Trans Fatty Acids

by Dijkstra, Albert J.; Hamilton, Richard J.; Hamm, Wolf

• ISBN13: 9781405156912
• ISBN10: 1405156910
• Edition: 1st
• Format: Hardcover
• Copyright: 2008-04-28
• Publisher: Wiley-Blackwell

Summary

Trans fatty acids (TFAs) have been used for many years to impart desirable physical characteristics to fats and fat blends used in food manufacturing. However, clinical trials and epidemiological studies conducted over the last thirty years have shown that TFAs can increase "bad" cholesterol levels in the blood while reducing "good" cholesterol. Accordingly, they are also linked with increased risks of coronary heart disease, thrombosis and strokes. For this reason, the food industry has been obliged to find alternatives to TFAs, thus enabling it to meet the presumed consumer demand for "low" or "no" trans fats products. The issue is becoming more and more pressing. For example, US labelling regulations now require that food manufacturers state the trans fat content of their products on the packaging. This book provides an overview of trans fatty acids in oils and fats used in food manufacture. Topics covered include: the chemistry and occurrence of TFAs; analytical methods for determining the fatty acid composition including TFAs of foods; processing techniques for reducing, minimising or even avoiding the formation of TFAs; TFA alternatives in food; health and nutrition concerns and legislative aspects. It is directed at chemists and technologists working in edible oils and fats processing and product development; food scientists and technologists; analytical chemists and nutritionists working in the food industry.

Author Biography

Albert J. Dijkstra, Consultant to the Oils and Fats Industry, St Eutrope-de-Born, France

