IMPROVING AGRICULTURE PRODUCTS QUALITY AND SAFETY BY NOVEL ANTIMICROBIAL RANDOM PEPTIDE MIXTURES

Microorganisms have a major role in food spoilage and safety. Improving existing ways to deal with microorganism in food and exploring the typical bacteria of each food product are essential for the development of effective antimicrobial tools to tackle them. In our research, we focus on milk as a food model that its shelf life depends on microorganism activity as it contains a variety of nutrients provide the bacteria an ideal growth environment and for human a nutritional value product. We used MALDI-TOF mass spectrometry method for identification of isolated bacteria from pasteurized milk that was spoiled in different conditions. MALDI-TOF mass spectrometry is a novel, rapid and simple method for bacteria identification based on unique fingerprint of specific bacteria. Novel antimicrobial random peptide mixtures[1] that we have developed recently were studied as active agents towards the isolated spoilage milk bacteria. Random peptides mixture material was generated using solid-phase peptide synthesis method in unconventional way, instead of using one pure amino acid at each coupling step we used a mixture of two amino acids in a defined proportion hydrophobic and cationic residues. Each mixture was random in terms of sequence, but highly controlled in terms of chain length and stereochemistry. We found that the random peptide mixtures have strong and broad antimicrobial activity towards most of the milk spoilage bacteria that were isolated during this study. According to these findings, we will develop milk bioactive food packaging using random peptide mixtures to increase milk safety and shelf life.

1. Hayouka Z. et al. Interplay among Subunit Identity, Subunit Proportion, Chain Length, and Stereochemistry in the Activity Profile of Sequence-Random Peptide Mixtures, J. Am. Chem. Soc. 2013, 135, 11748−11751