Glycative Stress Research
Online edition : ISSN 2188-3610
Print edition : ISSN 2188-3602
Received : July 20, 2018
Accepted : September 7, 2018
Published online : September 30, 2018
doi:10.24659/gsr.5.3_151

Original article

Effect of heat-moisture-treated high-amylose corn starch-containing food on
postprandial blood glucose.
Masayuki Yagi 1), Wakako Takabe 1), Ursula Wickramasinghe 1), Fuka Okuda 1), Misato Kon 1),
Aki Fujimura 2), Hideaki Nakamoto 2), Junichi Takahara 2), Yoshikazu Yonei 1)
1) Anti-Aging Medical Research Center and Glycative Stress Research Center, Faculty of Life and Medical Sciences,
Doshisha University, Kyoto, Japan
2) R&D Division, Sanwa Starch Co., Ltd, Kashihara, Nara, Japan

Abstract

Purpose: Heat-Moisture-Treated high-amylose corn starch (HMT-HAS) including a large amount of amylose is a recalcitrant
ingredient. The purpose of this study was to verify its effect on postprandial blood glucose level.
Methods: The subjects were 19 males and 13 females (30.9 ± 10.7 years) of healthy students and company workers. The
control food was a bread roll made with wheat starch blended with 50% wheat flour replacement and the test food was bread
blended with 50% HMT-HAS (Amylogel TM HB- 450). The postprandial blood glucose levels after ingesting these breads
were tested on different days. The blood glucose level tests were conducted with a self-blood glucose meter, 15, 30, 45, 60,
90 and 120 minutes after the subjects started ingesting the test food. A hematological test, blood biochemistry general test
and background test for subjects were conducted in advance. This study was conducted with the approval of the Doshisha
University ethical committee.
Results: The postprandial blood glucose levels of all subjects were higher after they ingested the control food (bread
including wheat starch) than the test food (bread including HMT-HAS). The incremental area under the curve (iAUC) of
blood glucose level changes were compared between the control food and test food, and as a result, it was significantly lower
after ingesting the test food than the control food and the maximum value of glucose concentration change (ΔCmax) was
significantly lower after ingesting the test food than the control food. As a subclass analysis, the result of the comparison
between company workers’ group (36.9 ± 9.3 years) and students’ group (22.6 ± 1.3 years) showed that the homeostasis
model assessment of insulin resistance (HORM-IR) was higher in the company workers’ group and the maximum value of
glucose concentration (Cmax) was significant higher in the same group; however, there was no significant difference in the
postprandial blood glucose levels after the ingestion of the food containing HMT-HAS.
Conclusion: The ingestion of the bread including HMT-HAS inhibited postprandial hyperglycemia more than the one
blended with wheat starch. Its inhibiting action on postprandial hyperglycemia was more remarkable in the groups of higher
age and higher insulin resistance. It was suggested that postprandial blood hyperglycemia can be alleviated by ingesting bread
blended with HMT-HAS and it can contribute to health maintenance.

KEY WORDS: heat-moisture-treated high-amylose corn starch (HMT-HAS), post-prandial hyperglycemia,		

wheat starch, amylose, insulin

Contact Address: Professor Yoshikazu Yonei, MD, PhD
Anti-Aging Medical Research Center,
Graduate School of Life and Medical Sciences, Doshisha University
1-3, Tatara Miyakodani, Kyotanabe, Kyoto, 610- 0394 Japan
Phone/Fax: +81-774 -65- 6394 Email: yyonei@mail.doshisha.ac.jp
Co-authors; Yagi M, yagi@yonei-labo.com ;Takabe W, wtakabe@mail.doshisha.ac. jp ; Wickramasinghe U, cygb2502@mail4.doshisha.ac. jp ;Okuda F, ctuc2017@mail4.doshisha.ac. jp ; Kon M, ctuc2013@mail4.doshisha.ac. jp ;Fujimura A, aki-fujimura@sanwa-starch.co. jp ; Nakamoto H, h-nakamoto@sanwa-starch.co. jp ;Takahara J, jun-ichi-takahara@sanwa-starch.co. jp_ 151 _

Glycative Stress Research 2018; 5 (3): 151-162(c) Society for Glycative Stress ResearchHeat-Moisture-treated High-Amylose Corn Starch and Postprandial Hyperglycemia

Introduction

The phenomenon that reducing sugars, such as glucose,
reacts with protein non-enzymatically and forms glycatedprotein, and as a result, generates advanced glycation end
products (AGEs), is called “glycation” 1, 2). The stress ona living body caused by reducing sugars and aldehyde iscalled “glycative stress,” and it is one of the risk factors forthe acceleration of physical aging. For the alleviation ofglycative stress, the inhibition of postprandial hyperglycemia,
inhibition of AGE generation and decomposition andelimination of AGEs are cited. For the purpose of inhibiting
postprandial hyperglycemia, there are methods of selecting
low glycemic index (GI) foods as staple foods by which therise of postprandial blood glucose (GLU) becomes gradual,such as ingesting dietary fibers such as vegetables before
carbohydrates and limiting the ingestion of carbohydrates 3).
A notable postprandial hyperglycemia (the maximum GLU
value [Cmax] more than 140 mg/dL) has been called a“glucose spike” ( Fig. 1 ), and it has been known to cause avariety of tissue damage, i.e. vascular endothelial disorder.
Recently, it has been clarified as the result of an in vitro
experiment that it is possible that the open-linear form of
glucose molecules exposes the aldehyde group and it causesa chain reaction and multiple various intermediate aldehydes
are produced in a simultaneous manner 4). We called thisphenomenon an “aldehyde spark.” From the viewpoint ofglycative stress, the prevention of postprandial hyperglycemia
leads to the prevention of an aldehyde spark, so that it ismore important than ever thought before.

