Antifungal Microbial Agents for Food Biopreservation—A Review

Abstract

Food spoilage is a major issue for the food industry, leading to food waste, substantial economic losses for manufacturers and consumers, and a negative impact on brand names. Among causes, fungal contamination can be encountered at various stages of the food chain (e.g., post-harvest, during processing or storage). Fungal development leads to food sensory defects varying from visual deterioration to noticeable odor, flavor, or texture changes but can also have negative health impacts via mycotoxin production by some molds. In order to avoid microbial spoilage and thus extend product shelf life, different treatments—including fungicides and chemical preservatives—are used. In parallel, public authorities encourage the food industry to limit the use of these chemical compounds and develop natural methods for food preservation. This is accompanied by a strong societal demand for ‘clean label’ food products, as consumers are looking for more natural, less severely processed and safer products. In this context, microbial agents corresponding to bioprotective cultures, fermentates, culture-free supernatant or purified molecules, exhibiting antifungal activities represent a growing interest as an alternative to chemical preservation. This review presents the main fungal spoilers encountered in food products, the antifungal microorganisms tested for food bioprotection, and their mechanisms of action. A focus is made in particular on the recent in situ studies and the constraints associated with the use of antifungal microbial agents for food biopreservation.

Use of Autochthonous Yeasts and Bacteria in Order to Control Brettanomyces bruxellensis in Wine

“…Autolyzed yeast can affect both the Brettanomyces cell population and volatile phenols' production, as reported in other studies [45]. In particular, the yeast cell wall affected the quantity of ethylphenols during winemaking, probably because of the adsorption of the phenolic compounds by the cell wall fragments [45,46].…”

“…Biocontrol strategies for the limitation of spoilage microorganisms, pathogens and microbial producers of compounds toxic for human health represent a keystone toward the goal of sustainable food systems [45,46]. B. bruxellensis is the main spoilage yeast in winemaking, detrimental for wine quality and mainly responsible for volatile phenols release, but also of biogenic amine bioproducts and responsible for considerable economic losses [20,47,48].…”

Lactic Acid Bacteria as Antifungal and Anti‐Mycotoxigenic Agents: A Comprehensive Review

“…Chemical preservatives such as calcium propionate, potassium sorbate, and sulfur dioxide are usually added to food to avoid spoilage caused by yeasts and molds. The addition of these preservatives is helpful to some extent, but the use of these is contradictory to the aim of developing "clean label" food products that do not contain any synthetic chemical preservatives (Salas et al, 2017). Some other methods to remove or detoxify mycotoxins in food and feed include both physical (the use of heat, ionizing radiations, and ultraviolet light) and chemical methods (the use of acids or alkaline based chemicals and miscellaneous reagents, including hydrolytic, chlorinating, oxidizing, or reducing agents; James & Zikankuba, 2018;Karlovsky et al, 2016).…”

The most heat‐resistant conidia observed to date are formed by distinct strains of Paecilomyces variotii

“…In general, industry prevents fungal food spoilage in their products by using preservation hurdles like pasteurization, lowering water activity, lowering pH or decrease storage temperature. Consumer demands towards more natural and preservative free food put a pressure on shelf life of food (Leyva Salas et al ., ). For instance, lowering heat treatments could lead to more beneficial organoleptic characteristics of the product and better retainment of vitamins or other temperature‐sensitive healthy components.…”