Proteins in food processing R Y Yada

Proteins in food processing


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Proteins in food processing
Edited by
R. Y. Yada


Published by Woodhead Publishing Limited
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Contents

Contributor contact details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xiii

1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R. Y. Yada, University of Guelph, Canada

1

2

Properties of proteins in food systems: an introduction . . . . . . . .
E. C. Y. Li-Chan, The University of British Columbia, Canada
2.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2
Chemical and physical properties of food proteins . . . . . . . . . . .
2.3
Factors affecting properties of proteins in food systems . . . . .
2.4
Structure and function of proteins: classification and
relationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5
Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.6
Sources of further information and advice . . . . . . . . . . . . . . . . . . .
2.7
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2

Part I
3

2
4
12
17
20
22
22

Sources of proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

The caseins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
P. F. Fox and A. L. Kelly, University College, Cork, Ireland
3.1
Introduction: the caseins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2
Heterogeneity of the caseins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3
Molecular properties of the caseins . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4
The caseins as food constituents and ingredients . . . . . . . . . . . . .
3.5
The casein micelle: introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6
Properties and stabilisation mechanisms of casein micelles . .

29
29
30
33
36
40
43


vi

Contents
3.7
3.8
3.9
3.10

4

5

6

7

Structure models of the casein micelle . . . . . . . . . . . . . . . . . . . . . . .
Stability of casein micelles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46
51
62
62

Whey proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A. Kilara, Arun Kilara Worldwide, USA and M. N. Vaghela,
Nestle R & D Center, USA
4.1
Introduction: whey proteins as food ingredients . . . . . . . . . . . . . .
4.2
Analytical methods for determining protein content . . . . . . . . . .
4.3
Structure of whey proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4
Improving functionality of whey proteins in foods: physical
processes and enzymatic modification . . . . . . . . . . . . . . . . . . . . . . .
4.5
Sources of further information and advice . . . . . . . . . . . . . . . . . . .
4.6
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

72

Muscle proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Y. L. Xiong, University of Kentucky, USA
5.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2
Structure of muscle proteins and endogenous proteases . . . . . .

5.3
Muscle protein functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4
Prepared muscle proteins as functional ingredients . . . . . . . . . . .
5.5
Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.6
Sources of further information and advice . . . . . . . . . . . . . . . . . . .
5.7
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

100

Soy proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D. Fukushima, Noda Institute for Scientific Research, Japan
6.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2
Soybean storage proteins: structure-function relationship of
-conglycinin and glycinin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3
Soy protein as a food ingredient: physiochemical properties
and physiological functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4
Improving soy protein functionality . . . . . . . . . . . . . . . . . . . . . . . . . .
6.5
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.6
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

123

Proteins from oil-producing plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S. D. Arntfield, University of Manitoba, Canada
7.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.2
Oilseed protein characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.3
Factors limiting protein utilization . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.4
Extraction and isolation of proteins . . . . . . . . . . . . . . . . . . . . . . . . . .
7.5
Functional properties of proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.6
Improving functionality of oilseed protein . . . . . . . . . . . . . . . . . . .

146

72
77
81
85
93
94

100
101
105
113

116
117
118

123
125
129
137
139
140

146
146
150
156
160
162


Contents
7.7
7.8
8

9

Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

166

167

Cereal proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
N. Guerrieri, University of Milan, Italy
8.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2
Protein function in cereals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.3
Classification of proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4
Gluten: formation, properties and modification . . . . . . . . . . . . . .
8.5
Processing and modification of cereal proteins in cereal
products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.6
Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.7
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

176

Seaweed proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J. Fleurence, University of Nantes, France
9.1
Introduction: seaweed and protein content of seaweed . . . . . . .
9.2
Composition of seaweed proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.3
Algal protein digestibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.4
Uses of algal proteins in food . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.5
Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.6
Sources of further information and advice . . . . . . . . . . . . . . . . . . .
9.7
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

197

Part II
10

11

vii

176
178
180
185
188
190
192

197
200
202
207

207
210
211

Analysing and modifying proteins . . . . . . . . . . . . . . . . . . . . . . . . .

