摘要
乳清蛋白是常用的成膜材料,乳清蛋白膜对氧气等气体有良好的阻隔能力,但其机械强度和水蒸气透过率较差。本实验研究木糖质量浓度和甘油体积分数对乳清蛋白的膜物理和机械特性以及水蒸气透过率的影响,优化成膜最佳条件,并对乳清蛋白和乳清蛋白-木糖美拉德反应产物的成膜特性进行比较。观察用乳清蛋白膜和乳清蛋白-木糖美拉德反应产物膜分别包裹核桃仁后对核桃仁脂质过氧化的影响。结果表明,乳清蛋白-木糖美拉德反应产物的成膜最佳条件为:乳清蛋白质量浓度10g/100 mL,木糖质量浓度5g/100 mL,甘油体积分数5%,在80℃加热45min或90℃加热30min。乳清蛋白-木糖美拉德反应产物膜的刺穿强度比乳清蛋白膜提高约1倍,拉伸强度提高约1.5倍,水蒸气透过率降低约24%。乳清蛋白-木糖美拉德反应产物膜包裹可以延缓核桃仁酸价的上升,而乳清蛋白膜对核桃仁的酸价上升无明显的抑制作用。
Whey protein isolate(WPI) is one of commonly used film-forming materials and has been considered as a good barrier to oxygen but a poor one to water vapor.In the present study,film-forming properties of Maillard reaction products(MRPs) formed from WPI and xylose such as physical and mechanical properties and water vapor permeability were investigated at different amounts of xylose and glycerol with the aim of optimizing film-forming conditions and a comparison with those of WPI was carried out.In addition,the effects of coating with WPI or WPI/xylose MRPs on lipid peroxidation in walnut kernel were probed.The results indicated that the optimal film-forming conditions of WPI/xylose MRPs were determined to be heating a reaction system containing 10 g of WPI,5 g of xylose and 5 mL of glycerol per 100 mL at 80 ℃ for 45 min or at 90 ℃ for 30 min.Compared with WPI film,WPI/xylose MRPs film revealed a two-fold increase in penetration strength,an around 2.5-fold elongation strength and a decrease in water vapor permeability by about 24%.Coating with WPI/xylose MRPs film could delay the increase in acid value of walnut kernel,whereas coating with WPI film had no obvious inhibitory effect.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2011年第5期58-64,共7页
Food Science
关键词
乳清蛋白
木糖
美拉德反应产物
可食用膜
核桃仁
whey protein isolate
xylose
Maillard reaction products
edible film
walnut