SEASONAL AND GEOGRAPHICAL ANALYSIS OF AFLATOXINS IN DIFFERENT VARIETIES OF BROWN RICE COLLECTED FROM TWO DISTRICTS OF PUNJAB-PAKISTAN

M. Kashif¹, M. Riaz^*1, S. Akhtar¹, K. Muaz¹, H. Nadeem², S. W. Ali^3, A. Ismail¹,

¹Faculty of Food Science and Nutrition, Bahauddin Zakariya University, Multan, Pakistan.

²Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan.

³Department of Food Science and Technology, Faculty of Agriculture, University of Punjab, Lahore, Pakistan.

^*Corresponding Author Email: riaz@bzu.edu.pk

ABSTRACT

Aflatoxins are highly toxic, carcinogenic compounds, widely prevalent worldwide, secreted by various fungal strains especially from genus Aspergillus including Aspergillus parasiticus and Aspergillus flavus. Brown rice having more than 17% moisture contents is considered as favorable substrates for fungal growth causing aflatoxins production. The objective of current study was to examine seasonal and geographical impact on production of aflatoxins including aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), aflatoxin G₁ (AFG₁) and aflatoxin G₂ (AFG₂) in different brown rice varieties procured from two districts of Punjab. High Performance Liquid Chromatography (HPLC) equipped with fluorescence detector was used to detect aflatoxins in samples including Super Kernel Basmati Rice (SK), Kainat (KN), and Supri (SP). Among aflatoxins, AFB₁ was the most common toxin detected in three varieties of brown rice especially in SK. AFG₁ and AFG₂ in the present study were not detected. A total of 200 samples were taken out of which 125 samples were positive. Among 125 samples, 100(80%) samples had greater AFB₁ content than permissible limit (2 µg/kg). In addition, 94(75%) samples had higher total aflatoxin contents than allowable limit (4 µg/kg). Aflatoxins contents in brown rice were dependent on rice varieties, regions, and months. The highest moisture and aflatoxins contents were observed in SK in the month of March collected from Gujranwala and lowest were observed in SP in the month of May collected from Multan. The seasonal comparison for aflatoxins concentrations in brown rice showed higher aflatoxins levels in the samples collected during the month of March than those procured in other months (November, January and May). Furthermore, a strong correlation between moisture contents and aflatoxins was also observed. The results of current study revealed that moisture management during storage is very significant to control aflatoxins production in brown rice varieties.