215

Testing protein functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R. K. Owusu-Apenten, Pennsylvania State University, USA
10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.2 Protein structure: sample characteristics and commercial
proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.3 Testing functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.4 Model foods: foaming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.5 Model foods: emulsification and gelation . . . . . . . . . . . . . . . . . . . .
10.6 Conclusions and future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.7 Sources of further information and advice . . . . . . . . . . . . . . . . . . .
10.8 Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.9 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

217

Modelling protein behaviour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S. Nakai, University of British Columbia, Canada
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.2 Computational methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.3 Computer-aided sequence-based functional prediction . . . . . . .
11.4 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

217
219
222
224
230
235
235
235
235
245
245
246
256
264


viii

Contents

11.5
11.6
11.7
11.8
12

13

Further information and advice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

264
267
267
267

Factors affecting enzyme activity in foods . . . . . . . . . . . . . . . . . . . . . .
J. R. Whitaker, University of California, USA
12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2 Types of enzymes and post-harvest food quality . . . . . . . . . . . . .
12.3 Parameters affecting enzyme activity . . . . . . . . . . . . . . . . . . . . . . . .
12.4 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.5 Sources of further information and advice . . . . . . . . . . . . . . . . . . .
12.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

270

Detecting proteins with allergenic potential . . . . . . . . . . . . . . . . . . . . .
R. Krska, E. Welzig and S. Baumgartner, IFA-Tulln, Austria
13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.2 Methods of analysing allergenic proteins . . . . . . . . . . . . . . . . . . . .
13.3 Methods of detecting food allergens . . . . . . . . . . . . . . . . . . . . . . . . .
13.4 Developing new rapid tests: dip-sticks and biosensors . . . . . . .
13.5 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6 Sources of further information and advice . . . . . . . . . . . . . . . . . . .
13.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14 The extraction and purification of proteins: an introduction . . . .

R. E. Aluko, University of Manitoba, Canada
14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.2 Factors affecting extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.3 Extraction and fractionation methods . . . . . . . . . . . . . . . . . . . . . . . .
14.4 Purification techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.5 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15

The use of genetic engineering to modify protein functionality:
molecular design of hen egg white lysozyme using genetic
engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A. Kato, Yamaguchi University, Japan
15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2 Lysozyme-polysaccharide conjugates . . . . . . . . . . . . . . . . . . . . . . . .
15.3 Constructing polymannosyl lysozyme using genetic
engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.4 Improving functional properties of lysozymes . . . . . . . . . . . . . . .
15.5 Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

270
270
275
287
289
290
292
292
294

296
314
316
317
317
323
323
324
328
332
345
346

352
352
353
355
359
368
368


Contents
16

17

Modifying seeds to produce proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A. M. Nuutila and A. Ritala, VTT Biotechnology, Finland
16.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16.2 Methods of seed modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.3 Application and use of modified seeds for protein production
16.4 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.5 Sources of further information and advice . . . . . . . . . . . . . . . . . . .
16.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ix
370
370
372
380
386
387
387

Processing approaches to reducing allergenicity in proteins . . .
E. N. C. Mills, J. Moreno, A. Sancho and J. A. Jenkins,
Institute of Food Research, UK and H. J. Wichers,
Wageningen UR, The Netherlands
17.1 Introduction: food allergens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.2 Protein allergens of animal origin . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.3 Protein allergens of plant origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.4 General properties of protein allergens: abundance,
structural stability and epitopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.5 Factors affecting protein allergenicity in raw foods . . . . . . . . . .
17.6 Reducing protein allergenicity during food processing . . . . . . .
17.7 Reducing protein allergenicity using enzymatic processing . .
17.8 Future trends: low allergen proteins . . . . . . . . . . . . . . . . . . . . . . . . . .
17.9 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.10 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

401
403
405
409
410
411
411

Part III Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

419

18

421

19

Using proteins as additives in foods: an introduction . . . . . . . . . . .
H. Luyten, J. Vereijken and M. Buecking, Wageningen UR,
The Netherlands
18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18.2 Rheological properties of proteins . . . . . . . . . . . . . . . . . . . . . . . . . . .
18.3 Surfactant properties of proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18.4 Protein-flavour relationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18.5 Protein structure and techno-functionality . . . . . . . . . . . . . . . . . . . .
18.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Edible films and coatings from proteins . . . . . . . . . . . . . . . . . . . . . . . .
A. Gennadios, Cardinal Health, Inc., USA

19.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19.2 Materials and methods used in protein film formation . . . . . . .
19.3 Properties of protein film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19.4 Treatments used for modifying the functional properties of
protein films and coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19.5 Commercial applications of protein films and coatings . . . . . .

