Tao Smart Fibres, Fabrics and Clothing

Fundamentals and Applications
1. Auflage 2001
ISBN: 978-1-85573-760-0
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 336 Seiten

Reihe: Woodhead Publishing Series in Textiles

This important book provides a guide to the fundamentals and latest developments in smart technology for textiles and clothing. The contributors represent a distinguished international panel of experts and the book covers many aspects of cutting edge research and development.Smart fibres, fabrics and clothing starts with a review of the background to smart technology and goes on to cover a wide range of the material science and fibre science aspects of the technology including: Electrically active polymeric materials and the applications of nonionic polymer gel and elastomers for artificial muscles; Thermally sensitive fibres and fabrics; Cross-linked polyol fibrous substrates stimuli-responsive interpenetrating polymer network hydrogel; Permeation control through stimuli-responsive polymer membranes; optical fibre sensors, hollow fibre membranes for gas separation; integrating fibre-formed components into textile structures; Wearable electronic and photonic technologies; Adaptive and responsive textile structures (ARTS); Biomedical applications including the applications of scaffolds in tissue engineeringIt is essential reading for academics in textile and materials science departments, researchers, designers and engineers in the textiles and clothing product design field. Product managers and senior executives within textile and clothing manufacturing will also find the latest insights into technological developments in the field valuable and fascinating.

Autoren/Hrsg.

