Keliani Bordin

Evaluation of gaseous allyl isothiocyanate against the growth of mycotoxigenic fungi and mycotoxin production in corn stored for 6 months: AITC use to inhibit fungi and mycotoxin production in corn

BACKGROUNDnBrazil produces approximately 63 million tons of corn kernels annually, which is commonly contaminated with fungi and mycotoxins. The objective of this study was to evaluate the efficacy of gaseous allyl isothiocyanate (AITC) to inhibit the growth of Aspergillus parasiticus and Fusarium verticillioides, and mycotoxin production (aflatoxins B1 , B2 , G1 and G2 , fumonisins B1 and B2 ) in corn during 180u2009days of storage.nnnRESULTSnAITC at 50u2009µLu2009L-1 resulted in a significant reduction of the fungal population (Pxa0<xa00.05) after 180u2009days, decreasing 3.17u2009log(CFUu2009g-1 ) and 3.9xa0log(CFUu2009g-1 ) of A.xa0parasiticus and F.xa0verticillioides respectively in comparison with the control. In addition, 10 and 50u2009µLu2009L-1 treatments prevented the production of fumonisin B1 for the whole period. Aflatoxins were not detected in either control or treated groups. Residual levels of AITC in corn treated with 10xa0µLu2009L-1 and 50u2009µLu2009L-1 were detected up to 14u2009days and 30u2009days respectively.nnnCONCLUSIONnProphylactic treatment with AITC reduced the fungal population and inhibited fumonisin B1 production in stored corn, exhibiting great potential to be applied in corn silos to prevent fungi contamination and minimize mycotoxin levels.

Combination of garlic essential oil, allyl isothiocyanate, and nisin Z as bio-preservatives in fresh sausage

The effects of natural antimicrobial compounds (garlic essential oil [GO], allyl isothiocyanate [AITC], and nisin Z [NI]) on microbiological, physicochemical and sensory characteristics of fresh sausage were assessed. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) towards Escherichia coli O157:H7 and Lactobacillus plantarum were determined in vitro. Sausages inoculated with E. coli O157:H7, were treated with different combinations of antimicrobials and assessed for microbiological and physicochemical parameters during storage (6C for 20 d). Treatments that presented the greatest antimicrobial effects were subjected to sensory evaluation. Combinations of 20u202fmg/kg NIu202f+u202f125u202fμL/kg GOu202f+u202f62.5u202fμL/kg AITC or 20u202fmg/kg NIu202f+u202f62.5u202fμL/kg GOu202f+u202f125u202fμL/kg AITC were effective in reducing E. coli O157H7 and spoilage lactic acid bacteria, and maintained the physicochemical characteristics of fresh sausage. Combinations of NI, GO and AITC were effective to improve the safety and the shelf life of fresh sausage, with no impact on its sensory acceptance.

Fumigation of Brazil nuts with allyl isothiocyanate to inhibit the growth of Aspergillus parasiticus and aflatoxin production

Abstract BACKGROUND Brazil produces approximately 40 000 tons of Brazil nuts annually, which is commonly contaminated with fungi and mycotoxins. Gaseous allyl isothiocyanate (AITC) was used to inhibit the growth of Aspergillus parasiticus and its production of aflatoxins (AFs) in Brazil nuts. RESULTS Nuts were inoculated with 104 spores g−1 of A. parasiticus and placed in airtight glass jars with controlled relative humidity (RH = 95 or 85%). Samples were treated with 0, 0.5, 1.0 or 2.5 µL L−1 of gaseous AITC and analyzed after 30 days to determine the fungal population and AFs content. Samples were also submitted to sensory evaluation. AITC at 2.5 µL L−1 could completely inhibit the fungal growth and AFs production in both the RH tested. AITC at 0.5 and 1 µL L−1 did not affect the microbial growth at RH = 95%, but 1 µL L−1 reduced the production of AFs by ∼50%. All AITC treatments reduced the fungal population and AFs to undetectable levels at RH = 85%. None of the concentrations altered sensory characteristics of Brazil nuts. CONCLUSION Gaseous AITC could be used as an alternative to inhibit the growth of A. parasiticus during storage and transport of Brazil nuts.

Toxicological effects of fumonisin B1 in combination with other Fusarium toxins

Fusarium is a fungal genus spread worldwide commonly associated to the production of several mycotoxins, where fumonisins (FBs) are of major importance due to its prevalence. Since mycotoxins have been reported to cause deleterious effects on mammalians, including carcinogenic, neurotoxic, estrogenic, and immune-suppressive, many countries had established regulations on the tolerated concentrations of such substances in foods and animal feed. Even though many mycotoxins - especially fusariotoxins - are concomitantly found in a single matrix, there is no regulation on co-occurrence levels. This is possibly a result of the lack of data in the literature on the toxicological interactions between different mycotoxins. Considering this, it is of utmost importance to gather what is currently known about the combination of FBs, considered to be the most ubiquitous mycotoxins, with other frequently reported fusariotoxins, such as zearalenone (ZEA), deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T-2), and other emerging mycotoxins. This paper gives an overview about the toxic effects of fusariotoxins individually and combined to FB1, also gathering the mechanisms and probable interactions between them. This important information may help to develop regulations covering multi-mycotoxins contamination, a growing concern of current days.

Combination of essential oil compounds and phenolic acids against Escherichia coli O157:H7 in vitro and in dry-fermented sausage production

Escherichia coli O157:H7 is a foodborne pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. The low dose of infection and severity of the disease represent a concern to public health. Natural compounds have been widely applied as food additives to replace synthetic preservatives. The aim of this study was to determine the efficiency of essential oil compounds (EOCs) in combination with phenolic acids (PA) in vitro and in dry-fermented sausage production. Minimum Inhibitory Concentration (MIC) and Fractional Inhibitory Concentration index (FICindex) were determined for a 5-strain mixture of E. coli O157:H7. Batches of sausage tainted with E. coli O157:H7 were produced using Pediococcus pentosaceus UM 116P and Staphylococcus carnosus UM 123M as starter cultures. The best combination of EOCs and PAs found in vitro was used as an additive. Chemical-physical and microbiological analyses were evaluated weekly from day 0 to 35 after production. Sensory evaluation (texture, odor, flavor, appearance and overall evaluation) of E. coli-free sausages was conducted using a 9-point hedonic scale with 56 untrained volunteers. The MIC values of allyl isothiocyanate (AITC), carvacrol (CAR), ferulic acid (FA), o-coumaric acid (CA) and p-hydroxybenzoic acid (AHB) were, respectively, 0.25; 1.3; 5.12; 18.27; and 37mM. AITC combined with CA had a synergistic effect (FICindex=0.25) and together they were applied in the production of dry fermented sausage at concentrations of 10× FIC and 20× FIC. Aw had no significant difference among treatments, whereas the pH of 10× FIC and 20× FIC were higher than the control. E. coli O157:H7 was reduced by >5logCFU/g with 20× FIC after 21d, and by 2.8logCFU/g with 10× FIC after 35d. Sensory analysis showed that the combination of AITC and ο-coumaric acid in both treatments presented lower scores in the 5 categories when compared to the control, but none of the parameters received a negative score. This study demonstrated that the combination of AITC and ο-coumaric acid at 20× FIC reduced E. coli O157:H7 in compliance with the North American legislation, but adjustments in the dose are necessary to improve the sensory characteristics of the final product.