This time, a clinical ingestion test was conducted forthe purpose of evaluating the effect of the food blended withprocessed starch (test food) on the GLU changes after the
food ingestion. The subjects were healthy males and females.
The control food was a table roll (bread) made with wheat
starch blended with 50% replacement of wheat flour. The
test food was bread blended with heat-moisture-treated highamylose corn starch (HMT-HAS) 5). The inhibition effect of
the test food in the rise of GLU was verified by an open-label
single ingestion test.

MethodSubjects

The subjects of this study were healthy males andfemales 20 years old or older and 60 years old or younger,
and they had submitted letters of consent for participationin this study. The test food was the table roll, bread blended
with HMT-HAS (Amylogel HB-450; Sanwa Starch Co.,
Ltd., Kashihara-city, Nara). The inhibition effect of the test
food on postprandial hyperglycemia was verified by a single
ingestion.
A briefing for the explanation of the test was conducted
after obtaining the approval of the ethical committee
concerning “studies involving human subjects” of Doshisha
University, and 32 subjects whose consents had been obtained
and who did not conflict with the following exclusion criteria
were incorporated in this study:

Fig. 1. “Glucose spike” evokes “Aldehyde spark.”

The glucose spike evokes an “aldehyde spark.” Various types of aldehyde are simultaneously formed with a chain-reaction, i.e. GO, MGO,
3DG, GA. Glucose is normally saccharides with a cyclic form, however, in 0.002% of glucose, a portion of the molecule structure isdecyclized to present an open-linear form, exposing the aldehyde group (-CHO) which is highly reactive.
AGEs, advanced glycation end products; RAGE, receptor for AGEs; ER, endoplasmic reticulum; GO, glyoxal; MGO, methyglyoxal; 3DG,
3-deoxyglucosone; GA, glyceraldehyde.

_ 152 _Glycative Stress Research

1. Individuals who are using medical products for any
disease
2. Individuals who are under treatment or have a historyof impaired glucose tolerance, mental disabilities, sleep
disorder, hypertension, diabetes, dyslipidemia or otherserious dysfunctions
3. Individuals who used a drug for treatment in the past 1
month (one-shot medicine for headache, menstrual pain
and colds are excluded)
4. Individuals who are under treatment of or have a historyof serious liver dysfunction, kidney damage, heart diseaseor blood disease
5. Individuals who are under treatment of or have a historyof digestive organ disease (a history of appendicitis is
excluded)
6. Individuals whose body mass index (BMI) is over
30 kg/m 2
7. Individuals who donated blood over 200 mL in the past 1
month or over 400 mL in the past 3 months
8. Individuals with serious anemia
9. Individuals who are sensitive to test products orindividuals who have the fear of severe allergy in otherfoods and medical supplies
10. Individuals who are pregnant or breastfeeding or
individuals who could possibly become pregnant
11. Individuals who had a habit to continuously ingest healthpromoting foods advocating glycometabolism or healthy
foods in the past 3 month or will ingest those foods
during the test period (ingest for the purpose of healthmaintenance is acceptable)
12. Individuals who were judged inappropriate as the
subjects for this study by a responsible doctor

Test Design
This test was an open-label test with a control.
Table roll made with HMT-HAS blended with 50%
replacement of wheat flour (bread containing HMT-HAS)
was used as the test food. Table roll made with wheat starch
blended 50% replacement (bread containing wheat starch)
was used as the control food ( Table 1-1, 1-2 ).
The subjects were instructed to avoid excessive exercise,
eat a specified dinner menu and sleep longer than 6 hours on
the day before the test. The menus of the dinner on the day
before the test are shown in Table 2 6, 7). The subjects selected
their dinner from ① and ② with their free will and decided
to take the same menu both times. Alcohol intake wasprohibited from the previous day of the test to the completionof the day of the test.
On the day of the test, they were waiting quietly insitting position, while DVDs of animation and travels
were televised and they were prohibited from telephoning,
sleeping, excessive brain activities and physical activities
with a possibility of sweating until the end of the test. Afterthe ingestion of the test food, they were only allowed to takewater.
On the day of the first test, after waiting quietly, thesubjects underwent physical measurements and, by collecting
blood samples, hematologic test and blood biochemical test.
At the same time, they conducted self-monitoring of GLU(the first time). After that, they ingested three pieces ofcontrol food (the dough was divided and baked so that the
carbohydrate amount was 75 g). A piece of control food was
cut into six pieces for the subjects to chew a piece 10 times
and swallow. Food ingest time was from 9 to 10 minutes.

