Prevention of ochratoxin a production by using food grade antioxidants

Abstract

Ochratoxin A (OTA) is the second mycotoxin, followed by aflatoxins, of significance in several agricultural products. During the last decades, OTA has been receiving considerable attention worldwide because of its nephrotoxic, immunotoxic, teratogenic and carcinogenic effects on animals. This toxin was included in the group 2B by the International Agency for Research on Cancer (IARC) since it is a potential carcinogen for humans. Penicillium verrucosum is the main OTA-producing species in temperate and cold climates, and A. ochraceus and related species in warm and tropical climates. Due to their physiological differences, each of these species occupies a specific ecological niche. Recently, several studies reported on the presence of potential OTA-producing Aspergillus section Nigri species in food and feeds. Aspergillus carbonarius is considered to be the main producer of OTA, followed by species belonging to the A. niger aggregate. The presence of this toxin has been extensively reported worldwide in several products such as coffee, wines, beers, grapes, dried grapes, cereals and derivatives destined for humans and animals, oilseeds and derived products and, occasionally, in body fluids, plasm, meat and kidneys of several animal species. One strategy to reduce the entry of mycotoxins into the food chain is the use of chemical treatments during the storage of cereals, grains and oilseeds to reduce fungal growth and production of toxins. From a human health perspective, the use of antioxidants such as butylated-hydroxyanisole (BHA), propyl paraben (PP) and butylatedhydroxytoluene (BHT) are allowed by the US Food and Drug Administration (FDA) as antimicrobial agents. Such compounds are regarded as safe (GRAS) chemicals. The last known studies have shown that these antioxidants have a protective action in food since they could maintain its organoleptic properties. This chapter reviews data showing that treatments with food grade antioxidants significantly influence growth parameters, enzymes production and OTA production of ocratoxigenic strains. In addition, the incubation time, temperature, water activity and their interactions are also important factors involved in the development of these fungal species and in the accumulation of toxins.