Functional and Speciality Beverage Technology

P Paquin

• Publisher: Woodhead Publishing
• Year: 2009
• Print ISBN: 9781845693428
• eBook ISBN: 9781845695569
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

As consumer demand for traditional carbonated drinks falls, the market for beverages with perceived health-promoting properties is growing rapidly. Formulating a nutritional, nutraceutical or functional beverage with satisfactory sensory quality and shelf-life can be challenging. This important collection reviews the key ingredients, formulation technology and health effects of the major types of functional and speciality beverage.Chapters in part one consider essential ingredients such as stabilizers and sweeteners, and significant aspects of formulation such as fortification technology and methods to extend shelf-life. Dairy-based beverages are the focus of Part two, with chapters covering methods to improve the nutritional and sensory quality and technological functionality of milk, a crucial ingredient in many healthful beverages. Chapters on newer dairy ingredients, such as whey and milk-fat globule membrane complete the section. Part three then reviews advances in the significant plant-based beverage sector, with chapters on popular products such as fruit juices, sports drinks, tea and coffee. Soy proteins are also covered. Chapters on product development and the role of beverages in the diet complete the volume.With its distinguished editor and contributors, Functional and speciality beverage technology is an essential collection for professionals and academics interested in this product sector. - Reviews the key ingredients, formulation technology and health effects of the major types of functional and speciality beverages - Essential ingredients such as stabilizers and sweeteners, and significant aspects of formulation such as fortification technology and methods to extend shelf-life are considered - Focuses on methods to improve the nutritional and sensory quality and technological functionality of milk

Part I

Beverage ingredients and technology

1

Ingredient selection for stabilisation and texture optimisation of functional beverages and the inclusion of dietary fibre

M.J. Fallourd Danisco, France

L. Viscione Danisco (UK) Ltd, UK

Abstract

A functional beverage is usually formulated by adding functional ingredients and/or by reducing levels of ingredients considered less healthy such as sugar and fat. The composition of the beverage has a direct impact on the ingredient selection needed to achieve the targeted texture and the stability of the beverage. To overcome these challenges the use of ingredients such as hydrocolloids and emulsifiers is key to monitoring the stability and texture of the final product. Tools for understanding the key parameters to consider when selecting the ingredients to texture and stabilise a defined beverage are given. The addition of fibre as a functional ingredient within the beverage matrix can have a direct effect on the mouthfeel, texture and flavour release in a chosen beverage system. The type of fibre ingredient must be chosen and evaluated carefully to ensure desirable textures and flavour profile.

Key words

beverage

dietary fibre

hydrocolloids

stability

texture

1.1 Introduction

The challenges faced when developing functional beverages are numerous. A functional beverage is usually formulated by adding functional ingredients and/or by reducing levels of ingredients considered as less healthy, such as sugar and fat. The objective is to secure health claims, yet develop stable beverages with an appealing flavour profile and mouthfeel throughout their shelf-life.

Incorporating the necessary amount of a functional ingredient into a beverage to allow for a health claim or to reach the targeted functional property targeted is often a challenge as these ‘functional’ ingredients may have a direct impact on the texture (e.g. fibres) and or on the stability (e.g. minerals, proteins). Reducing the fat or sugar level to aim for ‘lower/no/reduced’ type of claim has a direct impact on the texture of the beverage and in some cases on the stability.

These challenges in product development are increased by the nature of the finished product: a very low viscosity matrix. On a general basis, beverages are less robust to formulation and process variations than more viscous products.

The term beverage covers a very wide variety of types of food matrices and compositions. Classification can be made according to the formulation

• dairy-based beverages

acid

neutral

• plant-based products

containing protein beverages

without protein beverages

■ acid

■ neutral

The composition has a direct impact on the selection of the ingredients needed to achieve the targeted texture and stability of the beverage. Process parameters such as homogenisation, heat treatment (time, temperature) and filling temperature also play a key role. The use of ingredients such as hydrocolloids and emulsifiers are key to ensuring the stability and texture of the final product.

