Valero Ana, Farré Joan Ramón, Sanchis Vicente, Ramos Antonio J, Marín Sonia
Food Technology Department, University of Lleida, CeRTA-UTPV, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain.
Int J Food Microbiol. 2006 Jul 15;110(2):160-4. doi: 10.1016/j.ijfoodmicro.2006.04.006. Epub 2006 Jun 2.
Ochratoxin A is a well-known mycotoxin produced by species of the genera Penicillium and Aspergillus. OTA-producing species from A. section Nigri are considered the source of OTA detected in grapes, dried vine fruits and wines. Other fungi present in grapes during their maturation can grow and interact with OTA-producing Aspergillus species and affect OTA production. In this study seven fungi (Alternaria alternata, Cladosporium herbarum, Eurotium amstelodami, Trichoderma harzianum, Penicillium decumbens, P. janthinellum and Candida sp.) disolated from grapes and dried vine fruits were grown in SNM medium paired with OTA-positive A. carbonarius at two temperatures (20 and 30 degrees C) and at two water activities (0.92 and 0.97). OTA production was tested after 5, 7, 10, 14 and 18 days of incubation, at four distances (1, 2, 3 and 4 cm) from A. carbonarius inoculation point in the inter-colony axis. At 0.92 a(w) OTA production was almost negligible. At 0.97 a(w) and 30 degrees C OTA accumulation was reduced when A. carbonarius was grown in paired cultures, particularly with A. alternata, C. herbarum, P. decumbens and P. janthinellum. At 0.97 a(w) and 20 degrees C, there was no clear effect of the interacting species on OTA accumulation; in general E. amstelodami and Candida sp. seemed to stimulate OTA production, whereas T. harzianum and P. decumbens reduced it. Competing mycoflora acted as an additional control factor against OTA accumulation at 30 degrees C; but at 20 degrees C, where OTA production is optimal, this did not happen. Thus maintaining the temperature of grapes at or above 30 degrees C during dehydration may provide some control against OTA accumulation in grapes.
赭曲霉毒素A是一种由青霉属和曲霉属物种产生的著名霉菌毒素。来自曲霉属黑曲霉组的产OTA物种被认为是在葡萄、葡萄干和葡萄酒中检测到的OTA的来源。葡萄成熟过程中存在的其他真菌可以生长并与产OTA的曲霉属物种相互作用，影响OTA的产生。在本研究中，从葡萄和葡萄干中分离出的七种真菌（链格孢、草本枝孢、阿姆斯特丹散囊菌、哈茨木霉、斜卧青霉、淡紫青霉和念珠菌属）在SNM培养基中与OTA阳性的黑曲霉配对培养，培养温度为20和30摄氏度，水分活度为0.92和0.97。在培养5、7、10、14和18天后，在菌落间轴上距黑曲霉接种点四个距离（1、2、3和4厘米）处检测OTA的产生。在水分活度0.92时，OTA的产生几乎可以忽略不计。在水分活度0.97和30摄氏度时，当黑曲霉在配对培养物中生长时，OTA的积累会减少，特别是与链格孢、草本枝孢、斜卧青霉和淡紫青霉配对时。在水分活度0.97和20摄氏度时，相互作用的物种对OTA积累没有明显影响；一般来说，阿姆斯特丹散囊菌和念珠菌属似乎会刺激OTA的产生，而哈茨木霉和斜卧青霉则会降低OTA的产生。竞争性真菌群落作为30摄氏度下OTA积累的额外控制因素；但在20摄氏度时，OTA产生最佳，情况并非如此。因此，在脱水过程中将葡萄温度保持在30摄氏度或以上可能有助于控制葡萄中OTA的积累。
