Aziz Nagy H, el-Zeany Samia A, Moussa Lotfy A A
National Center for Radiation Research and Technology, Microbiology Department, P.O. Box 29, Nasr City, Cairo, Egypt.
Nahrung. 2002 Oct;46(5):327-31. doi: 10.1002/1521-3803(20020901)46:5<327::AID-FOOD327>3.0.CO;2-7.
The effect of gamma-irradiation and maize lipids on aflatoxin B1 production by Aspergillus flavus artificially inoculated into sterilized maize at reduced water activity (aw 0.84) was investigated. By increasing the irradiation doses the total viable population of A. flavus decreased and the fungus was completely inhibited at 3.0 kGy. The amounts of aflatoxin B1 were enhanced at irradiation dose levels 1.0 and 1.5 kGy in both full-fat maize (FM) and defatted maize (DM) media and no aflatoxin B1 production at 3.0 kGy gamma-irradiation over 45 days of storage was observed. The level in free lipids of FM decreased gradually, whereas free fatty acid values and fungal lipase activity increased markedly by increasing the storage periods. The free fatty acid values decreased by increasing the irradiation dose levels and there was a significant enhancement of fungal lipase activity at doses of 1.0 and 1.50 kGy. The ability of A. flavus to grow at aw 0.84 and produce aflatoxin B1 is related to the lipid composition of maize. The enhancement of aflatoxin B1 at low doses was correlated to the enhancement of fungal lipase activity.
研究了γ射线辐照和玉米脂质对在水分活度降低（aw 0.84）的灭菌玉米中人工接种黄曲霉产生黄曲霉毒素B1的影响。随着辐照剂量的增加，黄曲霉的总活菌数减少，在3.0 kGy时真菌被完全抑制。在全脂玉米（FM）和脱脂玉米（DM）培养基中，1.0和1.5 kGy的辐照剂量水平下黄曲霉毒素B1的量增加，在3.0 kGy γ射线辐照下储存45天未观察到黄曲霉毒素B1的产生。FM中游离脂质水平逐渐降低，而随着储存时间的增加，游离脂肪酸值和真菌脂肪酶活性显著增加。随着辐照剂量水平的增加，游离脂肪酸值降低，在1.0和1.50 kGy剂量下真菌脂肪酶活性显著增强。黄曲霉在aw 0.84下生长并产生黄曲霉毒素B1的能力与玉米的脂质组成有关。低剂量下黄曲霉毒素B1的增加与真菌脂肪酶活性的增强相关。
