Human and Clinical Nutrition

Arepas Made from High Amylose Corn Flour ProduceFavorably Low Glucose and Insulin Responses inHealthy Humans1»2

YVONNE GRANFELDT,3 ANDERS DREWS AND ¡NGERBJÖRCK

Department of Applied Nutrition and Food Chemistry, Chemical Centre,University of Lund, P.O. Box 124, S-221 00 Lund, Sweden

ABSTRACT The importance of the amylose:amylopectin ratio in the postprandial glycémieand insuli-nemic responses to corn was studied in food productsthat might realistically be consumed. Healthy subjectswere given test meals in the form of arepas made fromordinary (25% amylose) or high amylose (70% amylose)corn flour. The ordinary corn meal contained 45 g ofpotentially available starch. To exclude the possible influence of a lowered content of potentially availablestarch due to formation of resistant starch in the highamylose product, this product was evaluated at twolevels and included either on the basis of potentiallyavailable starch (45 g) or total starch (includingresistant starch) (45 g, i.e., 29 g potentially availablestarch), respectively. The rate of starch hydrolysis,measured in vitro employing a method based onchewing, was studied. In addition, the content of in vitroresistant starch was analyzed in all products. The mealscontaining high amylose corn flour produced lower areasunder the glucose and insulin response curves (57 and42% lower, respectively) than did the meals containingordinary cornmeal. This could not be explained by alower amount of potentially available starch. No differences were noted when subjects consumed the two highamylose meals of arepas, despite 36% lower potentiallyavailable starch in one of the meals. The rate of starchhydrolysis measured in vitro was slower in the highamylose corn products than in the ordinary corn product.Resistant starch in the ordinary product was 3 g/100 gdry matter, vs. -20 g/100 g dry matter in the highamylose products. We concluded that high amylose cornproducts have a potential to promote favorably lowmetabolic responses and high resistant starch contents.J. Nutr. 125: 459-465, 1995.

INDEXING KEY WORDS:

•resistant starch •starch hydrolysis•corn products •humans•glycémieand insulinemic responses

Differences exist between glucose and insulinresponses to various starchy foods (Jenkins et al. 1988,Thorburn et al. 1986). This has been attributed to a

number of factors (Truswell 1992), including the ratioof amylose to amylopectin. In most cereal starches,this ratio is about 20:80. However, among cereals likerice, corn and barley, genotypes varying in amylose:amylopectin ratio are available. Human studies withrice (Brand Miller et al. 1992, Goddard et al. 1984,Juliano and Goddard 1986), crackers prepared fromcornstarch (Behall et al. 1988) or meals incorporatingrice and/or cornstarch (Amelsvoort and Weststrate1992, Behall et al. 1989), have indicated that a higheramylose content is accompanied by a lowered metabolic response. Further, long-term intake of a high

amylose corn diet improved fasting triglycéride andcholesterol concentrations in healthy subjects, compared with a high amylopectin diet (Behall et al.1989). However, available data are not clear, especially regarding realistic high amylose starchy foods.In studies with rice, varieties with similar amylosecontents were shown to differ in starch digestibilityand glycémieresponse (Panlasigui et al. 1991). Also, ahigher amylose content in rice was accompanied byan increased rate of starch digestion both in vitro andin vivo (Rao 1970). Further, a slightly higher amylosecontent in barley porridge did not influence the postprandial glucose or insulin responses (Granfeldt et al.1994).

Results from in vitro studies show that a possiblemechanism for lowered metabolic responses to highamylose starch is a lowered rate of amylolysis. Thus,the rate of in vitro amylolysis of starch in barley

Supported by Cerealia Foundation for Research and development and The Swedish Council for Forestry and AgriculturalResearch.

2The costs of publication of this article were defrayed in part by

the payment of page charges. This article must therefore be herebymarked "advertisement" in accordance with 18 USC section 1734

solely to indicate this fact.3To whom correspondence should be addressed.

0022-3166/95 $3.00 ©1995 American Institute of Nutrition.Manuscript received 23 December 1993. Initial review completed 14 March 1994. Revision accepted 10 August 1994.

