


































Food Science and Nutrition Studies 

ISSN 2573-1661 (Print) ISSN 2573-167X (Online) 

Vol. 1, No. 2, 2017 

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61 
 

Comparative Study of Starch Characteristics, In-Vitro Starch 

Digestibility and Glycemic Index of Some Starchy Foods 

Consumed in Nigeria 

Israel Olusegun Otemuyiwa1*, Adedayo Muideen Sanni1 & Emmanuel Ayorinde Oyewumi1 

1 Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria 

* Israel Olusegun Otemuyiwa, E-mail: otemuyisegun@oauife.edu.ng 

 

Received: June 25, 2017           Accepted: July 8, 2017        Online Published: July 29, 2017 

doi:10.22158/fsns.v1n2p61        URL: http://dx.doi.org/10.22158/fsns.v1n2p61 

 

Abstract 

The study investigated the carbohydrate characteristics and in-vitro starch digestibility of some starchy 

food consumed in Nigeria. Ten foods samples (cassava, yam, red and white sorghum, rice, plantain, 

banana, semovita, noodles and bread) were selected. The content of starch, amylose and sugar were 

determined by colorimetric method, in vitro rate of starch hydrolysis was evaluated by multi-enzyme 

digestion method over a period of two hours, the glucose released was estimated by colorimetric 

method and was compared to the reference food (bread). The result showed that the percentage 

moisture content and total starch ranged from 9.8 to 15.3% and 236 to 248 mg/g, while amylose, 

Rapidly Digestible Starch (RDS) and Resistance Starch (RS) ranged from 8.41 to 19.2%, 30.8 to 51% 

and 7.8 to 37.4%, respectively. The in-vitro digestibility study indicated that the equilibrium 

Concentration (Cα), Kinetic constant (K ), Hydrolysis Index (HI) and Glycemic Index (GI) ranged from 

34 to 64.9, and 0.02 to 0.07, 56.6 to 104 and 71 to 96.8, respectively. Positive correlations (P < 0.05) 

exist between RDS and GI (r = 0.700) and RS and amylose (r = 0.899) The study revealed that, 

structure of dietary carbohydrate could greatly influenced the Glycemic Index, plantain and noodles 

with low RDS and low hydrolysis constant may be beneficial in management of diabetes whereas 

sorghum, semovita, cassava and bread with high RDS, and high GI should be taken sparingly or 

combined with high protein and low glycemic load foods. 

Keywords 

Glycemic Index, Resistant Starch, amylose, in vitro digestion, Nigeria 

 

1. Introduction 

In recent years it has become evident that significant health risks and benefits are associated with dietary 

food choice. A particular disease has been associated with carbohydrate foods with high Glycemic Index 



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and high digestibility rate. About 104 millions of people worldwide are being afflicted with the perfect 

epidemic known as the Diabetes. This figure is increasing daily. Diabetes meets all criteria for a public 

health disorder (Seal et al., 2003). Nutrition is a significant cornerstone of diabetes care as described in 

intensive management. The main focus in nutritional management of diabetes is to improve glycemic 

control by balancing food intake with endogenous and/or exogenous insulin level (Heacock et al., 2004). 

Historically, attempt has been made to control the glycemic response to food, particularly 

carbohydrate-containing foods, including use of very low carbohydrate and starvation diets, artificial 

sweeteners and pharmacological preparations such as fast acting insulin and inhibitors of carbohydrate 

absorption (Heacock et al., 2004).  

In Nigeria, the diet of the people is predominantly carbohydrate obtained from either root tuber or cereal 

grains. There are varieties of food that were consumed which complement one another without the 

empirical knowledge of their digestion rate and optimum intake that will give sufficient nutrient intake. 

Foods like carbohydrates for instance should be monitored carefully. There is the need to consider the 

rate at which these foods digest and be able to predict their Glycemic Index in order to prevent glucose 

induced ailment.  

One way to classify the glycemic response of various carbohydrate-containing foods is Glycemic Index 

(GI). The Glycemic Index (GI) is an in-vitro measurement based on glycemic response to 

carbohydrate-containing foods. The index allows ranking of carbohydrate foods on the basis of the rate 

of digestion and absorption (Jenkins et al., 1981; Englyst et al., 1992). In-vitro method has also been 

used to classify foods based on their digestion characteristics similar to the in vivo situation, and to 

identify slow release of carbohydrate in foods (Jenkins et al., 1984). The foods with GI values more 

than 70%, between 56% and 69% and lower than 55% were classified as high, medium, and low GI 

foods, respectively (Brand-Miller et al., 2003).  

