Shelf life extension of mozzarella cheese contaminated with Penicillium spp. using the antifungal compound ɛ-polylysine.

Molds are one of the most important spoilage organisms on cheese which can lead to economic loss as well as raising public health concerns due to the production of mycotoxins. This study investigates the use of ɛ-polylysine as natural antimicrobial to inhibit fungal growth. The minimal inhibitory concentrations and minimal fungicidal concentrations of ɛ-polylysine were determined against Penicillium roqueforti, Penicillium nordicum, and Penicillium solitum. Then, polylysine was tested as surface antimicrobial for the preservation of mozzarella slice cheese inoculated with these Penicillium spp. and stored in plastic trays during 25 days. The minimal inhibitory concentrations calculated for…

Determination of Fusarium mycotoxins enniatins, beauvericin and fusaproliferin in cereals and derived products from Tunisia

Abstract In this study, 51 samples of cereals (wheat, Barley, maize and Sorghum) and by-products (mainly pasta and couscous) purchased from Tunisian supermarkets were examined for contamination with the emerging Fusarium mycotoxins: Enniatins ENs (EN A, EN A 1 , EN B and EN B 1 ), beauvericin (BEA) and fusaproliferin (FUS). The extraction of the samples was performed with methanol using an Ultra-turrax homogenizer. Mycotoxins were analyzed with a liquid chromatography (LC) coupled to a diode array detector (DAD). The frequencies of contamination of total samples with ENs were 96%. EN A 1 was the most common EN found with the highest prevalence of 92.1%, levels ranged between 11.1 and 480 mg…

First report on the presence of emerging Fusarium mycotoxins enniatins (A, A1, B, B1), beauvericin and fusaproliferin in rice on the Moroccan retail markets

Seventy samples of rice purchased from local markets in six cities from Morocco (Rabat, Casablanca, Kenitra, Mohammadia, Tanger and Errachidia) were analyzed for the presence of six emerging mycotoxins: four enniatins ENs (ENA, ENA1, ENB and ENB1), beauvericin (BEA) and fusaproliferin (FUS). Samples were extracted with a mixture of acetonitrile/water (85/15, v/v) by using an ultra-turrax homogenizer. Mycotoxins were then identified and quantified with liquid chromatography (LC) coupled to diode array detector (DAD). Positive samples were confirmed with an LC-MS/MS. Analytical results showed that BEA was present in 75.7% of total analyzed samples. BEA levels varied between 3.8 and 26.3 mg/kg…

Reaction of zearalenone and α-zearalenol with allyl isothiocyanate, characterization of reaction products, their bioaccessibility and bioavailability in vitro.

This study investigates the reduction of zearalenone (ZEA) and α-zearalenol (α-ZOL) on a solution model using allyl isothiocyanate (AITC) and also determines the bioaccessibility and bioavailability of the reaction products isolated and identified by MS-LIT. Mycotoxin reductions were dose-dependent, and ZEA levels decreased more than α-ZOL, ranging from 0.2 to 96.9% and 0 to 89.5% respectively, with no difference (p⩽0.05) between pH 4 and 7. Overall, simulated gastric bioaccessibility was higher than duodenal bioaccessibility for both mycotoxins and mycotoxin-AITC conjugates, with duodenal fractions representing ⩾63.5% of the original concentration. Simulated bioavailability of reaction pro…

Antimicrobial packaging based on ɛ-polylysine bioactive film for the control of mycotoxigenic fungi in vitro and in bread

Abstract ɛ‐Poly‐l‐lysine (ɛ‐PL) is a cationic peptide with a broad‐spectrum antimicrobial activity. This study investigates the use of ɛ‐PL as natural antimicrobial to inhibit fungal growth and to reduce aflatoxins (AFs) production. Antifungal activity of starch biofilms with different concentrations of ɛ‐Poly‐l‐lysine (ɛ‐PL) was determined in solid medium against Aspergillus parasiticus (AFs producer) and Penicillium expansum. Then, biofilms were tested as antimicrobial devices for the preservation of bread loaf inoculated with A. parasiticus CECT 2681 and P. expansum CECT 2278. Shelf life and AFs content were examined. Biofilms with concentrations of ɛ‐PL less than 1.6 mg/cm2 showed no fu…

Influence of probiotic microorganisms on aflatoxins B 1 and B 2 bioaccessibility evaluated with a simulated gastrointestinal digestion

Aflatoxins (AFs) are produced mainly by the molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxin B1 (AFB1) is classified as carcinogenic to humans. The aim of this study was to evaluate the capacity of different strains of Lactobacilli (Lb.) and Bifidobacteria (Bf.) to reduce the bioaccessibility of AFB1 and aflatoxin B2 (AFB2), spiked in loaf bread, using a dynamic in vitro simulated gastrointestinal digestion system. Aliquots of 20 mL of gastric and duodenal fluids were sampled for the determination of the mycotoxins gastric and duodenal bioaccessibility respectively, by liquid-chromatography coupled to the mass spectrometry in tandem (LC–MS/MS). A reduction of AFs bioacc…

Determination of melatonin in Acyrthosiphon pisum aphids by liquid chromatography-tandem mass spectrometry.

