Development of Functional Bread with Beta Glucan and Black Tea and Effects on Appetite ...

259 Pages·2017·5.36 MB·English

Jalil, Abbe Maleyki Mhd (2016) Development of functional bread with
beta glucan and black tea and effects on appetite regulation, glucose and
insulin responses in healthy volunteers. PhD thesis.

http://theses.gla.ac.uk/7956/

Copyright and moral rights for this work are retained by the author
A copy can be downloaded for personal non-commercial research or study, without prior
permission or charge
This work cannot be reproduced or quoted extensively from without first obtaining
permission in writing from the author
The content must not be changed in any way or sold commercially in any format or
medium without the formal permission of the author
When referring to this work, full bibliographic details including the author, title,
awarding institution and date of the thesis must be given

Glasgow Theses Service
http://theses.gla.ac.uk/
[email protected]
Development of Functional Bread with Beta Glucan and
Black Tea and Effects on Appetite Regulation, Glucose
and Insulin Responses in Healthy Volunteers

Abbe Maleyki Mhd Jalil
BSc, MSc

A thesis submitted for the degree of Doctor of Philosophy
To
The College of Medicine, Veterinary and Life Sciences, University of Glasgow
July 2016
From research conducted at the
School of Medicine, Human Nutrition
University of Glasgow
Glasgow Royal Infirmary, 10-16 Alexandra Parade, G31 2ER
Glasgow, Scotland

© A.M.M Jalil 2016
Author's declaration

I declare that the original work presented in this thesis is the work of the author Abbe
Maleyki Mhd Jalil. I have been responsible for the organisation, recruitment, sample
collection, laboratory work, statistical analysis and data processing of the whole research,
unless otherwise stated.

Abbe Maleyki Mhd Jalil

ii
Acknowledgements

First of all I would like to thank my supervisors for their continual guidance and support
throughout this study. For Dr. Ada Garcia, I would like to thank her for the time, support,
instruction, and technical knowledge that she provided to me. For Dr Emilie Combet and
Professor Christine Edwards, I would like to express my sincere gratitude for their
knowledge, expertise, encouragement, support, and overall kindness. Without my
supervisors I could not have done it, thank you for being so thoughtful.
A big thank you to my good friend, Nuraiza Meutia for her help on cannulation. I would
also like to thank you my desk mates (Majid and Sulaiman) for their thoughts, foods,
advice and kind help. I would also like to give a special thanks to Dr. Dalia Malkova and
Hani Alfehaaid, who helped me with the lab analysis of appetite hormones.
I would like to acknowledge the lab technicians, Frances Cousins, Graeme Fyffe, John
McMillan and Susan Ridha for helping me with ordering and organizing our lab. Not to
forget Michael Logan, Mhairi McGowan, Hannah Harris, Jaafar Khan, Clare Clark, Eleni
Rizou, Susanna Palma, Maira Bouga, Min Hou, Vaios Svolos and Jaroslav for their
thoughts, laugh and good foods.
I would like to thank you to Ministry of Education (Malaysia) and Universiti Sultan Zainal
Abidin (UniSZA) for their sponsorship and support.

iii
Dedication

I would like to dedicate my thesis to my parents (Hasnah, Norehan, Mhd Jalil and Mohd
Nasser), my wife (Nadia Nazeerah Nasser) and my three little boys (Anas, Aqeel and
Ammar). I was very lucky that they were able to be close to me and encourage my every
step. I will be eternally grateful for their support, love and prayers.

iv
Table of Contents

AUTHOR'S DECLARATION II
ACKNOWLEDGEMENTS III
DEDICATION IV
TABLE OF CONTENTS V
LIST OF TABLES VIII
LIST OF FIGURES IX
ABBREVIATIONS XIII

