2009 Hachizume - Fibersol®-2 Resistant Maltodextrin

61

5Fibersol®-2 resistant Maltodextrin: Functional Dietary Fiber Ingredient

Chieko Hashizume and Kazuhiro Okuma

Introduction

Dietary fiber is considered an essential nutrient in Japan based on contin-ued research showing the health benefits of daily consumption along with the essential amino acids, essential fatty acids, vitamins, and minerals. The functions of dietary fiber are essential and of equal importance to the ben-efits of other essential nutrients. The beneficial effects of diets rich in dietary fiber include decreased risk of coronary heart disease and improvement in

CONTENTS

Introduction ........................................................................................................... 61What Is Resistant Maltodextrin? .........................................................................63Physiological Effects of Resistant Maltodextrin ...............................................64

Gastrointestinal Functions .........................................................................64Beneficial Effects on Bowel Movement .........................................65Improvement in Intestinal Environments ....................................65

Attenuation of Postprandial Blood Glucose Levels ................................ 69Improvement in Sugar and Fat Metabolism by Repeated

Ingestion—Decreases in Total Cholesterol and Triglyceride Levels ........................................................................... 70

Decreases in Body Fat Ratio ....................................................................... 71Safety and Food Applications .............................................................................72

Safety ............................................................................................................72Food Applications ........................................................................................ 74

Measuring Method of Total Dietary Fiber in Foods Containing Resistant Maltodextrin ................................................................................75

References ..............................................................................................................77

© 2009 by Taylor and Francis Group, LLC

62 Fiber Ingredients: Food Applications and Health Benefits

intestinal regularity. The research behind a possible relationship between fiber-rich diets and a lower risk of type 2 diabetes shows potential.

Although the importance of dietary fiber is well recognized, the actual intake of dietary fiber is declining. The Dietary Guidelines for Americans (2005) attributes this decline in dietary fiber intake to a lower consumption of whole grain foods, fruits, and vegetables. The problem is compounded by the lack of many foods that contain whole grains. While the recommended dietary fiber intake for Americans is 14 grams per 1000 calories (approxi-mately 38 and 25 grams per day for men and women respectively), the average dietary fiber intake among Americans is only about half these recommended amounts (Figure 5.1). Dietary fiber consumption among almost all industrial-ized countries is less than 20 grams per day. Changes in lifestyles, especially the increasing habit of eating processed foods or ready-to-eat meals, are also a contributing factor for the lower dietary fiber intake than the recommended intake. In order to increase the consumption of dietary fiber and fill the gap between the current intake and the recommended intake, it appears prudent to add more dietary fiber to processed foods.

Japanese scientists have developed various types of low-molecular-weight soluble dietary fibers and oligosaccharides to fill the fiber gap. One outstand-ing fiber product is Fibersol®-2, a resistant maltodextrin product developed and registered by Matsutani Chemical Industry Co., Ltd., Itami, Hyogo,

0

5

10

15

20

25

30

35

40

1–34–8

9–1314–18

19–3031–50

51–7071+

Actual I for malesActual I for femalesAdequate I for malesAdequate I for females

DF

Inta

ke (g

/day

)

(Age, years old)

Adequate Intake

Actual Intake

FIGuRe 5.1Dietary fiber intake of U.S. population: the gap between the actual intake and the adequate intake (AI). ■: actual intake amount of dietary fiber for males, ●: actual intake amount of dietary fiber for females, ■: adequate intake amount of dietary fiber suggested for males, ●: adequate intake amount of dietary fiber suggested for females. (Adapted from Dietary Refer-ence Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients), Food and Nutrition Board, Institute of Medicine, National Academies, 2005.)


Fibersol®-2 resistant Maltodextrin: Functional Dietary Fiber Ingredient 63

Japan. The resistant maltodextrin has the following physiological proper-ties associated with dietary fiber: (1) improvement of intestinal regularity; (2) moderation of postprandial blood glucose levels; and (3) the reduction of serum cholesterol and triglyceride levels.

What Is Resistant Maltodextrin?

Fibersol®-2 is prepared from moistened starch (corn, tapioca, etc.) by heating to 140ºC –160ºC with a trace amount of acid (Figure 5.2). During this most charac-teristic stage in the production process, both hydrolysis and transglucosidation of starch occur (dextrinization process). The resulting dextrin solution is hydrolyzed by enzymes, before being refined by fil-tration through activated carbon and an ion-exchange resin. After concentration, the non-digestible material is spray-dried. The final product is stable to any further hydrolysis by heat, acid, and/or enzymes, including the conditions found in the human digestive system. These proper-ties greatly contribute to its functionality and acceptance in food systems and food products.

