小麦粉中虫卵的快速检测技术的研究与比较

Comparison of the Rapid Methods for Detection the Insect Ovum in the Flour

为了建立一种快速检测小麦粉中昆虫虫卵的方法,比较研究了浮选法、尿酸检测法、几丁质检测法和染色法4种方法检测小麦粉中虫卵的效果及优缺点的比较。结果表明浮选法最高检出率为5.59%,不适用于虫卵检测;几丁质检测法只能证明虫卵中有几丁质,但无法定量;尿酸检测法中检测出的尿酸浓度与虫卵数成正相关,相关系数R2为0.998 6,最低检出限为0.1粒卵/g;利用溴甲酚绿和酸性品红将小麦粉染色的结果是溴甲酚绿将虫卵染成黄橙色,小麦粉染成褐绿色;酸性品红将虫卵和小麦粉都染成紫色,但小麦粉被染颜色更深。染色法虫卵检测率约为75%,初步可以用于小麦粉中虫卵的快速检测。随机取样的小麦粉检测与实际发生虫量比较发现尿酸检测法的检测率为73.3%,染色法的检测率为85%。说明了尿酸法和染色法可以初步用于小麦粉中昆虫虫卵的检测,其灵敏度和操作规范有待进一步优化和研究。

In order to establish a rapid method to detect the insect ovum content in flour, the flotation method, uric acid detection, chitin detection and the insect ovum staining have been studied for comparison to detect insect o- vum among flours. The results showed that the highest detection rate of flotation method was 5.59%, while not suit- able for detection insect ovum in flours. The chitin detection method in practice could detect insect ovum with the presence of chitin substance, but the results could not be quantified. There was a positive correlation （R2 = 0. 998 6） between uric acid concentrations and the numbers of insect ovum in the uric acid detection method. The minimum de- tection limit was 1 insect ovum/10 g （flour）. The results of staining methods by bromocresol green and acid fuehsin staining on the flours showed that bromocresol green dyed the insect ovum to be yellow -orange; dyed flour brown - green and fuchsin could be dyed both the insect ovum and flour pink. The maximum detection limit was 75% detection rate for the insect ovum in flours; the staining methods had been indicated to be used for rapid detection the insect ovum in the flour, All the results indicated that the uric acid detection method and staining method could be used as rapid detection of insect ovum in flour. The sensibility and operating rules will be further studied to optimize the condition.