Prevention of Mold Growth and Toxin Production through Control of Environmental Conditions

Formation and Control of Mycotoxins in Food

Preventing Growth of Potentially Toxic Molds Using Antifungal Agents

A very large number of filamentous fungi has been reported to produce the small lactone mycotoxins patulin, penicillic acid and moniliformin. Among the 167 reported fungal producers of patulin, only production by 29 species could be confirmed. Patulin is produced by 3Aspergillusspecies, 3Paecilomycesspecies, 22Penicilliumspecies from 7 sections ofPenicillium, and oneXylariaspecies. Among 101 reported producers of penicillic acid, 48 species could produce this mycotoxin. Penicillic acid is produced by 23 species in sectionAspergillussubgenusCircumdatisectionCircumdati, byMalbranchea aurantiacaand by 24Penicilliumspecies from 9 sections inPenicilliumand one species that does not actually belong toPenicillium(P. megasporum). Among 40 reported producers of moniliformin, five species have been regarded as doubtful producers of this mycotoxin or are now regarded as taxonomic synonyms. Moniliformin is produced by 34Fusariumspecies and onePenicilliumspecies. All the accepted producers of patulin, penicillic acid and moniliformin were revised according to the new one fungus – one name nomenclatural system, and the most recently accepted taxonomy of the species.

Significance of Mycotoxins to Food Safety and Human Health

Public Health Significance of Molds and Mycotoxins in Fermented Dairy Products

Occurrence of Toxigenic Fungi and Mycotoxins during Smoked Paprika Production

Production of Mycotoxins by Penicillium Species

Mycotoxin production by molds isolated from ‘Greek-style’ black olives

Inhibition of Mold Growth and Mycotoxin Production in High-Moisture Corn Treated with Phosphates

ABSTRACTA Penicillium sp. isolated from Cheddar cheese and tentatively identified as an atypical strain of Penicillium roqueforti was found to produce penicillic acid and patulin simultaneously. This study was done to determine the effects of substrate, incubation temperature and time on the ratio and quantities of toxins produced. Three substrates known to support mycotoxin production (yeast‐extract sucrose, potato‐dextrose and Raulin‐Thom broths), a medium containing lactose and casein, several foods (Cheddar cheese, Swiss cheese, sausage, cooked cornmeal, yellow dent corn and corn tortillas), and a shredded wheatnutrient broth medium known to support toxin production were used as substrates. Incubation temperatures of 5, 12 and 25°C were studied over several periods of time for each group of substrates. Of all the substrates studied, the broth substrates previously known to support mycotoxin production supported the most abundant toxin production under all conditions. The greatest concentrations of toxins were produced at 12°C followed by 5°C. The lowest quantities of both mycotoxins were produced at 25°C regardless of substrate. Patulin was produced predominately on potato‐dextrose broth, both penicillic acid and patulin were produced on yeast extract‐sucrose broth, and penicillic acid was predominately produced on Raulin‐Thom broth. Neither toxin was produced on Cheddar cheese, Swiss cheese, summer sausauge or corn tortillas, but penicillic acid was produced on cooked cornmeal and both penicillic acid and patulin were produced on yellow dent corn, with best production occurring at 12°C. Substrates low in carbohydrate did not support appreciable levels of mycotoxin production.

It has been reported that aflatoxin contamination in soybean was relatively low, but it was not guaranteed that soybean products is free from aflatoxin contamination. Naturally, soybean containing phytic acid and it bound zinc and protein. Zinc (Zn) is an important mineral for aflatoxin biosynthesis. Previous research indicated that some soybean products such as kecap was contaminated by aflatoxin. It might be Aspergillus flavus involved during kecap fermentation and it produced phytase for phytic acid degradation. Zinc will be released and available for aflatoxin biosynthesis. The aim of this research was to evaluate the effect of phytic acid, Zn and soybean extract on the growth and aflatoxin B1 (AFB1) production by Aspergillus flavus. Five kind of medium were used in the experiment, Glucose Ammonium Nitrate (GAN) medium, a special medium for aflatoxin production, GAN without Zn, GAN supplemented with phytic acid, GAN supplemented with soybean extract instead of glucose and soybean extract supplemented with phytic acid. Two and a half milliliter of spore suspension ��07spores/ml) was inoculated into 250 ml of each medium in 1 liter flask. Incuba�tion was done in shaker incubator at room temperature. The growth of mold and AFB� production were analy�ed on 3 and 6 days incubation time. The result indicated that phytic acid lowering the growth of mold in the early 3 days, but not at all after 6 days incubation. It seems that phytic acid delays the aflatoxin production. Lack of Zn in the medium brought about the lowering of aflatoxin production. Even glucose concentration in soybean extract medium was lower than in GAN medium, the growth of the mold was not inhibited but lower on glucose affect on decreasing of AFB1 production.

