Kerry / Ledward Meat Processing

Improving Quality
1. Auflage 2002
ISBN: 978-1-85573-666-5
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 480 Seiten

Reihe: Woodhead Publishing Series in Food Science, Technology and Nutrition

Meat is both a major food in its own right and a staple ingredient in many food products. With its distinguished editors and an international team of contributors, Meat processing reviews research on what defines and determines meat quality, and how it can be maintained or improved during processing.Part one considers the various aspects of meat quality. There are chapters on what determines the quality of raw meat, changing views of the nutritional quality of meat and the factors determining such quality attributes as colour and flavour. Part two discusses how these aspects of quality are measured, beginning with the identification of appropriate quality indicators. It also includes chapters on both sensory analysis and instrumental methods including on-line monitoring and microbiological analysis. Part three reviews the range of processing techniques that have been deployed at various stages in the supply chain. Chapters include the use of modelling techniques to improve quality and productivity in beef cattle production, new decontamination techniques after slaughter, automation of carcass processing, high pressure processing of meat, developments in modified atmosphere packaging and chilling and freezing. There are also chapters on particular products such as restructured meat and fermented meat products.With its detailed and comprehensive coverage of what defines and determines meat quality, Meat processing is a standard reference for all those involved in the meat industry and meat research. - Reviews research on what defines and determines meat quality, and how it can be measured, maintained and improved during processing - Examines the range of processing techniques that have been deployed at various stages in the supply chain - Comprehensively outlines the new decontamination techniques after slaughter and automation of carcass processing

Autoren/Hrsg.

Kerry, Joseph P.

Kerry, John F.

