[关键词]
[摘要]
通过添加成熟干酪、成熟干酪与微胶囊酶共用和微胶囊复合酶单作用三种促熟方法制备切达干酪样2、样3和样4,非促熟对照为样1,利用流变仪、扫描电镜分析促熟技术对干酪质地的影响。结果表明,随扫描频率增加,四种样品的复数粘度(η*)极显著降低,其G′值和G″值极显著增加(P<0.01);相同扫描频率时,四种样品的复数粘度值:样1>样3>样2>样4。所有样品的G′值和G″值都随着温度的升高而显著降低,tan δ值先增加后减小,说明动态扫描时温度变化对快速成熟干酪G′值和G″影响极显著(P<0.01)。样1、样2、样3和样4的转变温度分别为37.5 ℃、32.5 ℃、35 ℃和32.5 ℃。SEM测到样品的结构中“机械孔洞”数量和大小明显不同,对照样1和样3中机械孔洞数量多且较大,样2次之,样4几乎没有机械孔洞,说明样4的促熟后的质地相对最好。
[Key word]
[Abstract]
Three accelerated ripening methods were used to prepare cheddar cheese samples. Sample 1 was a non-accelerated-ripened control cheddar. Samples 2, 3, and 4 were prepared by addition of a ripened cheese slurry; using a mixture of ripened cheese slurry and encapsulated enzyme; and with encapsulated enzyme alone. A rheometer and scanning electron microscope (SEM) were used to study the qualities of the samples. The frequency sweep test results indicated that with increasing frequency, the complex viscosity η* values of the four samples decreased significantly while the storage modulus G′and loss modulus G″values increased significantly (P < 0.01). At the same scanning frequency, the rank order of the complex viscosity values of the samples was as follows: sample 1 > sample 3 > sample 2 > sample 4. The temperature sweep test showed that the G′and G″values of all of the samples decreased significantly with increasing temperature (P < 0.01). The damping factor (tanδ) values of all samples decreased after the initial rise, indicating that the temperature change had a significant effect on the G′and G″values of all of the accelerated-ripened cheese samples during the dynamic scanning. The transition temperatures of sample 1, sample 2, sample 3, and sample 4 were 37.5 ℃, 32.5 ℃, 35 ℃, and 32.5 ℃, respectively. The SEM images showed a large amount of large mechanical openness in samples 1 and sample 3, with less mechanical openness in sample 2. There was almost no mechanical openness in sample 4, indicating that sample 4 had a better texture after accelerated ripening.
[中图分类号]
[基金项目]
“十二五”国家科技支撑计划项目(2011BAD09B02-Ⅲ)