Natural Antimicrobials in Food Processing: Bacteriocins, Peptides and Chitooligosaccharides

Studies on bioactive proteins and peptides, as well as their potential applications, have continuously increased over the last 20 years. They can be found in all living organisms, from prokaryotes to eukaryotes, and have been detected in different food matrices, maybe the most useful and reliable sources of these molecules. These proteins are referred to as bioactive compounds since they can modify several cellular bioprocesses in order to improve human health human health. Bioactive molecules can occur naturally or can be released from a principal protein after chemical or enzymatic hydrolysis or food fermentation. Bioactive peptides and proteins derived from food matrices or released from microorganisms can present intrinsic antihypertensive, hormone-like, antimicrobial, anti-cancer or antioxidant activities. There is a large demand for natural preservatives and for minimally processed food, researchers have intensified the search for bioactive peptides and proteins, especially those with antimicrobial properties, which are powerful substitutes for conventional food preservatives. This chapter describes the features of antimicrobial peptides and their combination to polymeric materials for food preservation by preventing microorganism proliferation. For this purpose, the bioactive molecules are complexed to chitosan bioactive molecules with chitosan biofilms, creating an antimicrobial packaging. Despite the changes that can occur in the physical properties of these biofilms, the incorporation of antimicrobial peptides to bioplastic biofilms could guarantee the quality and safety of foodstuffs, contributing in extending their shelf life.

Keywords: Antimicrobial mechanism, Antimicrobial spectrum, Bacteriocins, Bioplastic films, Biopolymer, Chemical compounds, Chitosan, Food preservation, Food safety, Natural packing, Peptides.