared according to the new China National Dietary Guideline for School Children (2016) and Chinese Dietary Reference Intakes (2013). The provision of livestock and poultry meat in menus was almost 5-8 times the recommended amount. The amount of seafood was less than the recommended amount, and mostly came from half-processed food. The average percentage of energy from fat was more than 30% in students of all grades. The greatest amount of food wasted was vegetables with 53%, 42%, and 31%, respectively, among primary, middle and high school students. Intake of Vitamin A, Vitamin B2, calcium, and iron was about 50% of the recommended proportion. Only 24.0% students were satisfied with the taste of school lunches. Higher proportions of livestock and poultry meat and low intake of vegetables have become integral problems in school lunch programs. Additionally, more attention needs to be paid to the serving size in primary schools with five age groups.