Ledward, David

Inhaltsverzeichnis

1;Front Cover;1
2;Meat Processing: Improving Quality;4
3;Copyright Page;5
4;Table of Contents;6
5;Contributors;12
6;Chapter 1. Introduction;18
7;Chapter 2. Defining meat quality;20
7.1;2.1 Introduction: what is quality?;20
7.2;2.2 Consumer perceptions of quality;23
7.3;2.3 Supplier perceptions of quality;31
7.4;2.4 Combining consumer and supplier perceptions: the quality circle;33
7.5;2.5 Regulatory definitions of quality;36
7.6;2.6 Improving meat and meat product quality;38
7.7;2.7 References;40
8;Part I: Analysing meat quality;42
8.1;Chapter 3. Factors affecting the quality of raw meat;44
8.1.1;3.1 Introduction;44
8.1.2;3.2 Quality, meat composition and structure;44
8.1.3;3.3 Breed and genetic effects on meat quality;54
8.1.4;3.4 Dietary influences on meat quality;66
8.1.5;3.5 Rearing and meat quality;69
8.1.6;3.6 Slaughtering and meat quality;69
8.1.7;3.7 Other influences on meat quality;73
8.1.8;3.8 Summary: ensuring consistency in raw meat quality;73
8.1.9;3.9 Future trends;74
8.1.10;3.10 References;74
8.2;Chapter 4. The nutritional quality of meat;81
8.2.1;4.1 Introduction;81
8.2.2;4.2 Meat and cancer;83
8.2.3;4.3 Meat, fat content and disease;86
8.2.4;4.4 Fatty acids in meat;88
8.2.5;4.5 Protein in meat;95
8.2.6;4.6 Meat as a ‘functional’ food;96
8.2.7;4.7 Meat and micronutrients;99
8.2.8;4.8 Future trends;105
8.2.9;4.9 Conclusion;109
8.2.10;4.10 References;109
8.3;Chapter 5. Lipid-derived flavors in meat products;122
8.3.1;5.1 Introduction;122
8.3.2;5.2 The role of lipids in generation of meaty flavors;123
8.3.3;5.3 Lipid autoxidation and meat flavor deterioration;125
8.3.4;5.4 The effect of ingredients on flavor quality of meat;127
8.3.5;5.5 The evaluation of aroma compounds and flavor quality;133
8.3.6;5.6 Summary;134
8.3.7;5.7 References;134
8.4;Chapter 6. Modelling colour stability in meat;139
8.4.1;6.1 Introduction;139
8.4.2;6.2 External factors affecting colour stability during packaging and storage;140
8.4.3;6.3 Modelling dynamic changes in headspace composition;140
8.4.4;6.4 Modelling in practice: fresh beef;141
8.4.5;6.5 Modelling in practice: cured ham;145
8.4.6;6.6 Internal factors affecting colour stability;148
8.4.7;6.7 Validation of models;150
8.4.8;6.8 Future trends;151
8.4.9;6.9 References;152
8.5;Chapter 7. The fat content of meat and meat products;154
8.5.1;7.1 Introduction;154
8.5.2;7.2 Fat and the consumer;155
8.5.3;7.3 The fat content of meat;155
8.5.4;7.4 Animal effects on the fat content and composition of meat;158
8.5.5;7.5 Dietary effects on the fat content and composition of meat;161
8.5.6;7.6 Future trends;164
8.5.7;7.7 Sources of further information and advice;166
8.5.8;7.8 References;167
9;Part II: Measuring quality;172
9.1;Chapter 8. Quality indicators for raw meat;174
9.1.1;8.1 Introduction;174
9.1.2;8.2 Technological quality;174
9.1.3;8.3 Eating quality;177
9.1.4;8.4 Determining eating quality;183
9.1.5;8.5 Sampling procedure;183
9.1.6;8.6 Future trends;185
9.1.7;8.7 References;185
9.1.8;8.8 Acknowledgemnts;191
9.2;Chapter 9. Sensory analysis of meat;192
9.2.1;9.1 Introduction;192
9.2.2;9.2 The sensory panel;193
9.2.3;9.3 Sensory tests;195
9.2.4;9.4 Category scales;202
9.2.5;9.5 Sensory profile methods and comparisons with instrumental measurements;203
9.2.6;9.6 Comparisons between countries;206
9.2.7;9.7 Conclusions;206
9.2.8;9.8 References;207
9.3;Chapter 10. On-line monitoring of meat quality;210
9.3.1;10.1 Introduction;210
9.3.2;10.2 Measuring electrical impedance;212
9.3.3;10.3 Measuring pH;216
9.3.4;10.4 Analysing meat properties using NIR spectrophotometry;218
9.3.5;10.5 Measuring meat colour and other propertie;218
9.3.6;10.6 Water-holding capacity;220
9.3.7;10.7 Sarcomere length;220
9.3.8;10.8 Connective tissue;221
9.3.9;10.9 Marbling and fat content;223
9.3.10;10.10 Meat flavour;224
9.3.11;10.11 Boar taint;224
9.3.12;10.12 Emulsions;224
9.3.13;10.13 Measuring changes during cooking;225
9.3.14;10.14 Conclusion;228
9.3.15;10.15 Sources of further information and advice;228
9.3.16;10.16 References;229
9.4;Chapter 11. Microbiological hazard identification in the meat industry;234
9.4.1;11.1 Introduction;234
9.4.2;11.2 The main hazards;235
9.4.3;11.3 Analytical methods;248
9.4.4;11.4 Future trends;250
9.4.5;11.5 Sources of further information and advice;251