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products has been shown to be lower in a highamylose variety of Glacier than in a normal or waxygenotype (Björcket al. 1990, Granfeldt et al. 1994).The cause for reduced enzyme availability of starch inhigh amylose products is not clear, but could berelated to the tendency of amylose to recrystallize orinteract with lipids (Berry 1986, Holm et al. 1983).Further, although high amylose starch can be expected to be completely gelatinized <100°C,temperatures >100°C are necessary for complete swelling

(Eliasson et al. 1988). It is not known to what extentlimited swelling might affect the availability toamylolytic attack.

After heating and subsequent cooling, part of thestarch may be converted into an indigestible fractioncalled resistant starch. Resistant starch is defined asstarch or starch fragments remaining undigested inthe upper gastrointestinal tract of humans. Resistantstarch can be fermented by human gut bacteria andthus resembles to some extent certain dietary fibers(Björcket al. 1986). Upon heating and cooling of highamylose starches, high levels of resistant starch areformed (Berry 1986). From in vitro analysis and determination of fecal starch in rats treated with antibiotics (Granfeldt et al. 1993), it was found that -30%of the total starch in a high amylose corn bread wasenzyme resistant. This was probably due to formationof retrograded amylose during the four heating cyclesincluded during the corn bread preparation (Granfeldtet al. 1993). Further, a close association between formation of resistant starch and the amylose contentwas seen in autoclaved or boiled barley flour (Björcket al. 1990, Granfeldt et al. 1994), and a majorresistant starch fraction in processed cereals appearsto be retrograded amylose (Granfeldt et al. 1994, Lil-

jeberg et al. 1992).It is not clear to what extent resistant starch for

mation, by lowering the content of potentiallyavailable starch, could explain the low glycémieandinsulinemic responses reported after ingestion ofsome high amylose foods (Amelsvoort and Weststrate1992, Behall et al. 1988, 1989, Brand Miller et al.1992, Goddard et al. 1984, Juliano and Goddard 1986).A relationship between the amount of potentiallyavailable starch ingested and blood glucose responseareas has previously been found (Collier et al. 1987,Rasmussen 1993, Rasmussen and Gregersen 1992).Also, Jenkins et al. (1987) reported an inverse relationship between blood glucose response and "malab-sorbed" starch. Thus, when evaluating high amylose

products, problems are encountered with respect tostandardization of meal size.

The purpose of the present investigation was tostudy the importance of amylose:amylopectin ratioon the glucose and insulin responses to realistic cornproducts. To exclude the possible influence of a lowered content of potentially available starch due toresistant starch formation in case of the high amylose

product, this product was evaluated at two levels andincluded either on the basis of potentially availablestarch or total starch (including resistant starch).

MATERIALS AND METHODS

Test products. Grains from ordinary dent corn(25% amylose) were obtained from National Starchand Chemical Corporation (Bridgewater, NJ) andgrains from high amylose corn (Amy 7, 70-75%amylose) from Iowa State University (Ames, IA). Thecorn was soaked in cold water for 30 h before boilingfor 20 min and then left to cool in the boiling water.The boiled corn was partially dried in hot air (70°C)

for -25 min (to facilitate milling) and milled(Cemotec 1090 Tecator AB, Höganäs,Sweden). Toseparate the hulls, the milled flours were passedthrough a sieve.

Arepas (corn bread cakes typical in Colombia andVenezuela) were baked as follows. The sieved flourswere mixed with water (dent corn:water, 1:1.2 wt/wt:high amylose corn:water, 1:0.8 wt/wt), oil (20 g-kg"1flour basis) and NaCl (10 g-kg"1 flour basis) and there

after heated in a saucepan for 5 min. Finally, cakeswere formed and baked in an oven (175°C)for 20 min.

The arepas were allowed to cool at ambient temperature, kept in a refrigerator overnight and rewarmedin an oven (175°C)for 8 min to eating temperature

before being served. After these four heating cyclesconsiderable amounts of in vitro resistant starch waspresent, especially in the high amylose product. Asjudged from differential scanning calorimetry data,the gelatinization temperature of high amylose corn-starch (70% amylose) is about 75°C,which is onlyslightly higher than the 71°Creported for normal

cornstarch (Eliasson et al. 1988). With this definition,the starch in both arepas can be expected to be fullygelatinized. However, temperatures >100°C are re

quired to develop viscous properties in case of highamylose cornstarch. The swelling and hydration ofstarch was thus probably less in the high amylosearepas.

