Aflatoxins in selected Thai commodities

Abstract

Aflatoxin (AF) B1, B2, G1 and G2 were determined in 120 samples of selected Thai commodities including unpolished rice, unpolished glutinous rice, chilli powder, whole dried chilli pods and raw peanut. The mean concentrations of the total AFs for analysed samples were 0.16, 25.43, 14.18, 6.62 and 1.43 µg kg(-1) with positive incidences of 4%, 20%, 97%, 37% and 30%, respectively. Quantitative analysis was performed using HPLC equipped with post-column derivatisation and fluorescence detection. Sample clean-up was carried out using immunoaffinity columns for selective enrichment of AFs. The method was validated by using certified reference material, which showed recoveries over 85%. The limit of detections (LODs) and limit of quantifications (LOQs) were in a range between 0.01-0.11 µg kg(-1) and 0.03-0.38 µg kg(-1), respectively. The results clearly demonstrated that AFs were detectable in different matrices. Chilli powder was found to have the highest level of AFs contamination followed by chilli pods, peanut and rice, respectively. However, among the selected commodities, unpolished rice contained only trace levels of AFB1 and AFB2. With regard to the fact that AFs are a natural contaminant in commodities, this report calls to attention the regular monitoring and effective control of food commodities to prevent health hazards.

Occurrence of Penicillium brocae and Penicillium citreonigrum, which Produce a Mutagenic Metabolite and a Mycotoxin Citreoviridin, Respectively, in Selected Commercially Available Rice Grains in Thailand

“…Anti-fungal chemicals, dichloran and rose bengal were inactive in depressing the growth of these fungi in the sample. Aflatoxin contamination in Thai commodities has been reported by several studies [2,8]. In this study, we also detected AFB 1 in a sample of Luem phua rice in the Pathum Thani region, close to Bangkok.…”

“…In Thailand, the major mycotoxins associated with cancer risk found in market commodities are aflatoxin (AF) B 1 and other aflatoxins [1]. AFB 1 is a strong class I carcinogen according to the International Agency for Research on Cancer, and several studies have reported rice contaminated with AFB 1 and other aflatoxins among Thai commodities [2,3,4]. In the postharvest condition, harvested rice grains may be damaged in several ways, such as fungal invasion, mycotoxin contamination, physicochemical changes, and insect activity.…”

Determination of Aflatoxin B1 in Feedstuffs without Clean-Up Step by High-Performance Liquid Chromatography

“…Nevertheless, fluorescent detection sensitivity of AFB 1 requires a conversion to more highly fluorescent derivatives (AFB 2a ). Several derivatization methods are available, including precolumn treatment with trifluoroacetic acid or postcolumn derivatization with pyridinium hydrobromide [ 2 , 17 ]. With an existence instrument, the method used the precolumn derivatization throughout the quantitative determinations.…”

Occurrence of aflatoxins in processed chili pepper sold in Myanmar

“…In previous studies in other countries, high prevalence of natural contamination of CP with AFB 1 was reported. For example, 77% in Sri Lankan CP 12) , 100% (10 out of 10) in Iranian red pepper 13) , and 96.7% (29 out of 30) in Thailand CP 14) . In most cases, besides AFB 1 , AFB 2 was sometimes simultaneously detected, while AFG 1 nor AFG 2 was not detected, as in the case of this study.…”