How Flavor Works

244 Pages·2021·2.51 MB·English

How Flavor Works

How Flavor Works

The Science of Taste and Aroma

Nak-Eon Choi
Director, Sias Co. Ltd
Oksan-myun, Heungdeok-gu, Cheongju-si, Chungcheongbukdo,
South Korea

Jung H. Han
Adjunct Associate Professor in the Department of Food Science and Human
Nutrition, University of Illinois at Urbana/Champaign, USA

This edition first published 2015 © 2015 by John Wiley & Sons, Ltd

Registered office: John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester,
West Sussex, PO19 8SQ, UK

Editorial offices: 9600 Garsington Road, Oxford, OX4 2DQ, UK
The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK
111 River Street, Hoboken, NJ 07030-5774, USA

For details of our global editorial offices, for customer services and for information
about how to apply for permission to reuse the copyright material in this book please
see our website at www.wiley.com/wiley-blackwell.

The right of the author to be identified as the author of this work has been asserted in
accordance with the UK Copyright, Designs and Patents Act 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, except as permitted by the UK Copyright,
Designs and Patents Act 1988, without the prior permission of the publisher.

Designations used by companies to distinguish their products are often claimed as
trademarks. All brand names and product names used in this book are trade names,
service marks, trademarks or registered trademarks of their respective owners. The
publisher is not associated with any product or vendor mentioned in this book.

Limit of Liability/Disclaimer of Warranty: While the publisher and author(s) have
used their best efforts in preparing this book, they make no representations or
warranties with respect to the accuracy or completeness of the contents of this book
and specifically disclaim any implied warranties of merchantability or fitness for a
particular purpose. It is sold on the understanding that the publisher is not engaged in
rendering professional services and neither the publisher nor the author shall be liable
for damages arising herefrom. If professional advice or other expert assistance is
required, the services of a competent professional should be sought.

Library of Congress Cataloging-in-Publication Data

Choi, Nak-Eon, 1965-
How flavor works : the science of taste and aroma / Nak-Eon Choi, Jung H. Han.
pages cm
Includes bibliographical references and index.
ISBN 978-1-118-86547-7 (pbk.)
1. Taste. 2. Smell. I. Han, Jung H., 1964- II. Title.
QP456.C477 2015
612.8’7–dc23
2014031608

A catalogue record for this book is available from the British Library.

Wiley also publishes its books in a variety of electronic formats. Some content that
appears in print may not be available in electronic books.

Cover image: artichokes at market © laughingmango/iStockphoto; Woman eating
salad © aldomurillo/iStockphoto; Eating sandwich © mediaphotos/iStockphoto; and
indian spices collection © bonchan/iStockphoto
Cover design by Translation by DIYPIA, Inc., S. Korea

Typeset in 10/13pt Palatino by Laserwords Private Limited, Chennai, India

1
2015

Contents

Preface
xi
About the Authors
xiii

1
What is Taste?
1
Four basic tastes, as proposed by Aristotle
5
Taste is complex
7
Most food ingredients are tasteless, odorless,
and colorless
7
Variations in odor during fermentation and aging
due to changes in molecular weight
10
2% is not a small amount
12

2
The Origins of Taste: Why do we Taste?
15
Sweetness is for identifying energy sources
(Carbohydrates)
15
Umami is a tool used to search for proteins
22
Carbohydrates are for sweetness, proteins are for umami,
but what are lipids for?
28
Saltiness: the ocean was the source of all life
30
The role of salt in cooking is not merely to provide saltiness
33
The contrast effect
33
The suppression effect
34
Acidity monitors the biological metabolism
34
Bitterness: if it’s bitter, spit it out!
37
Some people enjoy bitter tastes
39
The reason we consume caffeine despite its bitterness
40
The olfactory sense is the dominant sensory perception
of animals
42
The search for food
42
Avoid danger!
43
Know who it is!
44
Find a mate!
45
References
46

vi
Contents

3
Taste is General Science
47
Taste improves with harmonized combinations
48
The taste of meals = saltiness + umami + savory flavor
48
The taste of dessert (and fruit) = sweetness + sourness
+ sweet odor
49
Tastes influence odors
50
Food has to be dissolved for us to taste and chewed
to enhance the taste
52
The main ingredients influence taste and odor
53
Sound has an influence on taste
55
Visuals, colors, and food styles
55
Why does color exist?
57
The basic structure of pigment: why are there no
naturally blue foods?
59
Perception varies with individual differences and
conditions
61
Differences due to age and sex
61
Individual variation is also significant
63
Differences due to race and history
65
The preference for smells is constantly changing
66
References
67

