Challenges of Lactobacillus fermentation in combination with acoustic screening for deoxynivalenol and deoxynivalenol conjugates reduction in contaminated wheat - based products

This study was dedicated to apply biological treatment using Lactobacillus (LAB) fermentation separately or in combination with an acoustic screening method for the prevention of mycotoxins in Fusarium spp. contaminated wheat-based products. Wheat samples of different contamination were treated separately using antimicrobial LAB strains (L. casei, L. plantarum, L. paracasei, and L. uvarum) and the changes on the level of deoxynivalenol (DON) and its conjugates such as 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), and DON-3-β-D-glucoside (D3G)) were evaluated using UHPLC-QqQ-MS/MS and UHPLC-Orbitrap-HRMS. Additionally, an acoustic device was used to analyse DON in the wheat raw samples (without treatment). High linear correlations were obtained between HPLC results and the penetrated acoustic signal amplitude (Ap) for DON and D3G (R2 = 0.85 and R2 = 0.82, respectively). The results of fermentation demonstrated that bio-treatment of contaminated wheat was very effective for DON and masked toxin reduction in the media. Contaminated wheat-based products fermentation using L. uvarum allowed to reduce DON and D3G content in the media up to 75.0% and 84.1%, respectively, while the values of DON conjugates (3-ADON, 15-ADON) were reduced below LOD/LOQ. Fusarium spp. contaminated wheat grains demonstrated different enzymatic profiles (amylolytic, xylanolytic, and proteolytic) which could be related with biological degradation of mycotoxins during fermentation. The amylolytic and xylanolytic activities of fungi correlated well with DON content (R2 = 0.8235, R2 = 0.8694, respectively) as well as with D3G (R2 = 0.9314, R2 = 0.9937, respectively). The findings of this study indicate that bio-treatment of contaminated wheat could efficiently reduce Fusarium mycotoxin levels below the LOD/LOQ in wheat-based products and improve the sustainability of grain production. However, before mycotoxin analysis LAB cells were not removed from the substrate and the results are focused on possible contaminants biodegradation. The acoustic technique could identify DON as well as D3G contamination in raw wheat grains and is a promising tool in the wheat grain processing chain.