Starch determination. To determine potentiallyavailable starch, an amount of homogenized arepascorresponding to 500 mg dry sample was suspended indistilled water (15 mL) and incubated with a thermostable bacterial a-amylase (40 /¿L;Termamyl 300L, Novo A/S, Copenhagen, Denmark) in a boilingwater bath for 20 min (Holm et al. 1986). The mixturewas then diluted to 50 mL with distilled water. To 1mL of this suspension were added amyloglycosidase(50 /¿L;14 U/mg, 10 g/L, Boehringer Mannheim,Mannheim, Germany) and 0.1 mol/L Na acetatebuffer, pH 4.75 (2.0 mL). The mixture was incubatedfor 30 min at 60 C, diluted to 100 mL with distilledwater and analyzed for glucose with a glucose ox-idase-peroxidase reagent. A standard curve was prepared using glucose, and starch content was expressedin polymer weight.

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Alkali treatment solubilizes crystalline regions instarch granules, unswollen starch, and firmlyretrograded amylose and also releases starch whichmay be enclosed within cell walls (Tovar et al. 1990).This analytical procedure therefore gives a measure oftotal a-glucans present. An amount of sample (500 mgdry sample basis), was suspended in 10 mL of water,and an equal volume of 4 mol/L KOH solution wasadded. The mixture was kept for 30 min at roomtemperature and then neutralized (pH 6.5-7) with 5

mol/L HC1. The analysis of total starch content wasthen performed as above.

In vitro resistant starch was obtained in twodifferent ways. 1) In vitro undigested starch bydifference was estimated as total starch less potentially available starch, based on direct analysis of theproducts as described above. 2) Resistant starch in thedietary fiber residue was analyzed according to Gran-

feldt et al. (1993). The dietary fiber residues wereprepared as described by Asp et al. (1983). Total starchremnants in the fiber residue were analyzed enzymat-

ically following solubilization in alkali as describedabove for total starch. Residual starch was analyzeddirectly, omitting pretreatment in alkali as describedabove for analysis of potentially available starch. Theresistant starch fraction that required solubilizationin alkali in order to be digested by analytical amylaseswas calculated as the difference between resistantstarch and residual starch. This fraction probably consisted mainly of crystalline retrograded amylose.However, in the high amylose product it cannot beexcluded that poorly hydrated or unswollen starchmay contribute. Resistant starch less residual starchwill therefore be referred to as nonhydrated starch.

Dietary fiber, protein and fat. Dietary fibercontent was analyzed by the enzymatic-gravimetricmethod of Asp et al. (1983). Reported dietary fibervalues are corrected for total starch remnants in thefiber residue, i.e., resistant starch (see above). Proteinand fat were calculated from analysis of the flour,using the Kjeldahl (N x 6.25) and the Schmid-Bond-zynski-Ratzlaff method (extraction in ether afterhydrolysation in HCl) (Croon and Fuchs 1980),respectively.

Evaluation of postprandial glucose and insulinresponses. Nine healthy subjects (four men, fivewomen) with an average age of 34 ±6 (means ±so)took part in the study. Their body mass indices werenormal, mean of 23 ±2 (means ±SD) kg-m~2, and all

had normal glucose tolerance.Three different test meals (see below) were taken at

breakfast after an overnight fast on separate mornings~1 wk apart. The meals were given between 0800 and0830 h and were eaten over 15 min. Zero time wasdetermined as the time eating commenced. Finger-prick blood samples were taken using mini lancets(Clean Chemical Sweden AB, Borlänge,Sweden) at -5,30, 45, 70, 95, 120 and 180 min. Capillary blood was

collected and analyzed for glucose with a glucoseoxidase/peroxidase reagent. Plasma insulin wasevaluated in the samples taken at -5, 30, 45, 95 and120 min employing an enzyme-linked immunoassaykit (Enzymun-Test® Insulin 1135 295, Boehringer

Mannheim). For comparison, areas under both1.5- and 2-h glucose and insulin curves were calculated. Concentration values below baseline were considered equivalent to zero.

This study was approved by the Research EthicsCommittee of the Medical Faculty at the Universityof Lund.

Test meals. The test meals consisted of 45 g potentially available starch from dent corn arepas (105 g,fresh weight) and high amylose corn (180 g, freshweight) arepas. Arepas made from high amylose cornwere also served providing 45 g total starch content(following alkali solubilization), corresponding to 29 gpotentially available starch (116 g, fresh weight). Thenutrient composition of the arepas and correspondingtest meals, including the resistant starch contents(calculated by difference and analyzed in the dietaryfiber residue), of the arepa products are shown inTable 1. The arepas were eaten with a glass of water(150 g) and a cup of coffee, tea or water (150 g) wasconsumed after the meal.

