Table of Contents

Cover

Title

Introduction

I.1. From empiricism to rational technology
I.2. From traditional foods to assembly technology

PART 1: Food from Animal Sources

1 From Milk to Dairy Products
1. 1.1. The biochemistry and physical chemistry of milk
2. 1.2. Biological and physicochemical aspects of milk processing
3. 1.3. Dairy product technology
2 From Muscle to Meat and Meat Products
1. 2.1. The biochemistry of muscle (land animals and fish)
2. 2.2. Biological and physicochemical changes in muscle
3. 2.3. Meat and fish processing technology
3 From Eggs to Egg Products
1. 3.1. Chicken egg – raw material in the egg industry
2. 3.2. Physicochemical properties of the different egg fractions
3. 3.3. The egg industry: technology and products

PART 2: Food from Plant Sources

4 From Wheat to Bread and Pasta
1. 4.1. Biochemistry and physical chemistry of wheat
2. 4.2. Biological and physicochemical factors of wheat processing
3. 4.3. The technology of milling, bread making and pasta making
5 From Barley to Beer
1. 5.1. Biochemistry and structure of barley and malt
2. 5.2. Biological and physicochemical factors of processing
3. 5.3. Brewing technology
6 From Fruit to Fruit Juice and Fermented Products
1. 6.1. Fruit development
2. 6.2. Biochemistry of fruit juice
3. 6.3. Fruit juice processing
4. 6.4. Cider
7 From Grape to Wine
1. 7.1. Raw materials
2. 7.2. Winemaking techniques
3. 7.3. Stabilization and maturation of wine
4. 7.4. Specific technology
8 From Fruit and Vegetables to Fresh-Cut Products
1. 8.1. Respiratory activity of plants
2. 8.2. Enzymatic browning
3. 8.3. Unit operations in the production of fresh-cut products: main scientific and technical challenges
4. 8.4. Modified atmosphere packaging
5. 8.5. Conclusion

PART 3: Food Ingredients

9 Functional Properties of Ingredients
1. 9.1. Interactions with water: hydration and thickening properties
2. 9.2. Intermolecular interactions: texture properties
3. 9.3. Interfacial properties: foaming and emulsification
10 Separation Techniques
1. 10.1. Proteins and peptides
2. 10.2. Carbohydrates
3. 10.3. Lipids
4. 10.4. Pigments and flavorings

Bibliography

List of Authors

Index

End User License Agreement

List of Tables

1 From Milk to Dairy Products

Table 1.1. Average lipid composition of cow’s milk (Source: [CHR 95])
Table 1.2. Fatty acid composition of milk and distribution on the three positions of glycerol (adapted from [CHR 95])
Table 1.3. Amino acid composition of cow’s milk casein (α_S1 (variant B), α_S2 (variant A), β (variant A), casein κ)
Table 1.4. Average composition of casein micelles in % (w/w)
Table 1.5. Average physicochemical properties of casein micelles at 20°C and pH 6.7 (modified from [MCM 84])
Table 1.6. Mineral composition of cow’s milk (according to [GAU 05])

2 From Muscle to Meat and Meat Products

Table 2.1. Comparison of the overall biochemical composition of fish and land animal muscle (in g per 100 g of muscle)
Table 2.2. Biochemical composition of the l. dorsi muscle of land animals (based on [LAW 98])
Table 2.3. Typical fat content (%) of some common fish, shellfish and crusteans (according to [PIC 87])
Table 2.4. Saturated and unsaturated fatty acid composition of some fish products (% of total fat) (according to [PIC 87])
Table 2.5. Protein composition of meat and fish muscles (in g per 100 g of total protein) (based on [LIN 94])
Table 2.6. Onset of rigor mortis in different species of fish (based on [HUS 88])
Table 2.7. Classification of charcuterie and canned products [FRE 16]
Table 2.8. Composition of the different types of flora present in the production of dried sausage

3 From Eggs to Egg Products

Table 3.1. Main techno-functional properties of eggs and their parts in food applications
Table 3.2. Average composition of whole chicken egg, egg white and yolk in % of total weight (according to [THA 94])
Table 3.3. Distribution of the constituents of chicken egg yolk [POW 86]
Table 3.4. Protein composition of egg white (based on [LIC 89, STE 91, GUE 06]