The resistant maltodextrin consists of a small ratio of saccharides that have the degree of polymerization (DP) 1–9, and a large amount of polysaccha-rides with a DP 10 or more. It has a typical carbohydrate composition of ~10 DE maltodextrin, with the average molecular weight of 2000. In 1990, the Matsutani Company obtained a letter of compliance from the U.S. Food and Drug Administration confirming that Fibersol®-2 meets the requirements for the GRAS status set forth in 21 CFR 184.1444 Maltodextrin. Therefore, it is officially recognized as a maltodextrin under the U.S. regulation.

The glucosidic linkages and the molecular structure model of the resistant maltodextrin are illustrated in Figure 5.3. The resistant maltodextrin has a higher amount of 1-6 linkage than conventional maltodextrin of the same DE. Resistant maltodextrin not only has 1-4 and 1-6 linkages that are found in starch, but also contains 1-2 and 1-3 linkages, which are formed during the dextrinization process.

The properties described above contribute to allow resistant maltodextrin to be approximately 10% digested and absorbed in the small intestine. Approxi-mately 50% is fermented in the large intestine and the remaining approximate

Starch (corn, etc.)

Dextrinization with acid at 140–160°C(Moistened powdery starch)

Hydrolysis with amylases

Removal of glucose by filtration

Decolorization by active carbon

Deionization by ion-exchange resin

Concentration and spray-drying

Weighing and packaging

Resistant Maltodextrin Product

FIGuRe 5.2Manufacturing process of resistant maltodextrins.



40% is excreted into the feces [1]. Therefore, the maltodextrin is distinguished from conventional digestible maltodextrin and the scientific categorization as “digestion-resistant maltodextrin” or “indigestible dextrin.”

Physiological Effects of Resistant Maltodextrin

Gastrointestinal Functions

As 90% of the resistant maltodextrin reaches the large intestine and 50% is fermented, these findings support and contribute to its physiological effects in the large intestine. The beneficial effects of Fibersol®-2 as a typical soluble dietary fiber are summarized in the following.

Glucosidic linkage 1 4 1 6 1 2 1 3

Conventional maltodextrin

-Enzymatic hydrolysis 94.7% 4.5% 0.0% 0.9%

-Acidic hydrolysis 91.6% 5.1% 1.2% 2.2%

58.5% 27.0% 3.2% 11.3%

CH2OH

O O

O

OCH2

O OH

CH2OH O

OH

OH OH CH2OH

CH2OH

CH2OH

CH2 HO

O OH

OH

O

CH2OH

HO

O OH

OH O

CH2OH O

OH

OH

O CH2OH

OH

OH

O

O OH

OH O

O OH

OH OH

CH2OH

O OH

CH2OH

O

O O

OH

O HO

O OH

OH O

OH

OH

CH2OH

O OH

OH O

O

OH

O CH2O

O

O

Chemical structure model of Fibersol®-2

O

Fibersol®-2

FIGuRe 5.3Structural characteristics of resistant maltodextrin: comparison with conventional maltodex-trins prepared by enzymatic or acid hydrolysis. (Adapted from Okuma, K. and Matsuda, I., J. Appl. Glycosci., 49, 479–485, 2002.)



Beneficial Effects on Bowel Movement

The effect of the resistant maltodextrin on bowel regularity was confirmed in a crossover ingestion study with eight male subjects [2]. During the five-day study, the subjects were administrated standard meals with a resistant maltodextrin product (dietary fiber content: 20 grams per day) (FS-2 group) and their fecal weight and fecal frequencies were compared with the data obtained by consuming the same controlled meals without resistant malto-dextrin (the control group). The FS-2 group had significantly more bowel movements compared to the control group (Table 5.1). The average total fecal weight for the period was significantly higher in the FS-2 group, 778.2 ± 93.2 g compared with 571.5 ± 58.7 g for the control group (p < 0.05); fecal moisture content was not changed in either group. From these results, it was confirmed that resistant maltodextrin is effective to improve bowel regularity, which is one of the important physiological properties consistent with dietary fiber. As suggested from the fecal moisture content, resistant maltodextrin did not cause diarrhea.