Tao, Xiaoming

Inhaltsverzeichnis

1;Front Cover;1
2;Solid Foods
;4
3;Copyright Page;5
4;Table of Contents;6
5;Contributor contact details;14
6;List of abbreviations;20
7;Part I: Consumers, texture and food quality;24
7.1;Chapter 1 Measuring consumer perceptions of texture: an overview;26
7.1.1;1.1 Introduction: texture and food quality;26
7.1.2;1.2 Perception and sensory assessment of food texture;29
7.1.3;1.3 Tests and test procedures;31
7.1.4;1.4 Instrumental measurement of texture;36
7.1.5;1.5 In vivo texture measurement;43
7.1.6;1.6 Future developments;46
7.1.7;1.7 Conclusions;49
7.1.8;1.8 References;51
7.2;Chapter 2. Consumers and texture: understanding their perceptions and preferences;56
7.2.1;2.1 Introduction: problems with consumer descriptions of texture;56
7.2.2;2.2 Investigating consumer descriptions of texture;57
7.2.3;2.3 Tests and test procedures;59
7.2.4;2.4 Understanding consumer preferences;62
7.2.5;2.5 Challenges to understanding consumer preferences;67
7.2.6;2.6 Future trends;71
7.2.7;2.7 Conclusions;73
7.2.8;2.8 References;74
7.3;Chapter 3. Texture and mastication;76
7.3.1;3.1 Introduction;76
7.3.2;3.2 The mastication process;78
7.3.3;3.3 Measuring mastication;79
7.3.4;3.4 Chewing, swallowing, salivation and bolus formation;89
7.3.5;3.5 Future trends;94
7.3.6;3.6 Mastication and particular foods;98
7.3.7;3.7 Reviews;99
7.3.8;3.8 Acknowledgement;99
7.3.9;3.9 References;100
7.4;Chapter 4. Understanding and measuring consumer perceptions of crispness;105
7.4.1;4.1 Introduction;105
7.4.2;4.2 Characterization and determination of crispness;108
7.4.3;4.3 Methods of data correlation, evaluation and analysis;114
7.4.4;4.4 Case-study: breaded chicken nuggets;117
7.4.5;4.5 Future trends;126
7.4.6;4.6 References;126
8;Part II: Instrumental techniques for analysing texture;130
8.1;Chapter 5. Force/deformation techniques for measuring texture;132
8.1.1;5.1 Introduction;132
8.1.2;5.2 Mechanical characterization of solid foods;133
8.1.3;5.3 Destructive measurements;141
8.1.4;5.4 Non-destructive measurements;151
8.1.5;5.5 Conclusions;161
8.1.6;5.6 References;162
8.2;Chapter 6. Sound input techniques for measuring texture;169
8.2.1;6.1 Introduction;169
8.2.2;6.2 Sound and its detection: what is sound?;170
8.2.3;6.3 Destructive testing;171
8.2.4;6.4 Non-destructive testing;178
8.2.5;6.5 Application of sound measurement techniques;181
8.2.6;6.6 Future trends;185
8.2.7;6.7 Sources of further information and advice;185
8.2.8;6.8 References;186
8.3;Chapter 7. Near infrared (NIR) diffuse reflectance in texture measurement;190
8.3.1;7.1 Introduction;190
8.3.2;7.2 Application of NIR to cereals and their products;193
8.3.3;7.3 Application of NIR to fruit and vegetables;196
8.3.4;7.4 Application of NIR to meat;199
8.3.5;7.5 Application of NIR to other foods;201
8.3.6;7.6 Conclusions and future trends;202
8.3.7;7.7 Sources of further information;203
8.3.8;7.8 References;203
8.4;Chapter 8. Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) in texture measurement;207
8.4.1;8.1 Introduction;207
8.4.2;8.2 Methods and analysis;210
8.4.3;8.3 Application of NMR: texture determination of solid foods;212
8.4.4;8.4 Application of MRI: texture determination of solid foods;218
8.4.5;8.5 Future trends;222
8.4.6;8.6 References;223
8.5;Chapter 9. Modelling food texture;228
8.5.1;9.1 Introduction;228
8.5.2;9.2 Factors affecting texture;234
8.5.3;9.3 Effects of enzymes on texture;241
8.5.4;9.4 Applying models to predict texture;245
8.5.5;9.5 Future trends;256
8.5.6;9.6 Notation;257
8.5.7;9.7 References;258
9;Part III: Understanding and improving the texture of particular foods;262
9.1;Chapter 10. Plant structure and fruit and vegetable texture;264
9.1.1;10.1 Introduction;264
9.1.2;10.2 Measurement of texture;265
9.1.3;10.3 Plant structure;267
9.1.4;10.4 Cellular basis of crispness, juiciness and mealiness in fruit tissue;267
9.1.5;10.5 Cellular stability during processing;272
9.1.6;10.6 Improving cell adhesion;274
9.1.7;10.7 Future trends;277
9.1.8;10.8 Acknowledgements;278
9.1.9;10.9 References;278
9.2;Chapter 11. Plant compounds and fruit texture: the case of pear;282
9.2.1;11.1 Introduction: variations in pear texture;282
9.2.2;11.2 Measuring and modelling fruit firmness;285
9.2.3;11.3 Chemical compounds affecting firmness: the example of Japanese pear;293