396

396
397
399

421
423
427
430
434
437
442
442
443
446
448
451


x

Contents

19.6
19.7
19.8

20

21

22

Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sources of further information and advice . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

454
456
457

Protein gels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J. M. Aguilera, Universidad CatoÂlica de Chile and B. Rademacher,
Technical University of Munich, Germany
20.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20.2 Food proteins and their gels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20.3 Mechanisms of protein gel formation . . . . . . . . . . . . . . . . . . . . . . . .
20.4 Mixed gels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20.5 Conclusion and future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20.6 Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

468

Proteomics: examining the effects of processing
on food proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S. Barnes, T. Sanderson, H. McCorkle, L. Wilson, M. Kirk and
H. Kim, University of Alabama at Birmingham, USA
21.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21.2 Protein separation techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21.3 Using mass spectrometry to identify and characterize
proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21.4 The impact of food processing on soy protein . . . . . . . . . . . . . . .
21.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21.6 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Texturized soy protein as an ingredient . . . . . . . . . . . . . . . . . . . . . . . . .
M. N. Riaz, Texas A & M University, USA
22.1 Introduction: texturized vegetable protein . . . . . . . . . . . . . . . . . . . .
22.2 Texturized vegetable protein: raw material characteristics . . .
22.3 Soy based raw materials used for extrusion texturization . . . .
22.4 Wheat and other raw materials used for extrusion
texturization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.5 Effect of additives on texturized vegetable protein . . . . . . . . . . .
22.6 Types of texturized vegetable protein . . . . . . . . . . . . . . . . . . . . . . . .
22.7 Principles and methodology of extrusion technology . . . . . . . . .
22.8 Processing texturized soy protein: extrusion vs.
extrusion-expelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.9 Economic viability of an extrusion processing system for
producing texturized soy chunks: an example . . . . . . . . . . . . . . . .
22.10 Uses of texturized soy protein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

468
469
474
477
479
480
480
483
483
485
490
503
511
511
512
517
517
519
521
529
531
534
538
543
549
554
556


Contents

23

24

25

Health-related functional value of dairy proteins and peptides
D. J. Walsh and R. J. FitzGerald, University of Limerick, Ireland
23.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.2 Types of milk protein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.3 General nutritional role of milk proteins . . . . . . . . . . . . . . . . . . . . .
23.4 Milk protein-derived bioactive peptides . . . . . . . . . . . . . . . . . . . . . .
23.5 Mineral-binding properties of milk peptides . . . . . . . . . . . . . . . . .
23.6 Hypotensive properties of milk proteins . . . . . . . . . . . . . . . . . . . . .
23.7 Multifunctional properties of milk-derived peptides . . . . . . . . . .
23.8 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.9 Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.10 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The use of immobilized enzymes to improve functionality . . . . .
H. E. Swaisgood, North Carolina State University, USA
24.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.2 Modification of carbohydrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.3 Production of flavors and specialty products . . . . . . . . . . . . . . . . .
24.4 Modification of lipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.5 Modification of proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xi
559

559
559
562
566
573
579
590
590
591
591
607
607
609
613
615
618
625
626

Impact of proteins on food colour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J. C. Acton and P. L. Dawson, Clemson University, USA
25.1 Introduction: colour as a functional property of proteins . . . . .
25.2 Role of proteins in food colour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3 Improving protein functionality in controlling colour . . . . . . . .
25.4 Methods of maintaining colour quality . . . . . . . . . . . . . . . . . . . . . . .
25.5 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.6 Sources of further information and advice . . . . . . . . . . . . . . . . . . .
25.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

631

631
639
654
656
662
662
663

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

669


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Contributor contact details

Chapter 1

Chapter 3

Professor R. Y. Yada
Department of Food Science
University of Guelph
Guelph
Ontario N1G 2W1
Canada

