Efficacy of different hermetic bag storage technologies against insect pests and aflatoxin incidence in stored maize grain

Comparative utility of hermetic and conventional grain storage bags for smallholder farmers: a meta-analysis

Postharvest management is critical to attaining household food, nutrition, and income security. Hermetic grain storage bags offer an effective pesticide-free way to protect stored grain against fungal and insect infestation. We evaluated articles indexed in the Web of Science that included experiments comparing the storage efficacy of conventional and hermetic storage bags based on grain germination rate, insect infestation, physical damage, mycotoxin contamination, and changes in weight and moisture content. Compared with grain stored in hermetic bags, grain stored in conventional bags lost 3.6-fold more seed viability, contained 42-fold more insects, had 11-fold more physical damage, and lost 23-fold more grain weight, while grain moisture levels were similar for both hermetic and conventional storage bags. Mycotoxin contamination levels were not as frequently assessed. Levels could be low in grain stored in both types of bags, or levels could be low in hermetic bags and significantly higher in conventional bags. The improved properties of grain stored in hermetic bags can increase food security and household income by providing safe storage options for maintaining seed germinability, and for consumption and/or sale when food supplies are high, or when prices are low. Hermetic bags are economically feasible for use by subsistence farmers in Sub-Saharan Africa for grain for household consumption and for carrying-over seed for planting in the next season. Additional studies are needed to verify the mycotoxin contamination results and to determine if there are differences in functional food characteristics, e.g. flavor and cooking properties, that have not been as comprehensively studied. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Food aflatoxin exposure assessment in Sichuan Province, China

Aflatoxins (AFs) are frequent contaminants in crops worldwide and can cause adverse health effects in exposed humans. Since foods AFs (AFB₁, AFB₂, AFG₁, AFG₂) contamination in Sichuan Province are unexplored, we conducted a study to assess AFs exposure in the population. In total, 318 samples, including grains, red chilli, red chilli powder, and vegetable protein beverages, were collected from 13 cities of Sichuan Province, China, in 2022. AFs were detected in all types of foods except for wheat flour, the highest incidence was found in red chilli powder (75.0%). The concentrations of AF_tot (the total aflatoxins) ranged between ND (not detected) and 54.20 μg kg^-1. It was observed that the AFs profile was dominated by AFB₁. The AFB₁ content ranged from ND to 52.60 μg kg^-1 across food types. According to EU maximum limits (ML) of AFs, 2.8% of samples exceeded the AF_tot limits. For AFB₁, 0.4% and 4.3% of samples exceeded the China and EU limits, respectively. In this study, packaging types and sampling sites were selected as parameters influence food aflatoxin contamination. Nevertheless, there was no significant difference between different samples. According to exposure assessment and risk characterization, AF_tot daily exposure was shown to be 0.263 and 283.936 ng kg^-1 bw for the lower and upper exposure. The MOE value derived from consumption grains and red chilli pepper products were generally bellow 10 000, and liver cancer cases based on these two foods consumption could range from < 0.001 to 0.16 cases per year/10 000 persons.

Occurrence and exposure assessment of aflatoxins in Zhejiang province, China

The purpose of this study was to assess the risk of aflatoxins due to multiple food consumption among the Zhejiang population. Ultra-high-performance liquid chromatography coupled with tandem mass spectrometry method was used to determine aflatoxins in 792 samples. Aflatoxins were detected in 27.1% of the samples at levels between 0.07 and 262.63 μg kg^-1, and aflatoxins B₁ was the most frequently detected among different types of samples. 0.8% of peanut oil, 3.39% of nut products as well as 1.1% of condiments contaminated with aflatoxins B₁ exceeded China national tolerance limits. Peanut oil had the highest incidence of aflatoxin, with a range from 0.17 to 22.50 μg kg^-1. Using bags conferred limited advantages in reducing aflatoxin contents. Moreover, peanut and rice were the main contributors to dietary exposure to aflatoxins among Zhejiang residents. Finally, the margin of exposure values obtained by rice consumption were far from the safe margin of 10,000, indicating a potential risk to public health. The results pointed out the need for further prioritization of aflatoxins B₁ risk-management actions in Zhejiang.

Hermetic Bags for the Storage of Maize: Perspectives on Economics, Food Security and Greenhouse Gas Emissions in Different Sub-Saharan African Countries

During storage, cereals and legumes are vulnerable to insects, rodents, and fungi, which can cause loss of weight, damage or discoloration of products, and/or toxin formation. Hermetic bags can prevent excessive insect infestation, and toxin formation. This paper presents an analysis of the effects of hermetic bags for the storage of maize on food loss reduction by insects and on net greenhouse gas (GHG) emissions, based on practical data from field trials. Their economic feasibility, by optimizing the total income in markets with different price seasonalities in different Sub-Saharan African countries, is analyzed. The data of five field trials were combined and put in classes of 50 days of increasing storage time to get a realistic loss of produce during storage using regular bags (with or without the use of pesticides) and hermetic bags. The maize for storage trials were used as is, bought locally or used direct from the field. Scenario studies with standard storage, standard storage combined with pesticides and hermetic bag storage show significant losses by insects after 100 storage days for standard and standard with pesticides storage, whereas with hermetic bags, product losses are kept to a minimum of 2%. The economic analysis shows less clear-cut outcomes: the interventions' effectiveness depends largely on the rate of seasonal price fluctuation of the commodity. For farmers' personal consumption, when the quality is less critical, the use of hermetic bags is only more economical compared with other methods of storage for produce kept over 100 days. Since the quality of maize is well-preserved by the hermetic bag, the return on the investment is shorter when the maize is sold at the market. However, for countries with a low seasonal price gap, the investment cannot be recouped. As the use of hermetic bags is a good intervention for preventing food loss, it is best promoted not only for providing direct profits to farmers but also for health benefits, as bag use implies a lower need for pesticides and a possible reduction in aflatoxin intake.