Table 1-1. Composition of test meal (%).

Flour
StarchVital gluten
Yeast
Yeast foodRefined sugar
Salt
Powdered skim milk
Margarine
Water

Control food

Test food

25.9

24.1

0.8

0.7

26.7

24.9

1.1

1.0

0.1

0.0

6.4

6.0

1.0

0.9

1.6

1.5

6.4

6.0

30.2

34.9

Table 1-2. Nutrition facts of test meal.

test food

unit
(g)

energy(kcal)

protein
(g)

fat
(g)

carbohydrate
(g)

sugar
(g)

fiber
(g)

sodium chloride
equivalent(g)Control food

100

298.4

4.8

6.6

53.5

52.6

0.9

1.2

Test food

100

244.6

4.6

6.1

49.6

32.5

17.1

1.1

_ 153 _

Heat-Moisture-treated High-Amylose Corn Starch and Postprandial Hyperglycemia

Table 2. Dinner menu on the day before the test.

Selection ①

Selection ②

Cooked white rice

200 g

300 g

Ingredients of beef bow

1 pack1 pack－1 packFreeze-dried miso soup1 pack1 packEnergy intake (kcal)

668

1,014

12 : 39 : 48

12 : 41 : 46

Ingredients of beef bow (mini size)

PFC ratio

Cooked rice: “Papatto Rice” Koshihikari (Hagoromo Foods Corporation, Suruga-ku, Shizuoka).
Side dishes: Ingredients of beef bowl, Ingredients of beef bowl (mini size) (Yoshinoya Holdings Co., Ltd., Chio-ku,
Tokyo, Japan) 5, 6), Freeze-dried miso soup: Yoshinoya Holdings Co., Ltd

The subjects conducted self-monitoring of GLU 15 minutes(the 2nd time), 30 minutes (the 3rd time), 45 minutes (the
4th time), 60 minutes (the 5th time), 90 minutes (the 6thtime) and 120 minutes (the 7th time) after starting ingestion.
On the day of the second test, the subjects conducted selfmonitoring of GLU after waiting quietly (the 1st time). Thenthey ingested three pieces of test food together with 200 mLof water. The ingestion method, the way of waiting quietly
during self-monitoring of GLU and the test implementation
time were the same as those of the first test.
The test period was from August 2017 to December 2017.

Self-monitoring of GLU

The subjects conducted self-monitoring of GLU using
a self-monitoring blood glucose meter (Glucocard G Black:GT -1830, Arkray Co., Kamigyo-ku, Kyoto, Japan). The
measurement was conducted twice and the average value wasused. When the difference between the two values was morethan 10%, a 3rd value was measured and the average valueof the two values with the least difference was used.

Physical measurements

Body height, body weight, body fat percentage, BMI,
systolic and diastolic blood pressures and pulse rate were
measured.

Blood tests

Peripheral blood tests and biochemical tests wereconducted using blood samples. The test items for thisanalysis were white blood count (WBC), red blood count(RBC), hemoglobin content (Hb), hematocrit value (Ht), mean
corpuscular volume (MCV), mean corpuscular hemoglobin(MCH), mean corpuscular hemoglobin concentration(MCHC), platelet count (PLT), blood urea nitrogen (BUN),
creatinine (CRE), uric acid (UA), aspartate aminotransferase(AST), alanine aminotransferase (ALT), gamma-glutamyltranspeptidase ( γ - GTP), total cholesterol (TC), triglyceride(TG), low-density-lipoprotein cholesterol (LDL-C), highdensity lipoprotein cholesterol (HDL-C), HbA1c, fasting

plasma glucose (FPG), insulin (imunoreactive insulin: IRI)
and glucagon. The measurements using blood samples wereconducted at LSI Medience Corporation (Chiyoda-ku, Tokyo,
Japan).

Statistical analysis

Analytical items were GLU measured value, incremental
area under the curve (iAUC) of GLU level changes, amountof change from initial value (Δ blood glucose value), Cmax
and change value of Cmax (Δ Cmax), and fundamental
statistics (average value, standard deviation and 95%
confidence range) were calculated.
For the test of significant difference, the comparisons
between groups at the time of ingesting the control foodand the test food were evaluated using unpaired t test or
Bonferroni’s multiple test (paired). For the test of significant
difference, an appropriate statistical analytical software(Excel Statistics, Social Survey Research Information Co.,
Ltd.) was used. The level of significance was assumed totend to be less than 5% and 10%. This system was preparedso that various statistical analyses can be done from theviewpoint of exploratory research such as a stratified analysis
in responding to subject characteristics and research ofcorrelation from the viewpoint of affectivity.

