Professor Wang Zhongfu’s team has made new progress in the research field of goat milk characteristic oligosaccharides
By: Date: 2022-07-28 Categories: foodtechnology Tags: ,
Goat milk has high nutritional value, easy digestion and absorption, low sensitization and other advantages. It is one of the important sources of milk based ingredients of infant formula. Goat milk contains a series of active oligosaccharides with diverse structures, which can promote the healthy growth and development of infants and regulate intestinal flora. The content of mature goat milk oligosaccharides (GMOs) can reach 0.25-0.3 g/l, which is 4-10 times that of cow’s milk. The content of active oligosaccharides is much higher than that of other animal milk, which is close to the composition of human milk oligosaccharides. It is expected to become a new functional ingredient for the development of breast milk based infant formula.
 
Professor Wang Zhongfu’s team has carried out a series of work around the study of goat milk oligosaccharides for many years. In the early stage, based on the biological mass spectrometry technology, we qualitatively and quantitatively compared the differences of goat lactose protein n/o-oligosaccharide groups in different lactation periods and different parity, and found that with the extension of lactation period, the content of glycoprotein n/o-oligosaccharide group increased first and then decreased, which was complementary to the change trend of free oligosaccharide; With the prolongation of parity, the content of glycoprotein n/o-oligosaccharide group showed an upward trend (food chem. 2021, 16; 342:128221; J. agric. food chem. 2020, 68 (7):2174-2182.).
 
Based on the previous research, this study carried out in-depth mass spectrometry analysis of goat milk characteristic free oligosaccharide galactosyllactose, established a highly sensitive method for the separation and identification of goat milk characteristic oligosaccharide galactosyllactose isomers, and used high performance liquid chromatography (HPLC) combined with full methylation analysis The differences of galactosyllactose isomers in goat milk at different lactation stages were qualitatively and quantitatively compared by multi-stage tandem mass spectrometry (ESI MSN) and on-line liquid chromatography-mass spectrometry. The results showed that galactosyllactose was the most abundant oligosaccharide in goat milk with many isomers, which were:β 6′-GL、 α 6′-GL、 β 4′-GL、 α 3′-gl and β 3′-gl, where α 6′-gl and β 4′-gl is the first discovery of goat milk characteristic galactosyllactose structure. Through relative quantitative analysis, it was found that the total content of five galactosyllactose isomers was the highest in transition milk, β 3′-gl is the main isomer in colostrum, α 3′-gl is the main isomer in transitional milk and mature milk. Transitional milk β 3′-gl is 5 times that of colostrum and 2 times that of mature milk α The content of 3′-gl is twice that of colostrum and 10 times that of mature milk; After absolute quantitative analysis, it was found that β The content of 3′-gl is the most abundant, 32.31 mg/l, in transition milk and mature milk α The content of 3′-gl is the most abundant, 88.12 mg/l and 36.25 mg/l respectively. The results lay a foundation for the in-depth study of the structure and function relationship of galactosyllactose in goat milk, are of great significance for the development of goat milk and its product quality control system with characteristic oligosaccharide molecules as markers, and provide a scientific basis for the development of functional food with galactosyllactose as ingredients.
 
The study was titled”qualitative and quantitative mass spectrum comparison of characteristic galactosyl lactose isomers from good milk at different lactation stages” and was published in the international famous academic journal Journal of Dairy Science (Q1, top journal, ranking first in the global dairy science field, if=4.225), with Master Wang Xinyi as the first author, Associate Professor Lu Yu and Professor Wang Zhongfu are co correspondents. The research was supported by the National Natural Science Foundation of China (No. 31972024 and 31870798) and the Shaanxi Provincial innovation capability support program and scientific and technological innovation team (2020td-044).
 
Paper link:https://doi.org/10.3168/jds.2021-21701