Yeast cells as adsorbing tools to remove ochratoxin A in a model wine

Monitoring of mycotoxins and pesticides in winemaking

This study monitored concentrations of both pesticides 2,4-dichlorophenoxyacetic acid (2,4-D) and procymidone, and mycotoxin ochratoxin A (OTA) in stages of the winemaking process. Sampling was carried out in the usual vinification process of red wine in a winery between the steps to obtain must and alcoholic fermentation. The highest transference of contaminants in the process occurred in the crushing step to 2,4-D (100%) and maceration to OTA and procymidone (100%). Removal of contaminants in the winemaking process corresponded to 100%, with a half-life (T1/2) longer for procymidone (216.5 h) and shorter for 2,4-D (38.5 h) and OTA (96 h). The processing factors (PFs) (0) for the contaminants, together with the data obtained, characterize winemaking as a process of reducing mycotoxin and pesticides. Results highlight the importance of fermentation to reduce contaminants and that yeasts promote detoxification

Unveiling ochratoxin a controlling and biodetoxification molecular mechanisms: Opportunities to secure foodstuffs from OTA contamination

Anarchic growth of ochratoxin A (OTA) producing fungi during crop production, prolonged storage, and processing results in OTA contamination in foodstuffs. OTA in food exacerbates the risk of health and economic problems for consumers and farmers worldwide. Although the toxic effects of OTA on human health have not been well established, comprehensive preventive and remedial measures will be essential to eliminate OTA from foodstuffs. Strict regulations, controlling OTA at pre- or post-harvest stage, and decontamination of OTA have been adopted to prevent human and animal OTA exposure. Biological control of OTA and bio-decontamination are the most promising strategies due to their safety, specificity and nutritional value. This review addresses the current understanding of OTA biodegradation mechanisms and recent developments in OTA control and bio-decontamination strategies. Additionally, this review analyses the strength and weaknesses of different OTA control methods and the contemporary approaches to enhance the efficiency of biocontrol agents. Overall, this review will support the implementation of new strategies to effectively control OTA in food sectors. Further studies on efficacy-related issues, production issues and cost-effectiveness of OTA biocontrol are to be carried out to improve the knowledge, develop improved delivery technologies and safeguard the durability of OTA biocontrol approaches.

Exposure assessment and risk-based limit levels evaluation of ochratoxin A in Astragali Radix in China

Ochratoxin A (OTA) is a mycotoxin found in a variety of foods and herbal medicines, and several governmental bodies around the world have set maximum allowable levels of OTA in different foods and herbal medicines. This study aims to evaluate the health risk of OTA in Astragali Radix (AR) in China, and to evaluate the effects of different limit levels on the risk control of OTA in AR. The concentrations of OTA in 187 samples of AR were investigated, and 61 (32.6%) samples were positive. The mean, 50th and 95th percentile values of OTA in positive samples were 56.2, 5.1 and 304.5 μg/kg, respectively. A margin of exposure (MOE) approach was applied to assess the risk. Considering other food sources, long-term consumers have a relatively high risk of OTA exposure due to the ingestion of AR. Theoretical limit levels of OTA in AR were evaluated from two dimensions by weighing the costs and the benefits. The results indicated that the limit levels that might be applied to the management of OTA contamination in AR in China could be screened out through risk-based evaluation of limit levels.

Reduction the contamination of patulin during the brewing of apple cider and its characteristics

Patulin is one of the most significant food safety problems in fruit and derived products. The reduction of patulin contamination in food processing has always been the focus of research. In this study, nine yeast strains were applied for the brewing of apple cider and the fate of patulin was determined. In this process, the patulin contamination can be decreased by adsorption onto and degradation of yeast cells in the main fermentation (20.8-49.1%), as well as the adsorption removal during clarification (18.7-58%), inverted cans (21.3-31.4%) and aging (1.0-5.8%). Saccharomyces cerevisiae (1027) was selected to reveal the elimination mechanism of patulin in main fermentation. The decrease of patulin content was mainly due to degradation and the intracellular enzymes played a more important role than extracellular ones. In addition, the synthesis of enzymes was related to the induction of patulin. Furthermore, the degradation product of patulin in the main fermentation was identified as E-ascladiol, which is less toxic than patulin. Based on the representative strain of S. cerevisiae 1027, patulin contamination can be effectively eliminated during apple cider brewing. This study provides a new insight into eliminating patulin contamination in the brewing of apple cider.