4 From Wheat to Bread and Pasta

Table 4.1. Chemical composition of cereal grains (%)
Table 4.2. Main physical characteristics of wheat grains
Table 4.3. Types of polysaccharides in wheat as a percentage of total cell wall polysaccharides [PLA 97]
Table 4.4. Proportion of lipid fractions of wheat [DRA 79]
Table 4.5. Proportion of fat (%) in different milling products
Table 4.6. Nutritional value per 100 g flour
Table 4.7. Average micronutrient composition per 100 g flour
Table 4.8. Relationship between flour types and extraction rate
Table 4.9. Commercial classification of French flours
Table 4.10. Distribution of minerals in wheat
Table 4.11. Example of the classification of semolina based on particle size S (sifting), SSS (three sifting passages), E (export), F (fine), M (medium), C (coarse), and D groats (durum groats)
Table 4.12. Analysis of Chopin alveograph parameters based on French bread (without additives)
Table 4.13. Indicative values of W for different types of bread
Table 4.14. Analysis of Hagberg falling numbers
Table 4.15. Main yeast and bacteria in natural leavening agents and starter cultures
Table 4.16. Types of durum wheat semolina
Table 4.17. Main characteristics of pasta made from durum wheat semolina
Table 4.18. Main characteristics of couscous made from durum wheat semolina

5 From Barley to Beer

Table 5.1. Biochemical constituents of barley (% w/w dry matter)

10 Separation Techniques

Table 10.1. Average composition of the various milk liquids that are sources of lactose

List of Illustrations

Introduction

Figure I.1. New products and assembly technology

1 From Milk to Dairy Products

Figure 1.1. Composition and main characteristics of milk fat globules
Figure 1.2. Diagram of the structure of a native milk fat globule membrane (Source: [MIC 01]). For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 1.3. Chemical structure of lactose
Figure 1.4. Main mineral balances of milk (salt concentrations shown are for milk under physiological conditions)
Figure 1.5. Structure of the milk fat globule membrane after homogenization. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 1.6. Impact of the main physicochemical factors on casein micelle structure and stability
Figure 1.7. Change in micelle structure during acidification
Figure 1.8. Change in micelle structure during rennet coagulation (CMP = caseinomacropeptide)
Figure 1.9. Time–temperature diagram of pasteurization
Figure 1.10. Processing diagram for the production of microfiltered whole milk (VRF = Volume reduction factor)
Figure 1.11. Diagram of the influence of heat treatment on the protein constituents of milk and rheological properties (G’) of the gels obtained
Figure 1.12. Synergistic action of starter cultures in yoghurt
Figure 1.13. Processing diagram for the production of low-heat skimmed milk powder
Figure 1.14. Processing diagram for the production of skimmed milk powder by microfiltration and ultrafiltration (Primin^® powder)
Figure 1.15. Main properties of milk powders [PIS 81, MAS 91]
Figure 1.16. Processing diagram for the production of ultra-low-heat skimmed milk powder (VRF = volume reduction factor)
Figure 1.17. Processing diagram for the production of Primin milk powder (VRF = volume reduction factor)
Figure 1.18. Steps of cheese production
Figure 1.19. Standardization of the fat and protein content of milk intended for cheese production
Figure 1.20. Types of coagulation and categories of cheese. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 1.21. Drainage and acidification kinetics and processing types (according to [MIE 91])
Figure 1.22. Manufacturing process of fresh cheese
Figure 1.23. Manufacturing process of industrial Camembert
Figure 1.24. Manufacturing process of Saint Paulin
Figure 1.25. Manufacturing process of Beaufort
Figure 1.26. Change in constituents during ripening
Figure 1.27. Structure of butter
Figure 1.28. Manufacture of butter based on the NIZO method

2 From Muscle to Meat and Meat Products

Figure 2.1. Structure of muscle and connective tissue in meat
Figure 2.2. Structure of muscle, connective and adipose tissues in meat
Figure 2.3. Structure of fish muscle
Figure 2.4. Muscle cell structure. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 2.5. Structure of myofibrils
Figure 2.6. Cross-section of a myofibril fragment
Figure 2.7. Change in myoglobin and variation in meat color
Figure 2.8. Structure of myosin
Figure 2.9. Structure of actin
Figure 2.10. Structure of collagen and tropocollagen. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 2.11. Hurdle technology [LEI 85]
Figure 2.12. Production process of the surimi base
Figure 2.13. Formation of kamaboko gel

