研究了低温长时巴氏杀菌(low temperature long-time,LTLT)、高温短时巴氏杀菌(high temperature short-time,HTST)、超高温瞬时杀菌(ultra-high temperature,UHT)、喷雾干燥(spray drying,SP)和保持灭菌(retort sterilizing,RS)等5种商业热处理对山羊乳蛋白二级结构、氧化程度和美拉德反应产物的影响.结果表明,不同热处理对山羊乳蛋白的损伤程度为LTLT、HTST＜UHT、SP＜RS.与新鲜山羊乳相比,LTLT和HTST处理对山羊乳蛋白粒径、电位和美拉德反应产物的积累变化不显著,乳清蛋白二级结构和氧化指数出现轻微上升.RS处理影响最显著,其中羰基质量摩尔浓度升高418％、巯基质量摩尔浓度下降65％,乳清蛋白变性程度高达95％.UHT和SP处理对乳蛋白损伤程度接近,从乳蛋白粒径、电位、氧化指数、内荧光和表面疏水性上看,SP处理对乳蛋白的影响比UHT处理更小;从美拉德反应产物糠氨酸(furosine)和羟甲基糠醛(5-HMF)的积累来看,UHT处理相较SP处理对山羊乳蛋白的影响更小.总体来说,山羊乳蛋白损伤与加热温度和时间相关,喷雾干燥过程更容易造成美拉德反应产物的积累.
Effects of Commercial Heat Treatment on the Structure,Oxidation Degree and Maillard Reaction Product Accumulation of Saanen Goat Milk Protein
The effects of five commercial heat treatments including pasteurization(LTLT at low temperature long-time,HTST at high temperature short-time),UHT(Ultra-high temperature),spray drying(SP),and retort sterilized(RS)on the secondary structure of goat milk protein,the degree of oxidation,and the accumulation of Maillard reaction products were studied.The damage degree of goat milk protein caused by different heat treatments was LTLT,HTST＜UHT,SP＜RS.Compared with raw milk,the accumulation of particle size,potential and Maillard reaction products of goat milk protein treated with LTLT and HTST did not change significantly,while the secondary structure and oxidation index of whey protein slightly changed and increased.RS treatment had the most significant effect.The carbonyl content in RS milk was 418％higher than that in raw milk,the sulfhydryl content was 65％lower,and the denaturation degree of whey protein was up to 95％.The damage degree of UHT and SP to milk protein was similar.From the perspective of particle size,potential,oxidation index,internal fluorescence and surface hydrophobicity of milk protein,the effect of SP on milk protein was smaller than that of UHT,but according to the accumulation of Furosine and 5-HMF from Maillard reaction products,the effect of UHT on goat milk protein production was smaller than that of SP.In general,goat milk protein damage is related to heating temperature and time,and the spray drying process is more likely to cause the accumulation of Maillard reaction products.
万方数据
维普
