Bioactive Peptides from Food

Sources, Analysis, and Functions

Leo M.L. Nollet, Semih Ötleş, Leo M.L. Nollet, Semih Ötleş

• Publisher: CRC Press
• Year: 2022
• Print ISBN:
  9780367608538
• eBook ISBN:
  9781000551983
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

A growing body of scientific evidence has revealed that many food peptides exhibit specific biological activities in addition to their established nutritional value. Bioactive peptides present in foods may help reduce the worldwide epidemic of chronic diseases that account for a great number of premature deaths annually. Bioactive peptides can be defined as isolated small fragments of proteins which provide some physiological health benefits. They act as potential modifiers reducing the risk of many chronic diseases.

Bioactive Peptides from Food: Sources, Analysis, and Functions considers fundamental concepts, sources, hydrolysis, fractionation, purification, analysis, chemical synthesis, functions, and regulatory status of nutraceutical bioactive peptides. Methods of isolation of these peptides from different protein sources with their in vitro and vivo physiological effects are addressed. Divided into seven sections, this book delves into how these peptides play a major role in the development of various functional foods. Numerous bioactive peptides have been reported in recent years as naturally present or generated from food proteins of different origins like milk, eggs, soya, fish, and meat.

Key Features:

• Includes a detailed study of the different sources of bioactive peptides
• Discusses the health benefits, such as antimicrobial, antiallergic, antihypertensive, antitumor, and immunomodulatory properties of peptides
• Explorates the state of the art analysis methods of peptides
• Discovers the bioinformatics of possible bioactive peptides

Written by experts in their field from around the world, Bioactive Peptides from Food reveals the world of databases of peptides. It is a great resource for food scientists, technologists, chemists, nutrition researchers, producers, and processors working in the whole food science and technology field as well as those who are interested in the development of innovative functional products.

Section 1
Bioactive Peptides

Chapter 1 Bioactive PeptidesAn Overview

Alessandro Colletti and Arrigo F.G. Cicero

DOI: 10.1201/9781003106524-2

Contents

Introduction

Sources

Animal Sources

Vegetal Sources

New Sources

From Production to Commercialization

Stability and Bioavailability

Applications

Anti-Inflammatory Activity

Antihypertensive Activity

Lipid-Lowering Activity

Anticancer Activity

Immunomodulatory Activity

Other Biological Activities

Discussion

Conclusions

References

Introduction

Bioactive peptides (BP) are a heterogeneous class of molecules contained in a wide range of plants and animals (Karaś et al., 2019). The first bioactive peptide was identified in 1950 by Olaf Mellander, who isolated BP from casein (which improves bone calcification in rachitic children) (Mellander, 1950).

BP can be defined as protein fragments that include between 2 and 20 amino acids able to modulate physiological functions in humans (Aluko, 2012). In general, the protein in BP is inactive in the precursor molecule, but becomes active after release to the active site (Karaś, 2019). The precursor protein undergoes enzymatic or chemical hydrolysis in the gastrointestinal tract through microbiota fermentation processes and the BP can thus be absorbed through specific peptide transporters (Mazorra-Manzano et al., 2017). This is the most important difference that allows the classification of BP into exogenous and endogenous molecules, obtained via gastrointestinal digestion and artificially, respectively (Udenigwe and Aluko, 2012).

Even though BP have been commonly used as additives to give body to broths, soups, and sauces for many years, recent research shows that BP have important health benefits. Today the estimated peptide-based product market is around $40 billion per year (Lemes et al., 2016), demonstrating the strong demand from health-conscious consumers. BP are routinely used in different fields, including pharmacology, nutraceuticals, cosmetology, and human and pet food. For the most part, they are classified as functional foods, but some countries have different rules (Ozuna et al., 2015). However, one of the most important applications of BP regards the nutraceutical sector. It is well-known that BP regulate many important body functions (Figure 1.1), exercising antimicrobial, antioxidant, anti-inflammatory, anticoagulant, anticancer, lipid-lowering, antihypertensive, and antihyperglycemic effects through various pathways of action (depending on their structure and amino acid composition) that are, in many ways, still unknown (Jakubczyk et al., 2020).

FIGURE 1.1 Bioactive peptides and clinical applications.

Recently, new extraction and isolation techniques have been developed that use both vegetable (e.g., bromelain, ficin, papain) and animal (e.g., trypsin, chymotrypsin, pepsin, milk-peptides) matrices, to obtain BP with specific activities and improve the bioactivity as well as the bioavailability (Arulrajah et al., 2020). In effect, the bioactivity and the bioavailability of isolated peptides majorly depend on the degree of hydrolysis during the isolation process; this is the reason BP require both in vitro and in vivo studies before their commercialization (Girgih et al., 2014). Currently, at least 1500 BP have been reported in the BIOPEP database, but only a few of them have been studied for clinical applications (Singh et al., 2014).