The study carried out using human subject by Asinobi et al. (2016) to determine the blood sugar response 

of some traditional fortified staple meals in Nigeria concluded that unripe plantain had the lowest 

Glycemic Index value with lowest postprandial glucose response. Also Fasanmade and Anyakudo (2007) 

concluded that yam based food product should be generously used by diabetes patient because of its low 

Glycemic Index. These experiments were carried out under in-vivo conditions as such none of the 

researcher addressed the nature and characteristics of the starch present in foods analysed.  

The digestibility of starch in foods may vary widely (Björck et al., 1994). Hence, a nutritional 

classification of dietary starch has been proposed, which takes into account both the kinetic component 

and the completeness of its digestibility, thus comprising Rapidly Digestible (RDS), Slowly Digestible 

(SDS), and indigestible or resistant fractions (RS) (Englyst et al., 1992). 

The objectives of this study were to carry out in-vitro digestibility studies of some starchy staple diets 

consumed in Nigeria, determine the rate of hydrolysis and the starch content characteristics, and also 

predict the Glycemic Index. The study would provide an insight into the basic cause of epidemics 

associated with elevated glucose induced type 2-diabetes among Nigerians. 



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2. Materials and Methods 

2.1 Sample and Sample Preparation 

The samples selected for this study are yam flour, cassava flour, unripe plantain flour, unripe banana 

flour, flour of white and red sorghum, semovita, rice, noodles and bread. The samples were dried and 

milled using a locally fabricated mill (Lawood Metals, Osogbo, Nigeria). The milled samples were 

sieved using a local sieve (aperture size of 0.6 mm) to remove the coarser fragments. All the samples 

were milled as one batch, mixed thoroughly and sub-samples randomly taken from different parts of 

each milled sample, mixed together and stored in the freezer until analyzed. 

2.2 Analysis of Proximate Composition 

The proximate composition of the samples (moisture, ash, Crude fibre) were determined by the method 

of AOAC (2000). 

2.3 Determination of Total and Reducing Sugar Content 

Soluble sugar was extracted from 2.0 g sample with 85% ethanol using soxhlet extractor and refluxed 

for 2 h as described by Bambridge et al. (1996) Reducing sugar and total sugar were determined from 

the ethanolic extract by the ferricyanide method (AOAC, 1984). Glucose was used as a standard and 

the glucose content of the sample was calculated using a linear equation y = 1.6216 - 0.001x (R2 = 

0.972). 

2.4 Determination of Total Starch 

The total starch content of the samples was determined on the residue obtained after ethanolic 

extraction of sugar. Residue (200 mg) was refluxed with 0.7 M HCl for 2.5 h. The acid hydrolysate was 

neutralized to pH 7.0 using 5.0 M NaOH, pour into 500 mL standard flask and made up to volume with 

distilled water. The hydrolysate was filtered through a Whatman no. 541 filter paper and the starch was 

determined as the reducing sugar using the ferricyanide method (Bainbridge et al., 1996). The glucose 

content was calculated using a glucose standard linear equation and then converted to starch content 

using the AOAC (1984) equation.  

2.5 Determination of Amylose Content 

Amylose content in rice samples were determined based on the Iodine-binding procedure as described 

by Thomas et al. (2013). The sample (100 mg) was measured into 100 mL standard flask, 1.0 ml of 

ethanol (95%) and 9.0 ml of 1.0 M NaOH were added, the mixture was heated on a boiling water bath 

for 10 min to gelatinize the starch. 5.0 ml of the gelatinized starch solution was transferred to a 100 ml 

standard flask, 1.0 mL of 1.0 M acetic acid and 2.0 ml of iodine solution were added and made up to 

volume with distilled water. All the contents were thoroughly vortex mixed and allowed to stand for 20 

min. The absorbance was measured at 620 nm using a UV-Spectrophotometer (Model AA-6650, 

Shimadzu Co. Japan). The amylose content was calculated from the standard curve of potato amylose 

using the linear equation (R2 = 0.899). 