Bio-control on the contamination of Ochratoxin A in food: Current research and future prospects

Ochratoxin A (OTA) is a secondary metabolite of several fungi and widely exists in various species of foods. The establishment of effective methods for OTA reduction is a key measure to ensure food processing and human health. This article reviews the current research of OTA reduction by biological approaches, summarizes the characteristics and efficiency of them, and evaluates the transformation pathways and metabolites safety of each degradation technology. The shortcomings of various methods are pointed out and future prospects are also proposed. Biological methods are the most promising approaches for OTA control. The defect of them is the long processing time and the growth of microbial cells may affect the product quality. Therefore, the control of OTA contamination should be conducted according to the food processing and their product types. Besides, it is significant for the exploitation of new strains, enzyme and novel adsorbents.

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The application of physical and chemical methods has been restricted.

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Existing biological methods can effectively detoxify OTA.

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OTA reduction systems should be established for different food.

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The exploitation of novel equipment, enzyme and adsorbents is essential.

Microbiological Decontamination of Mycotoxins: Opportunities and Limitations

The contamination of food and feeds with mycotoxins poses a global health risk to humans and animals, with major economic consequences. Good agricultural and manufacturing practices can help control mycotoxin contamination. Since these actions are not always effective, several methods of decontamination have also been developed, including physical, chemical, and biological methods. Biological decontamination using microorganisms has revealed new opportunities. However, these biological methods require legal regulations and more research before they can be used in food production. Currently, only selected biological methods are acceptable for the decontamination of feed. This review discusses the literature on the use of microorganisms to remove mycotoxins and presents their possible mechanisms of action. Special attention is given to Saccharomyces cerevisiae yeast and lactic acid bacteria, and the use of yeast cell wall derivatives.

Characterization, mechanism of cypermethrin biosorption by Saccharomyces cerevisiae strains YS81 and HP and removal of cypermethrin from apple and cucumber juices by inactive cells

Cypermethrin is a common food contaminant and environmental pollutant that cause health threats to animals and humans. In this study, the characterization, mechanism, and application of cypermethrin removal by Saccharomyces cerevisiae were investigated. The binding of cypermethrin by the strains S. cerevisiae YS81 and HP was rapid and reached equilibrium at 2-8 h. The removal efficiency was dependent on incubation temperature and yeast concentration, whereas cypermethrin binding was not affected by pH. Heat and acid treatments enhanced the binding ability. Both strains survived in simulated digestion juices and removed cypermethrin effectively under simulated gastrointestinal conditions. Among the strains tested, the YS81 strain was the better candidate for cypermethrin concentration reduction. For the two S. cerevisiae strains, the biosorption kinetics and isotherm followed the pseudo-second-order model and Langmuir model well. The cell walls and the protoplasts were the main yeast cell components involved in cypermethrin binding. Fourier transformed infrared spectroscopy analysis revealed that -OH, -NH, -C-N, -COO^-, and -C-O played a major role in binding cypermethrin. Inactive cells effectively removed cypermethrin from apple and cucumber juices and did not affect the physico-chemical properties. Therefore, S. cerevisiae strains YS81 and HP may be used for cypermethrin reduction in food or feed.