Ethical review

This study was conducted in compliance with thedeclaration of Helsinki (revised at 2013 WMA General
Assembly, Fortaleza, Brazil) and the ethical guideline
regarding the “medical and health research involving humansubjects (announced by the Ministry of Education, Culture,
Sports, Science and Technology and the Ministry of Health,Labour and Welfare). For this test, the “Committee for
Medical Test involving human subjects” was held at the
Ethical Review Committee concerning the “study involving
human subjects” of Doshisha University (Kamigyo-ku,
Kyoto, Japan), where the morality and validity of this test
was discussed, and approval was granted (Application No.
17054). This test was pre-registered as a clinical trial (UMINNo.000029026).

_ 15 4 _Glycative Stress Research

Resultin carbohydrate metabolism between the groups was within
the reference range. The insulin resistance associated withaging tends to increase in the corporate workers’ group( Table 4 ).

General backgroundAll 32 subjects of this study did not fall under the
Judgment Classification D, requiring medical treatment, of
the Japan Society of Ningen Dock and they were all in ahealthy condition ( Table 3 ). The breakdown of subjects was
19 males and 13 females, and their average age was 30.9 ±10.7.
The subjects can be classified in the two groups of 13
college students (Doshisha University students and graduate
students, 6 males and 7 females) and 19 company workers(Sanwa Starch Co., Ltd., 13 males and 6 females). The
company workers were higher in age, body weight, BMI,
TC, LDL-C and homeostasis model assessment of insulin
resistance (HORMA-IR) than the college students (p < 0.01).
On the other hand, their pulse rates and IRI values weresignificantly lower than those of students (p < 0.01). The
difference between the average ages of the two groups was
14.3 and it is presumed that aging affected the differencein the test values. Regarding the test items concerning
carbohydrate metabolism, company workers’ IRI values were
2.7 μunit/mL (1.8 times) lower than those of the students’group and their HORMA-IR values were 0.5 points higher(1.7 times) than those of the students’ group. The difference

Table 3. Subject background profile.

Average

SD

Age

year

30.9

±

10.7

Height

cm

166.7

±

7.7

Weightkg

60.0 ±

10.8

BMI

---

21.5 ±

2.7

±

13.1

Blood pressure(systolic)

mmHg(diastolic)mmHg

70.7 ±

10.4/min

66.8 ±

14.1

Pulse

119.7

n = 32. BMI, body mass index; SD, standard deviation.

Table 4. Comparison between College students and Company workers.

College student(n=13)

Company worker(n=19)

6

13

Male

GenderFemaleAge7p value
0.419

6

22.6

±

1.3

36.9

±

9.3

< 0.001

Height

cm

164.1

±

7.1

168.1

±

8.0

0.118

Weight

kg

52.3

±

6.4

64.1

±

9.1

< 0.001

BMI

---

19.4

±

1.6

22.6

±

2.1

< 0.001

Blood pressure (systolic)

mmHg

124.2

±

13.1

119.1

±

16.4

0.095

(diastolic)

mmHg

70.4

±

9.5

73.9

±

13.8

0.899

Pulse

/min

74.7

±

15.4

61.9

±

11.5

0.005

TC

mg/dL

165.9

±

22.5

196.9

±

39.3

0.004

LDL-C

mg/dL

88.5

±

18.5

107.4

±

34.5

0.004

HDL-C

mg/dL

63.5

±

10.3

75.6

±

17.5

0.500

TG

mg/dL

76.5

±

32.9

72.4

±

39.3

0.782

FPG

mg/dL

82.9

±

6.6

89.9

±

9.4

0.454

HbA1c

%

5.1

±

0.2

5.2

±

0.2

0.138

IRI

μU/mL

5.9

±

2.3

3.2

±

1.1

0.002

Glucagon

pg/mL

107.5

±

10.4

112.8

±

14.2

0.793

0.7

±

0.2

1.2

±

0.6

0.004

HORMA-IR

Data are expressed as mean ± SD, paired t test. BMI, body mass index; TC, total cholesterol; LDL-C, low-density-lipoprotein-cholesterol; HDL-C,
high-density-lipoprotein-cholesterol; TG, triglyceride; FPG, fasting plasma glucose; IRI, immunoreactive insulin; HORMA-IR, homeostasis model assessment of
insulin resistance; SD, standard deviation.

_ 155 _

Heat-Moisture-treated High-Amylose Corn Starch and Postprandial Hyperglycemia

which was the same as the analysis of GLU change curvesof all subject groups. Postprandial GLU levels significantly
lowered 30 minutes after starting test food intake comparing
with control food (p < 0.05) and tended to lower 45 minutes
after starting test food intake (p < 0.1, Table 9, Fig. 4 ). There
was no significant difference in iAUC and Cmax between thetwo groups. A significant reduction was shown in ΔCmax
by ingesting test food compared with control food ( p < 0.05,
Table 10, Fig. 5 ).
In the company workers’ group, a higher GLU change
curve was shown by ingesting test food compared with
control food, which was the same as the analysis of all
subjects’ groups after ingesting each food. The postprandial
GLU showed a significant reduction 45 minutes, 60 minutes,
90 minutes and 120 minutes after starting ingestion of thetest food compared with control food (p < 0.01, Table 11,
Fig. 6 ). iAUC was significantly reduced by ingesting test
food compared with control food (p < 0.05, Table 11, Fig.
7- a ). Cmax and ΔCmas were significantly reduced byingesting test food compared with control food (p < 0.05,
Table 11, Fig. 7-a, b).

