21 - Peptides from plants and their applications

Abstract

Bioactive peptides can be endogenous or exogenous. Exogenous bioactive peptides are sequences of amino acids 2–30 in length that are inactive within the parent protein source but are released through the action of proteolytic enzymes during fermentation, hydrolysis, and food processing. These exogenous bioactive peptides have health benefits that go above and beyond basic, human nutrition and they exert “hormone-like beneficial activities” in the consumer if taken in relevant quantities and if they survive breakdown by proteolytic enzymes present in the gastrointestinal tract. Plant-derived bioactive peptides are thought to be a source of health-enhancing compounds and are consumed as part of a healthy, balanced diet. In plants, endogenous biologically active or bioactive peptides have been shown to inhibit insect feeding and act as part of the defense response as well as in cell division control and reproductive mechanisms. A large number of both peptides are known today and were isolated from plants including both cereals and legumes. Their bioactivities and potential health beneficial effects have been tabulated in databases such as BIOPEP (http://www.uwm.edu.pl/biochemia) and are known to range from angiotensin-I-converting enzyme (ACE-I; EC 3.4.15.1) inhibition to wound healing and antimicrobial/anticancer activities. These peptides are known to be selective, effective, safe, and well tolerated once consumed and have potential for use in functional foods, pharmaceuticals, and medicines. This chapter discusses bioactive peptides of plant origin including cereals and legumes and their use as functional foods. Examples of plant peptide-derived products currently on the market are given. The availability of the pharmaceutical peptide drugs market and emerging opportunities in peptide food and drug development are also discussed.