Improving Qualityedited by
Douglas B. MacDougall
This important collection reviews how colour is perceived and measured, and ways in which it can be better understood and controlled in food.
Part 1 looks at colour perception and measurement. Chapter 2 discusses the concept of the total appearance of food, of which colour is one component, and relates this to sensory assessment techniques. The following chapters consider the principles of instrumental colour measurement, models of colour appearance, colour measurement by colour reflectance, and sorting by colour.
Part 2 begins with a review of the chemistry of food colorants. This provides a context for the following chapters which focus on the factors determining colour stability in vegetables, fruits and meat. A final group of chapters then look at colour enhancement of foods from the use of genetic modification to developments in natural colourings.
Contents
Chapter 1: Introduction
Part 1: Perceiving and measuring colour
Chapter 2: The perception and sensory assessment of colour
J Hutchings, Consultant
- Introduction
- Expectations and the information transfer process
- Total appearance
- Viewer dependent variables
- Scene dependent variables
- The mechanics of vision
- Colour perception
- Colour vision deficiency
- Sensory assessment of appearance properties
- Panel selection, screening and training
- Factors affecting panel performance
- Halo effects
- Physical requirements for food appearance assessment
- Lighting for appearance assessment
- Appearance profile analysis
Chapter 3: Colour measurement of food: principles and practice
D B MacDougall, formerly The University of Reading
- Colour vision: trichromatic detection
- The influence of ambient light and food structure
- Appearance
- Absorption and scatter
- Colour description: the CIE system
- Colour description: uniform colour space
- Instrumentation
- Food colour appearance measurement in practice
- Fresh meat
- Orange juice
- Coffee
- Breakfast cereals
- Illuminant spectra and uniform colour
Chapter 4: Changing models of colour perception and colour appearance
S Westland, Colour Imaging Institute, Derby University
- Colour specification systems and colour appearance models
- The retinal image
- Colour appearance: colour constancy
- Colour appearance: simultaneous colour contrast
- Colour appearance: colour assimilation
- The nature of colour contrast
- Contrast sensitivity functions
- Vision models: models of colour constancy
- Models of colour appearance: CIECAMs
- Image quality assessment
Chapter 5: Colour measurement of foods by colour reflectance
P Joshi, Nestle Research Centre, Lausanne; and C J B Brimelow, Nestle R & D Centre, Shanghai
- Food colour and quality
- Colour measurement principles and methods
- Colour measurement methodology
- Colour measurement of typical food materials
- Powders, granules and flakes
- Particulate and lumpy solids
- Large area food solids
- Pastes and slurries
- Liquids
- Conclusions and future trends
Chapter 6: Colour sorting for the bulk food industry
S C Bee and M J Honeywood, Sortex Ltd, London
- The optical sorting machine
- Assessing objects for colour sorting
- Spectrophotometry
- Monochromatic and bichromatic sorting
- Dual monochromatic and trichromatic sorting
- Fluorescence and infrared techniques
- Optical sorting with lasers
- The optical inspection system
- Illumination
- Background and aperture
- Optical filters and detectors
- The sorting system: feed
- The sorting system: ejection
- Cleaning and dust extraction
- The electronic processing system
- The limitations of colour sorting
Part 2: Colour control in food
Chapter 7: The chemistry of food colour
B Moss, Queen's University Belfast
- Classification of food colorants
- Isoprenoid derivatives
- Benzyopyron and tetrapyrolle derivatives
- Melanins, melanoidins and caramels
- Other natural colorants
- Chemical structure and light absorption
- Molecular orbital theory and food colorants
- Chemical stability of food colorants
- Thermal stability
- Irradiation
- High pressure processing
Chapter 8: Colour stability in vegetables
U Kidmose, M Edelenbos, R Norbaek and L P Christensen, Danish Insitute of Agricultural Sciences
- The chemistry and occurrence of vegetable pigments: chlorophylls, carotenoids, flavonoids and betalains
- The stability of pigments
- Post-harvest influences on vegetable colour
- Heating and vegetable colour
- Freezing and vegetable colour
- Maintaining vegetable colour
Chapter 9: Modelling colour stability in meat
J M Jakobsen and G Bertelsen, Royal Veterinary and Agricultural University, Denmark
- External factors affecting colour stability during packaging and storage
- Modelling dynamic changes in headspace composition
- Modelling in practice: fresh beef
- Modelling in practice: cured ham
- Internal factors affecting colour stability
- Validation of models
Chapter 10: Analysing changes in fruit pigments
8 F Artes, Technical University of Cartagena; M I Minguez and D Hornero Instituto de la Grasa (CSIC), Spain
- Pigments in fruits: chlorophylls, carotenoids and anthocyanins
- Categorising fruits by pigment composition
- The formation and transformation of pigments during fruit development and ripening
- Chlorophylls
- Carotenoids
- Anthocyanins
- Postharvest changes in fruit pigment composition
- Fruit colour, pigment composition and quality
- Physio-chemical and enzymatic factors affecting fruit stabiliy
- Measuring colour and pigment composition
Chapter 11: Improving natural pigments by genetic modification of crop plants
I Amaya and V Valpuesta, Universidad de Malaga, Spain
- The genetic modification of crop plants
- Pigments in fruits
- Enhancing fruit pigments: flavonoids
- Enhancing fruit pigments: carotenoids
Chapter 12: Food colorings
F Jack Francis, University of Massachusetts
- Food, drug and cosmetic colorants
- Carotenoid extracts
- Lycopene
- Lutein
- Annatto and saffron
- Paprika
- Synthetic carotenoids
- Anthocyanins
- Betalains
- Chlorophylls
- Tumeric
- Cochineal and carmine
- Monascus
- Iridoids
- Phycobilins
- Caramel
- Brown polyphenols
- Titanium dioxide
- Carbon black
- Miscellaneous colorants
Chapter 13: Developments in natural colourings
S Roenfeldt Nielson and S Holst, Christian Hansen, Denmark
- The use of natural colourings in food
- The range of natural colourings
- Factors in selecting natural colours
- Quality issues
- Storage and handling issues
- Improving natural colour functionality
- Microencapsulation
- Addition of antioxidants
- Emulsions
- Oil suspensions
Index
to see books • videos • cd-roms of related interest