Food Hydrocolloids as Encapsulating Agents in Delivery Systems

Adil Gani, F.A. Masoodi, Umar Shah, Shah Asima

• Publisher: CRC Press
• Year: 2019
• Print ISBN: 9781138600140
• eBook ISBN: 9780429894169
• Edition: 1
• Topic: Commerce
• Subtopic: Industrie pharmaceutique, biotechnologique et de la santé

This book addresses the use of food hydrocolloids as agents for encapsulating biological active ingredients. It details the challenges of poorly-controlled rate of hydration, thickness, decrease in viscosity upon storage, and susceptibility to microbial contamination. Food Hydrocolloids as Encapsulating Agents in Delivery Systems briefly describes various emerging biomaterials including food gums, starches, beta glucans, and proteins for their potential role as wall material in the development of nutraceutical delivery systems. Further, it describes different techniques of fabrication of nanodelivery systems.

Features:

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• Provides an introduction to food hydrocolloids as encapsulating agents

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• Covers starches and their derivatives as delivery systems

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• Includes gum-based delivery systems

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• Discusses the classification, isolation, and purification of protein delivery systems

This book would be helpful to food scientists and pharmaceutical scientists working in areas including nanotechnology, polymer chemistry, and nutraceutical delivery, as well as regulators and government researchers in US FDA, USDA, and UK FSA regulatory agencies.

1

INTRODUCTION TO FOOD HYDROCOLLOIDS

BASHARAT YOUSUF

Aligarh Muslim University

NISAR AHMAD MIR AND MAMTA BHARDWAJ

Sant Longowal Institute of Engineering and Technology

KHALID GUL

Gyeongsang National University

ALI ABAS WANI

Fraunhofer Institute of Process Engineering and Packaging IVV

Contents

1.1Introduction

1.1.1Food Hydrocolloids as Encapsulating Agents

1.1.2Regulatory and Health Aspects of Hydrocolloids

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1.1.2.2Health-Related Aspects of Hydrocolloids

1.1.3Well-Known and Commonly Used Food Hydrocolloids in Encapsulation Technologies

1.1.4Approaches in Use of Hydrocolloids for Encapsulation

1.1.5Need to Shift Encapsulation Technology from Micro to Nano Level

1.1.5.1Food Hydrocolloids and Their Use as Nanoencapsulating Agents

1.1.6Future Prospects

References

1.1 Introduction

The term “hydrocolloid” is derived from the Greek word hydro meaning “water” and kola meaning “glue.” Hydrocolloids are colloidal substances that consist of hydrophilic, long-chain, and high-molecular-weight molecules with a strong affinity for water. Hydrocolloid is a contraction of hydrophilic colloid and is the more scientific name for gums. Hydrocolloids produce highly viscous suspensions or gels when dispersed in water and are termed as hydrophilic colloids or hydrocolloids considering their strong hydrophilic nature and for producing a dispersion, which is intermediate between a true solution and a suspension (Saha and Battacharya, 2010). Hydrocolloids are obtained from botanical sources (starch, cellulose, pectin, gum arabic, karaya, tragacanth, β-glucan, etc.), seaweeds (agar, alginate, and carraggenan), animal sources (gelatin, chitosan, and hyaluronan), and bacterial sources (xanthan, gellan, and dextran). Table 1.1 shows different types of food hydrocolloids and their sources.

Hydrocolloids form the basis for much of the energy and nutrients required by the human body and also contribute to the macroscopic structure of foods (Gidley, 2013). They, therefore, play a major role in defining both the sensory and nutritional qualities of human diets. Hydrocolloids are primarily used for thickening and/or gelation, but they often exhibit related secondary functions, such as emulsifying, suspending, whipping, viscosifying, and encapsulating (Janaswamy & Youngren, 2012). They are ubiquitous—no other ingredient contributes more to viscosity, texture, and body in processed foods like they do. Once dispersed in water, hydrocolloids give a thickening or viscosity-producing effect. This property of thickening is common to all hydrocolloids, and the primary reason behind the ample use of hydrocolloids in foods is their ability to modify the rheology of food systems. This includes flow behavior (viscosity) and mechanical solid property (texture), which are the two basic properties of food systems (Milani & Maleki, 2012). The extent of thickening depends on the type and nature of hydrocolloids used. Most of the hydrocolloids result in high viscosities at concentrations below 1%, whereas a few result in low viscosities at a fairly high concentration (Glicksman, 1982). The selection of a hydrocolloid in processed foods is dictated by the functional characteristics required, but the price and security of supply influence the usage. Starches are, therefore, being widely used in food industries as gelling and thickening agents.

Table 1.1 Commonly Used Hydrocolloids in Food Industries and Their Sources

Food hydrocolloids being an important additive are finding increasing applications for the encapsulation of nutraceuticals and functional ingredients. They are very convenient as a wall material for nutraceuticals and other food ingredients, since the majority of the hydrocolloids are soluble in aqueous solutions, thus avoiding toxicity problems (Pérez-Masiá et al., 2015). In this chapter, food hydrocolloids as encapsulating agents, their regulatory aspects, and their current applications are discussed.

1.1.1 Food Hydrocolloids as Encapsulating Agents

The most important groups of ingredients used in stabilizing and protecting flavors are the hydrocolloids. Hydrocolloids are hydrophilic polymers that are extracted from plants and animals and have been successfully used for the entrapment, protection from the environment, and controlled release of high-valued food products such as antioxidants, antimicrobials, flavors, and probiotics. Hydrocolloids have been successfully demonstrated to protect the encapsulated molecules from external stressors, preserve functionality, and deliver efficiently at the target site (Polowsky & Janaswamy, 2015). Considering incompatibilities to the human digestive system, some hydrocolloids are modified using physicochemical and biochemical methods to improve their encapsulating properties.