The reason for choosing 45-g starch meals insteadof the commonly used 50 g, was the bulkiness of thearepa meal when provided at the higher level.

In vitro starch hydrolysis. Starch hydrolysis wasmeasured in vitro employing a method based onchewing (Granfeldt et al. 1992). An equivalentamount of potentially available starch (1 g) from dentcorn and high amylose corn arepas were tested.Arepas made from high amylose corn were also testedusing 1 g total starch (0.6 g potentially availablestarch). The products were prepared in the same wayas for in vivo evaluation. The samples were chewed ina standardized way, expectorated quantitatively into abeaker, and incubated with pepsin (pH 1.5 for 30min). After the pepsin incubation, the samples wereneutralized using NaOH, porcine pancreatic a-amylase was added, and the incubate was transferredto dialysis tubing. The bags were incubated at 37°C

for 3 h. Every half hour, the dialysate was analyzed forreducing power with the 3,5-dinitrosalicylic acidmethod (Hostettler et al. 1951). A standard curve wasprepared using maltose. The extent of hydrolysis wascalculated as the proportion of starch degraded tomaltose (percentage maltose equivalents). Ahydrolysis index was calculated as the area under thehydrolysis curve (0-180 min) with the product as apercentage of the corresponding area with whitewheat bread, chewed by the same person (Granfeldt etal. 1992).

Statistical analysis. The results are expressed asmeans ±SEM. Significant differences (P < 0.05) werecalculated by Wilcoxon matched-pair signed test,with each person being his or her own control.

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TABLE 1

Composition of the arepas and the corresponding test meals made from ordinary corn and high amylose corn, respectively

High amylose arepas

FatProteinStarchTotalPotentially

availableInvitro determination of resistantstarch:Undigestible

"bydifference"Starch

remnants in the fiberresidueTotalNon-hydrated

starchfractionDietary

fiberTotalSolubleDry

matter, % of freshweightEnergy,kjOrdinaryg/100

gdrymatter8.410.371.568.82.73.11.95.60.162com

arepasCorresponding

testmealg5.56.746.845.01.82.01.23.60.061082Corresponding

test meal's

availablestarchg/100

gdrymatter10.011.269.244.724.518.810.915.20.45629

g6.57.345.029.015.912.27.1S7.30.285845gg10.111.369.845.024.718.911.015.30.41331

RESULTS

In vitro determination of resistant starch. Thedifference between total and potentially availablestarch was considerable in the dent corn product (3 g/100 g dry matter) vs. the high amylose product (25 g/100 g dry matter) (Table 1). The content of in vitroindigestible starch estimated from analysis of starchremnants in dietary fiber residue gave similar results,or 3 g/100 g and 19 g/100 g, respectively (dry matter).The major undigestible starch fraction required priorsolubilization in alkali to render it available to analytical enzymes. Two g/100 g and 11 g/100 g (drymatter) in the arepas made from dent corn and highamylose corn, respectively, were nonhydrated starch.

Postprandial glycémieand insulinemic responses.Figure 1 presents the mean glucose responses to thetest meals. No differences were noted between thehigh amylose meals, containing 45 and 29 g of potentially available starch, respectively. The dent cornproduct elicited higher responses than both the highamylose corn products during the first 70 min. Nomajor differences were observed between the dent orhigh amylose products in the late postprandial phase(95, 120 and 180 min), although values for the dentcorn product showed a sharper postpeak decrease anda drop below the fasting glucose concentration.

The mean insulinemic responses, shown in Figure2, revealed similar trends as the blood glucose

responses. The insulin response curve generated afterconsumption of the dent corn product was significantly higher than that generated after both mealscontaining the high amylose corn products during thefirst 45-min period.

ordinary oorn (46g)hlgh-«myloi«corn (40g)rilgh-imylo» oorn (2tg)

-0,530 60 90 120

Time (min)IM

FIGURE 1 Comparison of mean incremental bloodglucose responses in healthy subjects after ingestion ofarepas meals made from ordinary or high amylose cornflour. Figures within parentheses represents the amount ofpotentially available starch in the meals. "Denotes a sig

nificant difference between ordinary and high amylose cornbread meals at that time point (P < 0.05). Values are means±SEM; n = 9.

