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Glycemic index lowering effect of chicken solids was studied using a model system approach. Experimental samples were prepared by adding chicken powder at varying levels (10 mg, 20 mg, 30 mg, 40 mg) to 50 mg of corn starch as carbohydrate base. The chicken powder had a proximate protein content of 81.1 per cent, fat 9.1 per cent, ash 6 per cent and moisture 3.7 per cent. In vitro starch digestibility and estimated glycemic index (eGI) of the samples were estimated. It was found that only sample B and C could reduce the eGI of the sample by 22.8 per cent and 21.8 per cent respectively, with an eGI value of 68.05 and 68.9 respectively. Samples containing 30 mg and 40 mg chicken powder did not affect the eGI significantly and values were close to eGI values for the control (corn starch alone). It is concluded that chicken solids exhibit a significant (p < 0.05) glycemic index lowering effect at a level of 17 per cent to 29 per cent of the formulation, and not linearly with an increase in protein content.
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NOMENCLATURE
eGI Estimated glycemic index
GI Glycemic index
AUC Area under the curve
HBV High biological value
DM Diabetes mellitus
C Percentage of starch hydrolysed at time t in min
t Time (m)
C Equilibrium percentage of starch hydrolysed at 180 m
K Kinetic constant
HI Hydrolysis index
1. INTRODUCTION
       
carbohydrate rich, low glycemic foods and should be able to
provide sustained energy release for minimum of 5 h - 6 h.
These foods must aid in preventing hypoglycaemia. Designer
foods incorporating non vegetarian ingredients have not yet
      
The addition of chicken solids to a carbohydrate base can make
the food more nutritious in terms of protein content and can
also exert a glycemic Index lowering effect, which has not
been studied extensively.
Carbohydrate constitutes the major part of Indian diets
and is considered to be the predominant factor affecting
postprandial blood glucose control1. Blood glucose response
of a food is commonly assessed using the GI2.
         
(AUC) for the blood glucose response post prandial relative
to AUC of a reference food (white bread or glucose) given
in an equivalent carbohydrate amount (50 g or 25 g)3. It is a
ranking of foods and there are three categories of GI foods-
low (GI<55), moderate (GI 55-69) and high (GI>70)4. A
low GI diet is related to be clinically useful for diabetes and
       5.
Excess intake of processed carbohydrates leads to a vicious
cycle of transient spikes in blood glucose and insulin, after
a meal trigger reactive hypoglycaemia and hunger. Repeated
consumption of a diet high in processed carbohydrates leads to
excess visceral fat, in turn increasing both, insulin resistance
    
cardio vascular diseases5.
      
type 2 DM is to achieve an optimal blood glucose control
post-prandial6. This can be achieved either by delaying the
absorption of glucose or inhibiting its uptake.
Research has shown other factors like fat, protein, GI7
and processing8       
glucose levels. Minimally processed foods increase post-
prandial glucose to a much lesser extent than the processed
foods8. Lean protein of high biological value (HBV) reduces
post-meal glucose level and also improves satiety. Nilsson9, et
al. conducted a study in healthy individuals, and reported a
decrease in post-prandial blood glucose area under the curve
approximately by 56 per cent, upon addition of whey protein to
a pure glucose drink. Thus, HBV protein foods like egg whites,

non-fat dairy protein) when consumed with meals, reduce the
post-prandial blood glucose response10.
Among the therapeutic drugs used in prevention of a high

Glycemic Index Lowering Effect of Chicken Solids on Corn Starch
Shefali Bhardwaj*, V.K. Shiby, and M.C. Pandey
Freeze Drying and Animal Products Technology Division, Defence Food Research Laboratory, Mysuru - 570011, India
*E-mail: bhardwaj_shefali@yahoo.co.in
ABSTRACT
Glycemic index lowering effect of chicken solids was studied using a model system approach. Experimental
samples were prepared by adding chicken powder at varying levels (10 mg, 20 mg, 30 mg, 40 mg) to 50 mg of
corn starch as carbohydrate base. The chicken powder had a proximate protein content of 81.1 per cent, fat 9.1 per
cent, ash 6 per cent and moisture 3.7 per cent. In vitro starch digestibility and estimated glycemic index (eGI) of
the samples were estimated. It was found that only sample B and C could reduce the eGI of the sample by 22.8 per
cent and 21.8 per cent respectively, with an eGI value of 68.05 and 68.9 respectively. Samples containing 30 mg and

         
a level of 17 per cent to 29 per cent of the formulation, and not linearly with an increase in protein content.
Keywords: Estimated- glycemic index; In-vitro starch digestibility; Chicken solids; Protein; Cornstarch
     
