Physical adsorption of patulin by Saccharomyces cerevisiae during fermentation

Patulin (PAT), a mycotoxin mainly produced by various species of fungi, is frequently detected in moldy fruit- and vegetable-based products, which pose a health risk to the consumer. Over the past decades, a few studies reported that PAT content could be significantly decreased by microbial fermentation process. However, the physical adsorption mechanism between PAT and yeast during fermentation is still unclear. In this paper, we focused on the physical adsorption of PAT by Saccharomyces cerevisiae CCTCC 93161 during fermentation in aqueous solutions. Firstly, morphology of differently treated yeast cells were analyzed by scanning electron microscope, then the interactions between PAT and yeast cells were investigated by infrared absorption spectra of differently treated S. Cerevisiae cells before and after the adsorption of PAT. The results showed that the efficiency of PAT removal raised significantly with the increase of fermentation temperature and time, whereas it decreased significantly with the increase of initial PAT concentration in the fermentation system. The proteins and polysaccharides in the cell walls of yeast interacted with PAT and accounted for the physical adsorption. The current work would possibly provide some new insights on PAT control for fermented foods.