Changes pf postprandial GLU (Whole analysis)

The GLU change curves of all subjects show that they
were higher after ingesting control food (bread containing
wheat starch) than after ingesting test food (bread containing
HMT-HAS). The postprandial GLU levels showed significant
decreases 30, 45, 60, 90 and 120 minutes after starting test
food intake ( Table 5, Fig. 2 ). iAUC showed a significantly
lower level in test food compared with control food (p < 0.01,
Table 6, Fig. 3-a). Cmax showed a significantly lower levelin test food compared with control food (p < 0.01, Table 7,
Fig. 3-b). ΔCmax showed a significantly lower level in test
food compared with control food ( p < 0.05, Table 8, Fig.
3-c).

Changes of postprandial GLU (Subclass analysis)

All subjects were classified into two groups of 13 college
students and 19 company workers and analyzed. In the groupof college students, the GLU change curve after ingesting
the control food was higher than after ingesting the test food,Table 5. Changes in GLU (mg/dL) after meals: Total analysis.
0 minControl
food
Test
food

15 min30 min45 min60 min90 min

120 min

0.0 ± 0.0 - 16.3 ± 16.6 5.7 58.8 ± 17.1 5.9 61.9 ± 20.5 7.1 48.1 ± 18.0 6.3 33.5 ± 18.3 6.4 29.5 ± 17.7 6.1
0.0 ± 0.0 - 17.6 ± 13.1 4.5 48.0 ± 17.8 6.2 49.5 ± 22.4 7.8 35.8 ± 20.6 7.1 25.8 ± 16.1 5.6 15.0 ± 12.7 4.4

Data are expressed as mean ± SD, 95% CI, n = 32. GLU, blood glucose; SD, standard deviation; CI, confidence interval.

Blood glucose (mg/dL)

80

Control

Test

70
60
50
40

＊＊

＊＊

30

＊＊

20

＊

10

＊＊

0
0

15

30

45

60

90

105

120

Time (min)Fig. 2. Changes in GLU level after meals.

Data are expressed as mean ± 95% CI, n = 32, * p < 0.05, ** p < 0.01 vs control by Bonferroni multiple comparison analysis with related
data. GLU, blood glucose; CI, confidence interval.

_ 15 6 _Glycative Stress Research

Table 6. iAUC, Cmax and ΔCmax: Total analysis.
iAUC
Control
food
Test
food

Cmax (mg/dL)

ΔCmax (mg/dL)

4583.9 ± 1422.1 492.7

162.5 ± 22.2

7.7

68.5 ± 17.6

6.1

3530.5 ± 1202.9 416.8

151.3 ± 20.8

7.2

57.4 ± 19.4

6.7

Data are expressed as mean ± SD, 95% CI, n = 32. GLU, blood glucose; iAUC, incremental area under the curve; Cmax, maximum value of GLU concentration;
ΔCmax, maximum value of GLU concentration change; SD, standard deviation; CI, confidence interval.

Table 7. Multiple comparison analysis by Bonferroni: Total analysis.
Level 2

Level 2Control

Test

Changes in GLU level (min)
0

15

30

45

60

90

120

-

1.000

0.007

0.001

0.001

0.033

< 0.001

iAUC

Cmax

ΔCmax

< 0.001

0.001

0.001

n = 32. GLU, blood glucose; iAUC, incremental area under the curve; Cmax, maximum value of GLU concentration; ΔCmax, maximum value of GLU
concentration change.

Table 8. Changes in GLU (mg/dL) after meals: Subclass analysis in College students.
0 min
Control
food
Test
food

15 min30 min45 min60 min90 min

120 min

0.0 ± 0.0 - 17.3 ± 15.7 5.4 62.0 ± 17.0 5.9 64.2 ± 19.1 6.6 46.7 ± 16.7 5.8 31.5 ± 13.3 4.6 30.8 ± 20.2 7.0
0.0 ± 0.0 - 22.1 ± 14.0 4.8 49.5 ± 14.4 5.0 49.0 ± 22.2 7.7 36.2 ± 23.3 8.1 29.1 ± 18.1 6.3 19.0 ± 14.5 5.0

Data are expressed as mean ± SD, 95% CI, n = 13. GLU, blood glucose; SD, standard deviation; CI, confidence interval.

a

b
6,000

200

100
＊＊

4,000
3,000
2,000
1,000
0

150

ΔCmax (mg/dL)＊＊

Cmax (mg/dL)

5,000

iAUC

c

100
50
0

Control

Test

80
＊
60
40
20
0

Control

Fig. 3. Comparison between test group and control.
a: iAUC, b: Cmax, c: ΔCmax.

Test

Control

Test

Data are expressed as mean ± 95% CI, n = 32, * p < 0.05, ** p < 0.01 vs control by Bonferroni multiple comparison analysis with related
data. GLU, blood glucose; iAUC, incremental area under the curve; Cmax, maximum value of GLU concentration; ΔCmax, maximum
value of GLU concentration change; CI, confidence interval.

