Chemical Structure, Occurrence and Health Hazard Status of Ochratoxin A (OTA) in Cereal Food and Feeds of Pakistan: A Review

摘要

Ochratoxin A (OTA) is the second most important and naturally occurring mycotoxin after aflatoxin produced as a secondary metabolite by 8 kinds of Aspergillus and 6 species of Penicillium, which can contaminate a wide variety of food and feedstuffs. But it is mainly produced in cereals by moulds viz., Aspergillus ochraceus, A. carbonarius and Penicillium verrucosum. There are more than 19 natural and synthetic ochratoxins, the most common and naturally occurring one is OTA. It could be determined by various analytical techniques. However, biochemical method by using aptamers (synthetic bioreceptors) has gained more attention in affinity based assays. OTA being nephrotoxic, carcinogenic (Group 2B), tetratogenic, hepatotoxic and immuno-suppressive imparts several human and animal health problems. It causes a disease known as ochratoxicosis. The main controlling factors which affect the distribution and growth of OTA producing fungi during farming, harvesting, and storage (conditions and periods) of cereal food and feeds are moisture, temperature, medium composition, and the time a product kept under adverse climatic conditions. Results based on the status of OTA contamination in cereals in general and corn and rice food and feed in particular is alarming in Pakistan. Most of the analyzed cereal food in general and feed samples in particular are exceeding the acceptable or permissible limit (5ppb) as proposed by European Union (EU) regulatory commission, and other renowned food and feed monitoring agencies in the world. In the light ofpublished reports, it is suggested that proper harvesting, storage of feed be done and unhygienic method of processing and production be avoided, and there must be also a regular monitoring system to check the health hazard status of OTA of agricultural commodities in general, and cereal food and feeds in particular.