Advance Journal of Food Science and Technology 5(7): 866-870, 2013

ISSN: 2042-4868; e-ISSN: 2042-4876

© Maxwell Scientific Organization, 2013
Submitted: March 11, 2013 Accepted: April 08, 2013 Published: July 05, 2013

Enhancing the Nutritional Value of Gluten-Free Cookies with Inulin

1
Sofyan Maghaydah, 2Selma Abdul-Hussain, 3Radwan Ajo, 1Bayan Obeidat and 1Yousef Tawalbeh
1
Departement of Nutrition and Food Technology , Faculty of Agriculture, Jordan University of Science
and Technology, P.O. Box 3030, Irbid 22110, Jordan
2
Departement of Food Science and Biotechnology, College of Agriculture, University of Baghdad,
Baghdad, Iraq
3
Applide Science Department, Al- Huson University Collage, Al-Balqa Applied University, P.O. Box 50,
Al-Huson21510, Jordan

Abstract: Gluten-free products are usually not fortified and are regularly prepared from refined flour and starch.
Moreover, gluten-free products with high nutritional values are lacking in the market. The main objective of this
study was to enhance the nutritional value of gluten-free cookies with inulin as a source of both prebiotics and fibre.
Inulin was added at four levels (3.0, 3.5%, 4.0 and 4.5%) to the gluten-free cookie control formula (corn flour, corn
starch, rice flour and lupine flour). Chemical, physical and sensory characteristics were determined. The results
indicated that the addition of 3.0% inulin resulted in the highest protein, fat and ash content, while 4.0% inulin gave
the highest moisture content. The total dietary fibre content increased with the inulin level, but the spread factor
decreased with increasing inulin level. The sensory evaluation demonstrated that the addition of dietary fibre (inulin)
at different concentrations did not compromise the sensory characteristics and incorporation of 4.0% inulin had
satisfactory consumer acceptance. It was concluded that enhancing gluten-free cookies with a new fibrous prebiotic
substance met the nutritional demands in relation to practical demand.

Keywords: Coeliac disease, gluten-free cookie, inulin, dietary fibres, prebiotic

INTRODUCTION bifidobacteria. The increased presence of beneficial

bacteria has been shown to reduce the presence of
The World Health Organization and food-industry pathogenic or potentially pathogenic bacteria (such as
companies place rather high expectations on food Clostridium perfringens and salmonella) and may be
products that meet consumer demand for a healthy useful in preventing and treating various diseases or
lifestyle, with the aim of reducing the risk of chronic conditions such as diarrhoea (Tuohy et al., 2007).
illnesses. In this context, functional foods play a special Moreover, the main metabolites upon fermentation of
role since they are intended not only to satisfy hunger inulin are lactate, acetic and short-chain fatty acids,
and provide humans with the necessary nutrients, but such as butyric and propionic acids. Some effects of
also to prevent nutrition-related diseases as they contain these short-chain fatty acids include increased water
ingredients with an additional health value that produce and sodium absorption in the colon, mucosal cell
beneficial physiological and metabolic effects (Brasil proliferation, provision of energy and acidification of
et al., 2011). Inulin, a dietary fibre, is found mainly in the luminal environment, which may protect against
endive roots (Cichoriumintybus L.) and several edible colon cancer (Neven, 2001). Coeliac Disease (CD), a
fruits and vegetables such as tomatoes, bananas, gluten-sensitive enteropathy, is an immunological
chicory, garlic, asparagus and onions. The inulin disease in genetically susceptible people, resulting from
commonly used in the food industry is derived from an inappropriate T-cell-mediated immune response
chicory and composed of fructose units connected by β- caused by intolerance to gluten, which is a protein
(2, 1) links; therefore, inulin resists hydrolysis by found in wheat, rye and barley (Beers and Berkow,
human digestive enzymes and reaches the large 2004). Coeliac disease causes many problems, such as
intestines virtually intact, where they are fermented by malabsorption of macro- and micronutrients and failure
the intestinal microflora (Roberfroid, 2007). In to thrive. The effective treatment of CD includes a
addition, inulin is among the most studied and well- lifelong gluten-free diet. Therefore, it is important to
established prebiotics. This attribute makes it ideal for provide CD patients with a variety of nutritious and
fermentation in the colon, thus stimulating the growth healthy products. However, the available array of
of health-promoting bacteria, mainly Lactobacilli and products suitable for CD patients is limited and scarce