Fate of anthocyanins in the presence of inactivated yeasts and yeast cell walls during simulation of wine aging

In the present research, two inactivated yeast strains (W13 and BM45) and a commercial yeast cell wall preparation (YCW) already tested for their ability to removal ochratoxin A were used to simulate the wine aging. During the simulated aging, the concentrations of the main 4 anthocyanins decreased in both the control wine and the wines added with yeasts, although at rates depending on the type of yeast and on the nature of anthocyanins. Peonidin-3-O-glucoside decreased by about 20% in the control wine and by ~ 50% in the wines added with yeast strains or the commercial yeast preparation. Malvidin-3-O-glucoside decreased by about 80% in the control wine and in the wine added with YCW and by about 96% in the wines added with W13 and BM45 strains. Cyanidin-3-O-glucoside decreased by 47% in the control wine, by 65-66% in the wines added with W13 and BM45 strains, and by 73% in the wine added with YCW. Delphinidin-3-O-glucoside decreased by 100% already after 21-28 days of aging in all the wines.

Advances in Biodetoxification of Ochratoxin A-A Review of the Past Five Decades

Ochratoxin A (OTA) is a toxic secondary fungal metabolite that widely takes place in various kinds of foodstuffs and feeds. Human beings and animals are inevitably threatened by OTA as a result. Therefore, it is necessary to adopt various measures to detoxify OTA-contaminated foods and feeds. Biological detoxification methods, with better safety, flavor, nutritional quality, organoleptic properties, availability, and cost-effectiveness, are more promising than physical and chemical detoxification methods. The state-of-the-art research advances of OTA biodetoxification by degradation, adsorption, or enzymes are reviewed in the present paper. Researchers have discovered a good deal of microorganisms that could degrade and/or adsorb OTA, including actinobacteria, bacteria, filamentous fungi, and yeast. The degradation of OTA to non-toxic or less toxic OTα via the hydrolysis of the amide bond is the most important OTA biodegradation mechanism. The most important influence factor of OTA adsorption capacity of microorganisms is cell wall components. A large number of microorganisms with good OTA degradation and/or adsorption ability, as well as some OTA degradation enzymes isolated or cloned from microorganisms and animal pancreas, have great application prospects in food and feed industries.

Mitigation potential of distillery sludge against ochratoxin A induced immunological alterations in broiler chicks

Ochratoxin A (OTA) is a potent mycotoxin injurious to poultry health and an alarming factor for poultry industry while distillery sludge (DS) is a waste product of molasses based industries rich in proteins and certain essential vitamins and other nutrients. The present study was done to estimate the immunological alterations induced by OTA in broiler chicks and amelioration of these alterations by dietary supplementation of DS. For this purpose, 480 one-day old broiler chicks procured from a local hatchery, were divided into sixteen equal groups and were given different combinations of OTA (150, 300 and 1000 µg/kg feed) and DS (5, 10 and 20 g/kg feed). Parameters studied were antibodies response to sheep red blood cells (SRBCs), lymphoproliferative response to PHA-P and phagocytic index as studied by carbon clearance assay. The results of this study showed that feeding DS with 150 and 300 µg/kg OTA ameliorated OTA induced alterations, but this amelioration was partial when 1000 µg/kg OTA was used along with DS. From this study it could be concluded that DS has beneficial effects in birds suffering from ochratoxicosis. However, the proper level of DS to produce such mitigation against specific level of OTA is yet to be determined.

Metabolites of Microbial Origin with an Impact on Health: Ochratoxin A and Biogenic Amines

Safety and quality are significant challenges for food; namely, safety represents a big threat all over the world and is one of the most important goal to be achieved in both Western Society and Developing Countries. Wine safety mainly relies upon some metabolites and many of them are of microbial origin. The main goal of this review is a focus on two kinds of compounds (biogenic amines and mycotoxins, mainly Ochratoxin A) for their deleterious effects on health. For each class of compounds, we will focus on two different traits: (a) synthesis of the compounds in wine, with a brief description of the most important microorganisms and factors leading this phenomenon; (b) prevention and/or correction strategies and new trends. In addition, there is a focus on a recent predictive tool able to predict toxin contamination of grape, in order to perform some prevention approaches and achieve safe wine.

