Prevalence of Aflatoxins in Selected Dry Fruits, Impact of Storage Conditions on Contamination Levels and Associated Health Risks on Pakistani Consumers

Abstract

Dry fruits and nuts are nutritious foods with several health-promoting properties. However, they are prone to contamination with aflatoxins at all stages of production and storage. The present study aimed to determine the natural occurrence of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), and total aflatoxins (AFT) in dates, pistachios, and walnuts collected from four districts of South Punjab (Pakistan), and to assess the associated health risks as estimated by dietary exposure and the Margin of Exposure (MoE) determinations. The contents of AFB1 and AFT in these food products were monitored during storage under three different conditions (open-air, hermetically closed jars, and refrigeration at 4 °C) to determine the most efficient conditions in preventing aflatoxin accumulation. HPLC-fluorescence analysis of 60 samples of these products for aflatoxin contamination showed that 52 (86.7%) samples were contaminated at different levels, with a maximum of 24.2 ng/g. The overall (all samples) mean concentrations of AFB1, AFB2, AFG1, AFG2, and AFT were 3.39 ± 2.96, 1.39 ± 1.68, 1.63 ± 1.48. 1.12 ± 1.23, and 7.54 ± 6.68, respectively. The Estimated Daily Intake (EDI) and MoE of aflatoxins through the consumption of the products ranged from 0.06 ng/kg bw/day to 2.0 ng/kg bw/day and from 84.84 to 2857.13, respectively, indicating that consumers are at high health risk. Significant differences were recorded between aflatoxin levels in the samples stored under different storage conditions, with storage under refrigeration (4 °C) being the most effective in controlling aflatoxin accumulation, although storage in closed jars was also efficient and offers a more flexible alternative to retailers. The findings of the study urge official authorities of Pakistan to implement appropriate regulatory and control measures and surveillance program to alleviate the potential public health risks associated with the consumption of dry fruits and nuts in the scope of their increased consumption.

A high‐performance method for quantitation of aflatoxins B1, B2, G1, G2: Full validation for raisin, peanut matrices, and survey of related products at Ho Chi Minh City

“…In addition, the carbohydrate‐rich raisins can be coated to prevent water from entering, and the semi‐closed storage method creates an oxygen‐poor, carbon dioxide‐rich environment. Such conditions are unfavorable for the growth and production of AF by strictly aerobic AF molds (Naeem et al, 2022 ).…”

Evaluation of ELISA and immunoaffinity fluorometric analytical tools of four mycotoxins in various food categories

“…Our results showed that nuts (oily seeds), spices, chili, and dried fruits were highly contaminated with total AFs highlighting the need for comprehensive monitoring and control strategies. Previous studies revealed how storage conditions affected AF levels in dried fruits, nuts (oily seeds) spices (Naeem et al 2022 ; Obonyo and Salano 2018 ; Duman 2010 ). The efficiency of storage circumstances in regulating the levels of AFs was in the following order: cold storage > hermetic storage in a glass jar > open-air storage (Naeem et al 2022 ; Duman 2010 ).…”

“…Previous studies revealed how storage conditions affected AF levels in dried fruits, nuts (oily seeds) spices (Naeem et al 2022 ; Obonyo and Salano 2018 ; Duman 2010 ). The efficiency of storage circumstances in regulating the levels of AFs was in the following order: cold storage > hermetic storage in a glass jar > open-air storage (Naeem et al 2022 ; Duman 2010 ). The hermetically sealed, waterproofed structure creates an interior-modified environment that is rich in carbon dioxide and deficient in oxygen because of the respiration of the biotic components of the stored food product.…”

“…The hermetically sealed, waterproofed structure creates an interior-modified environment that is rich in carbon dioxide and deficient in oxygen because of the respiration of the biotic components of the stored food product. Purely aerobic aflatoxigenic molds cannot grow or produce aflatoxin under such circumstances (Naeem et al 2022 ). Local shops frequently store nuts and dried fruits in bulk open-air storage, which could lead to higher levels of AF contamination before they are sold.…”

Occurrence, identification, and decontamination of potential mycotoxins in fruits and fruit by‐products

“…Certainly, dry fruits like dates, pistachios, and walnuts are more prone to AFB1, AFB2, AFG1, and AFG2 contamination at all stages, from harvest to marketing. However, a recent study reported that the margin of exposure determinations of the dry fruits stored at 4°C and closed glass containers curtailed the growth of the mycotoxigenic mold in South Punjab, Pakistan (Naeem et al., 2022). In a similar study, the AFs content in pekmez was analyzed to be 7.5 μg/kg of AFB1, 1.5 μg/kg of AFB2, G1 (AFG1), and G2 (AFG2), however after clarification, the levels decreased by 60.4, 76.7, 76.3, and 86.7%, respectively (Heshmati et al., 2019).…”