凝聚和储存对80%浓缩乳清蛋白和分离乳清蛋白风味稳定性的影响

Influences of Coagulation and Storage on Flavor Stability of 80 % Whey Protein Concentrate(WPC80) and Whey Protein Isolate(WPI)

研究检测了市场上的浓缩乳清蛋白（WPC80）和分离乳清蛋白（WPI）在储存18个月时长和凝聚后的风味及风味稳定性.凝聚和未凝聚的WPC80和WPI储存条件是21℃,相对湿度为50％.用固相微萃取法和气质联用仪一起进行挥发性成分的分析,每2个月进行一次描述性感官评定.每3或6个月测一次溶解度指数.与未凝聚的粉末相比,凝聚粉末的强度较高,脂质氧化口味（硬纸板味、葡萄干/肉汤味、黄瓜味和脂肪味）发展更快.挥发性分析结果证实了感官结果,与未聚集的粉末相比,凝聚产品中形成的醛酮更多.研究结果表明21℃时不凝聚的乳清蛋白最佳保存期限是12～ 15个月,凝聚的是9～12个月.

This study examined the influences of 18-month storage and coagulation on the flavor as well as the flavor stability of the combination of WPC80 and WPI on the market. Coagulable and non-coagulable WPC80 and WPI are stored under the conditions of a temperature of 21 ~C and relative humidity of 50 %. Volatile components were analyzed by means of solid phase micro extraction and GC-MS, sensory evaluation was made every two months, and solubility index were measured every three or six months. Experimental results indicated that, compared with non-coagulated powder, the coagulated powder was stronger and the lipid oxidation flavor （ardboard flavor, raisins/broth flavor, cucumber flavor and fat flavor ） volatilizes faster. Volatile analysis results verified the sensory description： coagulated products formed more aldehydes and ketones. The results showed that the best shelf life of non-coagulable whey protein under 21 ~C is 12-15 months,and coagulabe 9-12 months.