2.6 In-Vitro Starch Hydrolysis 

The in-vitro starch digestibility was determined by multi-enzyme procedure described by Deepa et al. 



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(2010). The sample (250 mg) was gelatinized in 10 mL distilled water on a hot plate. The gelatinized 

sample was homogenized with 10 mL of HCl-KCl buffer (pH 1.5) using a basic homogenizer (Kika 

Labortechnik 725, Janke and Kukel GmbH & Co., Stanfen Germany) at 9500 rpm for 1 min and the 

homogenate was then digested with 20 mg of pepsin (Sigma; CAS 2001/75-6, code 10132561, 666 

iu/mg, porcine gastric mucosa) solution (prepared by adding 1.0 g of pepsin/10 mL of HCl-KCl buffer) 

for 1 h in a shaking water bath at 37oC. The pH of the digestate was adjusted to 6.9 and the volume 

made to 25 ml using Tris-maleate buffer (pH 6.9). Then 5.0 mL of α-amylase (2.6 IU in 5 ml buffer pH 

6.9) was added to the digestate which was incubated at 37oC in a shaking water bath. One ml of sample 

aliquots was collected at intervals of 30 min for 180 min, the enzyme activity in the aliquot withdrawn 

was inactivated by immediately placing the tube in a boiling water bath maintained at 100oC for 5 min 

and then refrigerated till the end of the incubation period, To these aliquots, 3 ml of 0.4 M sodium 

acetate buffer (pH 4.75) and 60 µl amyloglucosidase (Sigma, No;10105-5GF,70 ui/mg. Aspegilius 

niger) were added and incubated at 60oC for 5 min to hydrolyse the starch to glucose. 

The glucose released was determined using dinitrosalicylic acid (Miller, 1959). The concentration of 

glucose was calculated from the linear equation of glucose standard (R2 = 0.980) and glucose was 

converted into starch by multiplying with 0.9. 

All the experiments were conducted thrice and with triplicate analysis each. 

The rate of starch digestion was expressed as the percentage of TS hydrolyzed at different times. The 

digestibility curve for each food sample was fitted into the first-order equation (Grandfeidt et al., 1992). 

)1( kt
t eCC 

   

where Ct is the percentage of starch hydrolyzed at time t (min), 

C∞ is the equilibrium starch hydrolysis after 180 min, 

k is a pseudo-first order rate constant. 

The parameters, k and Cα were estimated for each sample based on the data obtained from starch 

hydrolysis procedure using Microsoft Excel Software. 

Hydrolysis Index (HI) was obtained by dividing the area under the hydrolysis curve of the sample by 

the corresponding area of a reference food (white bread) expressed as a percentage (Grandfeidt et al., 

1992). 

Glycemic Index (GI) was estimated using the equation of Goni et al. (1997). 

)549.0(71.39 HIGI   

2.7 Determination of Rapidly Digestible, Slowly Digestible and Resistance Starch 

The method of Han et al. (2007) was used to estimate the rapidly digestible, slowly digestible and 

resistance starch. The Rapidly Digestible Starch (RDS) is the fraction of starch hydrolyzed within 30 

min of incubation, Slowly Digestible Starch (SDS) is the fraction hydrolyzed between 30 to 180 min 

and the fraction that remained un-hydrolyzed after 180 min is regarded as the Resistant Starch. 

2.8 Statistical Analysis 

Analyses were carried out in triplicate for each determination and the results were expressed as mean 



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and standard deviation. The data were subjected to analysis of variance, and pearson correlation 

coefficient and the levels of significant difference was performed. GraphPad InStat version 3.06 for 

Windows 2003 was used for statistical analysis. 

 

3. Results and Discussion 

The results of starch and sugar and chemical characteristics of the starch were presented in Table 1. The 

moisture content of the local foods ranged from 8.2 to 15.3%, the highest value was found in yam flour, 

these values compares with 12 to 14% predicted as optimum moisture content for storage of flour foods 

and for obtaining quality product during milling (Souilah et al., 2014).  

The fibre content ranged from 0.48% in rice to 4.9% in noodles. The fibre content of rice is expectedly 

low compared to others, this is because it rice has been subjected to the process of milling and polishing 

in which the outer layer (bran) containing fibre has been completely removed. Though flours of yam, 

cassava, plantain and sorghum were sieved during processing but still contain high fibre content which 

could be adduced to pore size of the sieve.  

