一种超高压方便粳米饭鉴别方法的建立与验证

Establishment and Verification of an Identification Method on Ultra-High Pressure Convenient Japonica Rice

为建立超高压方便粳米饭的鉴别方法,通过引入最低黏度差值比的概念,并利用20种典型粳米的试验进行验证。结果表明,米饭最佳取样工艺为:取制作完成30 d后的超高压方便粳米饭和普通方便粳米饭各220.0 g至烧杯,按质量比稀释3倍,利用Φ18 mm刀头以12000 r/min匀浆处理3 min,取100.0 g上述匀浆液,利用Φ10 mm刀头以12000 r/min处理1 min,即为待测样品。利用黏度测定仪按照升温程序(30~95℃,10 min;95~95℃,5 min;95~30℃,10 min;30~30℃,5 min),采样间隔1 s测定样品的最低黏度。得到的普通方便粳米饭和超高压方便粳米饭最低黏度的差值与超高压方便粳米饭最低黏度值的比值记为最低黏度差值比。以试验方法测得20种典型粳米的最低黏度差值比在9.69%~55.84%,实验室内部重复性变异系数均不大于5.72%。由此表明,试验建立的方法准确、可靠,可有效鉴别超高压方便粳米饭。

In order to establish the identification method of ultra-high pressure convenient japonica rice,the proportion of absolute difference of minimum viscosity was introduced and verified by the test of 20 typical japonica rice.The results showed that the best sampling process of rice was that:Take 220.0 g of ultra-high pressure and ordinary convenient japonica rice after 30 d of preparation and poured into beakers,diluted by 3 times,homogenized for 3 min at 12000 r/min withΦ18 cutter head;Take 100.0 g of the above homogenate,and useΦ10 cutter head to treat them for 1 min at 12000 r/min,which was the sample to be tested.The minimum viscosity was determined by using the viscosity tester according to the heating procedure(30-95℃,10 min;95-95℃,5 min;95-30℃,10 min;30-30℃,5 min),and the sampling interval was 1 s.The ratio between the difference of the lowest viscosity of the ordinary convenient rice and the ultra-high pressure convenient rice and the lowest viscosity of the ultra-high pressure convenient rice was denoted as the proportion of absolute difference of minimum viscosity.The proportion of absolute difference of minimum viscosity of 20 typical japonica rice measured was 9.69%-55.84%by this method,and the coefficient of repeatability in the laboratory was no more than 5.72%.The results showed that the new method was accurate and reliable,and could effectively identify ultra-high pressure convenient japonica rice.