In the present investigation different volatile compounds and food preservatives were tested for their efficiency in the control of growth and ochratoxin A (OTA) production by Penicillium verrucosum and Penicillium nordicum. Volatiles such as phenols and formic acid which have no residual effect were proved to be effective in checking the growth and OTA production by both the species of Penicillium under study. Vapours of phenols and formic acid significantly inhibited OTA produced by P. verrucosum, while aniline and toluene inhibited the OTA production by P. nordicum to a significant level. A positive correlation coefficient was observed between the growth and toxin production by P. verrucosum (0.55) and P. nordicum (0.66) against different volatile compounds tried. Among food preservatives, sodium acetate and sodium metabisulphate were responsible for total inhibition of OTA production by P. verrucosum at 150 µg/ml concentration. P. nordicum proved to be comparatively more resistant to these substances than P. verrucosum. In conclusion of present investigation, phenol, formic acid, amyl alcohol, propionic acid, sodium acetate and sodium metabisulphate were found to be effective in checking the growth and OTA production by both the species of Penicillium under investigation, and can be exploited in protecting the poultry feed from unwanted mould growth and mycotoxin production.

Mould spoilage and mycotoxin formation in grains as controlled by physical means

Aflatoxins represent a significant risk to food safety, and strategies are being implemented to reduce their entry into the food chain. The aim of this study was to evaluate the in vitro effect of four essential oils (EOs) (lavandins Grosso and Abrial, Origanum virens, and Rosmarinus officinalis) and four natural phenolic acids (PAs) (caffeic, chlorogenic, ferulic, and p-coumaric) on the growth and aflatoxins (B1, B2, G1, and G2) production by Aspergillus parasiticus. Minimal inhibitory concentration (MIC) and minimal fungicide concentration (MFC) were determined by the broth macrodilution method. Additionally, the mycelia weight was determined at concentration levels lower than MIC. The antiaflatoxigenic activity was evaluated in the two concentrations of the EOs right before MIC and at concentrations below the MIC value for the PAs. To this end, in-house validated methodology based on high-performance liquid chromatography with post-column photochemical derivatization and fluorescence detection (HPLC-PHRED-FLD) was used. EOs of O. virens and lavandins (Grosso and Abrial) completely inhibited mold growth. In addition, a significant reduction in mycelial mass (p < 0.05) was observed for all EOs and PAs at different concentrations. In all cases except for lavandin Abrial, EO concentrations just before the MIC value strongly reduced (p < 0.05) aflatoxins synthesis. Aflatoxins production was completely inhibited by all PAs at a concentration of 20 mM; although at low concentrations, mycotoxin production was stimulated in some cases. The present study provides a scientific basis for further study of the inhibiting mechanisms.

Alternaria alternata is a major contaminant of wine grapes, meaning a health risk for wine consumers due to the accumulation of toxic metabolites. To develop a successful biofungicide, the effectiveness of epiphytic wine grape yeasts against A. alternata growth and toxin production was assessed in vitro under temperature and aW conditions that simulate those present in the field. The effect of 14 antagonistic yeasts was evaluated on growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) production by three A. alternata strains in a synthetic medium with composition similar to grape (SN) at three temperatures (15, 25 and 30°C). All Metschnikowia sp. yeast strains evaluated completely prevented A. alternata growth and mycotoxin production at all temperatures in SN medium. Meanwhile, the growth inhibition exerted by Starmerella bacillaris yeast strains was higher at 30°C, followed by 25 and 15°C, being able to show a stimulating or inhibiting effect. Hanseniaspora uvarum yeast strains showed a growth promoting activity higher at 15°C, followed by 25 and 30°C. Even at conditions where A. alternata growth was stimulated by the S. bacillaris and H. uvarum yeasts, high inhibitions of mycotoxin production (AOH, AME and TA) were observed, indicating a complex interaction between growth and mycotoxin production. There is a significant influence of temperature on the effectiveness of biocontrol against A. alternata growth and mycotoxin production. Metschnikowia sp. strains are good candidates to compose a biofungicide against A. alternata. Among the different antagonistic yeasts evaluated, only Metschnikowia sp. strains were equally effective reducing A. alternata growth and mycotoxin at different temperatures underlining the importance of considering environmental factors in the selection of the antagonists.