Diets with a high content of fiber, have a positive effect on health since their consumption has been 

related to a decreased incidence of several types of diseases as due to its beneficial effects like 

increasing the volume of fecal bulk, decreasing the time of intestinal transit, lowering cholesterol and 

glycemic levels, and stimulating the proliferation of the intestinal flora (Dingra et al., 2012; Souilah et 

al., 2014). 

The total and reducing sugar content (Table 1) ranged from 5.8 to 25.6 mg/g and 1.2 to 12.1 mg/g, 

respectively. The sugar content of banana flour was higher (total and reducing sugar) and this could be 

attributed to glucose release resulting from the activity of endogenous enzymes during processing of the 

flour The presence of sugar will help improve taste of the food products. 

The total starch ranged from 222 to 293 mg/g, Plantain recorded the highest starch, the starch was not 

significantly different (P < 0.05) among banana, yam, sorghum and cassava flours. Amylose and 

amylopectin ranged from 8.41 to 26% and 74 to 92.4%, respectively. Sorghum and cassava flour 

recorded the least values for amylose though according to amylose classification in food (Juliano et al., 

1981), these samples could be categorise as having intermediated amylose content. The implication of 

this amylose level is that these foods is expected to be soft and not sticky and will not become hard when 

cooling. Heating of starch in the presence of water will lead to gelatinisation that makes starch more 

easily digested, however after cooling amylose tend to recrystallise and form retrograded amylose which 

is inaccessible to enzymatic hydrolysis. Amylose and amylopectin are important in determining the 

structure of a carbohydrate food which may have a profound effect on starch digestibility. The 

mechanism of how an increased amylose/amylopectin ratio affect glycemic response is that linear 

amylose chain form a compact structure that limit enzyme accessibility and rate of amylosis (Halistrom, 

2011). Amylopectin on the other hand with its branched structure is less ordered and therefore more 

easily digested. 



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The structural characteristics of digestible starch showed that Rapidly Digestible Starch (RDS), Slowly 

Digestible Starch (SDS) and Resistant Starch (RS) ranged from 31.8 to 55.2%, 8.9 to 40.2% and 7.8 to 

37.4%, respectively. Flours of cassava, banana, sorghum and bread were higher in RDS while low value 

was reported for plantain and noodles. Also the highest value for RS was found in rice (46.5%) followed 

by noodles and plantain and low values were found in white sorghum and yam flour though yam had high 

SDS. In foods, RS could corresponds to the physically inaccessible starches entrapped in cellular matrix 

or are native uncooked granules, the crystallinity of which makes them scarcely susceptible to hydrolysis 

or retrograded starch (Englist et al., 1999). RS has also been shown to have positive effects on colonic 

health by increasing faecal bulk and by generating Short Chain Fatty Acids (SCFAs) such as butyric 

acid, which is the main energy source for colonocytes and may therefore, have a protective role in 

inflammatory bowel diseases and colon cancer (Hallstrom et al., 2011). 

Several factors can explain the difference found in the Resistant Starch quantities, some of which are: 

interaction of starch with different components present in the food system such as proteins, fats; 

botanical source of starch; and storage conditions (Perera et al., 2010). 

From the results, it was observed that noodles recorded high value for fibre as well as Resistant Starch 

this could be from two sources; through enrichment of the ingredient with soluble dietary fibre or through 

heat processing of starch that lead to formation of retrograded starch which hinders enzymatic hydrolysis 

of starch (Englist et al., 1992). 

 

Table 1. Total Starch, Rapidly Digested Starch (RDS), Slowly Digested Starch (SDS), Resistance 

Starch (RS), Amylose and Amylopectin Content of Starchy Food (Expressed as% of Total Starch) 

