Meat Products Handbook

Practical Science and Technology

G Feiner

• Publisher: Woodhead Publishing
• Year: 2006
• ISBN:
  9781845691721
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

There has long been a need for a comprehensive one-volume reference on the main types of processed meat products and their methods of manufacture. Based on over twenty years' experience in the industry, Meat products handbook is designed to meet that need. It combines a detailed practical knowledge of processing and ingredients with the scientific underpinning to understand the effect of particular process steps and ingredients on product safety and quality.The first part of the book reviews meat composition and its effect on quality together with the role of additives. There are chapters on fat, protein and other components in meat, changes in meat pre- and post-slaughter, and additives such as phosphates, salts, hydrocolloids, proteins, carbohydrates and fillers. Part two reviews raw materials, additives, manufacturing processes and representative recipes from around the world for a range of particular meat products. It includes chapters on cooked ham and bacon, cooked, fresh and raw fermented sausages, raw fermented and non-fermented salami, cured air-dried products, burgers and patties, brawn and meat jelly, canned and marinated meat. The final part of the book discusses quality and safety issues, particularly meat microbiology.Meat products handbook is a standard reference for R&D, quality and production managers in meat processing.

• A one volume reference on processed meat products
• Combines detailed practical knowledge of processing and ingredients with scientific understanding
• A standard reference for research & development, quality and production managers in the meat industry

Part I

Meat composition and additives

Outline

Chapter 1: The protein and fat content of meat

Chapter 2: The biochemistry of meat

Chapter 3: The tenderness of fresh meat

Chapter 4: Definitions of terms used in meat science and technology

Chapter 5: Additives: phosphates, salts (sodium chloride and potassium chloride, citrate, lactate) and hydrocolloids

Chapter 6: Additives: proteins, carbohydrates, fillers and other additives

Chapter 7: Colour in fresh meat and in cured meat products

1

The protein and fat content of meat

Publisher Summary

Total quality of meat and meat products includes characteristics that can be measured, such as microbiological status, tenderness, color, juiciness, shelf life, pH value, and the pesticide levels. The total quality also includes an aspect that is less easy to measure: the consumer’s personal perception of the value of meat and meat products. This perception is different for every individual human being as external factors such as television advertising for example have an influence on perceptions of total quality. The term “quality”, from the consumer’s point of view, could be simply said to mean whether the consumer thinks a product is good value for money and this judgment would vary from person to person and from product to product. The study of meat technology is concerned with the three major building blocks used to make a meat product, namely, raw materials, additives and the manufacturing technologies applied, as well as all possible interactions between the three. Manufacturing technology combines raw materials and additives with each other to obtain a product of the desired quality within a certain economic framework.

Humans have eaten meat and meat products for thousands of years and our teeth have evolved so that they are shaped to tear apart and to chew meat. Countless highly valuable vitamins, minerals and trace elements are present in a concentrated form within meat, and meat and meat products remain part of a balanced and healthy diet today. There are also those, nevertheless, who opt not to eat meat for a variety of reasons.

Most countries today interpret pork meat in their respective food standards as meaning ‘muscle meat including fat and skin’, rather than lean muscle tissue only. This fact can be confusing to the ordinary consumer as most understand lean muscle tissue as ‘meat’ and do not know that fat and skin are classified as ‘meat’ as well. When other types of meat are described, however, the term meat does not include fat and skin. The amount of lean meat obtained out of a carcass is in cattle around 35%, in pigs around 45%, in veal around 38% and in lamb around 35%. Fat is also part of balanced human diet and the presence of fat in meat and meat products serves technological as well as organoleptic and nutritional purposes. The relationship between fat consumption and weight gain, however, is currently a topic of interest, as excessive consumption of fat may be a cause of the increased levels of obesity worldwide.

The quality of meat and meat products is also a topic of frequent discussion. There is currently no consensus on what the term ‘quality’ really stands for, given that ‘quality’ is generally seen as a combination of two major elements. On the one hand, ‘total quality’ of meat and meat products includes characteristics which can be measured, such as microbiological status, tenderness, colour, juiciness, shelf life, pH value and pesticide levels. On the other hand, total quality also includes an aspect which is less easy to measure: the consumer’s personal perception of the value of meat and meat products. This perception is different for every individual human being as external factors such as television advertising for example have an influence on perceptions of total quality. The term ‘quality’, from the consumer’s point of view, could be simply said to mean whether the consumer thinks a product is good value for money and this judgement will vary from person to person and from product to product.

The study of meat technology (Fig. 1.1) is concerned with the three major building blocks used to make a meat product, namely raw materials, additives and the manufacturing technologies applied, as well as all possible interactions between the three. Manufacturing technology combines raw materials and additives with each other to obtain a product of the desired quality within a certain economic framework.

Fig. 1.1 Overview of meat technology.