9.4.6;11.6 References;251
10;Part III: New techniques for improving quality;254
10.1;Chapter 12. Modelling beef cattle production to improve quality;256
10.1.1;12.1 Introduction;256
10.1.2;12.2 Elements of beef cattle production;257
10.1.3;12.3 Challenges for modellers;261
10.1.4;12.4 Simple model of herd structure;268
10.1.5;12.5 Future developments;271
10.1.6;12.6 References;272
10.2;Chapter 13. New developments in decontaminating raw meat;276
10.2.1;13.1 Introduction;276
10.2.2;13.2 Current decontamination techniques and their limitations;277
10.2.3;13.3 Washing;279
10.2.4;13.4 The use of chemicals;280
10.2.5;13.5 New methods: steam;284
10.2.6;13.6 Other new methods;289
10.2.7;13.7 Future trends;290
10.2.8;13.8 Sources of further information and advice;293
10.2.9;13.9 References;294
10.3;Chapter 14. Automated meat processing;300
10.3.1;14.1 Introduction;300
10.3.2;14.2 Current developments in robotics in the meat industry;301
10.3.3;14.3 Automation in pig slaughtering;302
10.3.4;14.4 Case study: the evisceration process;304
10.3.5;14.5 Automation of secondary processes;307
10.3.6;14.6 Future trends;311
10.3.7;14.7 References and further reading;313
10.4;Chapter 15. New developments in the chilling and freezing of meat;314
10.4.1;15.1 Introduction;314
10.4.2;15.2 The impact of chilling and freezing on texture;316
10.4.3;15.3 The impact of chilling and freezing on colour;317
10.4.4;15.4 The impact of chilling and freezing on drip loss and evaporative weight loss;319
10.4.5;15.5 The cold chain;321
10.4.6;15.6 Temperature monitoring;323
10.4.7;15.7 Optimising the design and operation of meat refrigeration;325
10.4.8;15.8 Sources of further information and advice;327
10.4.9;15.9 References;327
10.5;Chapter 16. High pressure processing of meat;330
10.5.1;16.1 Introduction: high pressure treatment and meat quality;330
10.5.2;16.2 General effect of high pressure on food components;331
10.5.3;16.3 Structural changes due to high pressure treatment of muscle;332
10.5.4;16.4 Influence on enzyme release and activity;335
10.5.5;16.5 High pressure effects on the sensory and functional properties of meat;335
10.5.6;16.6 Pressure assisted freezing and thawing;337
10.5.7;16.7 Effects on microflora;338
10.5.8;16.8 Current applications and future prospects;340
10.5.9;16.9 References;341
10.6;Chapter 17. Processing and quality control of restructured meat;349
10.6.1;17.1 Introduction;349
10.6.2;17.2 Product manufacture;350
10.6.3;17.3 Factors affecting product quality: temperature, ice content, particle size and mechanical properties;355
10.6.4;17.4 Factors affecting product quality: protein solubility and related factors;360
10.6.5;17.5 Factors affecting product quality: cooking distortion;364
10.6.6;17.6 Sensory and consumer testing;366
10.6.7;17.7 Future trends;368
10.6.8;17.8 Sources of further information and advice;370
10.6.9;17.9 References;370
10.7;Chapter 18. Quality control of fermented meat products;376
10.7.1;18.1 Introduction: the product;376
10.7.2;18.2 The quality concept;377
10.7.3;18.3 Sensory quality and its measurement;378
10.7.4;18.4 Appearance and colour: measurement and development;380
10.7.5;18.5 Texture: measurement and development;382
10.7.6;18.6 Flavour: measurement and development;385
10.7.7;18.7 Taste and aroma: measurement and development;389
10.7.8;18.8 The control and improvement of quality;394
10.7.9;18.9 Future trends in quality development;398
10.7.10;18.10 References;399
10.8;Chapter 19. New techniques for analysing raw meat quality;411
10.8.1;19.1 Introduction;411
10.8.2;19.2 Defining meat quality;411
10.8.3;19.3 Current state of art techniques;414
10.8.4;19.4 Emerging technologies;416
10.8.5;19.5 The genetics of meat quality;422
10.8.6;19.6 The future;424
10.8.7;19.7 Sources of further information and advice;425
10.8.8;19.8 References;425
10.9;Chapter 20. Meat packaging;434
10.9.1;20.1 Introduction;434
10.9.2;20.2 Factors influencing the quality of fresh and processed meat products;436
10.9.3;20.3 Vacuum packaging;441
10.9.4;20.4 Modified atmosphere packaging;445
10.9.5;20.5 Bulk, master or mother packaging;452
10.9.6;20.6 Controlled atmosphere packaging and active packaging systems;454
10.9.7;20.7 Packaging materials used for meat products;456
10.9.8;20.8 Future trends;460
10.9.9;20.9 References;461
11;Index;469