Improvement in Intestinal Environments

Prebiotic Effect: Improvement of Intestinal Microflora

The in vitro fermentability of Fibersol®-2 was evaluated with stock strains of human intestinal bacteria (Table 5.2) [3]. It was well fermented by major strains of Bifidobacterium and Bacteroides. The degree of fermentation by Bacteroide organisms was comparable or slightly inferior to that of glucose. In an in vivo test with six healthy male subjects who ingested 10 grams of the resistant maltodextrin with every meal for four weeks, the changes in the

Table 5.1

Improvement of Stool Conditions by Resistant Maltodextrin

StoolWet Weight

(g)

StoolDry Weight

(g)Moisture

(%)

Defecation Frequencies

(n)

Test Group (n = 8)

Control (n = 8)

778.2 ± 93.2*

571.5 ± 58.7

180.5 ± 12.9*

137.9 ± 5.6

76.8 ± 1.8

76.2 ± 1.7

5.92 ± 0.40a

4.76 ± 0.36

Note: Test group was administered a resistant maltodextrin product (dietary fiber content: 20 g per day). A crossover study. Eight healthy male subjects were administrated controlled meals through the 5-day study period with or without the resistant maltodextrin. Whole stools were collected between the first defecation of a red color indicator taken on the 1st day and the next defecation of the indicator taken on the 5th (last) day.

a Significantly different at p <0.05.

Source: Satouchi, M. et al., Effects of indigestible dextrine on bowel movements, Japanese J. Nutrition. 51, 31-37, 1993.



Table 5.2

Fermentability of the Resistant Maltodextrin by Various Intestinal Bacteria

Strains Fermentability

Bacteroides B. vulgatus ATCC 848 ± B. thetaiotaomicron ATCC 12552 + B. fragilis NCTC 9343 + B. ovatus VPI 10649 ++ B. distasonis VPI 4243 ++Eubacterium E. aerofaciens VPI 1003 – E. biforme VPI 9218 –Peptostreptococcus P. productus YIT 0192 ++Clostridium C. perfringens PB 6 K – C. paraputrificum ATCC 25870 – C. bifermentans NCTC 506 –Staphlococcus S. aureus 209 P –Enterobacteriaceae E. coli H-1 – K. pneumoniae H-2 – E. cloacae H-3 –Streptococcus S. thermophilus YIT 2001 – S. faecium YIT 2004 ±Lactobacillus L. gasseri YIT 0192 – L. acidophilus YIT 0070 – L. salivarius YIT 0089 –L. fermentum YTT 0081 – L. bulgaricus YTT 0098 – L. helveticus YTT 0100 – L. plantarum YTT 0101 – L. casei YTT 9018 –Bifidobacterium B. bifidum 4007 – B. bifidum E 319 – B. infantis S-12 – B. breve YIT 4010 ± B. breve S-1 ± B. breve As-50 ± B. longum 194 b ± B. longum H-1 ± B. adolescentis 194 a – B. adolescentis YJ-9 ++Fusobacterium F. varium ATCC 8501 –Propionibacterium P. acnes ATCC 6919 –

Note: Acid production: +++, within 1 day; ++, 2 days; +, 3 days. ± ~ –: negative.Source: Adapted from Ohkuma, K. et al., Pyrolysis of Starch and Its Digestibil-

ity by Enzymes, Denpun Kagaku, 37, 104–114, 1990.



intestinal microflora counts (log number of colony-forming unit per gram of feces) were examined, and the ratios of Bacteroides and Bifidobacterium in per-centages are reported in Table 5.3. Although the number of subjects in this study was rather small, a significant change in the intestinal microflora was observed after one month of consuming the resistant maltodextrin on a daily basis. While the population of Bifidobacterium organisms increased, the level of Bacteroides organisms and other non-specified organisms decreased.

Production of Short-Chain Fatty Acids

Saccharides that are resistant to digestion and reach the large intestine are fermented by intestinal bacteria, producing short-chain fatty acids (SCFA) and gases. The SCFA are considered to have the following properties in the large intestine: anti-inflammatory; a specific energy source for intestinal mucosal cell to promote cell growth, primarily butyric acid; aiding in water movement across the large intestine; and interfering with bile acid reabsorp-tion thus lowering blood cholesterol levels.