An important source of BP are by-products, defined as “materials generated by a production chain” particularly interesting to reduce food waste and make suitable use of resources (zero-waste approach) (Colletti et al., 2020). Several by-products of the various phases of food production have been studied to find ways to limit food production’s environmental and economic impact, and researchers have experimented with new processes for the recovery of BP components (Calcio Gaudino et al., 2020). For example, it can be estimated that about 170,000 tons of soybean curd residue, also known as “okara”, are produced from 1 million tons of soymilk (protein content 3.5%) (Wang et al., 1996). okara contains around 15–30% of proteins, among which the low molecular weight fraction (less than 1 kDa) consists of digestible bioactive peptides, has the potential to inhibit the angiotensin-converting enzyme (ACE) and shows great antioxidant activity (Jimenez-Escrig et al., 2010).

The aim of this chapter is to describe the main animal and plant sources of BP, a summary of the production methods, the bioactivity and bioavailability of BP, and their limitations in clinical practice. Finally, the nutraceutical applications as well as the future perspectives will also be reviewed.

Sources

BP are mostly present inside bioactive proteins of different origins. To date, bovine milk, cheese, dairy products, meat, eggs, and fish, such as tuna, sardine, salmon and herring, are the greatest animal sources of BP, while wheat, maize, soy, rice, mushrooms, pumpkin, sorghum, and amaranth represent the greatest vegetal sources of BP derived from foods (Cicero et al., 2016).

BP from both animal and vegetal sources can be released during gastrointestinal digestion by trypsin or other microbial enzymes; and then, in addition to supplying the required raw materials for protein biosynthesis (nutritional value) and presenting a source of energy, they exhibit distinct biological activities (Sánchez and Vázquez, 2017).

Animal Sources

Milk and dairy products are some of the most important sources of BP, which are released during gastrointestinal digestion or food processing, presumably confirming the importance of breastfeeding in the first months of life (Moller et al., 2008). Bovine and maternal milk contains different peptides with immunomodulatory (such as lactoferrin and immunoglobulins), neurotrophic (opioid peptides derived mostly from the hydrolysis of casein), cytotoxic, anti-carcinogenic, antibacterial, and anti-thrombotic activities described in the next chapters (Sánchez and Vázquez 2017). Both human and bovine colostrum are also rich sources of growth factors and BP, which appear to play a significant role in postnatal development (Chai et al., 2020). Other important, but less known, sources of BP are buffalo, donkey, camel, goat, mare, sheep, and yak milk (El-Salam and El-Shibiny 2013). Endogenous peptides derived from donkey milk (EWFTFLKEAGQGAKDMWR, GQGAKDMWR, REWFTFLK, and MPFLKSPIVPF) have been investigated in cardiovascular disease prevention (Zenezini Chiozzi et al., 2016). The enzymatic proteolysis of whey proteins gives rise to several antihypertensive peptides, including α-lactorphin (Tyr-Gly-Leu-Phe) and β-lactorphin (Tyr-Leu-Leu-Phe), Tyr-Pro, Lys-Val-Leu-Pro-Val-Pro-Gln, α-lactalbumin, and β-lactoglobulin (Sipola et al., 2002). The use of lactic acid bacteria represents a new strategy to obtain BP from the fermentation processes of milk proteins. As an example, L.helveticus LBK-16H fermented milk contains the BP Val-Pro-Pro and Ile-Pro-Pro which are well-known for their antihypertensive activities, acting as ACE inhibitory molecules (Cicero et al., 2016).

Eggs are also a good source of many BP used in medicine and the food industry (Sun et al., 2016). The peptide Arg-Val-Pro-Ser-Leu from egg white protein exhibits antihypertensive properties (Yu Z. et al., 2011). From boiled eggs, more than 60 peptides have been identified and some of them demonstrate anti-inflammatory and antioxidant effects through in vitro studies (Remanan and Wu 2014).

BP derived from meat products have the potential to be studied as functional foods and nutraceuticals. Both meat and fish BP have been shown to exhibit antimicrobial, anti-proliferative and cardiovascular-protection activities in vitro and in vivo even if a limited number of nutraceuticals containing meat-derived BP are commercially available (Cicero et al., 2016). Arg-Pro-Arg peptide from pork meat showed the greatest antihypertensive activity in vivo in addition to Lys-Ala-Pro-Val-Ala and Pro-Thr-Pro-Val-Pro (Escudero et al., 2012).

Vegetal Sources

Vegetal sources a...

Table of contents

• Cover
• Half-Title
• Series
• Title
• Copyright
• Contents
• Series Preface
• Preface
• Editors
• List of Contributors
• SECTION 1 BIOACTIVE PEPTIDES
• SECTION 2 SOURCES OF BIOACTIVE PEPTIDES
• SECTION 3 FROM PROTEINS TO PEPTIDES
• SECTION 4 ANALYSIS OF BIOACTIVE PEPTIDES
• SECTION 5 CHEMICAL SYNTHESIS OF PEPTIDES
• SECTION 6 FUNCTIONS OF BIOACTIVE PEPTIDES
• SECTION 7 REGULATORY STATUS OF BIOACTIVE PEPTIDES
• Index