Effect of γ-radiation on the production of aflatoxin B1 by Aspergillus parasiticus in raisins (Vitis vinifera L.)

Current and promising strategies to prevent and reduce aflatoxin contamination in grains and food matrices

Mycotoxins are secondary metabolites produced by filamentous fungi that colonise various crops around the world and cause major damage to the agro-industrial sector on a global scale. Considering the estimative of population growth in the next decades, it is of fundamental importance the implementation of practices that help prevent the economics and social impacts of aflatoxin contamination. Even though various approaches have been developed – including physical, chemical and biological approaches – there is not yet one that strikes a balance in terms of safety, food quality and cost, especially when considering large scale application. In this review, we present a compilation of advantages and disadvantages of different strategies for prevention and reduction of aflatoxin contamination. Biological approaches represent the trend in innovations mainly due to their specificity and versatility, since it is possible to consider the utilisation of whole microorganisms, culture supernatants, purified enzymes or even genetic engineering. However, challenges related to improvement of the efficiency of such methods and ensuring safety of treated foods still need to be overcome.

Aspergillus flavus and Aspergillus ochraceus inhibition and reduction of aflatoxins and ochratoxin A in maize by irradiation

Grains are susceptible to contamination by molds; some cause spoilage and others produce certain mycotoxins that cause a serious health threat to humans and animals. Aspergillus flavus and Aspergillus ochraceus and their mycotoxins, aflatoxins and ochratoxin A, are natural contaminants of various agricultural commodities. Control of these molds and their mycotoxins in food commodities is of utmost importance; therefore, the target of this research was to explore the effects of gamma irradiation doses on the growth of A. flavus and A. ochraceus in artificially inoculated yellow maize as well as on the production of aflatoxin B1, ochratoxin A, and the formation of toxins in maize. The irradiated dose of 6.0 kGy was found to completely inhibit the growth of the two molds, while a dose of 4.5 kGy reduced the production of their mycotoxins. Maximum degradation of the formed aflatoxins and ochratoxin A in maize occurred at 20 kGy, with best reduction rates of 40.1%, 33.3%, and 61.1% observed for aflatoxin B1, aflatoxin B2, and ochratoxin A, respectively. We recommend grains irradiation by gamma radiation at 6.0 kGy to decontaminate mycotoxin-producing molds before they produce mycotoxins. The study represents a proactive, efficient, and potent method for avoiding potential contamination of fungus during grains storage and transfer for one to two months.

Effective pretreatment technologies for fresh foods aimed for use in central kitchen processing

The central kitchen concept is a new trend in the food industry, where centralized preparation and processing of fresh foods and the distribution of finished or semi-finished products to catering chains or related units take place. Fresh foods processed by a central kitchen mainly include fruit and vegetables, meat, aquatic products, and edible fungi; these foods have high water activities and thermal sensitivities and must be processed with care. Appropriate pretreatments are generally required for these food materials; typical pretreatment processes include cleaning, enzyme inactivation, and disinfection, as well as packaging and coating. To improve the working efficiency of a central kitchen, novel efficient pretreatment technologies are needed. This article systematically reviews various high-efficiency pretreatment technologies for fresh foods. These include ultrasonic cleaning technologies, physical-field enzyme inactivation technologies, non-thermal disinfection technologies, and modified-atmosphere packagings and coatings. Mechanisms, applications, influencing factors, and advantages and disadvantages of these technologies, which can be used in a central kitchen, are outlined and discussed. Possible solutions to problems related to central-kitchen food processing are addressed, including low cleaning efficiency and automation feasibility, high nutrition loss, high energy consumption, and short shelf life of products. These should lead us to the next step of fresh food processing for a highly demanding modern society. © 2020 Society of Chemical Industry.

Characteristics, Occurrence, Detection and Detoxification of Aflatoxins in Foods and Feeds

Mycotoxin contamination continues to be a food safety concern globally, with the most toxic being aflatoxins. On-farm aflatoxins, during food transit or storage, directly or indirectly result in the contamination of foods, which affects the liver, immune system and reproduction after infiltration into human beings and animals. There are numerous reports on aflatoxins focusing on achieving appropriate methods for quantification, precise detection and control in order to ensure consumer safety. In 2012, the International Agency for Research on Cancer (IARC) classified aflatoxins B1, B2, G1, G2, M1 and M2 as group 1 carcinogenic substances, which are a global human health concern. Consequently, this review article addresses aflatoxin chemical properties and biosynthetic processes; aflatoxin contamination in foods and feeds; health effects in human beings and animals due to aflatoxin exposure, as well as aflatoxin detection and detoxification methods.

Assorted Methods for Decontamination of Aflatoxin M1 in Milk Using Microbial Adsorbents

Aflatoxins (AF) are carcinogenic metabolites produced by different species of Aspergillus which readily colonize crops. AFM1 is secreted in the milk of lactating mammals through the ingestion of feedstuffs contaminated by aflatoxin B1 (AFB1). Therefore, its presence in milk, even in small amounts, presents a real concern for dairy industries and consumers of dairy products. Different strategies can lead to the reduction of AFM1 contamination levels in milk. They include adopting good agricultural practices, decreasing the AFB1 contamination of animal feeds, or using diverse types of adsorbent materials. One of the most effective types of adsorbents used for AFM1 decontamination are those of microbial origin. This review discusses current issues about AFM1 decontamination methods. These methods are based on the use of different bio-adsorbent agents such as bacteria and yeasts to complex AFM1 in milk. Moreover, this review answers some of the raised concerns about the binding stability of the formed AFM1-microbial complex. Thus, the efficiency of the decontamination methods was addressed, and plausible experimental variants were discussed.

Innovative technologies to manage aflatoxins in foods and feeds and the profitability of application - A review

Aflatoxins are mainly produced by certain strains of Aspergillus flavus, which are found in diverse agricultural crops. In many lower-income countries, aflatoxins pose serious public health issues since the occurrence of these toxins can be considerably common and even extreme. Aflatoxins can negatively affect health of livestock and poultry due to contaminated feeds. Additionally, they significantly limit the development of international trade as a result of strict regulation in high-value markets. Due to their high stability, aflatoxins are not only a problem during cropping, but also during storage, transport, processing, and handling steps. Consequently, innovative evidence-based technologies are urgently required to minimize aflatoxin exposure. Thus far, biological control has been developed as the most innovative potential technology of controlling aflatoxin contamination in crops, which uses competitive exclusion of toxigenic strains by non-toxigenic ones. This technology is commercially applied in groundnuts maize, cottonseed, and pistachios during pre-harvest stages. Some other effective technologies such as irradiation, ozone fumigation, chemical and biological control agents, and improved packaging materials can also minimize post-harvest aflatoxins contamination in agricultural products. However, integrated adoption of these pre- and post-harvest technologies is still required for sustainable solutions to reduce aflatoxins contamination, which enhances food security, alleviates malnutrition, and strengthens economic sustainability.