4
How do we Smell Odors?
69
Olfactory receptors are G-protein coupled receptors
69
G-Receptors differentiate isomers, resulting in different
odors
71
G-Receptors perceive multiple chemical substances
73
G-Receptors work simply as on/off switches
75
Depending on the binding affinity to receptors, similar
molecules can be recognized as completely different
tastes and odors
76
The broad spectrum of the olfactory sense
77
The transduction of sensory signals
79
Olfactory fatigue is also a functional activity for life
80
The recognition and integration of perceptions
82
Parts of the brain
82
Continuous circulations in the loop
83
G-Receptors can perceive light
85
Understanding G-receptors can provide many answers
85
Pheromones are not mysterious substances
89
References
89

Contents
vii

5
What Creates Smell?
91
Odorous molecules are mainly created by plants
91
Why do plants produce aroma compounds?
92
Attracting bacteria, insects, and animals
92
As a defensive mechanism
94
Attacking tools
95
Coincidental byproducts
96
Animals generally smell odorants, not produce them
97
Animal-origin raw materials
97
Unconditional surrender to pheromones
98
Is body odor a coincidental byproduct?
99
Most flavors that we enjoy are created by cooking
100
Flavor production by enzymatic or microbial
fermentations
101
Flavor production by heat processes
104
Flavor production by pyrolysis: smoke flavor
106
Compound flavor: creation of new flavors
by mixing various odors
107
References
108

6
Technological Advancements Brought about
by the Love of Flavors
109
Why do people combine flavors?
112
How many flavors are there in the world and how many
ingredients are required to make all of these flavors?
114
How many odorous chemicals are needed to create a
tomato flavor?
116
Perfumers and flavorists create flavors
119
Olfactory training: flavorists must first distinguish odorous
chemicals before creating compound flavors
120
Compounding flavors: aromas are completed through
imagination
124
To become a perfumer, a heavy smoking habit and age do
not matter
126
The important factor is harmony
126
Applications of compound flavors
128
Types of odorants
128
Synthetic flavors versus natural flavors: which is safer?
129
Advantages and limitations of natural flavors
137
Advantages and limitations of compound flavors
138
References
139

viii
Contents

7
How Flavors Influence us
141
Brain development began with the olfactory sense
141
The human olfactory sense is less sensitive and inarticulate
144
Humans’ sense of smell has degenerated greatly
145
Proust phenomenon: odor-evoked autobiographical
memory
146
Sensorial preference changes destinies
147
Do silkworms only eat mulberry leaves?
148
Humans live with smells
149
Stage of development
149
What happens if you can no longer feel taste or smell?
150
Are humans free from pheromones
152
The healing power of aromas
156
Aromatherapy
157
Aromachology
158
Phytoncide
159
Is geosmin foul or pleasant?
161
Multiple chemical sensitivity (mcs): there are people who
are really intolerant to odorous chemicals
162
References
164

8
Taste is Regulated by Flavor, and Flavor is Regulated
by the Brain
167
The sense of smell is directly connected to the imbic
system, in other words, to survival and emotion
167
Neuroplasticity in the brain
169
Is synesthesia a malfunction or a blessing?
170
Taste is a typical phenomenon of synesthesia and
neuroplasticity
172
Orbitofrontal cortex: where sight, taste, smell, and touch
meet
173
Taste is a part of pleasure, and that pleasure becomes a
part of taste
174
Experience affects taste: familiar foods are preferred
176
The feeling of disgust can be acquired through learning
177
Taste is affected by temperature
178
Price: expectation affects the taste
179
Prejudices are effective at distorting perceived senses
180
Even the data from an expert research firm cannot promise
success in sales
181
Sensorial perception is an illusion
183
Taste and aroma do not exist
185