ABSTRACT 1
1 CHAPTER 1: INTRODUCTION 3
1.1 Food matrix interactions of dietary fibre, (poly)phenols and macronutrients 6
1.1.1 (Poly)phenols-dietary fibre interaction 6
1.1.2 Interaction of (poly)phenols, dietary fibre and macronutrients 8
1.2 Functional foods 11
1.3 β-Glucan in functional foods 13
1.4 Physiological effects of soluble viscous fibres in the upper gut 21
1.4.1 Effects of viscous fibres on gastric emptying 25
1.4.2 Effects of viscous soluble fibres on digestion and absorption 27
1.4.3 Postprandial glucose and insulin 29
1.5 Physiological roles of β-Glucan in lower gastrointestinal tract 35
1.5.1 Colonic fermentation 35
1.5.2 Colonic fementation products 37
1.6 Stimulation of gastrointestinal hormones 44
1.6.1 CCK 46
1.6.2 Peptide YY (PYY) 48
1.6.3 GLP-1 52
1.7 Dietary (poly)phenols 54
1.7.1 Basic (poly)phenol structures 55
1.7.2 Tea (poly)phenols 58
1.7.3 Tea in food products 62
1.8 Physiological effects of tea (poly)phenols 63
1.8.1 Tea (poly)phenols metabolism and absorption 64
1.8.2 Colonic fermentation of tea (poly)phenols 68
1.8.3 Effects of tea intake on postprandial glucose and insulin levels 70
1.9 Effects of drinking tea on perceived satiety 74
1.10 Hypothesis to be tested in this thesis 79
2
CHAPTER 2: GENERAL MATERIALS AND METHODS 80
2.1 Study one: Bread development, starch functionality, antioxidant activity and short-
chain fatty acid production from in vitro fermentation 82
2.1.1 Bread development 82
2.1.2 Materials for bread making 82
2.1.3 Bread preparation 82
2.2 Proximate analysis 84
2.2.1 Protein content (Kjedahl method) 84
2.2.2 Fat content (solvent extraction, Soxlet method) 84
2.2.3 Resistant starch (RS) and solubilised (digestible) starch 85
2.2.4 β-Glucan content 88
2.2.5 Starch hydrolysis of breads 89
2.2.6 Microscopic study of breads structures 90
2.2.7 In vitro digestion model 90
2.2.8 Determination of total (poly)phenols 93
2.2.9 Determination of ferric reducing ability of plasma (FRAP) assay 93
2.2.10 In vitro batch fermentation 94
2.3 Study two: Effects of functional breads on palatability and satiety 99
2.3.1 Breakfast meal preparation 99
2.3.2 Ad libitum lunch and energy intake estimation 101
2.3.3 Satiety and palatability scoring (adaptive visual analogue scale, AVAS) 101
2.4 Study three: Effects of functional breads on postprandial glucose, insulin and gut
hormones 103
2.4.1 Blood collection 103
2.4.2 Total cholecystokinin (CCK) determination 105
2.4.3 Active glucagon-like peptide (GLP-1) determination 107
2.4.4 Total peptide YY (PYY) determination 108
3
CHAPTER 3: COMBINED EFFECTS OF ΒETA GLUCAN AND BLACK TEA ON
STARCH HYDROLYSIS, ANTIOXIDANT POTENTIALS AND IN VITRO BATCH
FERMENTATION 110
3.1 Introduction 112
3.2 Materials and methods 115
3.2.1 Materials and bread preparation 116
3.2.2 Proximate analysis 116
3.2.3 Determination of resistant starch (RS) and digestible (solubilised) starch 116
3.2.4 β-Glucan content 117
3.2.5 Starch hydrolysis of bread 117
3.2.6 Microscopic study of breads structures 117
3.2.7 In vitro digestion model 117
3.2.8 Determination of total (poly)phenols 118
3.2.9 Determination of ferric reducing ability of plasma (FRAP) assay 118
3.2.10 In vitro batch fermentation 119
3.3 Statistical analysis 119
3.4 Results 120
3.4.1 Bread characteristics 120
3.4.2 Nutrient composition 120
3.4.3 Microscopic study of bread structure 123
3.4.4 Starch hydrolysis of breads 123
3.4.5 Total (poly)phenols released and antioxidant activity of breads 127
3.4.6 Short chain fatty acid production 130
3.5 Discussion 136
3.6 Conclusions 140
4
CHAPTER 4: PALATABILITY, PERCEIVED SATIETY AND AD LIBITUM
ENERGY INTAKES AT LUNCH AFTER INTAKE OF FUNCTIONAL BREAD
PREPARED WITH ΒETA GLUCAN AND BLACK TEA 141
4.1 Introduction 143
4.2 Experimental design 145
4.2.1 Study design 145
4.2.2 Sample Size 145