Leseproben

3 Factors affecting the quality of raw meat
R.K. Miller    Texas A & M University, College Station 3.1 Introduction
Establishing an understanding of raw meat eating quality and consistency is an important component of meat production systems. It is generally understood that production of meat must be tied to the production of a product that consumers find visually appealing, that they will continually purchase and that consistently delivers an acceptable eating experience. Therefore, meat quality encompasses the visual appearance and eating quality. Both of these quality factors can be influenced by ante-mortem and post-mortem production factors. This chapter will concentrate on ante-mortem production factors of breed and genetic effects, dietary influences, and rearing effects on meat quality and the post-mortem factor of the slaughter effect will be discussed as a post-mortem production factor. This information will provide a basis of understanding for subsequent discussions on meat quality in ensuing chapters. 3.2 Quality, meat composition and structure
Meat is composed of lean tissue or muscle fiber cells, fat and connective tissue. Fat or adipose cells can be found in up to three depots or locations in meat. Fat can be deposited intramuscularly as marbling or contained between muscles (defined as seam fat) or it can be found as external fat or subcutaneous fat. Additionally, meat may include bone, but the trend has moved toward boneless meat cuts and therefore bone will not be discussed in this chapter. Nervous tissue and components of the blood system are contained within meat but their total weight or proportional contribution to meat is small and so will not be discussed. These three major components of meat, fat, lean or the myofibrillar component, and connective tissue, affect meat quality in different ways. 3.2.1 Fat component
Intramuscular fat content has been shown to affect flavor, juiciness, tenderness and visual characteristics of meat. Savell and Cross (1988) developed the Window of Acceptability to demonstrate the general relationship between the role of increased intramuscular fat on meat pork, lamb and beef palatability (Fig. 3.1). In general, as fat content increases, palatability increases; however, improvements in palatability with increasing fat percentage are not equal across all fatness levels. If fat content is less than 3%, palatability decreases markedly with each decrease in fat percentage. In fact, this is the steepest slope on the curve. As fat increases from 3% to about 6%, meat palatability improves, but not as dramatically as reported at the lower levels. As fat content exceeds 7.3%, fat is highly visible and has been identified as too fatty by health-conscious consumers. Too much visible fat has raised questions about consumption of fat in meat products and increased incidence of coronary heart disease, obesity or some forms of cancer in humans; these issues can affect consumers’ perception of acceptability. Therefore, meat with fat content between 3 and 7.3% is generally considered acceptable. Diet/health-conscious consumers may be willing to sacrifice palatability for lower fat content. Fig. 3.1 The Window of acceptability. Adapted with permission from Designing Foods: Animal Product Options in the Marketplace. Copyright 1988 by the National Academy of Sciences. Courtesy of the National Academy Press, Washington, DC. How does intramuscular fat affect palatability? One way is through the relationship of intramuscular fat with meat juiciness. As intramuscular fat increases, humans perceive that the meat is juicier. During mastication or during the first bites, if fat is present, some of it is released and the salivary glands are stimulated. This results in a perception of juiciness, additionally, meat with a higher fat content may give a longer sustained perception of juiciness. Savell and Cross (1988) stated that ‘fat may affect juiciness by enhancing the waterholding capacity of meat, by lubricating the muscle fibers during cooking, by increasing the tenderness of meat and thus the apparent sensation of juiciness, or by stimulating salivary flow during mastication’. A second way that intramuscular fat affects palatability is through the relationship between fat content and tenderness. Interestingly, there is conflicting evidence as to the meat