1.1 Amino acids

Amino acids are the building blocks of proteins. Even though around 190 amino acids are known today, only 20 different amino acids are required by humans to synthesize all necessary proteins. All these 20 amino acids are alpha-amino acids, given that both functional groups, the ‘acid’ carboxyl group (–COOH), as well as the ‘alkaline’ amino group (–NH₂), are attached to the same carbon atom, the α-carbon atom or C_α. This α-carbon atom is also referred to as the ‘chiral centre’; glycine, the simplest amino acid, is the only non-chiral amino acid. The rest (R) of the molecule is in most cases the primary portion of the amino acid and determines the identity of the amino acid itself as well as whether the amino acid is polar or non-polar.

As stated above, almost all α-amino acids are chiral, meaning that two arrangements of the same molecule are non-identical mirror images. Chiral amino acids exist in two configurations known as L or D stereoisomers (Fig. 1.2), which correspond to left-handed (L) or right-handed (D) three-dimensional shapes. D originates from the Latin word dexter and the NH₂ group is on the right-hand side of the molecule, whilst L is from the Latin word laevus, meaning left. All amino acids found in proteins are L isomers except for glycine, the simplest amino acid, which is not chiral. Depending on the side chains within the amino acid, neutral, acid or alkaline amino acids are formed.

Fig. 1.2 L-alanine and D-alanine.

Amino acids exhibit side groups, which can be made out of a hydrogen atom or other ring-structured molecules (Fig. 1.3). In turn, those side groups can show different groups such as hydroxyl groups (–OH) and, in conjunction with the carboxyl and amino group of the main structure of the amino acid, these affect the structure of a protein.

Fig. 1.3 Typical configuration of an amino acid.

Eight of those 20 amino acids are ‘essential’ and have to be supplied to the human body by consuming food which contains these essential amino acids. The body cannot synthesize these eight essential amino acids. If they are not supplied to the human body via the intake of food, illness and even death may occur. The remaining 12 amino acids can be synthesized by the human body, as long as the food consumed provides all the elements needed to synthesize those amino acids. Protein-containing food is broken down by digestion into individual amino acids, from which the required body proteins are synthesized.

The essential amino acids are as follows.

Isoleucine	Threonine
Leucine	Valine
Lysine	Tryptophan
Methionine	Phenylalanine

All the other 12 amino acids can be synthesized by the human body itself using nitrogen, which is supplied by consuming food containing nitrogen; these amino acids are the following.

Alanine	Asparagine
Arginine	Cysteine
Aspartic acid	Glutamic acid
Proline	Histidine
Tyrosine	Glutamine
Serine	Glycine

The nutritional value of food is determined by the presence of essential amino acids at their lowest relative concentration. A food might contain seven of the eight essential amino acids at a high concentration but one at only a very low level and it is the one present at a low level that determines the nutritional value of the food. This is based on the fact that, if only this particular type of food were consumed to provide essential amino acids, the one present at the low concentration would always be ‘missing’ and illness would be the result, given that the body cannot synthesize this one essential amino acid.

Amino acids are ‘weak acids’ present in a solution as zwitterions (Fig. 1.4) at a pH value of 5.4–5.7. In such a situation, the COOH group is present as a negatively charged COO⁻ ion and can take up a hydrogen (H⁺) ion, while the NH₂ group is present as a positively charged ${\text{NH}}_3^{+}$

ion, which can give away, or donate, one H⁺ ion.

Fig. 1.4 An amino acid present as a zwitterion.

Amino acids can act as an ‘acid’, or as an ‘alkali’, depending on their pH environment. At low pH values, or in a sour environment, the negatively charged carboxyl group (COO⁻) can take up an H⁺ ion and act as an ‘alkali’. The gain of a hydrogen ion neutralizes the COOH group and the entire amino acid becomes positively charged owing to the excess H⁺ ion on the ${\text{NH}}_3^{+}$

group. In high-pH conditions, or in an alkaline environment, the positively charged ${\text{NH}}_3^{+}$

group of an amino acid releases an H⁺ ion and acts therefore as an ‘acid’. The NH₂ group is neutralized and the entire amino acid becomes negatively charged owing to the COO⁻ group still present within the amino acids. Amino acids can donate or absorb H⁺ ions without changing their pH value, which explains the ‘buffer capacity’ of amino acids and subsequently proteins. The buffer capacity depends on the concentration of ions donated or absorbed and, once the buffer capacity is exceeded, the pH value of the protein will change.

1.2 Prote...

Table of contents

• Cover image
• Title page
• Table of Contents
• Related titles
• Copyright
• Preface
• Acknowledgements
• Disclaimer
• Abbreviations
• Part I: Meat composition and additives
• Part II: Technologies for particular meat products
• Part III: Quality and safety issues
• Index