Accepted : 25 April 2017, Online published : 19 September 2017
518-522
Defence Science Journal, Vol. 67, No. 5, September 2017, pp. 518-522, DOI : 10.14429/dsj.67.11870
2017, DESIDOC
BHARDWAJ, et al.:     
519

bound enzyme at the epithelium of the small intestine
responsible for the cleavage of glucose from disaccharide) are
effective in delaying glucose absorption11,12. However, it has
      

and diarrhoea13. Some investigations related to the delay of
glucose absorption by food have been made14.
      
        
management of type 2 DM or in lowering blood glucose
levels post consumption. Researchers have reported effective
anti-diabetic compounds from natural materials15,16, like
polysaccharides from tea leaves17, hydrolysate from sardine
muscle1819, egg albumin20.
Starch digestibility varies among various carbohydrate
foods and has attracted much interest in development of low
GI foods and in the treatment of type 2 DM21. However, there
have been mixed reports on effect of protein on reduction of
glycemic index or post prandial blood glucose levels. Gullifor22,
et al. reported a decrease in the blood glucose level with a diet
consisting of 25 g carbohydrate from potato and 25 g protein
   
in the blood glucose after addition of fat was noticed. The
difference between the glycemic responses after addition of

with the carbohydrate-only diet. Papadaki23, et al. reported no
       
         
impact on GI due to its effect on the satiety, weight loss and
fat oxidation. Pineli24, et al. developed low GI quinoa milk and
suggested the GI to be lowered due to the protein content. Also,
protein is reported to have different effect on blood glucose with
or without carbohydrate, i.e. 30 mg protein with carbohydrate
affects blood glucose25 but when consumed alone, 75 g of
protein is needed to see an effect on blood glucose26.
The present study was undertaken with an aim to develop
a low GI functional food with animal protein. A model system
approach has been employed to assess the level or range within
which chicken exhibits GI lowering effect. To our knowledge,
          
within which the protein exhibits the GI lowering effect.
2. MATERIALS AND METHODS
2.1 Materials
Corn starch and boneless chicken were procured from the
local market of Mysore, India. Boneless chicken was washed
with potable water twice and care was taken to select the lean
protein by manually removing fat before further processing.
Lean chicken was cooked, minced and dried in a hot air oven
at 60 °C - 65 °C for 5 h - 6 h. The dried chicken was ground
to a powder using a domestic mixer. The chicken powder was
stored in an airtight container till further use.
2.2 Proximate Composition
Moisture content (gravimetric method), protein (Kjedahl),
ash (incineration), fat (soxhlet method) were analysed as per
standard procedures of AOAC (1995)27.
2.3 In-vitro Starch Digestibility and estimated-
Glycemic Index
      
from A to E, where A constituted 50 mg corn starch only, B
was a mix of 50 mg corn starch +10 mg chicken powder, C was
50 mg corn starch +20 mg chicken powder, D was 50 mg corn
starch+ 30 mg chicken powder and E was 50 mg corn starch+
40 mg chicken powder.
The eGI of the products were determined according
to the methodology described by Goñi28, et al. with a few

POD glucose kit (Erba Manheim, Transasia Bio-medicals
Ltd., Solan (HP), India) and the absorbance was measured in
a UV/VIS spectrophotometer (Perkin-Elmer Lambda 40 Uv/
      
nm. Glucose was converted to starch using a multiplication
factor of 0.9. Starch digestion rate was expressed through the
percentage of starch released at each time (mg/100g sample) (0
min, 30 min, 60 min, 90 min, 120 min, 150 min, and 180 min).

( 1 )
kt
CCe
=
(1)
C is percentage of starch hydrolysed at time t in minutes,
Cis the equilibrium percentage of starch hydrolysed at 180
min, and k is the kinetic constant. Every product has its own
Cand k value.
Hydrolysis curves were built (disregarding the value at
time 0), and the area under the curve (AUC) was calculated
(AUC) as per Eqn. (2):
0
()
0
( ) ( ) [1 ]
f
kt t
f
AUC C t t C k e
=−− −
(2)
The hydrolysis index (HI) for each sample was calculated
as the ratio between the AUC of sample and the AUC of white

