Effect of storage temperature on fungal growth and aflatoxin formation in oils extracted from wild almond nuts

Abstract

The current research was performed to assess the fungal contamination in oils extracted from wild almonds (Alok) during 60 days of storage. To assess the influence of storage temperature on fungal growth and aflatoxin production, three batches of wild almond nuts were kept at 25, 30, and 35°C for 60 days, and extracted oils from nuts were evaluated at six periods of intervals. Storage at 25°C enhanced the fungal growth more rapidly while compared with the other temperatures, mainly due to offering the optimum temperature for the fungal proliferation. The highest level of aflatoxin B1 was noted at storage at temperature 30°C despite lower fungal growth at this temperature while compared with 25°C, which can be correlated with the optimum temperature for aflatoxin B1 production by Aspergillus species. Therefore, the association between fungi and aflatoxin production was not linear, while various environmental parameters affect this correlation. Practical applications Food products contaminated by fungi may be the source of aflatoxins at various stages like harvest, storage, extraction, and process, which can cause some health issues besides enormous economic losses. In this regard, the main postharvest issue correlated with wild almond is fungal growth on the kernels of grain through storage, which can result in an additional reduction in the quality of extracted oil including nutrients and unacceptability by consumers.