3 From Eggs to Egg Products

Figure 3.1. Internal structure of a hen’s egg. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 3.2. Schematic representation of egg yolk low-density lipoprotein. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 3.3. Stability with regard to the creaming of oil-in-water emulsions containing yolk, plasma and granules; 30/70 O/W emulsions, protein concentration in the aqueous phase: 25 mg ml^-1
Figure 3.4. Compression isotherm at the air–water interface of LDL, liposomes and the different lipid components of LDL. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 3.5. Schematic description of the adsorption mechanism of egg yolk LDL and liposomes at the air–water interface. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 3.6. Effect of ionic strength on the thermogelation of ovalbumin: mechanistic model (based on [DOI 93]) and electron microscopy images of corresponding egg white gels [CRO 02])
Figure 3.7. Effect of temperature on the viscosity of solutions of egg yolk, plasma and granules (pH 6.1, 0.17 M NaCl, 24% solids)
Figure 3.8. Process flow diagram for the primary processing of egg products
Figure 3.9. Change in foaming and gelling properties during dry-heating of egg white at 67°C and 75°C [BAR 03]

4 From Wheat to Bread and Pasta

Figure 4.1. Traditional methods of processing wheat
Figure 4.2. Baking in a vertical tandoor oven in Pakistan
Figure 4.3. Different aspects of wheat grains: a) common wheat; b) common wheat (section); c) durum wheat; d) durum wheat (section)
Figure 4.4. Longitudinal cells of starchy endosperm (× 200 magnification)
Figure 4.5. A and B starch in the cells of starchy endosperm (scale: 20 µm)
Figure 4.6. Outer layers of the grain
Figure 4.7. Native starch granules of common wheat
Figure 4.8. Diagram of starch chains in a granule. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 4.9. Wheat starch granules at the start of gelatinization at 60°C
Figure 4.10. Gelatinization and gelation curve from a Brabender amylograph
Figure 4.11. Simplified illustration of an arabinoxylan chain
Figure 4.12. Wheat starch partly hydrolyzed by amylase (enzymes). This enzymatic attack cuts the chains, allowing the separation of glucose molecules
Figure 4.13. Qualitative classification of wheat proteins [FEI 00]
Figure 4.14. Different structures to reduce the firmness of flour dough. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 4.15. Diagram of the changes in two dough structures before (1, 4) and after (2, 3, 5, 6) cooking. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 4.16. Diagram of dough at the beginning of and during mixing. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 4.17. a) Pressing without vacuum (the presence of too many air bubbles); b) Insufficient pressure in the screw press
Figure 4.18. Effects of compression at the shaping stage
Figure 4.19. Cracked pasta
Figure 4.20. Roller milling system: a) roller mills in a modern mill; b) gyrating sifter (sieves)
Figure 4.21. Comparison of grain reduction between millstones and roller mills [WIL 90]
Figure 4.22. Block diagram of the milling of wheat
Figure 4.23. Particle size of hard and soft wheat. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 4.24. Dough deformation based on the Chopin alveograph ICC standard N° 121
Figure 4.25. Alveograph (resistance curve of a bubble as a function of expansion)
Figure 4.26. Hagberg device
Figure 4.27. Overview of French bread production by direct yeast fermentation based on the type of mixing
Figure 4.28. Mixing using a fork mixer
Figure 4.29. Dough expansion measurement device to quantify fermentation activity
Figure 4.30. Production of French bread with pre-ferments
Figure 4.31. Production flow diagram of French bread obtained by increased mixing and direct yeast fermentation at a low temperature
Figure 4.32. Mechanical division of dough
Figure 4.33. Different stages of dough shaping
Figure 4.34. Bread just released from a hearth deck oven
Figure 4.35. Dried pasta and couscous
Figure 4.36. Cooking time for pasta. From top to bottom: overcooked, optimal, undercooked
Figure 4.37. Cooking tolerance of pasta: a) pasta with good cooking tolerance; b) sticky pasta that disintegrates (poor cooking tolerance). (Photos: J Abecassis, INRA)
Figure 4.38. General diagram of the industrial production of pasta
Figure 4.39. Long pasta entering a dryer
Figure 4.40. Diagram of the industrial production of couscous