_ 157 _

Heat-Moisture-treated High-Amylose Corn Starch and Postprandial Hyperglycemia

Table 9. Multiple comparison analysis by Bonferroni: Subclass analysis in College students.
Level 2

Level 2Control

Test

Changes in GLU level (min)
0

15

30

45

60

90

120

-

0.837

0.036

0.051

0.225

1.000

0.178

iAUC

Cmax

ΔCmax

0.144

0.264

0.048

n = 13. GLU, blood glucose; iAUC, incremental area under the curve; Cmax, maximum value of GLU concentration; ΔCmax, maximum value of GLU
concentration change.

Blood glucose (mg/dL)

80

Control

70

Test

60
50
40

＊

†

30
20
10
0
0

15

30

45

60

90

105

120

Time (min)Fig. 4. Changes in GLU level after meals in College students.

Data are expressed as mean ± 95% CI, n = 13, * p < 0.05, † p < 0.1 vs control by Bonferroni multiple
comparison analysis with related data. GLU, blood glucose; CI, confidence interval.

Table 10. Changes in GLU level after meals: Subclass analysis in Company workers.
0 min
Control
food
Test
food

15 min30 min45 min60 min90 min

120 min

0.0 ± 0.0 - 15.7 ± 17.5 6.1 56.5 ± 17.2 6.0 60.3 ± 21.8 7.6 49.0 ± 19.3 6.7 34.9 ± 21.4 7.4 28.6 ± 16.3 5.7
0.0 ± 0.0 - 14.5 ± 11.8 4.1 46.9 ± 20.0 6.9 49.9 ± 23.1 8.0 35.5 ± 19.2 6.6 23.6 ± 14.6 5.1 12.3 ± 10.8 3.8Data are expressed as mean ± SD, 95% CI, n = 19. GLU, blood glucose; SD, standard deviation; CI, confidence interval.

ΔCmax (mg/dL)

100
80

＊

60
40
20
0

Fig. 5. ΔCmax in College students.

Control

Test

Data are expressed as mean ± 95% CI, n = 13, * p < 0.05 vs control by Bonferroni multiple comparison analysis withrelated data. GLU, blood glucose; ΔCmax, maximum value of GLU concentration change; CI, confidence interval.

_ 158 _Glycative Stress Research

Table 11. Multiple comparison analysis by Bonferroni: Subclass analysis in Company workers.
Level 2

Level 2Control

Test

Changes in GLU level
0

15

30

45

60

90

120

-

1.000

0.168

0.031

0.003

0.005

< 0.001

iAUC

Cmax

ΔCmax

< 0.001

0.003

0.017

n = 19. GLU, blood glucose; iAUC, incremental area under the curve; Cmax, maximum value of GLU concentration; ΔCmax, maximum value of GLU
concentration change.

Blood glucose (mg/dL)

80

Control

70

Test

60
50
40

＊

30

＊＊

20

＊＊

10

＊＊

0
0

15

30

45

60

90

105

120

Time (min)Fig. 6. Changes in GLU level after meals in Company workers.

Data are expressed as mean ± 95% CI, n = 19, * p < 0.05, ** p < 0.01 vs control by Bonferroni multiple comparison analysis
with related data. GLU, blood glucose; CI, confidence interval.

a

b
6,000

200

100
＊＊

4,000
3,000
2,000
1,000
0

150

ΔCmax (mg/dL)＊＊

Cmax (mg/dL)

5,000

iAUC

c

100
50
0

Control

Test

80
＊
60
40
20
0

Control

Test

Fig. 7. Comparison between test group and control in Company workers.
a: iAUC, b: Cmax, c: ΔCmax.

Control

Test

Data are expressed as mean ± 95% CI, n = 19, * p < 0.05, ** p < 0.01 vs control by Bonferroni multiple comparison analysis with related
data. GLU, blood glucose; iAUC, incremental area under the curve; Cmax, maximum value of GLU concentration; ΔCmax, maximum
value of GLU concentration change; CI, confidence interval.