Melatonin is a hormone mainly involved in the regulation of circadian and seasonal rhythms in both invertebrates and vertebrates. Despite the identification of melatonin in many insects, its involvement in the insect seasonal response remains unclear. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for melatonin analysis in aphids (Acyrthosiphon pisum) for the first time. After comparing two different procedures and five extraction solvents, a sample preparation procedure with a mixture of methanol/water (50:50) was selected for melatonin extraction. The method was validated by analyzing melatonin recovery at three spiked concentrations (5, 50 and 100 p…

Bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey fermented with lactic acid bacteria.

Microbial fermentation with lactic acid bacteria (LAB) is a natural food biopreservation method. Yellow mustard and milk whey are optimum substrates for LAB fermentation. The aim of the present study was to evaluate the bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey both with and without LAB fermentation. All extracts were subjected to a simulated digestion process. Total polyphenols, DL-3-phenyllactic acid (PLA), lactic acid, and the antioxidant activity were determined in the studied matrices before and after simulated digestion. Yellow mustard flour was significantly richer in total polyphenols, whereas significantly higher concentrati…

Beauvericin degradation during bread and beer making

Abstract Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium species and known to have various biological activities. This study investigated the degradation of the minor Fusarium mycotoxin BEA present at the concentration of 5 mg/kg in barley and wheat flour during beer and bread making. The influence of the making processes and of the formation of degradation products of BEA were evaluated during the beer and bread making. The concentration of BEA and its evolution during the production processes were determined with the technique of the liquid chromatography tandem mass spectrometry in tandem (LC-MS/MS), whereas the formation of the BEA degr…

In vitro antifungal activity of bioactive peptides produced by Lactobacillus plantarum against Aspergillus parasiticus and Penicillium expansum

Abstract Food spoilage caused by mycotoxigenic moulds represents an important problem in food security. The antimicrobial peptides are compounds of natural origin constituted by a variable number (5–100) of amino acids held together through peptide bonds. In this work, the cell free supernatants (CFSs) containing peptides obtained from four strains of LAB were lyophilized, filtered and tested to determine the antifungal activity against Aspergillus Parasiticus and Penicillium expansum . CFS obtained by Lactobacillus plantarum showed the highest inhibition activity. CFS was fractionated by size exclusion chromatography and injected into the liquid chromatography coupled to diode array detect…

Reduction of the enniatins A, A1, B, B1 by an in vitro degradation employing different strains of probiotic bacteria: Identification of degradation products by LC–MS–LIT

Abstract The degradation of the Fusarium mycotoxins ENs by 9 bacterial strains characteristic of the gastrointestinal tract like Bb. longum , Bb. bifidum , Bb. breve , Bb. adolescentes , Lb. rhamnosus , Lb. casei–casei , S. termofilus , Lb. ruminis , Lb. casei and twenty two strains of Saccharomyces cerevisiae was studied. The fermentations were carried out in the liquid medium of De Man Rogosa Sharpe (MRS) under anaerobic conditions for Bifidobacteria Streptococcus and Lactobacillus, and in Potato Dextrose Broth (PDB) for Saccharomyces strains, during 48 h. The degradation of the bioactive compounds ENs was also studied in a food system composed by wheat flour naturally contaminated by ENs…

Antibacterial activity of the emerging Fusarium mycotoxins enniatins A, A1, A2, B, B1, and B4 on probiotic microorganisms

Abstract Enniatins (ENs) are secondary metabolites produced by several Fusarium strains, chemically characterized as N-methylated cyclohexadepsipeptides. These compounds are known to act as antifungal and antibacterial agents, but they also possess anti-insect and phytotoxic properties. In this study, the antimicrobial effect of pure fractions of the bioactive compounds ENs A, A 1 , A 2 , B, B 1 , and B 4 was tested towards nine probiotic microrganisms, twenty-two Saccharomyces cerevisiae strains and nine Bacillus subtilis strains. Antimicrobial analyses were carried out the disc-diffusion method using ENs concentrations ranging from 0.2 to 20,000 ng. Plates were incubated for 24 h at 37 °C…

Antifungal and antimycotoxigenic activity of polylysine biofilms