主要粮食品种储藏期间霉菌活动特性研究

研究了稻谷、玉米和小麦在25℃,相对湿度分别为75%、85%和95%储藏,以及在高于安全水分2%的相似水活度条件下储藏期间霉菌的活动特性.结果表明,小麦最易出现霉菌生长活动,稻谷的抗霉菌生长作用最强,玉米介于小麦和稻谷之间;其中85%相对湿度下储藏至28 d,小麦的微生物活性值升高了475 u,分别是稻谷和玉米同期升高值的5.6和3.5倍.储粮中霉菌活动特性的不同表现与各粮种的吸湿性能及粮粒外皮(颖壳或种皮)的霉菌可生长性差异有关,但将相同霉菌活动强度的储粮样品作相关品质指标的检测,发现小麦的黏度、发芽率变化不明显,而玉米和稻谷的脂肪酸值和发芽率则有较大的变化.因此,对于储藏品质较稳定但易滋长霉菌的小麦应该重点关注霉菌活动的状况,仅仅监测品质指标变化难以准确判断储藏的安全性和粮食相关的食品安全性.

Mould Development Characters of Different Stored Grains

The characters for mould development of paddy, corn and wheat, stored at 25℃ and RH 75%, 85% or 95%, or with excess moisture of 2% over safe moisture, were investigated. Results: Wheat occurs mould development most easy; paddy exhibits best anti - mould growing ability ; and corn exhibits at the middle between wheat and paddy. Stored in RH 85% for 28d, the microbe activity of wheat increases by 475 u that is 5.6 times and 3.5 times higher than those of paddy and corn in the same period. The differences are found to be related with the hygroscopic character of the grain and the usable property for mould of the grain coat On the other hand, comparing the grains in the same mould activity status, it is found that the fatty acid value and germination percentage change remarkably for paddy and corn, but not evidently for wheat. Therefore, attention should be emphasized on mould de-velopment for stored wheat with easy growing character for mould, in order to insure the quality of stored wheat and the related food safety.