Professor P. F. Fox and Dr A. L. Kelly

Department of Food and Nutritional
Sciences
University College, Cork
Ireland

Tel: 519 824 4120 Ext. 8915
Fax: 519 824 0847
E-mail:

Chapter 2
Dr E. C. Y. Li-Chan
The University of British Columbia
Faculty of Agricultural Sciences
Food Science Building
6650 N W Marine Drive
Vancouver BC V6T 1Z4
Canada
Tel: 604 822 6182
Fax: 604 822 3959
E-mail:

Tel: 353 21 490 2362
Fax: 353 21 427 0001
E-mail:

Chapter 4
Dr A. Kilara
Arun Kilara Worldwide
1020 Lee Road, Suite 200
Northbrook

Illinois 60062-3818
USA
Tel/fax: 847 412 1806
E-mail:


xiv

Contributors

Dr M. N. Vaghela
Group Manager ± Ice cream
Nestle R & D Center
809 Collins Avenue
Marysville
OH 43040
USA
Tel: 937 645 2313
Fax: 937 645 2355
E-mail:


Chapter 5
Professor Y. L. Xiong
Department of Animal Sciences
206 Garrigus Building
University of Kentucky
Lexington
KY 40546
USA

Tel: 859 257 3822
Fax: 859 257 5318
E-mail:

Chapter 6
Dr D. Fukushima
Noda Institute for Scientific Research
399 Noda
Noda-shi
Chiba-ken 278-0037
Japan
Tel: 048 641 1873
Fax: 048 641 1886
E-mail:

Chapter 7
Professor S. D. Arntfield
Food Science Department
University of Manitoba
Winnipeg MB R3T 2N2
Canada
Tel: 1 (204) 474 9866
Fax: 1 (204) 474 7630
E-mail:

Chapter 8
Dr N. Guerrieri
Department of Agrifood Molecular
Science
University of Milan

Via Celoria 2
20133 Milan
Italy
Tel: +39 (0) 25031 6800/23
Fax: +39 (0) 25031 6801
E-mail:

Chapter 9
Professor J. Fleurence
Faculty of Sciences
Marine Biology Laboratory
University of Nantes
BP 92208
44 322 Nantes Cedex 3
France
Tel: 33 2 51 12 56 60
Fax: 33 2 51 12 56 68
E-mail:



Contributors

xv

Chapter 10

Chapter 13

Dr R. K. Owusu-Apenten

Department of Food Science
Borland Laboratory
Pennsylvania State University
University Park
PA 16802
USA

Dr R. Krska, Dr E. Welzig and Dr S.
Baumgartner
Center for Analytical Chemistry
Institute for Agrobiotechnology (IFATulln)
Konrad Lorenzstr 20
A ± 3430 Tulln
Austria

Tel: 814 865 5444
Fax: 814 863 6132
E-mail:

Chapter 11
Professor S. Nakai
Food, Nutrition & Health, 107A Food
Science Building
University of British Columbia
6650 NW Marine Drive
Vancouver
BC V6T 1Z4
Canada
Tel: (604) 822 4427
Fax: (604) 822 3959

E-mail:

Tel: +43 2272 66280 401
Fax: +43 2272 66280 403
E-mail:

Chapter 14
Dr R. E. Aluko
University of Manitoba
Department of Foods and Nutrition
400A Human Ecology Building
Winnipeg MB R3T 2N2
Canada
Tel: (204) 474-9555
Fax: (204) 474-7592
E-mail:

Chapter 15
Chapter 12
Professor J. Whitaker
College of Agricultural and
Environmental Sciences
Department of Food Science and
Technology
University of California
One Shields Avenue
Davis
CA 95616 8598
USA
Tel: (530) 753 2381

Fax: (530) 752 4759
E-mail:

Dr A. Kato
Department of Biological Chemistry
Faculty of Agricultural Science
Yamaguchi University
Japan
Tel: 083 933 5852
Fax: 083 933 5820
E-mail:


xvi

Contributors

Chapter 16

Chapter 18

Dr A. M. Nuutila and Dr A. Ritala
VTT Biotechnology
PO Box 1500
FIN ± 02044 VTT
Finland

