Functional Food Product Development

Jim Smith, Edward Charter, Jim Smith, Edward Charter

• Publisher: Wiley-Blackwell
• Year: 2011
• ISBN:
  9781444390391
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

According to an August 2009 report from PricewaterhouseCoopers, the United States market for functional foods in 2007 was US$ 27 billion. Forecasts of growth range from between 8.5% and 20% per year, or about four times that of the food industry in general. Global demand by 2013 is expected to be about $100 billion. With this demand for new products comes a demand for product development and supporting literature for that purpose. There is a wealth of research and development in this area and great scope for commercialization, and this book provides a much-needed review of important opportunities for new products, written by authors with in-depth knowledge of as yet unfulfilled health-related needs.

This book addresses functional food product development from a number of perspectives: the process itself; health research that may provide opportunities; idea creation; regulation; and processes and ingredients. It also features case studies that illustrate real product development and commercialization histories. Written for food scientists and technologists, this book presents practical information for use in functional food product development. It is an essential resource forpractitioners in functional food companies and food technology centres and isalso of interest to researchers and students of food science.

Key features:

• A comprehensive review of the latest opportunities in this commercially important sector of the food industry
• Includes chapters highlighting functional food opportunities for specific health issues such as obesity, immunity, brain health, heart disease and the development of children. New technologies of relevance to functional foods are also addressed, such as emulsion delivery systems and nanoencapsulation.
• Includes chapters on product design and the use of functional ingredients such as antioxidants, probiotics and prebiotics as well as functional ingredients from plant and dairy sources
• Specific examples of taking products to market are provided in the form of case studies e.g. microalgae functional ingredients

• Part of the Functional Food Science and Technology book series (Series Editor: Fereidoon Shahidi)
  
  

Part I: New Technologies for Functional Food Manufacture

1: Microencapsulation in functional food product development

Luz Sanguansri and Mary Ann Augustin

1.1 Introduction

Functional foods provide health benefits over and above normal nutrition. Functional foods are different from medical foods and dietary supplements, but they may overlap with those foods developed for special dietary uses and fortified foods. They are one of the fastest growing sectors of the food industry due to increasing demand from consumers for foods that promote health and well-being (Mollet & Lacroix 2007). The global functional food market, which has the potential to mitigate disease, promote health and reduce health care costs, is expected to rise to a value of US$167 billion by 2010, equating to a 5% share of total food expenditure in the developed world (Draguhn 2007).

Functional foods must generally be made available to consumers in forms that are consumed within the usual daily dietary pattern of the target population group. Consumers expect functional foods to have good organoleptic qualities (e.g. good aroma, taste, texture and visual aspects) and to be of similar qualities to the traditional foods in the market (Klont 1999; Augustin 2001; Kwak & Jukes 2001; Klahorst 2006). The demand for bioactive ingredients will continue to grow as the global market for functional foods and preventative or protective foods with associated health claims continues to rise. Over the last decade, there has been significant research and development in the areas of bioactive discovery and development of new materials, processes, ingredients and products that can contribute to the development of functional foods for improving the health of the general population.

New functional food products launched in the global food and drinks market have followed the route of fortification or addition of desirable nutrients and bioactives including vitamins, minerals, antioxidants, omega-3 fatty acids, plant extracts, prebiotics and probiotics, and fibre enrichments. Many of these ingredients are prone to degradation and/or can interact with other components in the food matrix, leading to loss in quality of the functional food products. To overcome problems associated with fortification, the added bioactive ingredient should be isolated from environments that promote degradation or undesirable interactions. This may be accomplished by the use of microencapsulation where the sensitive bioactive is packaged within a secondary material for delivery into food products. This chapter covers the microencapsulation of food components for use in functional food product formulations and how these components can be utilised to develop commercially successful functional foods.

1.2 Microencapsulation

Microencapsulation is a process by which a core, i.e. bioactive or functional ingredient, is packaged within a secondary material to form a microcapsule. The secondary material, known as the encapsulant, matrix or shell, forms a protective coating or matrix around the core, isolating it from its surrounding environment until its release is triggered by changes in its environment. This avoids undesirable interactions of the bioactive with other food components or chemical reactions that can lead to degradation of the bioactive, with the possible undesirable consequences on taste and odour as well as negative health effects.

It is essential to design a microencapsulated ingredient with its end use in mind. This requires knowledge of (1) the core, (2) the encapsulant materials, (3) interactions between the core, matrix and the environment, (4) the stability of the microencapsulated ingredient in storage and when incorporated into the food matrix and (5) the mechanisms that control the release of the core. Table 1.1 gives examples of cores that have been microencapsulated for use in functional food applications. The molecular structure of the core is usually known. However, information is sometimes lacking on how the core interacts with other food components, its fate upon consumption, its target site for action and in the case of a bioactive core, sometimes its function in the body after ingestion may also be unclear (de Vos et al. 2006).