Starch and its derivatives, maltodextrins, cellulose, agar, carrageenans, gum arabic, alginates, low methoxyl (LM) pectin, chitosan, gellan gum, and gelatin are the natural polymers which are potentially used for encapsulation (King, 1995). Protein-based delivery systems have also been used for the encapsulation recently. The properties that make natural polymers useful for encapsulation–entrapment applications have been reviewed by Reineccius (1989) and Grover (1993) and Whistler (1993).

The selection of wall material is very important because it influences the encapsulation efficiency and stability. The ideal wall material should not be reactive with the core, have the ability to seal and maintain the core inside the capsule, be able to provide maximum protection to the core against adverse conditions, lack an unpleasant taste, and be economically viable. Food hydrocolloids offer all these benefits and are, therefore, an ideal choice as a wall material for encapsulation. Different techniques have been used to encapsulate functional components using polymeric materials, including extrusion (Li et al., 2011), fluidized bed coating (Zuidam & Shimoni, 2010), nanoemulsions (Silva et al., 2012), coacervation (Tamjidi et al., 2012), spray cooling (Gibbs et al., 1999), and spray drying (Murugesan & Orsat, 2012). The techniques used for the encapsulation strongly influence the stability and delivery of the encapsulated substances, which are beyond the scope of this book.

1.1.2 Regulatory and Health Aspects of Hydrocolloids

1.1.2.1 Regulatory Aspects of Hydrocolloids

1.1.2.1.1 Joint FAO/WHO Expert Committee on Food Additives

There are no separate laws for regulation of hydrocolloids. They are dealt in the category of food additives or food ingredients. For regulation, a committee called Joint FAO/WHO Expert Committee on Food Additives (JECFA) administered jointly by the Food and Agriculture Organization (FAO) of the United States and the World Health Organization (WHO) was enacted to evaluate the safety of food additives. JECFA provides reports related to specifications, safety, and other aspects of a food additive to the Codex Committee on Food Additives and Contaminants (CCFAC). If the members of the Codex Alimentarius Commission agree, then the specified food additive is assigned with a unique identification number International Numbering System (INS) and included in the Codex General Standard for Food Additives (GSFA). An online database called GSFA is available to check the provisions related to a food additive covered under FAO/WHO Food Standards Codex Alimentarius (Phillips & Williams, 2009).

1.1.2.1.2 European System

Different Commission regulations have been developed for the list of approved food additives and the specifications of food additives. The food additives that have been approved by the European Union are available in Commission Regulation (EU) No 1129/2011 amending Annex II to Regulation (EC) No 1333/2008. This regulation covers the names and E numbers of different additives, definitions for the group of additives, foods to which they may be added, and the conditions in which they can be used. Another regulation covers the specifications of approved food additives such as criteria of purity, origin, and other relevant information. The specifications are covered in Commission Regulation (EU) No 231/2012. Table 1.2 shows the E numbers assigned to hydrocolloids as food additives and the statuses related to ADI value, quantum satis, and GRAS, which are described as follows: E number is an indicative of the code assigned to a substance which has been permitted to be used as a food additive under the European system. ADI value represents the acceptable daily intake amounts of the food additive in question. GRAS covers those food additives which are “generally recognized as safe” for human consumption. Quantum satis is a term used to indicate that no maximum level has been specified for the food additive.

1.1.2.1.3 Manufacturing Process Changes and, Safety, and Regulatory Status of Hydrocolloids

A book guidance for the industry has been developed by the Food and Drug Administration (FDA) for determining the influence of manufacturing process changes on different food ingredients and food contact substances, and this covers manufacturing processes of hydrocolloids as well. For example, under 21 CFR 172.620 regulation, carrageenan is defined as “a refined hydrocolloid prepared by aqueous extraction from specific red seaweeds.” In this regulation, the seaweeds from which carrageenan is extracted are listed. Any change in the manufacturing process is submitted to FDA so as to get the GRAS status. Another example is xanthan gum, which is regulated by 21 CFR 172.695 regulation (FDA, 2012).

Table 1.2 European Union Specifications of Some Hydrocolloids

1.1.2.2 Health-Related Aspects of Hydrocolloids

Health-related aspects of hydrocolloids are greatly determined by their amount and the way of their incorporation into the food system. In general, some common properties of hydrocolloids are credited for their positive as well as negative health-related impacts, for example, viscosity and gel-forming properties (guar gum, alginates, inulin, pectin, etc.), bulk or water-sequestering properties (cellulose derivatives, hemicellulose, etc.), and the ability to get fermented (pectin, resistant starch, some oligosaccharides, etc.) (Cummings et al., 1992; Dikeman & Fahey, 2006). Various gums such as guar gum, locust bean gum, and xanthan gum exhibit blood cholesterol-lowering properties; polysaccharides such as cellulose and hemicellulose derivatives aid in maintaining the colon health (Gidley, 2013); and others such as inulin show prebiotic effects (Hecker et al., 1998). Thus, in the case of encapsulation, the synchronized effect on health can be observed because of the target and the encapsulating hydrocolloid, depending upon the concentration or amount of hydrocolloid and the nature of target in question. The first and fo...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Contents
• Preface
• Editors
• Contributors
• Chapter 1 Introduction to Food Hydrocolloids
• Chapter 2 Gum-Based Delivery Systems
• Chapter 3 Starch-Based Delivery System
• Chapter 4 β-Glucan–Based Delivery System
• Chapter 5 Protein-Based Delivery Systems
• Chapter 6 Nanoscale Encapsulation
• Index