Dr H. Luyten, Dr J. Vereijken and Dr
M. Buecking
Wageningen University and Research

Centre
Agrotechnology & Food Innovations
(A&F)
PO Box 17
6700 AA Wageningen
The Netherlands

Tel: 358 9 456 4454
Fax: 358 9 455 2103
E-mail:

Chapter 17
Dr E. N. C. Mills, Dr J. Moreno,
Dr A. Sancho and Dr J. A. Jenkins
Food Materials Science
Institute of Food Research
Norwich Research Park
Colney
Norwich
NR4 7UA
UK
Tel: +44 1603 255295
Fax: +44 1603 507723
E-mail:
Dr H. J. Wichers
Wageningen UR
Agrotechnology & Food Innovations
Programme Leader Food and Health
Bornsesteeg 59
6708 PD Wageningen

The Netherlands
Tel: +31 (0) 317 475228
Fax: +31 (0) 317 475347
E-mail:

Tel: +31 (0) 317 475120
Fax: +31 (0) 317 475347
E-mail:

Chapter 19
Dr A. Gennadios
Cardinal Health, Inc.
Oral Technologies Business Unit
14 Schoolhouse Road
Somerset NJ 08873
USA
Tel: 732 537 6366
Fax: 732 537 6480
E-mail:

Chapter 20
Dr J. M. Aguilera
Department of Chemical and
Bioprocess Engineering
Universidad CatoÂlica de Chile
Santiago
Chile
Tel: (562) 686 4256
Fax: (562) 686 5803
E-mail:

Contributors
Dr B. Rademacher
Institute of Food Process Engineering
Technical University of Munich
Weihenstephan
Germany
Tel: +49 8161 714205
Fax: +49 8161 714384
E-mail:


xvii

Mr L. Wilson and Mr M. Kirk
Comprehensive Cancer Center Mass
Spectrometry Shared Facility
University of Alabama at Birmingham
Birmingham
AL 35294
USA
Tel: 205 975 0832
Fax: 205 934 6944
E-mail:


Chapter 21
Professor S. Barnes and Professor H.
Kim

Department of Pharmacology and
Toxicology
Room 452 McCallum Building
University of Alabama at Birmingham
1530 3rd Avenue South
Birmingham
AL 35294
USA
Tel: 205 934 7117
Fax: 205 934 6944
E-mail:
Mr T. Sanderson and Mr H. McCorkle
2D-Proteomics Laboratory
University of Alabama at Birmingham
Birmingham
AL 35294
USA
Tel: 205 975 0832
Fax: 205 934 6944
E-mail:


Chapter 22
Dr M. Riaz
Food Protein R&D Center
Texas A & M University
College Station
TX 77843 2476
USA
Tel: 979 845 2774

Fax: 979 458 0019
E-mail:

Chapter 23
Dr D. J. Walsh and Professor R. J.
FitzGerald
Department of Life Science
University of Limerick
Limerick
Ireland
Tel: +353 61 202 598
Fax: +353 61 331 490
E-mail:


xviii

Contributors

Chapter 24

Chapter 25

Professor H. E. Swaisgood
Department of Food Science
North Carolina State University
Raleigh
NC 27695 7624
USA

Dr J. C. Acton and Dr P. L. Dawson
Food Science and Human Nutrition
Department
Clemson University
A203J Poole Hall
Clemson
SC 29634-0316
USA

Fax: 919 515 7124
E-mail:

Tel: 864 656 1138
Fax: 864 656 0331
E-mail:


1
Introduction
R. Y. Yada, University of Guelph, Canada

Through their provision of amino acids, proteins are essential to human growth,
but they also have a range of structural and functional properties which have a
profound impact on food quality. Proteins in food processing reviews the
growing body of research on understanding protein structure and developing
proteins as multi-functional ingredients for the food industry.
Chapter 2 describes what we know about the common chemical and physical
properties of proteins and the range of factors that influence how these
properties are expressed in particular food systems. It provides a context for Part
I which discusses the diverse sources of proteins, whether from milk, meat or

plants. Individual chapters review the structure and properties of these groups of
proteins and ways of improving their functionality as food ingredients.
Part II builds on Part I by summarising the range of recent research on
analysing and modifying proteins. A first group of chapters reviews ways of
testing and modelling protein behaviour, understanding enzyme activity and
detecting allergenic proteins. They are followed by chapters reviewing the range
of techniques for extracting, purifying and modifying proteins. The book
concludes by analysing the many applications of proteins as ingredients, from
their use as edible films to their role in modifying textural properties and
improving the nutritional quality of food.
The financial support from the Natural Sciences and Engineering Research
Council of Canada is gratefully acknowledged.


