From Milk By-Products to Milk Ingredients

Upgrading the Cycle

Ruud de Boer

• Publisher: Wiley
• Year: 2014
• Print ISBN: 9780470672228
• eBook ISBN: 9781118598702
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

Milk is a complex substance, and a variety of constituents can be extracted from it for use as ingredients in other foods. The main ingredients from milk are milk fat, cheese and serum, but this range is continually expanding as food companies, dairies and dairy scientists seek to utilize as many raw materials and by-products as possible, to reduce waste, maximize efficiency, and increase productivity. 

Ingredients from Milk is a concise, fresh approach to ingredients derived from milk, containing guidance and new techniques for dairy industry professionals and scientists.

has a structure is designed to mirror the process of extracting ingredients from milk, beginning with the basic concepts and following through the processes until finally arriving at the consumer products which constitute the end uses of ingredients from milk. 

This book is primarily targeted at the dairy industry, but also provides a valuable insight for academics and students seeking an industry perspective.

1
Ingredients

An ingredient is a part of a recipe that gives valuable properties to the final product. Food ingredients are used, for instance, to enhance flavour, nutrition and texture. Thousands of recipes can be found in a wide variety of cookbooks. Some of them have a long history. Cookbooks have the great advantage that the information is properly recorded and is not dependent on oral transmission. In antiquity, milk or a part of it, such as cheese, was already applied in various recipes. Ingredients from milk were born. In the course of time food habits were developed; for instance, a combination of cheese and fish was already disliked in Italy in the fifth century BC. The origin of this lies in the difference in diet between the farmers who prepared the cheese, and the fishermen, who were active on the coast (Sancisi-Weerdenburg, 1995).

Preparation of food is a time-consuming activity. Nowadays, processed foods are commonly used and the time spent in the kitchen is reduced considerably. A lot of work in the kitchen has been moved from home to process plants. For example, sauces and dressings containing various ingredients are sold in huge variety in supermarkets and are rarely prepared at home today. Advantages are that the outcome in the meal is predictable and its quality is meticulously controlled. The reproducibility of the processed food relies on the properties of the individual ingredients. They are produced in specialized ingredient plants. Large-scale manufacture is not only responsible for a consistent quality, but also the shelf life is improved and the cost of the ingredients is reduced. Consistency is crucial in processing. Deviations in quality result in defective products, which is expensive due to loss of raw materials, energy and process time.

Food labels in today's supermarkets are an interesting source of information. The ingredient list reflects the choice of ingredients of the manufacturer. Sometimes up to 50 ingredients are mentioned on the label of the package, drawn from a family of tens of thousands of food ingredients. Important categories of food ingredients, including additives, are carbohydrates and sweeteners, oil and fats, vegetable and animal proteins, water, spices, fruits and flavours, stabilizers, emulsifiers, vitamins, minerals, colours and preservatives. The numbers are still growing over time. Milk ingredients represent approximately 5% of the total number of ingredients, based on the author's own estimation and various buyers' guides (Food Product Design, 2007–2008).

The proportion of ingredients from milk used in any given product will depend on the type of industry considered. In case of one of the largest dairy companies, FrieslandCampina, the average proportion of milk ingredients in the overall ingredients list is about 25% (GRA van der Werff, 2010, personal communication). However, there can be big differences between the various segments of the dairy industry itself. Large users of all kinds of ingredients are processed cheese, imitation cheese and liquid milk products. The latter can be complex products, which include, for instance, fruit yoghurts, drinks and desserts. In summary it can be concluded that the dairy industry is an important customer of its own ingredients.

Since the publication of the well-known book entitled Byproducts from Milk (Whittier & Webb, 1950), enormous development has taken place in the dairy industry. At that time the basis of this industry was dominated by butter, cheese, liquid milk and cream. The remaining by-products were used as liquid animal feed or applied as fertilizer. The farmers' milk price was based on milk fat only; the value of milk protein was underestimated, while lactose was totally out of the picture. Changes in consumer preference took place particularly after World War II. The gradual switch from traditional products to convenience foods posed a new challenge for the food industry. The dairy industry also took part in this development, for instance by the introduction of coffee whiteners and desserts. Milk proteins in the form of caseinates were developed and introduced in all kinds of food products such as sausages. After 1970 new technologies emerged, of which various membrane processes were a major breakthrough. Separation of undenatured whey proteins became a reality. The foaming, gelling and emulsifying properties of undenatured whey proteins were favourable for new applications. The end uses of this type of ingredient increased substantially. In selecting an ingredient, adding value became an important topic for both end users and suppliers. Addition of value can be related to several properties of the finished product such as texture, flavour, nutritional value and colour, and also to yield.

At the same time the cooling of raw milk on the farm became more common. The scientific knowledge that cooling of milk (<4°C) retarded bacterial growth considerably was translated into the design and adoption of bulk storage tanks. The prolonged storage of milk made the distance of the farm to the process plant less critical. It favoured the development of larger plants and kept costs at a reasonable level. In areas with a large dairy industry, for instance in The Netherlands, ingredient plants with an enormous capacity could be constructed.

After 1970 environmental issues became more critical than ever as the industry had to pay for its own pollution. This forced the dairy industry to use all of the milk constituents and close the cycle as much as feasible. All these developments helped to create a situation in which by-products such as whey became actual ingredients.

An ingredient is a word that can be applied in various ways. In case of ingredients from milk their application is not limited to food. As will be shown in this chapter and in Chapter 7 (‘End User’), these include applications in feed, pharmaceuticals and personal care products. The following definition will be used in this book:

• An ingredient is a substance of dairy origin, which is used in the manufacture or preparation of a variety of food and non-food finished products.

Ingredient is the key concept. A food ingredient distinguishes itself from a food additive. Milk and milk derivatives are normally considered characteristic ingredients of a food (EU, 2008). Dairy ingredients are safe to use and in general do not require extensive permission procedures. The description is simpler than the statutory definition of a food ingredient (EU, 2011) because of the limitation to dairy origin. Milk powder, which is applied in finished products such as reconstituted liquid milk and yoghurts, is also included in the definition. Besides food ingredients the field of application is much wider as non-food finished products are included too. Manufacture as well as preparation is mentioned, which reflects the possible scale of operation of the end user. Indeed, it may take some years before an application reaches maturity.

In the following sections the focus will be on ingredient list, ingredient and cycle, and ingredient and adding value.

1.1 Ingredient list

Based on various food laws, for instance in the USA and the European Union (EU), food labels have to contain information about ingredients in order to allow customers to make more informed purchasing decisions. In most countries it is a meticulously regulated area. The food label includes a list of ingredients, nutrition information and shelf life, but it should also hold warnings against allergens. In this chapter we will restrict ourselves to the list of ingredients as it fits best in the context of this book. The list of ingredients mostly includes also small percentages of additives, which are applied for purposes such as texture, flavour, colour and shelf life. Additives, being approved substances, are not considered to have nutritive va...

Table of contents

• Cover
• Titlepage
• Copyright
• Dedication
• Epigraph
• Contents
• Foreword
• Preface
• Acknowledgements
• Introduction
• 1 Ingredients
• 2 Milk Specifics
• 3 Patents
• 4 Reuse
• 5 Outside Constraints
• 6 Vital Membrane Processes
• 7 End Users
• Information Sheets
• Index