9.2.4;11.4 The effect of constituents on fruit texture;298
9.2.5;11.5 Use of near infrared spectroscopy (NIR) to evaluate textural properties;302
9.2.6;11.6 Future trends;306
9.2.7;11.7 Sources of further information and advice;311
9.2.8;11.8 Acknowledgement;312
9.2.9;11.9 References;313
9.3;Chapter 12. Controlling the texture of fruit and vegetables: the role of oxidising enzymes;318
9.3.1;12.1 Introduction: distribution of polyphenoloxidases (PPOs) and peroxidases (PODs) in plants and plant cells;318
9.3.2;12.2 Biochemical and physiological role of PPOs and PODs;319
9.3.3;12.3 PPOs and PODs: structure and mechanisms of action;323
9.3.4;12.4 PPOs, PODs and texture development;327
9.3.5;12.5 Controlling PPO and POD activity;330
9.3.6;12.6 PPOs and PODs: implications for food texture;334
9.3.7;12.7 Future trends;334
9.3.8;12.8 Sources of further information;335
9.3.9;12.9 References;335
9.4;Chapter 13. Improving fruit and vegetable texture by genetic transformation;344
9.4.1;13.1 Introduction;344
9.4.2;13.2 Tools of genetic modification;346
9.4.3;13.3 Approaches to the manipulation of texture: the tomato;350
9.4.4;13.4 Other approaches to the manipulation of texture;356
9.4.5;13.5 Future trends;358
9.4.6;13.6 References;359
9.5;Chapter 14. Raw materials quality and the texture of processed vegetables;365
9.5.1;14.1 Introduction;365
9.5.2;14.2 Vegetable texture determined by starch;365
9.5.3;14.3 Vegetable texture determined by cell wall polysaccharides;372
9.5.4;14.4 Vegetable texture affected by phenolic reactions;377
9.5.5;14.5 Future trends;381
9.5.6;14.6 Sources of further information and advice;382
9.5.7;14.7 References;383
9.6;Chapter 15. Improving the texture of processed vegetables by vacuum infusion;387
9.6.1;15.1 Introduction;387
9.6.2;15.2 Vacuum infusion technology;388
9.6.3;15.3 Applications to improve texture;396
9.6.4;15.4 Future trends;406
9.6.5;15.5 Sources of further information and advice;406
9.6.6;15.6 References;407
9.7;Chapter 16. Improving the texture of frozen fruit: the case of berries;411
9.7.1;16.1 Introduction: the effects of freezing and thawing on berry texture;411
9.7.2;16.2 Maintaining texture: conventional pre-freezing treatments;413
9.7.3;16.3 Maintaining texture: alternative pre-freezing treatments;416
9.7.4;16.4 Application: frozen berries and jams;423
9.7.5;16.5 Future trends;428
9.7.6;16.6 References;428
9.8;Chapter 17. Improving the texture of processed fruit: the case of olives;433
9.8.1;17.1 Introduction: the texture of table olives;433
9.8.2;17.2 Factors affecting the texture quality of raw olives;435
9.8.3;17.3 Influence of processing on table olives;441
9.8.4;17.4 Improving texture;448
9.8.5;17.5 Future trends;449
9.8.6;17.6 Sources of further information and advice;451
9.8.7;17.7 References;453
9.9;Chapter 18. Improving the texture of bread;455
9.9.1;18.1 Introduction;455
9.9.2;18.2 Textural characteristics of bread and other cereal-based foods;457
9.9.3;18.3 Definitions of texture;459
9.9.4;18.4 Measuring texture;460
9.9.5;18.5 Influence of processing and storage;465
9.9.6;18.6 Improving texture;468
9.9.7;18.7 Future trends;470
9.9.8;18.8 Sources of further information and advice;471
9.9.9;18.9 References;472
9.10;Chapter 19. Analysing and improving the texture of cooked rice;474
9.10.1;19.1 Introduction;474
9.10.2;19.2 Criteria for evaluating rice quality;475
9.10.3;19.3 Hydration of rice;478
9.10.4;19.4 Factors affecting cooking quality;482
9.10.5;19.5 Testing texture quality;487
9.10.6;19.6 Problems and challenges;492
9.10.7;19.7 Sources of further information and advice;493
9.10.8;19.8 References;493
9.11;Chapter 20. Improving the texture of pasta;498
9.11.1;20.1 Introduction;498
9.11.2;20.2 Measuring the texture of cooked pasta;501
9.11.3;20.3 Influence of raw materials;507
9.11.4;20.4 Influence of processing;513
9.11.5;20.5 Trends in consumer preference;515
9.11.6;20.6 References;517
9.12;Chapter 21. Improving the texture of fried food;524
9.12.1;21.1 Introduction;524
9.12.2;21.2 Measuring texture;524
9.12.3;21.3 Factors influencing texture;527
9.12.4;21.4 The use of response surface methodology (RSM);531
9.12.5;21.5 A case study: fried gluten balls;537
9.12.6;21.6 Conclusions;544
9.12.7;21.7 References;545
10;Index;547