5 From Barley to Beer

Figure 5.1. Ear of six-row barley (J. Barloy, Agrocampus Ouest Rennes)
Figure 5.2. Cross section of a barley grain
Figure 5.3. Changes in barley grain caused by the action of hydrolases. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 5.4. Hop cones (J. Barloy, Agrocampus Ouest Rennes)
Figure 5.5. Hop-derived bitter compounds
Figure 5.6. Development of malt starch and proteins during brewing and fermentation
Figure 5.7. Different stages of malting. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 5.8. Different stages of beer production. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip

6 From Fruit to Fruit Juice and Fermented Products

Figure 6.1. Stages of fruit development; a) main changes during the development of an apple; b) changes in carbohydrate
Figure 6.2. Diagram of metabolic pathways during the ripening of climacteric fruit
Figure 6.3. Structure of isoprene, the basic structural element of terpenes
Figure 6.4. Structure of pectin
Figure 6.5. Homogalacturonan sequence of pectic substances; R₁ = -CH₃ or-H, H+, Na+, K+, etc.; R₂ = -OCOCH₃ or –OH
Figure 6.6. Rhamnogalacturonan I sequences of pectic substances: a) RG I backbone; b) Arabinan; c) Arabinogalactan I; d) Arabinogalactan II
Figure 6.7. Structure of rhamnogalacturonan II (adapted from [ORT 09])
Figure 6.8. Reaction catalyzed by pectin methylesterases (PME). For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 6.9. Reaction catalyzed by endopolygalacturonases (endo-PG)
Figure 6.10. Reaction catalyzed by pectin lyase (PL)
Figure 6.11. Reactions catalyzed by arabinanases: (1) α-L-arabinofuranosidase II (exo-enzyme); (2) Endo-arabinanase; (3) α–L-arabinofuranosidase I (non-reducing end exo-enzyme)
Figure 6.12. Structure of some limonoids in citrus fruits: a) limonoic acid; b) limonin; c) 17-β–D-Glup-limonoic acid; d) nomilin
Figure 6.13. Structure of some flavanones in citrus fruit; a) bitter compounds; b) easily crystallizable compounds
Figure 6.14. Principle of pulsed electric fields applied to the extraction of juices; a) modulation of the electric field (E) between the spaced electrodes (d) by a pulsed electric voltage (U); b) effect of the electric field on the migration of cellular ionic charges depending on its value relative to the critical value (Ec) specific to a given tissue and consequences on plasmalemma permeability
Figure 6.15. Production of citrus fruit juice using different techniques (cut-back, add-back and Fresh note)
Figure 6.16. Production of cloudy apple juice using clear concentrate
Figure 6.17. Production of clear apple juice and concentrates
Figure 6.18. Reaction catalysed by limonoate dehydrogenase

7 From Grape to Wine

Figure 7.1. Chemical composition of grapes
Figure 7.2. Red winemaking (traditional) and white winemaking
Figure 7.3. Maceration time to produce white wine, rosé, and red wine to be kept from red skin grapes
Figure 7.4. Malolactic fermentation

8 From Fruit and Vegetables to Fresh-Cut Products

Figure 8.1. Measurement of the oxygen consumption of chicory as a function of time and polynomial fit of the kinetics (20°C) [CHA 05]
Figure 8.2. Lineweaver-Burk plot: determination of the apparent Km (O₂) and RR_maxO₂ of chicory (20°C) [CHA 05]
Figure 8.3. Transcriptional mechanism of the injury signal
Figure 8.4. Diagram of the operating principle of heat treatment on enzymatic browning in plants [SAL 00]
Figure 8.5. Unit operations in the production of ready-to-eat salad greens
Figure 8.6. The principle of “forward flow”
Figure 8.7. Segmentation and temperature gradient in the processing units
Figure 8.8. Trimming table with hydraulic belt
Figure 8.9. Diagram of a water jet cutting system [BEG 96]
Figure 8.10. Browning of apple slices cut in air or water, measured by the difference in absorbance at 440 nm as a function of storage time, in air at 25°C [KUC 93]. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 8.11. Diagram of a traditional washer. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 8.12. Diagram of a cascade washer [BEG 98]
Figure 8.13. Principle of modified atmosphere packaging
Figure 8.14. Different types of perforation. a) laser; b) cold needle (photo INRA)
Figure 8.15. Change in levels of oxygen and carbon dioxide in a LDPE package containing 500 g of endives (20°C) [CHA 05]