Tools to determine which key parameters to consider when selecting the ingredients to texture and stabilise a defined beverage will be given. The approach is relatively general as details for each beverage category are addressed in the following chapters.

1.2 Challenges faced when formulating functional beverages with a good stability, texture and mouthfeel

Prior to formulating it is important to identify and define the final functionality we wish the ingredients to fulfil.

1.2.1 Definitions of texture and stabilisation in beverages

In order to quantify or measure texture, a viscosity measurement is often referred to. Viscosity, however, describes only one attribute of the product as it is measured at a given shear rate. Texture is, on the other hand, a very wide term which covers a number of rheological properties and sensory descriptors. Texture covers the whole appearance and sensation when drinking the beverage:

• appearance when pouring;

• glazing on the bottle;

• first mouth sensation;

• coating of the mouth;

• residual perception.

The importance of the rheological behaviour, and more specifically, of flow properties of gums (hydrocolloids) is that the behaviour can be related to the mouthfeel or textural properties of the gum (Glicksman, 1982).

Stabilisation is a very wide and general term which relates to many different, complex biophysicochemical mechanisms. Each stabilisation parameter needs to be properly described and categorised in order to be addressed. Generally, a stabilised beverage refers to a homogeneous and smooth beverage. Depending on the beverage formulation and final functionalities targeted, stabilisation can be further defined as follows:

• Particle stabilisation: The particles such as pulps, cacao particles and minerals are evenly suspended throughout the beverage.

• Emulsion stabilisation: There is no oil or fat ring on the top of the beverage container or bottle.

• Protein stabilisation:

the proteins contained in the beverage have not flocculated, nor become sediment;

the beverage exhibits a smooth and non-sandy mouthfeel.

• Stabilisation of the texture, often including the functionalities mentioned above. The viscosity and appearance is homogeneous throughout the beverage, meaning

no gel points, or lumps;

no viscosity gradient;

no layer formation;

no phase separation;

no clarification;

no flocculation.

Each parameter has a different ingredient solution and depends on the formulation and the process of the beverage.

1.3 Mechanism involved in texture and stabilisation of beverages

1.3.1 Thickening and gelling agents

Hydrocolloids can roughly be divided into two categories on the basis of their functionality in beverages: thickening agents and gelling agents. Thickening agents provide texture to the beverage, but are not capable of suspending particulates. They slow the settling of particles or the rising of oil droplets, but they cannot stop separation from occurring (Hoefler, 2004). Gelling agents form links between their molecules, building a threedimensional network. The result is that the particles or oil droplets become permanently suspended in the matrix and do not separate out, provided that the density of the particulates is lower than the yield value created by the network (Hoefler, 2004).

In the particular case of protein stabilisation in acid beverages, casein and more generally food proteins will tend to agglomerate and form a sediment. In these cases the proteins are also very sensitive to dehydration and can easily become sandy after heat treatment. In order to avoid protein agglomeration, chalky texture and sedimentation, formulation with specific hydrocolloids that have a direct interaction with the proteins through electrostatic interactions is essential.

Most food proteins (isoelectric point around 5) can form complex coac-ervates with anionic polysaccharides such as high ester pectins, carboxy-methylcellulose (CMC) or propylene glycol alginate (isoelectric point around 3.5) in the intermediate region where the two macromolecules carry opposite net charges: pH above the isoelectric point of the polysaccharide below the isoelectric point of the protein.

The strength of the polysaccharide – protein interaction will depend on several factors, such as the distribution of the carboxyl groups on the backbone, the three-dimensional protein structure and the distribution of the ionisable groups on its surface. The whole interaction will also depend on factors such as pH, ionic strength, and presence of sugars or fat (Futo, 1993).

The ideal way of characterising a beverage is to measure its flow curve. Figure 1.1 shows the idealised flow curve of a thi...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright page
• Contributor contact details
• Preface
• Part I: Beverage ingredients and technology
• Part II: Dairy-based beverages
• Part III: Plant-based beverages
• Part IV: Beverage development and consumption
• Index