An in vitro experiment using human feces to ferment resistant maltodex-trin was used to illustrate the potential changes in SCFA and pH values in the colon (Figure 5.4) [4]. Three sources of dietary fiber were incubated under anaerobic conditions with fecal samples taken just after defecation. The for-mation of SCFA and changes in pH were observed over a 24-hour period. Fructooligosaccharide is known to be completely fermented. The fermenta-tion of resistant maltodextrin and FOS, as measured by the production of SCFA, was similar over the first 1.5 hours. After 6 hours, the fermentation of FOS was basically complete, but the fermentation of resistant maltodextrin was only 56% of that observed for FOS. While it took the complete 24 hours to ferment the gum arabic to achieve SCFA levels equivalent to that observed with FOS, the amount of SCFA resulting from the fermentation of resistant maltodextrin was only approximately 75%. This lower level of SCFA pro-duction of resistant maltodextrin compared to the fermentation of equal amounts of FOS and gum arabic attribute to the fact that not all resistant maltodextrin is fermented in the large intestine after ingestion (Figure 5.4). This in vitro experiment helps support the concept that resistant maltodex-

Table 5.3

Changes in the Ratios of Bifidobacterium and Bacteroides in Total Colon Bacteria (%) among Six Healthy Male Subjects Consuming 30 g of the Resistant Maltodextrin per Day (10 g per meal) for Four Weeks.

Bacteria Baseline After 4 weeks After 8 weeksa

Bacteroides 49.4 ± 6.0 43.2 ± 2.5 49.8 ± 3.9Bifidobacterium 10.5 ± 3.4 17.9 ± 2.7 13.7 ± 1.9Others 40.1 ± 4.2 38.9 ± 2.5 36.5 ± 2.9

a Second measurement made four weeks after consumption of resistant maltodextrin was stopped.



trin is both effective in aiding laxation and serves as an energy source for intestinal bacteria, a prebiotic. The rapid fermentation of resistant maltodex-trin observed at the start of the incubation indicates that the low-molecular-weight fraction of resistant maltodextrin can be easily utilized by a variety of bacteria in the large intestine.

Maintenance of Digestive Tract Functions

When a non-residual, completely digested and absorbed enteral feeding sys-tem is administrated for a long period of time, the patient can suffer from gastrointestinal malfunctions such as diarrhea, constipation, or abdomi-nal distention, all caused by lack of dietary fiber. During these extended periods of non-residual enteral nutrition, the intestine will lose its normal physiological functions and significantly reduce its absorptive surface area, mainly the reduction in size of the intestinal villi. The intestine will begin to atrophy. The favorable effect of the resistant maltodextrin when added to a non-residual enteral formula was evaluated in a two-week feeding study in rats. An enteral nutrition formula was fortified with or without 1.4% Fiber-sol®-2, while stock diet was fed to a third group of rats as the control. Distinct morphological changes were observed in jejunal mucosal microvilli with the microscope. More regularly spaced and orientated microvilli were observed in the jejunal sections of rats’ intestines fed the stock diet and enteral for-mula with resistant maltodextrin compared to that fed the non-residual enteral formula without resistant maltodextrin (Figure 5.5). Although not evaluated in this study, the production of SCFA through the fermentation of fermentable carbohydrates is considered to help maintain the structure and physiological functions of small intestinal mucosa [5]. These are examples of

Total SCFA (mmol/g)Time (hr) FOS MD GA

1.5 1.08 1.02 0.066 7.12 3.20 0.30

11 7.26 4.08 1.4224 7.66 6.01 8.08

FOS: Fructo Oligo SaccharideMD: Fibersol-2GA: Gum Arabic

5.5

6.0

6.5

7.0

0 6 12 18 24Time (hr)

pH

FOSRMDGA

SCFA Production pH Value Changes

FIGuRe 5.4Total short-chain fatty acids accumulation and changes in pH values by in vitro fermentation with human feces. 1 ml of diluted human feces (1:10 wt/v) was incubated with 75 mg of each substrate in 9 ml of buffer. FOS (■): fructooligosaccharides, MD (●): resistant maltodextrin, GA (▲): gum arabic. (Adapted from Flickinger, E. A., Wolf, B. W., Garleb, K. A., Chow, J., Leyer, G., J., John, P. W., and Fahey, G. C., J. Nutr. 130, 1267–1273, 2000.)



events occurring in the intestine that help maintain it by impacting primary and secondary nutritional aspects.

attenuation of Postprandial blood Glucose levels

In a rat study in which these animals were fed digestible disaccharides and larger (DP≥2), the addition of Fibersol®-2 to their diet suppressed the post-prandial rise in blood glucose and insulin levels. However, the resistant maltodextrin was not effective to attenuate postprandial blood glucose and insulin levels when rats were fed glucose or fructose, such as monosaccha-rides [6].

