Study on the characterisation and application of synthetic peptide Snakin-1 derived from potato tubers – Action against food spoilage yeast

The demand for more natural forms of food preservation by consumers has risen in recent years. Food spoilage by microorganisms, in particular food spoilage yeast, has been reported in different food matrices. Zygosaccharomyces species, for example, are well known for their spoilage in high sugar content foods. In the battle against food spoilage, natural antimicrobial peptides derived from plants could be a potential new source of food preservatives. The antimicrobial peptide investigated in this study was Snakin-1, derived from potato tubers. A synthetic form of Snakin-1 was synthesised based on the amino acid sequence of its natural peptide. The peptide was characterised for its inhibitory effect against a number of food spoilage yeast. The peptide's minimum inhibitory concentration was generated and its mechanism of action against Zygosaccharomyces bailii was examined. Membrane permeabilisation caused by the presence of the peptide was observed at the highest concentrations applied, and its ability to withstand high salt concentrations, thermal treatment and a range of pH was also investigated. The peptide's safety for human consumption was studied and no adverse effects were found. Finally, the peptide was applied into different beverages commonly spoiled by Zygosaccharomyces bailii in order to demonstrate the potential application of this synthetic plant antimicrobial peptide.