测试条件对搅拌型酸乳质构特性测定的影响

Effect of Test Conditions on the Determination of Textural Properties of Stirred Yoghurt

以搅拌型酸乳为研究对象,应用质构仪建立酸乳质构特性的测试方法,考察测试探头直径、压缩距离、触发力、容器体积、测试速率、测前速率及测后速率对酸乳质构特性测定的影响,通过L_9(3~4)正交试验进一步研究测前速率、测试速率及测后速率对酸乳硬度、弹性及黏性测定的影响。通过原包装原位测试技术测定市面上流行的8种酸乳的质构特性、黏度及弹性模量。结果表明:各测试条件均影响酸乳质构特性测定,对于搅拌型酸乳,合适的测试参数为测前速率1 mm/s、测试速率1 mm/s、测后速率10 mm/s、压缩距离30 mm、测试探头直径35 mm、触发力5 g、测试容器体积100 mL。在α=0.05水平上,对于酸乳硬度与弹性,测试速率为显著影响因子,对于黏附力,测后速率为显著影响因子。不同酸乳的质构特性差异明显,硬度、稠度、黏附力、黏附性及弹性与弹性模量相关,硬度、稠度、黏附力及黏附性与黏度相关。

In this paper, we investigated the effect of test conditions such as probe diameter, compression distance, trigger force, container volume, pre-test speed, test speed, post-test speed on the textural properties of stirred yoghurt, and we also evaluated the effect of pre-test speed, test speed, post-test speed on the firmness, elasticity and viscosity of yoghurt with an orthogonal experimental design L9(34). In addition, the textural properties, viscosity and elastic modulus of 8 kinds of popular commercial yogurt were in situ determined without destroying the original packaging. The results showed that all test conditions affected the textural properties of stirred yoghurt. The appropriate test conditions were as follows: 1 mm/s of pre-test speed and test speed, 10 mm/s of post-test speed, 30 mm of compression distance, 35 mm of probe diameter, 5 g of trigger force, and 100 mL of container volume. At the confidence level of α = 0.05, test speed had a significant effect on the firmness and elasticity, while post-test speed was a significant factor influencing the adhesive force. Moreover, there existed obvious differences in the textural properties of different kinds of yoghurt. Elastic modulus was correlated with firmness, consistency, adhesiveness, adhesive force and elasticity, and viscosity was correlated with firmness, consistency, adhesiveness and adhesive force.