_ 159 _

Heat-Moisture-treated High-Amylose Corn Starch and Postprandial Hyperglycemia

Discussion

Summary of results

The postprandial GLU showed a higher level for all
subjects by ingesting control food (bread containing wheat
starch) than test food (bread containing HMT-HAS). iAUC
was significantly reduced by ingesting test food comparedwith control food, and ΔCmas was significantly reduced byingesting test food compared with control food. From theseresults, it is predicted that HMT-HAS blended in test foodinhibits postprandial hyperglycemia.
From the subclass analysis, it is presumed that HMTHAS blended in the test food more effectively inhibitedthe postprandial hyperglycemia in the company workers’
group than in the college students’ group. The comparisonsof iAUC, Cmax and ΔCmax between college students’group and company workers’ group showed that only theCmax in company workers’ group after ingesting control
food was high (p < 0.05). It showed the possibility that thehyperglycemic state of the company workers’ group whose
insulin resistance tends to increase can be alleviated byreplacing their food with a food that contains HMT-HAS,
and it can also alleviate glycative stress.
Regarding the background factors of the 32 subjects ofthis study, they were classified into company workers’ groupand college students’ group. The average age of the company
workers was 14.3 years older than that of the college students,
and their body weight, BMI, TC, and LDL-C were higher
while their pulse rate was significantly lower than those ofcollege students. Regarding the items relating to carbohydrate
metabolism, the corporate workers were 2.7 μunit/mL (1.8
times) lower in IRI value than college students and their
HORMA-IR was high, so that it was presumed that they had
the tendency for higher insulin resistance. Looking at theefficacy of the test food, even though no clear efficacy wasobserved in college students, the effect to alleviate postprandial
hyperglycemia was observed in corporate workers. It waspresumed that the efficacy of this food can be exhibited in
the middle aged older than 30, those whose insulin resistanceincreases and those who are prone to have postprandial
hyperglycemia more than in young people around 20 years
old.
There are many opportunities to take bread as a staple
food at breakfast and lunch. HMT-HAS is a dietary fiber
material, so it is possible to ingest this material on a daily
basis by blending it into bread and it contributes to the healthmaintenance of those who ingest it.

StarchWhat represents staple foods eaten in the world are rice
and wheat, and the main component of both foods is starch.
Rice (rice plant) is cultivated everywhere in the world. Asianrice is broadly classified into Japonica rice and Indica rice.
Cooked Japonica rice is soft and sticky and cooked Indica
rice is hard and less sticky. The main component of rice isstarch which becomes the main energy source. The digestibilityof rice starch is affected by different shapes, such as powder
or particle, or cooked rice, noodle or rice cake 8, 9).
In Japan, there are various functional rice processed
foods including rice powder bread, rice powder noodles andsprouted brown rice centering on the new rice characteristic.
Sticky rice and low-amylose rice are fast in digestion andabsorption. On the other hand, the inhibiting effect ofhigh-amylose rice and super-hard rice on postprandial

hyperglycemia is recognized. It is also expected to have aneffect on the prevention and inhibition of the progressionof life-style diseases with strong glycative stress such as
visceral obesity, metabolic syndrome and type 2 diabetes 8, 9).
Starch is a natural polymer of polymerized glucose
and it consists of amylose, molecules of glucose arranged
in a straight chain, and amylopectin, a molecule with manybranches. The crystal structure of starch is maintained
because of amylose and amylopectin regularly arranged byhydrogen bonding. Starch is a white powdery substance that
does not dissolve in water and leaves deposits if it is left
alone in water. The origin of the Japanese word for starch,“denpun,” comes from the Japanese words of sediment andpowder.
In order to dissolve it, starch must be added to water andheated. The starch granules under water start absorbing water
above a certain temperature and swell. When the swelling
reaches the maximum point, starch is broken and becomes
pasty. This phenomenon is called the gelatinization of starch.
Gelatinization properties of starch differ depending on
the ratio of amylose and amylopectin. In the case of rice, thelower amylose ratio is, the more cooked rice becomes sticky.
HAS is a functional starch containing many dietaryfibers. It also has the names of indigestible starch andresistant starch. HAS expresses stickiness only at highconcentrations, and its gelatinization temperature is very
high 10, 11).
HMT-HAS was used in this test food. The test
food (HMT- HAS) containing dietary fibers increased
approximately three times compared to normal bread andwas developed by being heat-treated (heat-moisture treated)in a water amount in which starch is not gelatinized 5).

Animal study

An animal test using HAS, or feed containing HAS, hasbeen conducted. As the results of measuring fat metabolism
and the cumulative amount of body fat of the rats fed witha diet containing 10%-40% of HAS, the weight of epididymal
adipose tissue and the ratio of body fat and body protein weresignificantly lower or showed the tendency for a low levelin the groups ingesting HAS (10%, 20% and 40%). In theconcentrations of serum lipids (TG, TC and phospholipid)
and the content of neutral fat in the liver, decreases
depending upon the dose of HAS in the animal feed wererecognized 12).
The results of verification concerning the differenceof the content of amylose in the feed for mice showed thatthe postprandial GLU response of the high-amylose group(29% amylose) was low at all times compared with the lowamylose group (17% amylose), and it was significantly lower
in particular 15, 30, 45 and 60 minutes after ingesting it, and
AUC of the high-amylose group was 16% lower than that of
the low-amylose group 13).

GLU test

The responses of GLU and insulin of the high-amylose
group of human subjects (29% amylose) 60 minutes after
eating were significantly lower than those of the low-amylose
group (17% amylose), and the GLU response 30 and 60
minutes after eating and the insulin response and AUC
60 minutes after eating in the high-amylose group weresignificantly lower than those of the low-amylose group 13).
A GLU test comparing low GI rice blended with barley_ 16 0 _Glycative Stress Researchand high-amylose rice and the control rice for 10 patientswith type 2 diabetes showed that the degrees of elevation of
GLU and insulin 60 minutes after eating the rice blended
with high-amylose rice were significantly inhibited 14).
No inhibiting effect on GLU and insulin by glucagon wasobserved, and on the contrary, they were slightly increased.
A meal tolerance test (total energy 616 kcal; energy
ratio: carbohydrate 56%, lipids 27%, protein 14% and dietaryfibers 3%) was conducted on the patients with diabetes (n =21) using sulfonylurea drug only or together with other drugs,
and as a result of the comparison between high-amylose
rice (containing amylose 25%) and Koshihikari (containing
amylose 17%), the postprandial GLU by high-amylose rice
remained at a low level, and Cmax was significantly lower(7% in average, p < 0.001) 15).
There is a report that in the test where postprandial GLU
changes following the intake of foods containing different
amounts of amylose targeting seven adult males with normal
glucose tolerance, there was no significant difference in GLU
and insulin levels among three foods of 75 g of glucose,cooked rice and rice cakes containing the same amount of
glucose 16).