Leseproben

1 Measuring consumer perceptions of texture: an overview
D. Kilcast    Leatherhead Food International, UK 1.1 Introduction: texture and food quality
In prosperous societies, we have available an enormous and ever-increasing range of foods, and manufacturers find themselves in an intensely competitive situation. In less well-developed societies, hunger will be the constant driving force, and our diet will be determined by availability of any food that satisfies our basic nutritional needs. It is increasingly clear that if we are to understand what drives consumers’ choice of food, no single factor can be considered in isolation from others. For some years, psychology researchers have been developing models to understand consumer behaviour (e.g. Shepherd and Sparks, 1994). Although there are many possible circumstances under which non-sensory factors such as price and nutritional image can have dominant effects, the sensory characteristics of foods are central to their continued purchase. The importance of a holistic approach is also becoming more clear when the components of sensory perception are considered. During the sequences of actions that constitute food consumption, we perceive a whole range of different characteristics relating to the appearance, flavour and texture of the food. Numerous tools are available for investigating the sensory properties of foods, and the information required must be carefully defined if appropriate tools are to be selected. Systematic development of new products will inevitably depend on the use of different tools at different stages of the development cycle. 1.1.1 The human senses
It is generally accepted that human beings have five senses in operation, namely sight, smell, taste, touch and hearing, although warmth, cold, movement and pain may also be considered as senses of importance in a food context (Fig. 1.1). Foods are complex mixtures of chemical compounds, arranged into structural units. The perception of the sensory characteristics of foods results from the stimulation of all our senses to some extent by the physicochemical properties of the foods. The sensory characteristics of food are generally grouped into three categories, namely appearance, flavour and texture. These categories are, however, not independent of one another. For example, colour, which is obviously an important appearance characteristic, can be shown to have an influence on flavour perception; consumers will assign higher scores for flavour intensity to darker foods than to lighter foods. The interaction between appearance and flavour is referred to as ‘visual flavour’. Similarly, textural characteristics such as viscosity can influence the perception of flavour, and some flavour characteristics, e.g. acidity, can affect textural characteristics. One means of defining flavour, texture and appearance is by taking into account the fact that each can be attributed to the stimulation of one or possibly two of the senses. On this basis the International Standards Organisation (ISO, 1992) has proposed working definitions for flavour, texture and appearance, as given below. Fig. 1.1 Schematic diagram of the human senses and their operation in the perception of food quality. • Appearance: sensory characteristics of foods perceived largely by way of the visual sense. Input from other senses, especially smell, may contribute. • Flavour: the combination of taste and odour. Pain, heat, cold, tactile and visual sensations may also contribute. • Texture: sensory characteristics perceived largely by way of the senses of movement and touch. Input from other senses, especially vision and taste, may sometimes contribute. The above definitions give little information on how the senses are used in the perception of quality attributes. Appearance is sometimes, mistakenly, equated only with colour, and yet many other visual aspects of form, shape, translucency, etc., may influence our use of the visual senses. Taste (gustation) is strictly defined as the response by the tongue to soluble, involatile materials. These have classically been defined as four primary basic taste sensations: salt, sweet, sour and bitter, although umami, the sensation associated with monosodium glutamate, is now widely recognised as a basic taste. This list is frequently extended further to include sensations such as metallic and astringency. The taste receptors are organised groups of cells, known as taste buds, located within specialised structures called papillae. These are located mainly on the tip, sides and rear upper surface of the tongue. Taste stimuli are characterised by the relatively narrow range between the weakest and the strongest stimulants (ca 104), and are strongly influenced by factors such as temperature and pH (Meilgaard et al., 1999). The odour response is much more complex, and odours are detected as volatiles entering the nasal passage, either directly via the nose or indirectly through the retronasal path via the mouth. The odorants are sensed by the olfactory epithelium, which is located in the roof of the nasal cavity. Some 150–200 odour qualities have been recognised, and there is a very wide range (ca 1012) between the weakest and the strongest stimulants (Meilgaard et al., 1999). The odour receptors are easily saturated, and specific anosmia (blindness to specific odours) is common. It is thought that the wide range of possible odour responses contributes to variety in flavour perception. Both taste and odour stimuli can be detected only if they are released effectively from the food matrix during the course of mastication. The chemical sense corresponds to a pain response through stimulation of the trigeminal nerve. This is produced by chemical irritants such as ginger and capsaicin (from chilli), both of which give a heat response, and chemicals such as menthol and sorbitol, which give a cooling response. With the exception of capsaicin, these stimulants are characterised by high thresholds. The combined effect of the taste, odour and chemical responses gives rise to the sensation generally perceived as flavour, although these terms are often used loosely. Texture is perceived by the sense of touch, and comprises two components: somesthesis, a tactile, surface response from skin, and kinesthesis (or proprioception), which is a deep response from muscles and tendons. For many foods, visual stimuli will generate an expectation of textural properties. The touch stimuli themselves can arise from tactile manipulation of the food with the hands and fingers, either directly or through the intermediary of utensils such as a knife or spoon. Oral contact with food can occur through the lips, tongue, palate and teeth, all of which provide textural information. 1.1.2 Texture and food enjoyment
Most studies which have investigated the importance of different sensory modalities on consumer acceptability conclude that flavour is the most important modality, followed by texture and then appearance (e.g. Moskowitz and Krieger, 1995). Such conclusions do not reflect the enormous efforts that the food industry devotes to designing appealing textural characteristics, and to maintaining those characteristics to long-term production. Research with consumers in the USA carried out by Szczesniak and Kahn (1971) showed that awareness of texture lies at a subconscious level, and that textural properties are taken for granted. If the expectations of texture are violated, however, awareness of textural defects is accentuated, and texture becomes a focal point for criticism and rejection of the food. Expectations are being increasingly recognised as important factors in food choice by consumers (e.g. Vickers, 1991; Cardello, 1994). 1.1.3 The interactive role of texture
In addition to its direct contribution to consumer acceptance, texture has a vitally important secondary effect, through modulation of flavour release. If flavour components are to be perceived, they must be released from the food matrix in order to reach the appropriate receptors. This release of flavour is intimately related to the way in which the food structure breaks down in the mouth, and consequently to both the initial texture of the food and the change in texture throughout mastication (Section 1.2). In addition, the structural factors that deliver a specific texture can also influence appearance characteristics, for example the glossy surface of chocolate confectionery. 1.1.4 Texture and product design
Texture and food structure are inextricably linked; the micro- and macrostructural composition of foods will determine the sensory perception, and any change in structure carries the risk of changing perceived texture and violating consumer expectations. Industry therefore needs to take great care to ensure that products with key textural characteristics, such as snack foods and confectionery products, are manufactured to consistently high quality. This can present an enormous challenge for foods relying on primary components such as meat and vegetables that are naturally subject to high variability, and for any processed food manufactured on high-volume production lines. Product modifications, for example to produce low-fat variants, can introduce structural changes that can generate substantial textural modifications. Industry therefore needs...