2
Properties of proteins in food systems: an
introduction
E. C. Y. Li-Chan, The University of British Columbia, Canada

2.1

Introduction

The word `protein' is defined as
any of a group of complex organic compounds, consisting essentially of
combinations of amino acids in peptide linkages, that contain carbon,
hydrogen, oxygen, nitrogen, and usually, sulfur. Widely distributed in
plants and animals, proteins are the principal constituent of the
protoplasm of all cells and are essential to life. (`Protein' is derived
from a Greek word meaning `first' or `primary,' because of the

fundamental role of proteins in sustaining life.) (Morris, 1992)
Proteins play a fundamental role not only in sustaining life, but also in foods
derived from plants and animals. Foods vary in their protein content (Table 2.1),
and even more so in the properties of those proteins. In addition to their
contribution to the nutritional properties of foods through provision of amino
acids that are essential to human growth and maintenance, proteins impart the
structural basis for various functional properties of foods.
The objective of this chapter is to provide an introduction to the chemical and
physical properties of food proteins that form the basis for their structural and
functional properties. However, food scientists wishing to study proteins in food
systems must be cognizant of the complexity of such systems in terms of
composition and spatial organization. Food systems are usually heterogeneous
with respect to (a) protein composition (foods usually do not contain a single
protein entity, but multiple proteins); (b) other constituents (most foods contain
not only water and other proteins, but also lipids, carbohydrates as major
components, and various other minor components such as salt, sugars,


Properties of proteins in food systems: an introduction
Table 2.1

Total protein contents of the edible portion of some foods and beveragesa

Food

Total protein (%)

Almonds
Apples (raw, eating)
Bananas

Beans (canned, baked)
Beer (bitter)
Beef (lean, raw)
Beansprouts (raw)
Bread (white)
Cabbage (raw)
Cheese (Cheddar)
Cheese (Parmesan)
Chicken (lean, raw)
Chocolate (milk chocolate)
Chocolate (plain chocolate)
Cod fillet (raw)
Cornflakes
Egg (whole)
Ice cream
Lentils (dried)
Milk (cow's whole)
Milk (human)
Pasta
Potatoes (new)
Rice
Sweetcorn (canned)
Soya milk
Tofu (steamed)
Tuna (canned)
Yogurt (plain)

21.1
0.4
1.2

5.2
0.3
20.3
2.9
8.4
1.7
25.5
39.4
20.5
8.4
4.7
17.4
7.9
12.5
3.6
24.3
3.2
1.3
3.6
1.7
2.6
2.9
2.9
8.1
27.5
5.7

a

3

Adapted from Table 5.1 of Coultate (2002).

micronutrients, minerals, phenolic compounds, flavour compounds, etc.); and
(c) structural or spatial organization (proteins exist in foods as tissue systems,
gels, coagula, films, emulsions, foams, etc., and not usually as the dilute
solutions or crystalline forms that are typically investigated in model systems).
Furthermore, significant changes in the properties of the proteins are induced by
environmental factors and processing conditions that are typical of food systems.
Lluch et al. (2001) have written an excellent chapter describing the
complexity of food protein structures. The diversity of the structural role of
proteins in various food raw materials is illustrated by comparing protein
structures in the muscle tissues of meat, fish and squid, the protein bodies of
plant tissues such as cereals, legumes, oilseeds and shell (nut) fruits, and the
casein micelle structure of bovine milk. Interactions of proteins with other
components are exemplified in protein-starch interactions observed during
dough processing and baking, protein-hydrocolloid interactions in dairy


4

Proteins in food processing

products, protein-fat interactions in comminuted meat emulsions, mayonnaise
and cheese, protein-water as well as protein-protein matrix interactions in fish
surimi gels, yogurt and cheese (Lluch et al., 2001).
With this complexity in mind, in addition to describing the basic chemical
and physical properties of proteins and their amino acid building blocks, this
chapter provides an overview of the factors that can influence the properties of
proteins in food systems, and suggests approaches that may be useful to

elucidate the structure±function relationships of food proteins.

