Edam牦牛干酪成熟过程中品质变化及蛋白质降解  

Quality Changes and Protein Degradation in Edam Yak Cheese during Ripening

作　　者：王泽 张岩[2] 陈炼红[1] WANG Ze;ZHANG Yan;CHEN Lianhong(College of Food Science and Technology,Southwest Minzu University,Chengdu 610041,China;College of Animal and Veterinary Sciences,Southwest Minzu University,Chengdu 610041,China)

机构地区：[1]西南民族大学食品科学与技术学院,四川成都610041 [2]西南民族大学畜牧兽医学院,四川成都610041

出　　处：《食品科学》2023年第2期116-124,共9页Food Science

基　　金：西南民族大学中央高校基本科研业务费专项(2022NYXXS014)。

摘　　要：为研究Edam牦牛半硬质干酪成熟机理,分别测定成熟0、20、40、60、80 d Edam牦牛干酪的感官、理化、物性、蛋白质和脂肪分解指标,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和傅里叶变换红外光谱等方法研究酪蛋白降解情况,通过Pearson相关性分析成熟时间与各指标间的相关性。结果表明:随着成熟时间延长,感官评分先下降后上升;水分含量、pH值下降;亮度值(L^(*))下降,红度值(a^(*))和黄度值(b^(*))值上升;硬度、弹性、胶黏性均上升,凝聚性逐渐下降;储能模量和损耗模量升高,损耗角正切值始终小于1;成熟时间与总氮含量、pH 4.6和12%三氯乙酸条件下干酪中可溶性氮含量等呈极显著正相关(P<0.01);脂肪含量先升高后降低,游离脂肪酸含量和硫代巴比妥酸值逐渐增加。酪蛋白(casein,CN)降解研究结果表明:α_(s1)-CN、α_(s2)-CN、β-CN及κ-CN均随成熟时间延长而不断降解,成熟80 d时大分子蛋白降解明显;成熟过程中β-折叠、α-螺旋逐渐向无规卷曲转化;成熟时间与羰基含量、表面疏水性呈极显著正相关(P<0.01),与总巯基含量呈显著负相关(P<0.05)。In order to study the ripening mechanism of Edam yak cheese,the sensory,physicochemical and textural properties,and proteolysis and lipolysis indexes of Edam yak cheese were determined after 0,20,40,60 and 80 days of ripening.The degradation of casein was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)and Fourier transform infrared(FTIR)spectroscopy,and the correlation between maturation time and quality indices was analyzed by Pearson’s correlation analysis.The results showed that the sensory score decreased at first and then increased with increasing ripening time;the water content and pH decreased;the brightness value(L^(*))decreased,while the redness value(a^(*))and yellowness value(b^(*))increased;the hardness,elasticity and adhesiveness all increased,while the cohesiveness gradually decreased.The storage and loss moduli increased,and the tangent of the loss angle was always less than 1.The ripening time was positively correlated with the total nitrogen content,and the nitrogen content of soluble fractions at pH 4.6 and in 12%trichloracetic acid(TCA)(P<0.01).The fat content increased firstly and then decreased,and the free fatty acid content and thiobarbituric acid-reactive substances(TBARS)value increased gradually.The results of casein(CN)degradation showed thatα_(s1)-CN,α_(s2)-CN,β-CN andκ-CN were degraded continuously during cheese ripening,macromolecular proteins were degraded obviously after 80 days of maturation,andβ-sheet andα-helix were gradually transformed to random coil during maturation.The ripening time was positively correlated with the carbonyl content and surface hydrophobicity(P<0.01),but negatively correlated with the total sulfhydryl content(P<0.05).

关 键 词：牦牛干酪 Edam干酪 成熟 品质变化 蛋白质降解 

分 类 号：TS252.53[轻工技术与工程—农产品加工及贮藏工程]