Sample Moisture  

Total 

Starch 

RDS % SDS % RS % 

Amylose 

% 

Amylopect

in % 

Fiber % 

Total sugar 

mg/g 

Red sugar 

mg/g 

Plaintain flour 11.3 ± 0.1
c
 239 ± 13

c
 31.8 ± 1.0

f
 19.2 ± 0.4

f
 31.4 ± 0.5

c
 17.1 ± 0.3

c
 82.9 ± 0.3

c
 1.3 ± 0.02

b
 10.5 ± 0.5

e
 8.45 ± 1.4

b
 

Banana flour 9.8 ± 0.2
d
 242 ± 0.9

b
 53.7 ± 0.4

b
 8.9 ± 0.5

g
 37.4 ± 1.2

b
 17.7 ± 0.3

c
 82.3 ± 0.3

c
 1.4 ± 0.05

b
 24.6 ± 0.6

ab
 12.1 ± 0.6

a
 

Yam Flour 15.3 ± 0.3
a
 248 ± 1.0

b
 44.3 ± 0.2 

d
 47.9 ± 1.6

a
 7.8 ± 0.1

h
 14.5 ± 0.2

d
 85.5 ± 0.2

b
 3.22 ± 0.8

a
 21.1 ± 1.4

b
 1.45 ± 0.5

e
 

Red Sorghu 12.7 ± 1.1
b
 246 ± 0.9

b
 51.6 ± 0.6

bc
 33.3 ± 0.2

c
 15.1 ± 0.6

f
 14.4 ± 0.3

d
 85.6 ± 0.3

b
 2.29 ± 0.09

a
 15.6 ± 0.26

d
 2.6 ± 0.07

d
 

white Sorghum 13.1 ± 0.6
b
 241 ± 10

c
 49.4 ± 0.2

c
 40.2 ± 1.5

b
 10.4 ± 0.2

gh
 8.41 ± 0.7

e
 92.4 ± 0.5

a
 2.0 ± 0.07

ab
 17.1 ± 0.22

c
 2.2 ± 0.07

d
 

Cassava flour 12.5 ± 1.0
b
 248 ± 2.0

b
 55.2 ± 1.0

a
 22.6 ± 0.1

e
 22.2 ± 0.4

e
 12.8 ± 1.1

d
 87.8 ± 2.0

b
 3.6 ± 0.3

a
 10.08 ± 0.05

e
 1.83 ± 0.05

e
 

Rice  8.2 ± 0.3
e
 222 ± 0.14

c
 38.0 ± 0.3

e
 16.5 ± 0.2

f
 46.5 ± 0.9

a
 26.0 ± 0.8

a
 74.0 ± 0.6

e
 0.48 ± 0.01

c
 10.9 ± 0.02

e
 1.17 ± 0.13

e
 

Semovita 10.2 ± 1.2
cd

 237 ± 8.0
c
 43.8 ± 0.3

d
 27.9 ± 1.4

d
 28.3 ± 1.0

d
 17.4 ± 0.2

c
 82.6 ± 0.2

c
 2.4 ± 0.01

a
 25.6 ± 0.03

a
 2.71 ± 0.1

d
 

Noodles  12.4 ± 0.8
b
 236 ± 5.0

c
 30.8 ± 0.8

f
 35.4 ± 0.8

c
 33.8 ± 0.6

c
 19.2 ± 0.6

b
 80.8 ± 4.0

d
 4.9 ± 0.9

a
 5.8 ± 0.62

f
 5.3 ± 0.007

c
 

Bread 10.6 ± 0.3
cd

 293 ± 5.0
a
 49.0 ± 1.0

c
 21.0 ± 1.0

ef
 30.0 ± 2.0

c
 21.0 ± 0.2

b
 79.0 ± 0.8

d
 1.2 ± 0.02

b
 17.8 ± 0.67

c
 6.53 ± 0.5

b
 

Note. Mean ± SD—mean and standard deviation of triplicate analysis. 

Values in the same column with same superscript are not significantly different P ≤ 0.05. 

1 Rapidly digestible starch; 2 Slowly digestible starch; 3 Resistance starch. 



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The results of in-vitro digestibility and the kinetic parameter were presented in Figure 1 and Table 2, 

the results indicated that the equilibrium Concentration (Cα), kinetic constant (K), hydrolysis index (HI) 

and Glycemic Index (GI) ranged from 34 to 64.9, and 0.02 to 0.07, 56.6 to 104 and 71 to 96.8, 

respectively. With the exception of yam flour and noodles that recorded low hydrolysis index, all 

sample had both high hydrolysis and Glycemic Index. Correlation coefficient (Table 3) showed that 

there is a positive correlation HI and RDS (r = 0.700), GI and RDS (r = 0.701) whereas fibre was 

negatively correlated with GI (r = -0.624) and HI (r = -0.628). 