2.2

Chemical and physical properties of food proteins

2.2.1 Amino acids commonly found in proteins
It is commonly recognized that 20 amino acids form the building blocks of most
proteins, being linked by peptide (amide) bonds formed between -amino and
-carboxylic acid groups of neighbouring amino acids in the polypeptide
sequence. Nineteen of these 20 amino acids have the general structure of H2NCH (R)-CO2H, differing only in R, which is referred to as the side chain, while
the 20th amino acid is in fact an `imino' acid, in which the side chain is bonded
to the nitrogen atom. With the exception of the amino acid glycine, in which the
side chain is a hydrogen atom, the -carbon atom exhibits chirality. Typically,
only the L-form of the amino acids is found in proteins, being incorporated
through the transcription and translation machinery of the cell. The Denantiomers of amino acids are present in some peptides.
Table 2.2 shows the three-letter and single letter abbreviations as well as
some key properties of the 20 amino acids. The reader is referred to Creighton
(1993) and Branden and Tooze (1999) for illustrations depicting the structure of
the side chains of the 20 amino acids. Similar information can also be viewed at
numerous internet sites, such as those maintained by the Institut fuÈr Molekulare
Biotechnologie (2003a), and the Birbeck College (University of London) School
of Crystallography (1996). As shown in Table 2.2, the 20 amino acids can be
classified according to their side chain type: acidic (Asp, Glu), basic (Arg, His,
Lys), aliphatic (Ala, Ile, Leu, Val), aromatic (Phe, Tyr, Trp), polar (Ser, Thr),
thiol-containing (Cys, Met), amide (Asn, Gln). In addition, as noted above, two
amino acids are unique in being achiral (Gly) or an imino rather than amino acid
(Pro).
It is interesting to note that the two amino acid residues occurring at greatest
frequency in proteins possess aliphatic side chains (9.0 and 8.3% for Leu and

Ala, respectively), while Gly is the third most frequently occurring amino acid at
7.2% (Creighton, 1993). With the exception of His, more than 80 or 90% of the
basic and acidic amino acid residues in proteins usually locate such that they are
primarily exposed to the solvent (Institut fuÈr Molekulare Biotechnologie, 2003a;
Bordo and Argos, 1991). Similarly, amino acid residues with polar side chains
(Ser, Thr, Asn, Gln) as well as Pro are also primarily accessible to the solvent.
Conversely, with the exception of Tyr, which contains an aromatic phenolic


Table 2.2 Some properties of the 20 amino acid residues commonly found in proteins
Amino acid

Alanine
Arginine
Aspartic acid
Asparagine
Cysteine
Glutamic acid
Glutamine
Glycine
Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Proline
Serine
Threonine
Tryptophan

Tyrosine
Valine
a

Ala
Arg
Asp
Asn
Cys
Glu
Gln
Gly
His
Ile
Leu
Lys
Met
Phe
Pro
Ser
Thr
Trp
Tyr
Val

A
R
D
N
C

E
Q
G
H
I
L
K
M
F
P
S
T
W
Y
V

Massa

Side chain type

71.09
156.19
114.11
115.09
103.15
129.12
128.14
57.05
137.14
113.16

113.16
128.17
131.19
147.18
97.12
87.08
101.11
186.12
163.18
99.14

aliphatic hydrocarbon
basic -guanidyl
acidic -carboxyl
acid amide
thiol
acidic -carboxyl
acid amide
hydrogen
basic imidazole
aliphatic hydrocarbon
aliphatic hydrocarbon
basic -amino
thio-ether
aromatic phenyl
heterocyclic imino
polar hydroxyl
polar hydroxyl
aromatic indole
aromatic phenol

aliphatic hydrocarbon

pKa

b

12.0
3.9±4.0
9.0±9.5
4.3±4.5
6.0±7.0
10.4±11.1

9.7

Residue
nonpolar
surface
area c
Ê 2)
(A

Estimated
hydrophobic
effect, side
chain burial
(kcal/mol)