vi
4.2.3 Inclusion and exclusion criteria 146
4.2.4 Subject recruitments 146
4.2.5 Study protocol 146
4.3 Materials and methods 147
4.3.1 Breakfast meal preparation 147
4.3.2 Ad libitum lunch and energy intake estimation 147
4.3.3 Satiety and palatability scoring (adaptive visual analogue scale, AVAS) 148
4.4 Statistical analysis 148
4.5 Results 151
4.6 Discussion 163
4.7 Conclusions 168
5
CHAPTER 5: EFFECTS OF FUNCTIONAL BREADS PREPARED WITH ΒETA
GLUCAN AND BLACK TEA ON POSTPRANDIAL GLUCOSE, INSULIN AND
APPETITE HORMONES IN HEALTHY VOLUNTEERS 169
5.1 Introduction 171
5.2 Experimental design 172
5.2.1 Study design 172
5.2.2 Sample size 172
5.2.3 Inclusion and exclusion criteria 173
5.2.4 Subject recruitment 173
5.2.5 Study protocol 173
5.2.6 Statistical analysis 177
5.3 Results 178
5.4 Discussion 191

CHAPTER 6: GENERAL DISCUSSION 198
6.1 Summary of results 200
6.2 Relationship between in vitro and in vivo studies, and possible explanations 206
6.3 Reflections on methodology: strengths and limitations 208
6.4 Implications for food industry 212
6.5 Implications for healthy eating at the population level 213
6.6 Future research 214
6.7 Conclusions 215
7
REFERENCES 218

vii
List of Tables

Table 1-1. Current dietary fibre definitions from around the world. Adapted from (Jones,
2014) ........................................................................................................................... 15
Table 1-2. Different types and characteristics of soluble dietary fibres .............................. 18
Table 1-3. Different types and characteristics of β-glucan ................................................. 20
Table 1-4. Association between total dietary fibre (or whole grain) intakes and chronic
diseases (T2DM, cancers and CVDs). ........................................................................ 23
Table 1-5. Effect of β-glucan containing foods on postprandial glycaemia and insulin
levels in healthy subjects. ........................................................................................... 31
Table 1-6. Production of major SCFA (acetate, propionate and butyrate) after the
fermentation of soluble dietary fibres in in vitro, animal and human study. .............. 40
Table 1-7. Source, specific receptors and mode of action of hormones related to food
intake........................................................................................................................... 45
Table 1-8. Effects of viscous soluble fibres on postprandial CCK, PYY and GLP-1. ........ 50
Table 1-9. Tea in food products. ......................................................................................... 63
Table 1-10. Salivary, plasma and urine concentrations of tea (poly)phenols after green tea
extract ingestion (200 mL).......................................................................................... 64
Table 1-11. Acute human studies of teas on postprandial glucose and insulin levels in
healthy subjects. .......................................................................................................... 76
Table 1-12. Acute human studies of teas on perceived satiety and energy intake in healthy
subjects. ...................................................................................................................... 78
Table 2-1. Ingredients for making the test breads ............................................................... 83
Table 2-2. Retention times of individual SCFA in standard solution and faecal samples .. 98
Table 2-3. Breakfast meal and nutrient composition......................................................... 100
Table 3-1. Nutrient composition of breads ........................................................................ 121
Table 3-2. The pH in fermentation fluid containing breads at 0, 6 and 24 h .................... 130
Table 4-1. Baseline characteristics .................................................................................... 152
Table 4-2. Bread eating time (mean ± S.E.M) at breakfast in healthy volunteers (n = 23)
.................................................................................................................................. 153
Table 4-3. Baseline and postprandial perceived hunger (median (IQR)) after consuming
breads at breakfast in healthy volunteers (n = 23) .................................................... 157
Table 4-4. Fasting and postprandial perceived fullness (median (IQR)) after consuming
breads at breakfast in healthy volunteers (n = 23) .................................................... 158
Table 4-5. Fasting and postprandial perceived satiety (median (IQR)) after consuming
breads at breakfast in healthy volunteers (n = 23) .................................................... 159
Table 4-6. Fasting and postprandial perceived desire to eat (median (IQR)) after
consuming breads at breakfast in healthy volunteers (n = 23) ................................. 160
Table 4-7. Fasting and postprandial perceived prospective food intake (median (IQR))
after consuming breads at breakfast in healthy volunteers (n = 23) ......................... 161
Table 5-1. Participant characteristics (n = 15) .................................................................. 178