Differential Adsorption of Ochratoxin A and Anthocyanins by Inactivated Yeasts and Yeast Cell Walls during Simulation of Wine Aging

The adsorption of ochratoxin A (OTA) by yeasts is a promising approach for the decontamination of musts and wines, but some potential competitive or interactive phenomena between mycotoxin, yeast cells, and anthocyanins might modify the intensity of the phenomenon. The aim of this study was to examine OTA adsorption by two strains of Saccharomyces cerevisiae (the wild strain W13, and the commercial isolate BM45), previously inactivated by heat, and a yeast cell wall preparation. Experiments were conducted using Nero di Troia red wine contaminated with 2 μg/L OTA and supplemented with yeast biomass (20 g/L). The samples were analyzed periodically to assess mycotoxin concentration, chromatic characteristics, and total anthocyanins over 84 days of aging. Yeast cell walls revealed the highest OTA-adsorption in comparison to thermally-inactivated cells (50% vs. 43% toxin reduction), whilst no significant differences were found for the amount of adsorbed anthocyanins in OTA-contaminated and control wines. OTA and anthocyanins adsorption were not competitive phenomena. Unfortunately, the addition of yeast cells to wine could cause color loss; therefore, yeast selection should also focus on this trait to select the best strain.

Ochratoxin A in brewer's yeast used as food supplement

Brewer's yeasts are rich in vitamins of the B-group and contain other nutritive factors; therefore, they are recommended as valuable food supplements for people with special dietary requirements like pregnant women, children, and adolescents, or for people with high physical activity. Additionally, certain strains of brewer's yeast are known to be capable of adsorbing xenobiotics such as mycotoxins. Because of that, these yeasts are regarded as having positive effects in food, beverage, and feed technology. Their potential to bind mycotoxins such as ochratoxin A (OTA), however, can subsequently lead to a contamination of such brewer's yeasts used as food supplements. In the present study, we analyzed 46 samples of brewer's yeasts for the occurrence of OTA by HPLC with fluorescence detector (HPLC-FLD) and for confirmatory measurements by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Nearly 90% of the samples were contaminated with OTA, the levels ranging from the limit of detection (LOD, 0.01 μg/kg) to 4.2 μg/kg. The mean and median levels of contamination were 0.49 and 0.27 μg/kg, respectively. Based on these results, the additional weekly OTA exposure by regularly consuming such supplements was assessed. Depending on different subpopulations (adults, children) and levels of contamination used for calculation, the additional OTA intake via brewer's yeast products ranged from 9.3% (mean case) to 114% (worst case) of the published mean weekly OTA intake in Germany (adults 279.3 ng, children 195.3 ng). At present, maximum levels for OTA in nutritional supplements like brewer's yeast do not exist. Based on our results, however, it is recommended that producers of these dietary supplements should include mycotoxin analyses in ongoing and future self-monitoring programs and in product quality checks.

Saccharomyces cerevisiae cell wall components as tools for ochratoxin a decontamination

The aim of this study was to evaluate the usefulness of Saccharomyces cerevisiae cell wall preparations in the adsorption of ochratoxin A (OTA). The study involved the use of a brewer’s yeast cell wall devoid of protein substances, glucans obtained by water and alkaline extraction, a glucan commercially available as a dietary supplement for animals and, additionally, dried brewer’s yeast for comparison. Fourier Transform Infrared (FTIR) analysis of the obtained preparations showed bands characteristic for glucans in the resulting spectra. The yeast cell wall preparation, water-extracted glucan and the commercial glucan bound the highest amount of ochratoxin A, above 55% of the initial concentration, and the alkaline-extracted glucan adsorbed the lowest amount of this toxin. It has been shown that adsorption is most effective at a close-to-neutral pH, while being considerably limited in alkaline conditions.