Revalorization by lactic acid bacterial fermentation of goat whey from cheese industry as a potential antifungal agent

Abstract

The industry is continuously searching for new methods to reduce the use of chemical preservatives while still produce safer foods for the consumer. Goat whey is a waste from the cheese industry which is primarily treated as a residue. It is rich in different nutrients and has the potential to be used as a matrix for lactic acid bacteria fermentation. This work aims to find a revalorization of whey for the production of a natural origin antifungal agent by a fermentation that can be used as food ingredient. First different whey culture mediums were developed and fermented. Quantification of different antifungal molecules in whey culture mediums in comparation to a fermentation of De Man, Rogosa and Sharpe (MRS) culture medium evidenced that the production of this antifungal metabolites was similar. The in vitro qualitative and quantitative assays evidenced that the whey-based mediums increased the antifungal activity of the CFS in comparation to the MRS. The fermented whey produced bigger inhibition halos (above 1 cm) in the agar diffusion test in comparation to the fermented MRS (bellow 0.6 cm). Alike, in the minimal fungicidal concentration test the lowest antifungal concentrations were detected on the fermented whey mediums, averaging antifungal concentrations lower than 130 g/L. Finally, a multivariable data analysis determined that more antifungal metabolites yet to be detected were affecting in the antifungal activity from the whey samples. The fermented whey has the potential to be a tool in reducing the use of chemical preservatives in foods.