Richard J. Hamilton, Emeritus Professor, Liverpool John Moores University, UK

Wolf Hamm, Consultant to the Oils and Fats Industry, Harpenden, UK

Table of Contents

Contributors	p. ix
Preface	p. xi
Fatty acids: structure, occurrence, nomenclature, biosynthesis and properties	p. 1
Introduction	p. 1
Fatty acid nomenclature	p. 2
Saturated acids	p. 2
Monounsaturated acids	p. 4
Diunsaturated acids	p. 7
Triunsaturated acids	p. 7
Occurrence	p. 7
Fatty acid biosynthesis	p. 12
Saturated fatty acids	p. 12
Monoenoic fatty acids	p. 12
Polyunsaturated fatty acids	p. 14
Properties of trans fatty acids	p. 15
Melting points	p. 17
Ultraviolet spectra	p. 18
Infrared spectra	p. 20
Nuclear magnetic resonance spectroscopy	p. 22
Labelling and legislation	p. 23
Trans fatty acids intake: epidemiology and health implications	p. 25
Introduction	p. 25
Food sources of trans fatty acids	p. 26
Trans fatty acids intake	p. 30
Trans fatty acids in human milk	p. 39
Trans fatty acids intake and health implications	p. 40
Coronary heart disease	p. 40
Diabetes	p. 43
Cancer	p. 44
Concluding remarks	p. 45
Conjugated linoleic acid effects on body composition and clinical biomarkers of disease in animals and man: metabolic and cell mechanisms	p. 54
General introduction: conjugated linoleic acids and health	p. 54
Structure, dietary origins and consumption of CLAs in man	p. 55
Structure	p. 55
Origins of CLAs in the human diet	p. 56
Dietary consumption of CLAs in man	p. 59
CLAs in cancer prevention and treatment	p. 59
Epidemiology of dietary fats and cancer risk	p. 60
CLAs and breast cancer	p. 60
CLAs and prostate cancer	p. 62
CLAs in gastrointestinal cancer	p. 64
CLAs and other cancers (hepatic, pancreatic and dermal)	p. 66
Cellular mechanisms of CLAs' anti-cancer effects	p. 67
Inhibition of angiogenesis	p. 72
Attenuation of cancer metastasis	p. 73
Reduction of cancer cachexia	p. 74
Effect of CLAs on body composition and energy metabolism in animals and men	p. 75
Body composition in animals	p. 75
Body composition in man	p. 76
Possible mechanisms underlying reported changes in body composition	p. 78
Efficacy of different CLA isomers in regulating body composition	p. 78
Other reported health benefits of CLAs	p. 79
Effects on insulin resistance and diabetes	p. 80
Modulation of immune functions	p. 81
Effects of CLAs on biomarkers of cardiovascular disease	p. 87
Reported adverse health effects of CLAs in vivo and in vitro	p. 90
Conclusions	p. 91
Analysis of trans mono- and polyunsaturated fatty acids	p. 102
Introduction	p. 102
Isomeric fatty acids in the human diet	p. 102
Gas chromatography and Fourier transform infrared spectroscopy	p. 106
Direct GC analysis	p. 106
Analysis of monounsaturated isomers	p. 106
Isomers of linoleic and [alpha]-linolenic acids	p. 111
Resolution of eicosenoic and [alpha]-linolenic acid isomers	p. 113
Effect of the type of carrier gas and flow rate on cis and trans isomer resolution and fatty acid quantification	p. 114
Conjugated fatty acids	p. 116
Silver nitrate thin-layer and high-performance liquid chromatography separation of cis and trans isomers	p. 123
Monounsaturated fatty acid isomers	p. 123
Conjugated fatty acids	p. 125
Utilisation of pre-fractionation steps prior to chromatographic analysis: the case of dairy fats	p. 127
Conclusion	p. 128
Controlling physical and chemical properties of fat blends through their triglyceride compositions	p. 132
Introduction	p. 132
Defining triglyceride compositions	p. 133
Melting points and sfc	p. 135
The effect of oil processing on triglyceride groups	p. 136
Hydrogenation	p. 136
Fractionation	p. 138
Interesterification	p. 139
Other oil treatments	p. 141
Using triglyceride groups in product development	p. 143
Trans isomer control in hydrogenation of edible oils	p. 147
Introduction	p. 147
Hydrogenation process	p. 147
History of hydrogenation	p. 147
Reasons for hydrogenation	p. 147
Isomerisation	p. 148
Geometric and positional isomerisation	p. 148
Controlling isomerisation	p. 149
Reaction mechanism	p. 149
'Half-hydrogenated' intermediate	p. 149
Saturation, positional and geometric isomerisation	p. 149
Industrial hydrogenation	p. 150
Batch process	p. 150
Reactor types and features	p. 151
Reaction parameters	p. 151
Influence of feedstock on trans	p. 153
Influence of reaction conditions on trans	p. 157
Influence of catalyst on trans	p. 158
Influence of reactor design on trans	p. 160
Trans isomer control	p. 160
New developments in low trans hydrogenation	p. 162
Alternative reaction conditions	p. 162
Alternative hydrogenation processes	p. 163
Hydrogenation additives	p. 169
Alternate catalysts	p. 169
Summary	p. 175
Fractionation and interesterification	p. 181
Introduction	p. 181
Fractionation	p. 182
Historical	p. 182
Fat crystallisation theory	p. 183
Fat crystallisation practice	p. 185
Separation processes	p. 185
Fractionation products	p. 187
Interesterification	p. 191
Historical	p. 191
Interesterification mechanism	p. 192
Interesterification practice	p. 196
Interesterification products	p. 198
Food applications of trans fatty acids	p. 203
Introduction	p. 203
Margarine	p. 205
Table margarine	p. 205
Cake margarine	p. 208
Pastry margarine	p. 209
Biscuit fats	p. 210
Dough fats - short dough biscuits	p. 210
Dough fat - laminated biscuits	p. 211
Cream filling fat	p. 211
Fats for chocolate confectionery	p. 211
Fats for sugar confectionery	p. 214
Vanaspati	p. 215
Synthetic creams	p. 216
Whipped toppings	p. 216
Coffee whiteners	p. 216
Concluding remarks	p. 217
Food products without trans fatty acids	p. 219
Introduction	p. 219
Fat phase	p. 219
Margarine and related products	p. 222
Manufacturing process	p. 225
Optimal processing conditions	p. 230
Final remarks	p. 233
Index	p. 235
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