The effects of feeding a single meal with Fibersol®-2 are reported by Toku-naga and Matsuoka as illustrated in Figure 5.6 [7]. The subjects consumed a meal of wheat noodles and steamed rice with a tea beverage containing 5 g of Fibersol®-2 and were monitored for postprandial blood glucose levels. In Figure 5.6a, which shows the average of all subjects, the peak blood glucose levels (at 30 and 60 min) were significantly lower among subjects consum-ing the resistant maltodextrin compared to subjects not consuming resistant maltodextrin with their meal. The subjects were further classified into two groups based on the magnitude of the postprandial blood glucose responses. One group of subjects having the higher (Figure 5.6b) postprandial peak blood glucose levels than the average was compared to subjects having the lower postprandial peak blood glucose levels than the average (Figure 5.6c).

In the group of subjects having high postprandial blood glucose levels, their attenuation in postprandial blood glucose levels was significantly (p<0.01) more pronounced and therefore more beneficial with consumption of resistant maltodextrin (Figure 5.6b), compared to the attenuation observed in the subjects with lower postprandial blood glucose levels (Figure 5.6c). Consumption of 5 grams of resistant maltodextrin alone to fasting individu-als caused no change in their postprandial blood glucose levels (Figure 5.6d),

Control(Stock Diet)

Enteral Formula(no fiber)

Enteral Formulawith 1.4% Fibersol®-2

FIGuRe 5.5Micrograph of jejunal mucosal microvilli of rats fed on each diet for two weeks. (From Ohkuma, K., and Wakabayashi, S., Fibersol-2: a soluble, non-digestible, starch-derived dietary fibre, Advanced Dietary Fibre Technology, McCleary, B.V., and Prosky, L., Eds., Blackwell Science, Oxford, UK, 509–523, 2001.)



indicating that the resistant maltodextrin has no contribution to hypoglyce-mia or hyperglycemia.

The attenuation of postprandial blood glucose achieved with the con-sumption of resistant maltodextrin has been verified in other meal-loading experiments [8–11]; as part of the evidential studies for approving the Japa-nese Foods for Specified Health Use (FOSHU) products, more than 30 clini-cal studies have been reported on the meal-loading effect of Fibersol®-2 on blood glucose attenuations.

Improvement in Sugar and Fat Metabolism by Repeated Ingestion—Decreases in Total Cholesterol and Triglyceride levels

Long-term feeding studies in rats and humans fed Fibersol®-2 have demon-strated decreases in total cholesterol and triglyceride levels [12–14].

In rat studies, these animals were fed diets high in sucrose without cho-lesterol and their serum lipids were monitored. Total serum cholesterol and triglyceride levels were found to be significantly decreased with the admin-istration of resistant maltodextrin [13–14].

Five patients having non-insulin-dependent diabetes mellitus (NIDDM) accompanied with hyperlipidemia were given 20 grams of Fibersol®-2 per meal for three months. Changes in blood parameters over the 12-week period among these individuals are reported in Table 5.4. At the start of the experi-ment, fasting blood glucose levels, total cholesterol levels, and triglyceride levels were above normal ranges. However, after 12 weeks, significant reduc-

Bloo

d G

luco

se L

evel

s (m

g/dl

) a b c d250

200

150

100

500 1 2 0 1 2 0 1 2 0 1 2

Time (hour)

FIGuRe 5.6Effects of tea beverage containing the resistant maltodextrin on postprandial blood glucose (BG) levels when loaded a standard-meal (mean value). ●: standard meal + 340 g green tea (control), ◦: standard meal + test drink (340 g tea beverage containing Fibersol®-2). a: Mean BG curve of 40 subjects, b: Mean BG curve of 18 in 40 subjects whose peak BG levels were higher than the mean value (172 mg/dl) with standard meal + green tea loading, c: Mean BG curve of 22 in 40 subjects whose peak BG levels were <172 mg/dl, d: Mean BG curve of 6 subjects with 340 g test drink alone loading. *: p<0.05, **: p<0.01. (Tokunaga, K., and Matsuoka, J. Japan Diabetes Society, 42, 61–65, 1999.)



tions in blood glucose and cholesterol levels were observed (Table 5.4). Blood triglyceride levels decreased by 28%, but this decrease was not significant [15]. In another placebo-controlled double-blind study, subjects were given a tea beverage with 5 grams of the resistant maltodextrin or a placebo (with-out resistant maltodextrin) three times a day for four weeks. Triglyceride levels were significantly reduced (p<0.05) after consumption of the tea con-taining resistant maltodextrin (Figure 5.7) [16]. Triglyceride levels generally returned to starting levels after subjects stopped consuming the resistant maltodextrin.