viii
List of Figures

Figure 1-1. Interaction between tea (poly)phenols (TPL) and amylose through hydrogen
bonding (Chai et al., 2013). ........................................................................................ 11
Figure 1-2. Traditional British sticky malt loaf from BBC Good Food (BBC, 2016). ....... 13
Figure 1-3. Food and non-food related factors influencing digestibility of soluble β-glucan
in the gastrointestinal tract (Englyst and Englyst, 2005). ........................................... 24
Figure 1-4. Human proximal and distal colon. Adapted from Guarner (2014). ................. 36
Figure 1-5. Five major groups of (poly)phenols (Manach et al., 2004). ............................. 56
Figure 1-6. Subclass of flavonoids (flavonols, flavones, isoflavones, flavanones,
anthocyanidins, and flavanols) (Manach et al., 2004). ............................................... 57
Figure 1-7. Chemical structure of the most common flavan-3-ols in tea (Roowi et al.,
2010) ........................................................................................................................... 60
Figure 1-8. Theaflavins found in black tea (Del Rio et al., 2004) ...................................... 61
Figure 1-9. Tea flavan-3-ol absorption metabolism in the human body (Henning et al.,
2008) ........................................................................................................................... 66
Figure 1-10. Structures of main (-)-epicatechin conjugates in plasma (Clifford et al., 2013)
.................................................................................................................................... 67
Figure 1-11. Structures of phenolic acids from the catabolism of green tea flavan-3-ols
(Clifford et al., 2013) .................................................................................................. 70
Figure 2-1. Flow chart of general methodology for studies 1, 2 and 3 ............................... 81
Figure 2-2. Flow chart for hydrolysis and solubilisation of non-resistant starch. AMG,
amyloglucosidase ........................................................................................................ 86
Figure 2-3. Flow chart for the measurement of resistant starch (RS). ................................ 87
Figure 2-4. In vitro digestion procedure mimicking human digestion (Aura et al., 1999) . 91
Figure 3-1. Flow diagram of methodology for bread development, in vitro digestion and in
vitro fermentation. .................................................................................................... 115
Figure 3-2. Detail of bread structure. The structure of bread was visualised at 4x power.
(a) WB, white bread; (b) BT, black tea bread; (c) βG, β-Glucan bread; (d) βGBT, β-
Glucan plus tea bread................................................................................................ 122
Figure 3-3. Microscopic figures of bread structures. (a) WB, white bread; (b) BT, black tea
bread; (c) βG, β-Glucan bread; (d) βGBT, β-Glucan plus black tea bread.
Amylopectin granule stains brown, amylose dark brown (appears in the middle of
starch granule) and gluten light green. ..................................................................... 124
Figure 3-4. Starch hydrolysis based on percentage (%) of total hydrolysed starch of
different breads. WB, white bread; BT, black tea bread; βG, β-Glucan bread; βGBT,
β-Glucan plus black tea bread; SF, Standard flour (unprocessed, provided by
supplier). Values are expressed as mean ± standard deviation. Values with different
letters are significantly different at the level of p < 0.05 within same time point.
There were significant (p < 0.05) time interactions. Coefficient of variation (CV) is
less than 32.0%. ........................................................................................................ 125
Figure 3-5. Total area under the curve (TAUC0-180min) of percentage (%) hydrolysed
starch x min. WB, white bread; BT, black tea bread; βG, β-Glucan bread; βGBT, β-

ix