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GLUCOSE AND INSULIN RESPONSES TO CORN PRODUCTS 463

ordinary corn (46g)hlgh-amylot« corn (46g)

hlah-«myloi» corn (29g)

80 90Time (min)

150

FIGURE 2 Comparison of mean incremental serum insulin responses in healthy subjects after ingestion of arepasmeals made from ordinary or high amylose corn flour.Figures within parentheses is the amount of potentiallyavailable starch in the meals. 'Denotes a significant

difference between ordinary and high amylose corn breadmeals at that time point (P < 0.05). Values are means ±SEM;n = 9.

The calculated areas (0-95 and 0-120 min) underthe glucose and insulin curves are shown in Table 2.No differences were noted when subjects consumedeither of the high amylose meals. The areas under theglucose and insulin response curves after consumption of the dent corn arepas meal were -133 and80% larger than after consumption of the meals withthe high amylose product, respectively.

Rate of in vitro starch hydrolysis. The rate of invitro starch hydrolysis in dent com arepas, highamylose corn arepas and a white reference bread areshown in Figure 3, and the hydrolysis indices areprovided in Table 2. The rate of starch hydrolysis wasslowest in the case of high amylose corn arepas.Arepas tested at l g of total starch (i.e., 0.6 g potentially available starch) gave a significantly lowerhydrolysis index (36) than arepas with l g of potentially available starch (49). An increased in vitrohydrolysis rate (85) was observed for the dent cornarepas, although still significantly lower than for awhite reference bread (100).

DISCUSSION

The meal of high amylose corn arepas producedsignificantly lower metabolic responses than did thedent corn arepas meal. The areas under the postprandial glucose and insulin curves were -42 and57%, respectively, of the corresponding areas determined when subjects ate ordinary corn arepas.

As judged from the in vitro hydrolysis data, thedecreased metabolic response elicited by the highamylose corn products seems to be related to adecreased rate of enzymic digestion. Possible factorsleading to a lower rate of digestion include restrictedswelling of high amylose cornstarch resulting fromthe conditions used for food preparation (Eliasson etal. 1988), or formation of amylose lipid complexes

TABLE 2

Fasting values, postprandial glucose and insulin areas in healthy subjectsafter eating arepas made from ordinary or high amylose corn flour and in vitro hydrolysis characteristics1

Arepas made from

Ordinary corn High amylose corn High amylose corn

Plasma glucoseresponse4Fastingconcentrationjmmol-L"1)Area

under curve (0-95 min)(mmol-L~'-min~1)Areaunder curve (0-120 min)(mmol-Ir'-min"1)Plasma

insulinresponse4Fastingconcentration(pmol-L"1)Area

under curve (0-95 min)(nmol-L^-mur1)Areaunder curve (0-120 min)(nmol-L'^min"1)In

vitro starchhydrolysis^Area

under the hydrolysis curve (0-180min)Hydrolysisindex, %4.4

±0.1109±10a114±10a99

±1417±3a18±3a1

gpotentiallyavailablestarch4851

±118a85± 3a4.4

±0.144±5b49±5b88

±139±2b10±2b1

gpotentiallyavailablestarch2784

±Il7b49± 2b4.5

±0.146±8b49±8b87

±1210±2b11±2b1

g total starchofwhich0.6 gispotentially

available2070±115C36± Ie

Values are means ±SEM;values with different letters in each row are significantly different (P < 0.05).245 g potentially available starch.

45 g total starch of which 29 g is potentially available.4n - 10.

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464 GRANFELDT ET AL.

60

40

P.30

è•Ras

20

10

high-amylose corn (0.6g)

high-amyloae corn (1g)

ordinary corn (1g)

wheat (1g)

30 60 90 120Time (min)

150 180

FIGURE 3 Comparison of rate of the in vitro starchhydrolysis in white wheat bread and arepas made fromordinary corn or high amylose corn. Figures within parentheses represent the amount of potentially available starchin the products. A significant difference was obtained between the four products at all time points (P < 0.05). Valuesare means ±SEM; n = 6.