It can be assumed that the long-term regulation or attenuation in postpran-dial blood glucose and insulin levels by consuming the resistant maltodextrin with every meal affects these chronic triglyceride and total cholesterol levels.

Decreases in body Fat Ratio

It has been reported that the intake of a tea beverage containing 5 grams resistant maltodextrin with every meal for four weeks significantly lowered body weight, BMI, body fat ratio, and waist/hip ratio [16]. Similar results were observed in a study among 12 adult male subjects. They consumed 10 grams of resistant maltodextrin per meal for three months. At the start and upon termination of the three-month test period, glucose tolerance tests

Table 5.4

Effects of Resistant Maltodextrin (20 g per meal) on Serum Lipid and Plasma Glucose Levels, Erythrocyte counts, and Liver Function in NIDDM Patients (n = 5) with Hyperlipidemia.

Time (week) 0 2 4 8 12

FPG (mg/dl)Cholesterol (mg/dl)HDL-Cholesterol (mg/dl)Triglyceride (mg/dl)Ca (meq/l)Mg (mg/dl)P (mg/dl)Fe (μg/dl)RBC (×104/mm3)GOT (IU/l)GPT (IU/l)γ-GTP (IU/l)LDH (IU/l)

147 ± 17265 ± 1049 ± 2

243 ± 344.5 ± 0.32.0 ± 0.23.0 ± 0.296 ± 43

488 ± 3122 ± 1022 ± 569 ± 38

293 ± 36

112 ± 25211 ± 2945 ± 1

163 ± 334.3 ± 0.32.0 ± 0.23.3 ± 0.498 ± 29

—————

107 ± 7209 ± 22a

47 ± 3134 ± 24a

4.5 ± 0.22.0 ± 0.23.3 ± 0.599 ± 18

—————

147 ± 21205 ± 10b

49 ± 3148 ± 11a

4.5 ± 0.22.0 ± 0.23.2 ± 0.497 ± 16

—————

103 ± 7a

209 ± 9b

40 ± 3b

176 ± 424.5 ± 0.22.0 ± 0.13.4 ± 0.388 ± 14

488 ± 1419 ± 419 ± 463 ± 54

311 ± 95

Note: FPG: fasting plasma glucose, RBC: Erythrocyte count. Mean±SD, statistical significance:

a p<0.05, b p<0.01 compared with data at 0 week.

Source: Nomura, M., Nakajima, Y., and Abe, H., J. Jpn. Soc. Nutr. Food Sci., 45, 21-25, 1992.



were assessed and blood chemical parameters were measured. Body fat was also measured by impedance, and the area for visceral fat and subcutaneous fat were measured by computed tomography (CT) scans [17]. Results of this experiment are reported in Figure 5.8. Glucose tolerance, body fat ratios, and visceral fat areas were significantly decreased by the ingestion of the resis-tant maltodextrin. Two indices of insulin resistance, total immunoreactive insulin (Σ IRI) and homeostasis model assessment insulin resistance index (HOMA-IR), were also decreased after consumption of resistant maltodex-trin. It is assumed that resistant maltodextrin prevents the accumulation of fat (obesity) by moderating the postprandial rise in blood glucose and insu-lin levels, which would be a similar, but still unexplained mechanism(s) to decrease serum total cholesterol and triglyceride levels.

Safety and Food Applications

Safety

Fibersol®-2 has been approved as a Generally Recognized As Safe (GRAS) material, manufactured by enzymatic hydrolysis of pyrodextrin. Its safety was reviewed and authorized by the FDA in 1990 and it is classified as a

Test group

60

40

20

0

∆ Tr

igly

cerid

e (m

g/dl

)

–20

–40

–60

–80

Placebo group

AdministrationPeriod

*p < 0.026 (t-test)**p < 0.003 (paired t-test)

**

*

BeforePre-administration

BeforeAdministration

AfterAdministration

AfterPost-administration

FIGuRe 5.7Changes in serum triglyceride levels by four-week ingestion of the resistant maltodextrin.◆: test group, 250 ml of tea beverage containing 5 g Fibersol®-2, ■: placebo group, 250 ml of placebo tea beverage. Three times (every meal) per day ingestion for four weeks. Mean±SEM.(From Kajimoto, O. et al., J. Nutritional Food, 3 (3), 47–58, 2000.)