Long-term ingestion study

There is a report of clinical tests of the comparison
between high-amylose rice (containing amylose 25%) andKoshihikari (containing amylose 17%).
A test was conducted where the subjects withuntreated diabetes and glucose intolerance (52 adult males)
ingested one package each of the cooked rice (containing
carbohydrate 50 g) of high-amylose rice (containing amylose25%) or Koshihikari (containing amylose 17%) twice a
day for 12 weeks consecutively. As a result, no significant
difference was observed in fasting GLU levels, but the
HbA1c and 1.5-AG (anhydro-glucitol) levels of those who
ingested high-amylose rice were significantly improved 17).

Sensory evaluation

High-amylose rice, which is highly expected to improve
food self-sufficiency, does not taste good in the form ofbread, in particular, so improvement is required. Its taste has
been evaluated by the sensory evaluations of rice containing
various amyloses and the hardness of bread.
The taste of rice bread containing different amountsof amylose was evaluated by sensory test by the semantic
differential (SD) method and its physical property was tested
by a tensipresser, and the results are shown below 18).
As for its physical property, the more amylose it contained,
the harder it became. However, the high-amylose rice breadwhich is said to be not delicious showed room for improvement
and was evaluated as “ it rather does not taste good.” As theresult of the sensory evaluations of different varieties of ricecontaining different rates of amylose such as sticky rice(containing amylose 0%), low-amylose rice (containing
amylose 11.9%), middle-amylose rice (containing amylose
16.2%) and high-amylose rice (containing amylose 27.9%),
high-amylose rice was evaluated to be the hardest and not
sticky in the mouth 19).
The results of the sensory test of GI rice blended withbarley and high-amylose rice and the control rice (ordinaryrice) are shown below 14). There were three answers of “good”
and seven answers of “ordinary” in texture of ordinary
rice, and there were two answers of “not so good” and eightanswers of “medium” in the texture of low GI rice. As for thecondition of cooked rice, there were six answers of “perfect”
in ordinary rice and one answer of “perfect” in GI rice, andthere was one answer of “soft” in ordinary rice and three
answers of “soft” in low GI rice. There were five answersof “tasty but not great” in ordinary rice and four answers of“tasty but not great” and one answer of “not so tasty” in low
GI rice.” There were seven answers of “even though there isa slight uncomfortable feeling, if it is good for levels of GLU
and insulin, I will eat it,” and three answers of “ I will eat it
taking the cost into consideration.”
It is considerable that the food materials for further“delicious” and “soft” bread can be developed by further
studies in the future.

SafetyAmylogel HB-450 is an insoluble dietary fiber material
with the content of dietary fibers heightened by heat-moisturetreatment. Dietary fibers have the effect of excreting waste
and harmful materials out of the body (fiber detox). Amongthem, resistant starch is superior in process ability, so that it
has been applied to various food products.
As an edible product for humans, Amylogel HB- 450
started being sold in 1997 and it has been successfully used
for many food products. It is described in the certificate of
Quality Assurance Department of Sanwa Starch Co., Ltd.
that there has been no report about health damage by thisproduct.

Limitation of this study

The tests conducted for this study was to show that the
postprandial hyperglycemia after ingesting bread including
HMT-HAS was inhibited more than after ingesting
control food (bread containing wheat starch). Postprandial
hyperglycemia triggers aldehyde spark. However, in thisstudy, intermediate aldehydes (glyoxal (GO), methyglyoxal(MGO), 3-deoxyglucosone (3DG) and others) were notmeasured. Therefore, it was only to evaluate the possibility
by estimation that an aldehyde spark can be alleviated.
It was not possible to clarify to what extent the alleviationof postprandial hyperglycemia can be achieved by a single
intake and contribute to the alleviation of glycative stressfrom a long-term point of view based on the test in this study.

Conclusion

HMT-HAS has the effect of alleviating postprandial
hyperglycemia and glucose spikes as a material containing
dietary fibers, so that it is expected that it contributes to thehealth maintenance of those who ingest it by alleviating
glycative stress.

Acknowledgments

This study was presented at the 15 th Meeting of theSociety for Glycative Stress Research on May 18, 2018,
Tokyo.

Conflict of Interest Statement

The present study was partly supported by Sanwa StarchCo., Ltd.

_ 161 _

Heat-Moisture-treated High-Amylose Corn Starch and Postprandial Hyperglycemia

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