9 Functional Properties of Ingredients

Figure 9.1. Interactions between macromolecules or particles for increasing electrolyte concentrations (a, b, c)
Figure 9.2. Crosslinking of proteins by nucleophilic attack of thiolate on disulphide bonds
Figure 9.3. Formation of lysinoalanine
Figure 9.4. Influence of denaturation kinetics and molecular interactions on the formation of aggregates or gels (according to [TOT 02])
Figure 9.5. Result of attractive forces in a), a liquid b) at liquid/gas interfaces and c) at immiscible liquid/liquid interfaces
Figure 9.6. Concentration of amphiphilic molecules at the interface and reduction in surface tension

10 Separation Techniques

Figure 10.1. Overview of the main protein ingredients from milk. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 10.2. Production processes of whey protein/casein co-precipitates (heat treatment carried out at natural pH of milk)
Figure 10.3. Production processes of whey protein/casein co-precipitates (heat treatment carried out at a different pH to that of milk)
Figure 10.4. Production processes of rennet and acid casein
Figure 10.5. Production process of sodium caseinate from acid casein
Figure 10.6. Separation of caseins
Figure 10.7. Fractionation of α-lactalbumin
Figure 10.8. Extraction of lysozyme from egg white
Figure 10.9. Extraction of gelatin
Figure 10.10. General outline of the preparation of flours, concentrates and isolates (based on [BER 85])
Figure 10.11. Chemical formula of sucrose
Figure 10.12. Extraction of sugar from sugar beet. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 10.13. Extraction of sugar from sugar cane
Figure 10.14. Solubility curve of sucrose as a function of temperature
Figure 10.15. Crystallization of sucrose in three cycles
Figure 10.16. Water vapor sorption isotherm of crystalline sugar and amorphous sugar at 25°C
Figure 10.17. Different types of sugar
Figure 10.18. Purification of lactose. For a color version of this figure, see www.iste.co.uk/jeantet/foodscience.zip
Figure 10.19. Main lactose derivatives
Figure 10.20. Structure of amylopectin
Figure 10.21. Diagram of the purification of starch
Figure 10.22. Derivatives of starch
Figure 10.23. Chemical structure of carrageenan
Figure 10.24. Diagram of the purification of carrageenan
Figure 10.25. Chemical formula of β-D-mannuronic acid and α-L-glucuronic acid
Figure 10.26. Diagram of the purification of alginic acid and alginates
Figure 10.27. Chemical structure of pectin
Figure 10.28. Diagram of the purification of pectin
Figure 10.29. Chemical structure of xanthan gum
Figure 10.30. Diagram of the purification of xanthan gum
Figure 10.31. Solvent extraction of oil from cakes
Figure 10.32. Main stages of oil refining
Figure 10.33. Diagram of the hydrogenation of oils and fats
Figure 10.34. Transesterification at high and low temperatures
Figure 10.35. Principle of fractionation of oils and fats
Figure 10.36. Fractionation of oils and fats by a) continuous filtration and b) filter press filtration
Figure 10.37. Structure of the main carotenoids and xanthophylls (according to [LIN 94])
Figure 10.38. Structure of porphyrin
Figure 10.39. General structure of flavonoids
Figure 10.40. Influence of pH on the structure and color properties of anthocyanins (according to [LIN 94])
Figure 10.41. Structure of betalains
Figure 10.42. Examples of aromatic molecules
Figure 10.43. Extraction with solvent recycling
Figure 10.44. Continuous liquid/liquid extractor
Figure 10.45. Steam distillation
Figure 10.46. Structure of β-cyclodextrin

First published 2016 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc. Translated by Geraldine Brodkorb from “Science des aliments” © Tec & Doc Lavoisier 2006.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

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The rights of Romain Jeantet, Thomas Croguennec, Pierre Schuck and Gérard Brulé to be identified as the authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.

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ISBN 978-1-84821-934-2

Introduction

The processing into food of raw materials from hunting, gathering, fishing and subsequently arable and livestock farming has always had two objectives: to preserve nutrients in order to defer the time and place of consumption, and develop products with a wide variety of textures and flavors to satisfy the sensory needs of consumers. The development of arable and livestock farming has facilitated an improved control of supply, even though the provision of agricultural products has long remained very irregular due to climatic or health risks and the seasonality of certain products. Furthermore, the importance of stabilization and/or processing has significantly increased with the rural exodus, which has led to a distancing of production from consumption areas.