39.71 (0.549 )GI HI=+×
(3)
  
cent).
2.4 Statistical Analysis
       
exponential association equation using Graphpad Prism
version 5.03 software. Anova, mean and standard deviation
were calculated using MS Excel 2010.
3. RESULTS AND DISCUSSION
The prepared chicken powder was analysed for
its proximate composition (Table 1). The rate of starch
digestibility can be a determinant of the metabolic response to
a meal29. Evidences prove that slowly digested and absorbed
carbohydrates are recommended in the dietary management of
metabolic disorders, such as diabetes30
the starch digestibility rates, such as the type of starch, protein,
physical arrangement and lipids interactions, antinutrients,
  21 and food processing22. The
          
one or more reasons, mentioned earlier.
The presence of protein along with an equal amount
       
520
of starch in each sample, affected the starch digestibility in
         
digestibility can be accounted to the presence of peptides present
in chicken powder. Peptides have been documented to have
20.
These enzymes are essential for breakdown of carbohydrates to
glucose in the body. Peptides from sardine muscle20 hydrolyzed
using alkaline protease were reported to have similar inhibitory
effect on the enzyme activity. Due to this inhibitory activity,
these hydrolysates can be utilised successfully in preparation of
physiologically functional food, for diabetics. Novel peptides
derived from egg white protein have been documented to have
     31 and anti-

22. It is suggested that the
    
of peptides with the enzyme21. The eGI for all samples have
been shown in Table 2, and followed the order A> E>D>C>B.
Samples B (eGI 68.05) and C (eGI 68.9) could reduce the eGI
of the sample by 22.8 per cent and 21.8 per cent respectively.
Sample D and E could reduce the eGI only by 7.6 per cent
and 4.6 per cent respectively. The reason for this decrease
is attributed to the peptides interacting with the enzymes in

4. CONCLUSION
The model system approach was employed to understand
the GI lowering effect of chicken solids, as no such studies
have been reported till date. This study helps to assess the level
at which it can be used in development of functional foods with
an objective to lower the post prandial blood glucose or be
low GI. We conclude that in the functional food formulation,
chicken solids at a level of 17 per cent - 29 per cent has
maximum eGI lowering effect, and can be employed in the
         
spectrum of consumers including diabetics, sports personnel
and weight watchers.
Conflict of Interest : None
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Figure 1. Starch digestibility curve for the samples A
to E ; Sample A: 50 mg corn starch alone,
Sample B: 50 mg corn starch + 10 mg chicken powder,
Sample C: 50 mg corn starch + 20 mg chicken powder,
Sample D: 50 mg corn starch + 30 mg chicken powder
Sample E: 50 mg corn starch + 40 mg chicken powder.
Sample C
kAUC HI(%) eGI
A 70.29 0.1015 11960 88.15 88.104
B 46.32 0.0347 7003.8 51.622 68.05
C 60.48 0.0155 7220.3 53.218 68.927
D 60.73 0.0964 10301 75.926 81.393
E 63.87 0.1203 10966 80.823 84.082
Table 2. IVSD parameters and eGI of the samples ; Sample
A: 50 mg corn starch only or 0 % chicken, Sample
B: 50 mg corn starch + 10 mg or 17 % chicken
powder, Sample C: 50 mg corn starch + 20 mg or
29% chicken powder, Sample D: 50 mg corn starch+
30 mg or 38% chicken powder, and Sample E: 50 mg
corn starch + 40 mg or 44% chicken powder
Figure 2. Percentage decrease in eGI values with increase in
protein content.
Table 1. Proximate composition of chicken powder
Component Percentage (per
cent)
Protein 81± 0.26
 9.2± 0.10
Ash 6± 0.06
Moisture 3.7 ± 0.15
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CONTRIBUTORS
Ms S. Bhardwaj       
      
Research Laboratry, Mysuru, India. She has designed the
research plan, organised the study, participated in experiments,
coordinated the data analysis, and contributed to the writing
of the manuscript.
She has designed the research plan, organised the study,
participated in experiments, coordinated the data analysis,
andcontributed to the writing of the manuscript
Dr V.K. Shiby       
Engineering. Currently she is working as a Scientist ‘D’ at
           
food product development and process modelling. She received
DRDO Laboratory Acientist Award (2013).
She has participated in the experimental design, organisedthe reported
study and contributed to the writing of themanuscript.
Dr M.C. Pandey received his PhD in Agriculture Engineering.

           
area of agriculture and food engineering.
He contributed towards the experimental design, organised
thestudy and drafting of the manuscript.
ResearchGate has not been able to resolve any citations for this publication.
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