Table 1.1 Food ingredients that have been microencapsulated

Types of ingredients
Flavouring agents (including sweeteners, seasonings and spices)
Acids, bases and buffers (e.g. citric acid, lactic acid and sodium bicarbonate)
Lipids (e.g. fish oils, milk fat and vegetable oils)
Enzymes (e.g. proteases) and microorganisms (e.g. probiotic bacteria)
Amino acids and peptides
Vitamins and minerals
Antioxidants
Polyphenols
Phytonutrients
Soluble fibres

1.2.1 Encapsulant materials

Depending on the properties of the core to be encapsulated and the purpose of microencapsulation, encapsulant materials are generally selected from a range of proteins, carbohydrates, lipids and waxes (Table 1.2), which may be used alone or in combination. The materials chosen as encapsulants are typically film forming, pliable, odourless, tasteless and non-hygroscopic. Solubility in aqueous media or solvent and/or ability to exhibit a phase transition, such as melting or gelling, are sometimes desirable, depending on the processing requirements for production of the microencapsulated ingredient and for when it is incorporated into the food product. Other additives, such as emulsifiers, plasticisers or defoaming agents, are sometimes included in the formulation to tune the final product's characteristics. The encapsulant material may also be modified by physical or chemical means in order to achieve the desired functionality of the microencapsulation matrix. The choice of encapsulant material is therefore dependent on a number of factors, including its physical and chemical properties, its compatibility with the target food application and its influence on the sensory and aesthetic properties of the final food product (Brazel 1999; Gibbs et al. 1999).

Table 1.2 Materials that have been used as encapsulants for food application

	Encapsulant materials
Carbohydrates	Proteins	Lipids and waxes
Native starches Modified starches Resistant starches Maltodextrins Dried glucose syrups Gum acacia Alginates Pectins Carrageenan Chitosan Cellulosic materials Sugars and derivatives	Sodium caseinate Whey proteins Isolated wheat proteins Soy proteins Gelatins Zein Albumin	Vegetable fats and oils Hydrogenated fats Palm stearin Carnauba wax Bees wax Shellac Polyethylene glycol

The ability of carbohydrates to form gels and glassy matrices has been exploited for microencapsulation of bioactives (Reineccius 1991; Kebyon 1995). Starch and starch derivates have been extensively used for the delivery of sensitive ingredients through food (Shimoni 2008). Chemical modification has made a number of starches more suitable as encapsulants for oils by increasing their lipophilicity and improving their emulsifying properties. Starch that was hydrophobically modified by octenyl succinate anhydride had improved emulsification properties compared to the native starch (Bhosale & Singhal 2006; Nilsson & Bergenståhl 2007). Acid modification of tapioca starch has been shown to improve its encapsulation properties for β-carotene, compared to native starch or maltodextrin (Loksuwan 2007). Physical modification of starches by heat, shear and pressure has also been explored to alter its properties (Augustin et al. 2008), and the modified starch has been used in combination with proteins for microencapsulation of oils (Chung et al. 2008).

Carbohydrates used for microencapsulation of β-carotene, from sea buckthorn juice, by ionotropic gelation using furcellaran beads, achieved encapsulation efficiency of 97% (Laos et al. 2007). Interest in using cyclodextrins and cyclodextrin complexes for molecular encapsulation of lipophilic bioactive cores is ongoing, especially in applications where other traditional materials do not perform well, or where the final application can bear the cost of this expensive material. The majority of commercial applications for cyclodextrins have been for flavour encapsulation and packaging films (Szente & Szejtli 2004).

Proteins are used as encapsulants because of their excellent solubility in water, good gel-forming, film-forming and emulsifying properties (Kim & Moore 1995; Hogan et al. 2001). Protein-based microcapsules can be easily rehydrated or solubilised in water, which often results in immediate release of the core. Proteins are often combined with carbohydrates for microencapsulation of oils and oil-soluble components. In the manufacture of encapsulated oil powders, encapsulation efficiency was higher when the encapsulation matrix was a mixture of milk proteins and carbohydrates, compared to when protein was used alone (Young et al. 1993). Soy protein-based microcapsules of fish oil have been cross-linked using transglutaminase to improve the stability of the encapsulated fish oil (Cho et al. 2003). Protein-based hydrogels are also useful as nutraceutical delivery systems (Chen et al. 2006). The release properties of protein-based hydrogels and emulsions may be modulated by coating the gelled particles with carbohydrates. A model-sensitive core, paprika oleoresin, was encapsulated in microspheres of whey proteins and coated with calcium alginate to modify the core's release properties (Rosenberg & Lee 2004). Whey protein-based hydrogels with an alginate coating altered the swelling properties of the gelled particles. The stability of these particles was increased at neutral and acidic conditions both in the presence and absence of proteolytic enzymes (Gunasekaran et al. 2007).

Lipids are generally used as secondary coating materials applied to primary microcapsules or to powdered bioactive cores to improve their moisture barrier properties (Wu et al. 2000). Lipids can also be incorporated in an emulsion formulation to form a matrix or film around the bioactive core (Crittenden et al. 2006).

The increasing demand for food-grade materials that will perform under the different stresses encountered during food processing has spurred the development of new encapsulant materials. Understanding the glass transition temperature of various polymers (e.g. proteins and carbohydrates) and their mixtures is also becoming important as this can influence the stability of the encapsulated core. The low water mobility and slow oxygen diffusion rates in glassy matrices can improve stability of bioactives (Porzio 2003). It is possible to exploit thermally induced interactions between proteins and polysaccharides and then ...

Table of contents

• Cover
• Half Title Page
• Functional Food Science and Technology Series
• Title Page
• Copyright
• Preface
• Contributors
• Part I: New Technologies for Functional Food Manufacture
• Part II: Functional Ingredients
• Part III: Product Design and Regulation
• Part IV: Functional Foods and Health
• Food Science and Technology
• Color Plates
• Index
• End User License Agreement