Physiological Examination

Before Intake (start) 3-Month Intake Age (years old) Height (cm) Body Weight (kg) BMI Body Fat (%) Waist (cm) Hip (cm) W/H V: Area for Visceral Fat (cm2) S: Area for Subcutaneous Fat (cm2) V/S

46.1 ± 3.0 168.8 ± 1.3

73.7 ± 3.4 25.8 ± 0.9 27.7 ± 0.9 90.8 ± 2.4 98.8 ± 2.1

0.91 ± 0.01 108.0 ± 13.7 175.2 ± 25.2

0.70 ± 0.1

73.0 ± 3.3 25.6 ± 0.9 25.9 ± 1.0* 89.5 ± 2.3 98.3 ± 2.1

0.91 ± 0.01 101.9 ± 11 .6 163.9 ± 19.9

0.64 ± 0.07 “n = 12, average ± SEM” “n = 9, only for V, S, V/S values” *: Pair-matching t-test, significantly different from initial values at p < 0.05.

Glucose Tolerance

Time (min)

Start 3-month administration

Start 3-month administration

“n = 10, average ± SEM” *: Pair-matching t-test, significantly different from initial values at p < 0.05.**: Significantly different from initial values at p < 0.01.

Blood glucose levels 250

200

150

100

50 0 30 60 90 120

Insulin levels

Bloo

d G

luco

se (m

g/dl

)

Time (min)

100

75

50

25

0 30 60 90 120

Insu

lin (µ

U/m

l)

FIGuRe 5.8Changes in physical examination and glucose tolerance by three-month ingestion of the resis-tant maltodextrin. 10 grams, 3 times (every meal) per day (= 30 grams) of resistant maltodextrin was administrated for 3 months. Graphs of glucose tolerance test. Left: blood glucose levels, right: insulin levels. ●: glucose or insulin response at the start time, ◦: glucose or insulin response after three-month administration of resistant maltodextrin. (From Kishimoto, Y., Wakabayashi, S., and Tokunaga, K., J. Jpn. Assoc. Dietary Fiber Res., 4 (2), 59–65, 2000.)



maltodextrin (21 CFR §184.1444). Safety studies have been accomplished on the potential consumption of high levels of the resistant maltodextrin. The lethal dose (LD50) determined in a rat feeding experiment was over 40 g/kg body weight, the maximum dosage in the acute toxicity study. There is no evidence of any mutagenicity caused by the consumption of the resistant maltodextrin [18]. Dietary fiber has been reported to inhibit the absorption of essential microelements. However, resistant maltodextrin was found to have no binding capacity for mineral ions when evaluated in an in vitro experiment [19]. A study in which rats were fed water containing 10% resistant maltodextrin for five weeks, showed no harmful effects on internal organs such as the pancreas, kidneys, and liver, including func-tional indices [13].

The effects of large intakes of resistant maltodextrin on gastrointestinal responses and fecal parameters were evaluated in a study that used 74 healthy adult subjects. Subjects were given a single dose of the resistant maltodextrin ranging from 10 to 60 grams. This particular resistant maltodextrin prod-uct contained 58% dietary fiber. Feeding these varied amounts of resistant maltodextrin to these subjects did not cause any clinical or problematic gas-trointestinal symptoms. The ED50 (effective dose 50, the amount of material required to produce a specified effect in 50% of an animal population) to cause diarrhea was estimated to be more than 110 grams of a product con-taining 58% total dietary fiber (63 grams for a 100% dietary fiber product) [20]. Resistant maltodextrin would have less tendency to cause diarrhea com-pared to sugar alcohols or other totally fermentable oligosaccharides because it has a higher molecular weight than these materials, and approximately 40% is passed to the feces after consumption.

Food applications

Resistant maltodextrin is a very user-friendly dietary fiber because of its low viscosity and its tasteless and flavorless characteristics, in addition to high stability in heat and acid; it can be added easily into any type of foods in the same manner as sugar or salt. Before such user-friendly dietary fiber was developed, the fiber sources used to fortify processed food products would have been cereals, vegetable, fruits, etc. In place of such ingredients, resistant maltodextrin can be added to any processed foods as a source of dietary fiber to enable the producers to make dietary fiber fortification claims such as “Rich in fiber” or “Good source of dietary fiber” without compromising quality characteristics of the fortified products.

