Effect of relative humidity on biodeterioration of poultry feed and ochratoxin A production by Penicillium species

Abstract

Biodeterioration of poultry feed by fungal load due to improper storage is a major concern. The present investigation was carried out to determine the effect of relative humidity (RH) on biodeterioration of poultry feed, biochemical changes and ochratoxin A (OTA) production by Penicillium species examined during September 2009 to July 2010. All the relative humidities studied were supported 16 species of Penicillium with varying percentage of prevalence. Penicillium species produced different mycotoxins with ochratoxin A (OTA) predominating. The OTA production in feed, increased with increasing RH with increasing storage period. The feed stored under RH at 90 and 100% reached maximum OTA production 16.19 and 20.45 μg/g respectively on fourth month of storage period, while RH at 50 and 70% the amount of OTA increased gradually and reached maximum 11.37 and 14.48 μg/g respectively on sixth month of storage. The highest phenol and reducing sugar content was observed under all RH on fourth month of storage and maximum with RH at 70 and 90%, while protein, free amino acid content of feed initially decreased and increased on end of the storage period. In conclusion, relative humidity also plays a major role on biodeterioration of poultry feed and OTA production by Penicillium species.

Keywords

• poultry feed
• relative humidity
• biodeterioration
• penicillium
• ochratoxin a
• thin layer chromatography
• high performance liquid chromatography and high performance liquid thin layer chromatography