The production of certain foods that still form the basis of our diet today dates back several centuries or even millennia, as in the case of bread, cheese and wine for example. These products, particularly those derived from fermentation, were developed based on empirical observations, with no knowledge of the raw materials or phenomena involved in their processing. It was not until the work of Pasteur in the 19th Century that microorganisms gained a key role in the development and processing of agricultural products.

The agri-food industry has undergone a major change over the past few decades in order to better meet the quality requirements of consumers; while traditional food is the result of a series of increasingly understood and controlled biological and physicochemical phenomena, this is not the case for a number of new products designed to meet market expectations. These products are the result of an assembly of various ingredients (Figure I.1), the control of which is a real challenge for food technologists and engineers.

**Figure I.1**. *New products and assembly technology*

I.1. From empiricism to rational technology

The oldest forms of processing (milk to cheese, grain to bread or beer, grapes to wine, muscle to meat, etc.) were based on biological phenomena that could occur naturally under specific water content and temperature conditions, since the biological agents (enzymes or microorganisms) responsible for processing and the reaction substrates and growth factors were present in the raw materials and/or immediate environment; it was enough to simply mature (milk, meat), crush, grind and sometimes hydrate (fruit, grain) in order for biological reactions to take place. This is why these types of products were able to develop based solely on the observation of natural processes.

The knowledge acquired since the end of the 19th Century in the field of microbiology and the early 20th Century in the field of enzymology has gradually helped explain the biological phenomena involved in the development of certain food products. Based on this knowledge, the food industry has sought to control these processes rather than witness them, which is how the fermentation and then an enzyme industry arose, producing and marketing biological agents for each type of processing. The use of fermentation and in some cases enzymes has become indispensable given the existing food safety requirements, which include increasingly stringent hygiene conditions in production and processing, and technological treatments to eliminate potential pathogenic microorganisms (microfiltration, heat treatment). This change has led to a reduction in the endogenous biological potential, which needs to be replenished by adding fermentation steps and enzymes. Reconstituting microbial ecosystems through the assembly of exogenous flora requires the identification of the endogenous flora and their role in the characteristic features of the food; progress in the field of molecular biology should enable significant progress in this area.

Over the past 40 years, many teams have focused on the study of food science, which has resulted in a better understanding of the composition of various raw materials and the biological and physicochemical mechanisms involved in the development of texture, flavor and aroma; this work has allowed the food industry to better identify the key technological tools in the development of quality, and to rely less on empiricism and more on technology.

I.2. From traditional foods to assembly technology

The quality requirements of consumers are increasingly specific and segmented. Food must be absolutely safe (no pathogens, toxins, residues or contaminants), have the closest possible nutritional profile to that recommended by nutritionists, meet sensory needs, integrate practicality (ease of storage and use) and convey social values (fair trade, environmental protection and animal welfare) while remaining at an affordable price. These market expectations are identified by the marketing services of the food industry for specific target consumers whose needs depend on several factors (gender, age, activity, health, metabolic disorders, food trends, etc.). These services, in consultation with nutrition and health specialists, identify which nutrients and micronutrients (minerals and vitamins) to assemble and define the structure, sensory characteristics and practicality of the food based on consumer research. The path from conception to completion can sometimes be difficult, since food is a complex and thermodynamically-unstable system, which can be defined as a continuous, usually aqueous phase, a three-dimensional protein and/or polysaccharide network and dispersed elements (gas, fat globules, solids); the aim of technologists is to stabilize this system throughout the marketing period while taking into account mechanical (transport) and thermal (refrigeration, freezing, thawing) constraints.

The progress made in recent years in food science has provided insight into the key role of various biological components and particularly their structure, whether native or modified by technological treatments, in the development of texture, the thermodynamics of dispersed systems and the role of interfaces. This knowledge allows us to better understand and control the instability of food using technological processes or functional ingredients; the industry has a very large range of functional ingredients that is used to create texture and stabilize complex multiphase systems. It is therefore possible, by assembly, to create new foods that meet the quality requirements of the market.

Introduction written by Gérard BRULÉ.

Handbook of Food Science and Technology 3

Food Biochemistry and Technology

Introduction

I.1. From empiricism to rational technology

I.2. From traditional foods to assembly technology

PART 1
Food from Animal Sources

PART 2
Food from Plant Sources

PART 3
Food Ingredients