 

 

Figure 1. Starch Hydrolysis Curve of Some Starch Foods in Nigeria 

 

Table 2. Kinetic Parameters of In-Vitro Starch Hydrolysis of Starchy Foods 

* white bread—control sample. 

Mean and standard deviation of triplicate analysis. 

Cα-equilibrium concentration, K-rate constant, AUC-Area Under Curve, HI-Hydrolysis Index, 

GI-Glycemic Index. 

Values within the same column with different superscripts are significantly different at P ≤ 0.05. 

Sample Cα K AUC HI(%) GI (%) 

Plaintain flour 44.7 ± 1.0d 0.03 ± 0.001c 6606 ± 12c 73.01 ± 0.9d 79.8 ± 2.1c 

Banana flour 60.0 ± 3.0b 0.07 ± 0.002a 9442 ± 22a 104 ± 10a 96.8 ± 1.1a 

Yam Flour 43.7 ± 0.8 d 0.02 ± 0.001d 5911 ± 10g 65.32 ± 0.8e 75.6 ± 1.2d 

Semovita 55.2 ± 0.7c 0.05 ± 0.001b 8800 ± 2.9d 97.2 ± 0.5c 93.0 ± 2.8b 

White Sorghum flour  61.9 ± 0.1ab 0.07 ± 0.001a 9014 ± 23c 99.6 ± 1.4b 94.4 ± 3.0ab 

Red Sorghum flour 64.9 ± 2.0a 0.07 ± 0.004a 9113 ± 25b 100 ± 6.0b 94.8 ± 4.0a 

Cassava flour 60.0 ± 0.6b 0.07 ± 0.009a 9403 ± 15a 104 ± 0.7a 96.8 ± 1.2a 

Rice 58.6 ± 0.5c 0.03 ± 0.001c 8603 ± 9.0e 95.1 ± 2.6c 91.9 ± 0.5b 

Noodles  39.0 ± 0.4e 0.02 ± 0.002d 5123 ± 8.5h 56.6 ± 0.8f 71.0 ± 0.8e 

Bread* 54.5 ± 0.3c 0.07 ± 0.001a 9048 ± 12h 100 ± 0.0b 94.6 ± 0.3ab 



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The kinetic constant K of amylolysis has been proposed as a reliable index of the inherent susceptibility 

of flour starches to amylase hydrolysis (Goni et al., 1997; Frei et al., 2003). From the results, the 

hydrolysis constant of plantain flour, yam flour and noodles is low (k = 0.02), the content of RSD was 

lower and RS was higher than in bread, this implied that the rate at which they will digest may take a 

longer time which may not adversely affect the blood sugar. This observation agrees with the report 

from in-vivo study that yam and unripe plantain had low Glycemic Index (Fasanmade & Anyakuro, 

2007; Asinobi et al., 2016). 

Banana flour unlike plantain recorded high hydrolysis constant (K = 0.07) which is the same as bread, 

the flour recoded high RDS and sugar content which may result from enzymatic degradation 

(endogenous enzymes ) of starch that led to ripening. Sorghum flour (red and while cultivars) also 

recorded high hydrolysis rate which is higher than bread. 

The hydrolysis constant in cassava flour also did not differ from that of bread, processing of cassava 

into flour involve grating, soaking and fermentation to make pulp free of cyanide (a toxic compound 

that is lethal), during fermentation starch is broken down by enzymes an aerobically to sugar which is 

rapidly released when it is consumed as food. The Glycemic Index is even higher than white bread 

(reference food)  

From this study, it was discovered that the Glycemic Index of cassava flour, banana flour, semovita and 

sorghum flour (red and white cultivars) were higher whereas those of plantain flour, yam flour and 

noodles were lower compared to bread which was taking as standard high Glycemic Index food.  

 

4. Conclusion  

The study revealed that starchy foods which are staple diets among Nigerians are high glycemic load 

foods and that structure of dietary carbohydrate could greatly influenced the Glycemic Index of the 

foods, therefore, foods like plantain and noodles with low RDS and low hydrolysis constant may be 

beneficial in management of diabetes whereas sorghum, semovita, cassava and bread which contain 

high content of rapidly digestible starch should be taken sparingly. Hence, in order to effectively reduce 

the high incidence of type 2-diabetes, these foods should be complimented with high protein sources.  

 

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