The Japanese Ministry of Health, Labor and Welfare has an approval program called Tokuho, Food for Specified Health Use (FOSHU), in which the approved products are allowed authorized claims, such as “Improves intestinal regularity” or “Beneficial for those concerned about blood glucose



levels.” Numerous FOSHU products with Fibersol®-2 as the effective key ingredient have been introduced into the marketplace.

Resistant maltodextrin is also used in low-calorie foods. When added with high-intensive sweeteners such as aspartame, sucralose, stevia, or acesulfame K, resistant maltodextrin provides significant body and texture to achieve a highly desirable sweetness with no harsh aftertaste. The caloric value for Fibersol®-2 is considered ~1.0 kcal/g [1, 21, 22].

Measuring Method of Total Dietary Fiber in Foods Containing Resistant Maltodextrin

Although resistant maltodextrin functions fully as dietary fiber, it is neces-sary to determine its actual dietary fiber content for the purpose of nutri-tion labeling. The total dietary fiber value of resistant maltodextrin is not accurately determined by AOAC Official Method 985.29, in which the soluble dietary fiber components are precipitated in 78% ethanol. Therefore, an ana-lytical method was developed to accurately measure the total dietary fiber content in foods containing resistant maltodextrin (Figure 5.9). This method has been approved through AOAC collaborative study, and has received Final Action approval as AOAC Official Method 2001.03 [23]. This method is applicable for nutrition labeling.

As the first step, insoluble and high-molecular-weight soluble dietary fiber components are measured by AOAC Official Method 985.29. The material is treated with enzymes, four volumes of ethanol, and the residue and the filtrate are separated. The salts and protein remaining in the filtrate after the AOAC Official Method 985.29 protocol employed are removed by ion-exchange res-ins. The deionized filtrate is analyzed by high-performance liquid chromatog-raphy analysis to determine the low-molecular-weight soluble dietary fiber that does not precipitate in 78% ethanol. The amount of total dietary fiber is calculated by summing the insoluble and high-molecular-weight soluble dietary fiber with the low-molecular-weight soluble dietary fiber.



(Enzymatic-Gravimetric Method) 1.0 g Sample

0.08 M Phosphate buffer, pH 6.0

95°C, 30 min

pH 7.5 ± 0.1 Protease

60°C, 30 min

pH 4.5 ± 0.2Amyloglucosidase

60°C, 30 min4 vol. 95% EtOH

Filtration

Washing78% EtOH×395%EtOH×2 Aceton×2 (LC determination)

Residue Filtrate

Ash and Protein Correction Evaporation

IDF + HMWSDF Washing out the concentrate inside the flaskby using deionized water and pipetts several times

Glycerol solution Desalting

Evaporation

Adjusting vol.

HPLC

LMW RMD

α-amylase

FIGuRe 5.9Flow diagram for analytical procedure of the AOAC Official Method 2001.03, dietary fiber in foods containing resistant maltodextrin, high MW RMD by 985.29 (IDF and SDF) and low MW RMD by liquid chromatography. (From Official Methods of Analysis, 18th ed., AOAC Interna-tional, 2006.)



References

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8. Kishimoto, T., Wakabayashi, S., and Yuba, K., Effects of instant miso-soup containing indigestible dextrin on moderating the rise of postprandial blood glucose levels, and safety of long-term administration, J. Nutritional Food, 3(2), 19–27, 2000 (in Japanese).

9. Inoue, T. et al., Attenuation effect of bread containing indigestible dextrin on elevation of postprandial blood glucose level and its safety in long-term inges-tion, J. Jpn. Clin. Nutr., 26(4), 281–286, 2005 (in Japanese).

10. Morita, H., et al., Effect of yogurt containing indigestible dextrin on blood glu-cose and other blood components, J. Jpn. Council for Advanced Food Ingredients Res., 8(1), 33–42, 2005 (in Japanese).

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16. Kajimoto, O. et al., Beneficial effects of a new indigestible dextrin-containing beverage on lipid metabolism and obesity-related parameters, J. Nutritional Food, 3(3), 47-58, 2000 (in Japanese).

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2009 Hachizume - Fibersol®-2 Resistant Maltodextrin