tenderness and fat relationship. Savell and Cross (1988) supported the relationship between increased intramuscular fat and meat tenderness by proposing four hypotheses. The first hypothesis, the Bulk Density Theory, states that as fat is lower in density than heat-denatured protein in cooked meat, as the fat percentage increases, the overall density of the meat decreases. As bulk density decreases within a given bite of meat, the meat is more tender. The second hypothesis is defined as the Lubrication Effect. Intramuscular fat is mainly triglycerides stored in adipose cells embedded in the perimysial connective tissue wall of the muscle. As meat is cooked, triglycerides melt and bathe the muscle fibers. As the meat is chewed, fat is released, salivation increases and the meat is perceived as juicy. Additionally, the muscle fibers give or slide more easily resulting in an increased perception of tenderness. The third hypothesis, the Insurance Theory, states that fat provides protection against the negative effects of over-cooking or high heat on protein denaturation. Meat proteins are involved in binding water in the muscle fiber. As meat is cooked, proteins denature and lose some of their ability to bind water. Fat can act to insulate the transfer of heat or slow down the heat transfer so that protein denaturation is less severe and less moisture is lost during cooking. The fourth theory or the Strain Theory relates to the weakening of the perimysial connective tissue surrounding muscle bundles. As marbling is deposited as adipose cells dispersed in perimysial connective tissue, development and an increased number of adipose cells weaken the connective tissue structure resulting in more tender meat. To understand if marbling or intramuscular fat affected consumer acceptance and the subsequent relationship with trained sensory responses, the Beef Customer Satisfaction study was conducted (Lorenzen et al., 1999; Neely et al., 1998; Savell et al., 1999) in the United States. Beef top loin steaks from four USDA Quality Grade classifications were selected to represent four Quality Grade classifications where Low Select would contain beef top loin steaks with Slight00 to Slight50 degrees of marbling that would equate to about 3 to 3.5% chemical lipid; High Select steaks had Slight51 to Slight100 degrees of marbling or about 3.5 to 4.0% chemical lipid; Low Choice steaks had a small degree of marbling or about 4 to 5% chemical lipid; and Top Choice consisted of steaks with modest and moderate degrees of marbling or about 6 to 7% chemical lipid. Chemical lipid approximations were projected from Savell and Cross (1988). Steaks were evaluated by 300 households in four cities where each household contained two adult consumers who ate beef three or more times per week. Four top loin steaks from each carcass was served to four consumers in each city and one steak was evaluated by a trained meat descriptive attribute panel and Warner-Braztler shear force was conducted as a mechanical measurement of tenderness as described by AMSA (1995). Consumers rated Top Choice steaks highest for overall like and juiciness (Table 3.1). They liked the tenderness and flavor of Choice (Top Choice and Low Choice) steaks compared to Select steaks and they indicated that the Choice steaks had a higher intensity of flavor than Select steaks. Trained sensory panels also indicated that as marbling score increased, cooked beef top loin steaks were juicier, more tender, more intense in flavor and they had higher levels of beef flavor and beef fat flavor (Table 3.1). Warner-Bratzler shear force values decreased as marbling score increased (Table 3.1). In this same study, top sirloin and top round steaks also were evaluated. These steaks had slightly lower fat content than top loin steaks and the marbling to palatability relationship was not as strong. Table 3.1 Least squares means of top loin steaks from US Beef Customer Satisfaction Study for consumer sensory attributes,a trained meat descriptive sensory attributes and Warner-Bratzler shear force (kg) as effected by USDA quality grade Consumer sensory attributes a Overall like/dislike 19.2c 19.1c 18.8c 18.7c 3.06 0.0004 Juiciness 18.5c 18.5c 18.3d 18.0c 3.57 0.0006 Tenderness like/dislike 19.0cd 19.2d 18.6cd 18.6c 3.28 0.0001 Flavor intensity 19.1c 19.2d 18.9cd 18.9c 2.87 0.0009 Flavor...