The effect of heat treatment on the lactosylation of milk proteins.

Protein lactosylation is a significant modification that occurs during the heat treatment of dairy products, causing changes in proteins' physical-chemical and nutritional properties. Knowledge of the detailed lactosylation information on milk proteins under various heat treatments is important for selecting appropriate thermo-processing and identifying markers to monitor heat load in dairy products. In the present study, we used proteomics techniques to investigate lactosylated proteins under different heating temperatures. We observed a total of 123 lactosylated lysines in 65 proteins, with lactosylation even occurring in raw milk. The number of lactosylated lysines and proteins increased moderately at 75°C to 130°C, but dramatically at 140°C. We found that 6 out of 10, 9 out of 16, 6 out of 12, and 5 out of 15 lysine residues in κ-casein, ß-lactoglobulin, α-lactalbumin, and αS1-casein, respectively, were lactosylated under the applied heating treatment. Moreover, different lactosylation states of individual lysines and proteins can indicate the intensity of heating processes. Lactosylation of K14 in ß-lactoglobulin could distinguish pasteurized and UHT milk, while lactosylation of lactotransferrin can reflect moderate heat treatment of products.

Quantitative determination of contents of flavone glycosides in Chrysanthemum morifolium / 中草药

Object　To determine the amount of acacetin-7-O-β-D-glucoside and apigenin-7-O-β-D-glucoside in Chrysanthemum morifolium Ramat. from different localities. Methods　By the use of HPLC. Results　The contents of acacetin-7-O-β-D-glucoside in Boju1, Chuju2, Gongju3 and Hangju4 were 0.082 6%～0.124 9%, 0.015 7% and 0.033 5% respectively; the contents of apigenin-7-O-β-D-glucoside in Chuju, Boju, Gongju and Hangju were 0.012 6%, 0.027 4%, 0.117 7% and 0.587 7% respectively. Conclusion　The contents of the two flavone glycoside in C. morifolium from different localities were markedly different.

Isolation and identification of curdione in zedoary oil / 中成药

AIM:To study the isolation and identification of curdione from Zedoary oil. METHODS: Silica column was adopted to isolate constituents from Zedoary oil;IR,GC/MS and NMR methods were used to identify its structure. RESULTS: Three constituents were isolated from Zedoary oil,including crystal C_1,C_2 and C_3.Crystal C_1 was identified to be curdione and curdione content in Zedoary oil was 11.31%. CONCLUSION: This method is simple and convenient and it can be used to isolate more quantity of curdione for further pharmaceutical study.