Percentage
with solvent

exposed areac
Ê 2 <10A
Ê2
>30A

Frequency
in proteinsb
(%)

86
89
45
42
48
69
66
47
43+86
155
164
122
137
39+155
124
56
90
37+199
38+116
135

1.0
1.1
À0.1
À0.1
0.0
0.5
0.5
0.0
1.3
2.7
2.9
1.9
2.3
2.3
1.9
0.2
1.1
2.9
1.6
2.2

48
84
81
82
32
93
81
51
66

39
41
93
44
42
78
70
71
49
67
40

8.3
5.7
5.3
4.4
1.7
6.2
4.0
7.2
2.2
5.2
9.0
5.7
2.4
3.9
5.1
6.9
5.8
1.3

3.2
6.6

35
5
9
10
54
4
10
36
19
47
49
2
20
42
13
20
16
44
20
50

Mass of the amino acid (from NIST Chemistry WebBook, 2001) minus the mass (18.00) of a water molecule.
From Creighton (1993).
c
From Institut fuÈr Molekulare Biotechnologie (2003a) and Karplus (1997); aliphatic and aromatic surface areas are reported separately for aromatic amino acids;
Ê 2 were calculated based on 55 proteins in the Brookhaven database using solvent accessibility data
Ê 2 or <10A

percentages of each residue with solvent exposed area >30A
of Bordo and Argos (1991).
b


6

Proteins in food processing

group, less than 50% of the aliphatic and aromatic groups have solvent exposed
Ê . Nevertheless, only 40±50% of aliphatic and aromatic
areas greater than 30A
residues would be considered to be `buried', with solvent exposed areas of less
Ê . These observations indicate that while charged residues are almost
than 10A
always located near the surface or solvent-accessible regions of protein
molecules, the converse cannot be assumed for nonpolar aliphatic or aromatic
residues, probably due to insufficient capacity in the interior of the molecule.
Thus, both charged and hydrophobic groups reside at the surface or solventaccessible regions of protein molecules, whereas charged groups are found much
less frequently in the buried interior of protein molecules. In fact, it has been
reported that approximately 58% of the average solvent accessible surface or
`exterior' of monomeric proteins is nonpolar or hydrophobic, while 29% and
13% of the surface may be considered polar and charged, respectively (Lesk,
2001).
Table 2.2 shows that 54% of Cys residues are `buried' with solvent-exposed
Ê , although the estimated hydrophobic effect of Cys side chain burial is
area <10A
0.0 kcal/mol. The highly reactive thiol groups of Cys residues may interact with
other thiol-containing residues to undergo sulfhydryl-disulfide interchange
reactions or oxidation to disulfide groups. Internal disulfide bonds frequently

play an important role in the stability of the three-dimensional structure of
globular proteins, while disulfide bonds between Cys residues on the surface of
molecules may be responsible for the association of subunits or the formation of
aggregates from denatured molecules.
Similarly, as mentioned previously, the percentage of buried His residues is
higher than that observed for the other basic amino acid residues. The pKa of His
residues lies near neutrality, and the ionization state of imidazoyl groups has
been implicated in important biological or catalytic functions of His residues,
particularly those located in the interior of protein molecules, which may be
related to the unusual ionization properties that can result from the influence of
environment in the folded protein molecule.
2.2.2 Other naturally occurring amino acids
While most of this chapter will be focused on food proteins composed of the 20
amino acids listed in Table 2.2, it is important to acknowledge the presence of
other naturally occurring amino acids, as these can confer distinctive and
interesting properties to some food systems. Over 300 naturally occurring amino
acids have been reported, and the reader is encouraged to consult Mooz (1989)
and the references cited therein for a listing of these amino acids and their
properties. Some of these amino acids exist as free amino acids, while others
have been found in peptides or proteins.
Some examples of the unusual amino acids that have been reported from
food sources include O-phosphoserine in casein, 4-hydroxyproline in gelatin,
4-hydroxy-4-methyl-proline, 4-methylproline and pipecolic acid in apples,
citrulline in watermelon, 1-aminocyclopropane-1-carboxylic acid in pears and