(Holm et al. 1983). A higher level of resistant starchcould also reduce postprandial responses by loweringthe amount of starch available for absorption. In thisstudy, the same amount of potentially availablestarch (in vitro l g and in vivo 45 g) from highamylose corn arepas and ordinary com arepas werecompared. Thus, the difference cannot be assigned tothe high amount of in vitro indigestible starch in thehigh amylose product per se. However, the differencebetween total starch and potentially available starch(35%, total starch basis), as well as the total contentof in vitro indigestible starch as analyzed in the fiberresidue (27%, total starch basis), was extremely high.In the fiber residue, 16% of starch required solubili-

zation in alkali to render it available to the analyticalamylases (nonhydrated starch). These data suggestthat the high amylose product contained an appreciable portion (16 or 35%, total starch basis) ofnonhydrated starch, that is starch requiring solubili-

zation in alkali.Balance experiments with similar arepa products in

antibiotic-treated rats (Granfeldt et al. 1993) have

shown good correlation between the total amount ofstarch that passed the rat small intestine (32%, totalstarch basis), and resistant starch obtained from

analysis of starch remnants in fiber residues (32%,total starch basis). Because the comparison betweenthe arepas was made on an equal potentially availablestarch basis, our data suggest that the potentiallyavailable starch fraction in the high amylose productmay be crystalline (i.e., retrograded) to such an extentthat the overall rate of enzymic digestion was significantly lowered.

No differences were noted in glucose or insulinresponses between the high amylose arepa meals, despite 36% lower potentially available starch content(29 instead of 45 g) in one of the meals. These resultsdo not agree with those of previous reports (Collier etal. 1987, Rasmussen 1993). With larger differences inpotentially available starch content from bread (50 or100 g) or rice (20, 40 or 60 g) respectively, there was acorrelation between the magnitude of the area underthe postprandial glucose curve and the amount ofpotentially available starch ingested. A probable explanation is the high amount of resistant starch inprocessed high amylose corn. The lack of difference inglucose response to the high amylose meals indicatesthat there was a low rate of in vivo starch hydrolysisand that the additional 16 g of potential availablestarch did not increase the metabolic responses.

High amylose corn arepas contained a higher levelof total dietary fiber (15.2%, dry basis) than dent cornarepas (5.6%, dry basis). This is unlikely to haveaffected the glucose or insulin responses to the testmeals. According to Jenkins et al. (1983), whole wheatbread with unsoluble cereal fiber produced a glycémieresponse similar to that of white wheat bread. On theother hand, soluble viscous dietary fibers appear tolower the metabolic responses, at least when added tofood (Holm and Björck1992). The amount of solubledietary fiber were negligible in both dent corn (0.1 g/100 g dry matter, dry basis) and high amylose cornarepas (0.4 g/100 g, dry matter).

The in vitro hydrolysis index of starch in the dentcorn arepas was 85. The hydrolysis index has previously been shown to predict glycémieindices for alarge number of cereal and legume products with goodaccuracy (Granfeldt et al. 1992). Based on theequation glycémieindex = 0.858 hydrolysis index +8.286 (Granfeldt et al. 1992, and unpublished data), ahydrolysis index of 85 for the dent corn arepas corresponds to a glycémieindex of 81. Test meals withcorn have given a relatively wide range of glycémieindices in previous studies. Jenkins et al. (1988)reported a mean glycémieindex of 80 for sweet corn,which is in good agreement with that calculated inthis study. Contrary to the glucose and insulinresponses measured after subjects ate high amylosearepas, the in vitro hydrolysis curves increased withan increased amount of potentially available starch.Depending on the amount of potentially availablestarch (0.6 or 1 g), hydrolysis index varied between 36and 49 giving a calculated mean glycémieindex of 44for high amylose arepas. This is lower than the range

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reported for pasta (45-68) (Granfeldt and Björck1991).To our knowledge, no previous studies have beendone with realistic high amylose corn or cornproducts. However, meals containing high amylosecornstarch (70-75% amylose) have been shown toreduce postprandial glucose and insulin responses inhealthy subjects compared to meals containing ordinary cornstarch (Behall et al. 1988 and 1989).

We concluded that the high amylose corn productproduced favorably low metabolic responses. Thiscould not be explained in terms of a lowered amountof potentially available starch but rather to a reducedenzymic accessibility of the potentially availablestarch fraction. Also, the products were palatable.Consequently, there is an interesting potential forhigh amylose corn as a means of blunting glucose andinsulin responses.

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