Corresponding Author: Sofyan Magadha, Departement of Nutrition and Food Technology, Faculty of Agriculture, Jordan
University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan
866
 Adv. J. Food Sci. Technol., 5(7): 866-870, 2013

because it is a challenge to manufacture bakery width in millimetres. The cookies’ Thickness (T) was
products without wheat since gluten is responsible for measured by stacking six cookies on top of one another,
the Viscoelastic properties and the formation of then restacking in a different order and measuring them
cohesive dough (Kulp and Ponte, 2002). Cookies are to get the average in millimetres. Spread Factor (SF)
important baked products that are considered the most was determined by the following equation: SF = W/T
desirable products for all ages due to their low
manufacturing cost, convenience, long shelf-life and Colour measurement: The colour of all gluten-free
good eating quality. Moreover, cookies can be used as a samples was measured using a Minolat colorimeter CR-
vehicle to deliver essential nutrients to CD patients. 300 (Ramsey, N.J., U.S.A) and recorded in the L*a*b*
However, the most common types of cookie are empty colour system. The L*a*b* colour system consists of a
of prebiotic content. CD patients require an increase in luminance or lightness component (L*) and two
their daily recommendation of calories, protein, fibre, chromatic components: the (a*) component for green (-
vitamins and minerals due to intestinal damage, which a) to red (+a) and the (b*) component from blue (-b) to
leads to malabsorption of macro- and micronutrients, yellow (+b). The colorimeter was calibrated using a
abdominal distension, diarrhoea and severe constipation standard white plate. Values of white standard were L =
(Beers and Berkow, 2004).A deficit of fibre intake in
97.1, a = +0.13, b = + 1.88. Colour was measured at
the diet of an average consumer raised the issue of the
two positions onboth sides. Duplicate samples were
development and production of dietary fibre-enriched
used for each blend and then the measurements were
cookies as the point of interest for both producers and
researchers (Popov-Raljić et al., 2013) Due to the averaged.
above-mentioned health benefits of prebiotics and the
scarcity of healthy products that are available for CD Sensory analysis: A selected panel of ten was trained
patients, gluten-free cookies were fortified with inulin by the researcher using standard product evaluation
(a prebiotic source) to enhance nutritional value, which criteria developed by Hussain et al. (2006) and
is the main objective of this study. Rababah et al. (2006) six training sessions of two hours
each was conducted in which the panellists were trained
MATERIALS AND METHODS to evaluate sensory attributes of the gluten-free cookie.
The panellists used the orientation session to improve
Gluten-free flour (20% lupine flour their reproducibility and accuracy. Randomly coded
(Lupinusalbus), 30% rice flour (Oryzasativa), 20% corn samples were served to the panellists individually.
flour (Zea mays) and 30% corn starch) was obtained Panellists were supplied with distilled water for
from Modern Flour Mills and Macaroni Factories cleansing the palate between samples. The attributes
(Amman, Jordan). The other cookie ingredients were were analysed based on their respective factors of
used to improve the overall quality of the product, importance regarding the quality of a cookie according
including vegetable hydrogenated shortening (36%), to (Dutcosky, 2007): their overall impression, overall
sugar (40%), milk (10%), sodium bicarbonate (0.5%), flavour, overall texture, overall colour, crust colour,
salt (1%) and two commercial food-grade gum samples: crumb colour, hardness and aftertaste of the sample.
Arabic gum (1.5) and Guar gum (2%) from Foodchem The Hedonic scale test was used for overall impression,
International Corporation (China). Inulin was obtained flavour, texture and crust colour of the sample as
from (AzienzaChimica E Farmaceutica (Italy). Five follows: 1= dislike extremely to 9 = like extremely.
samples were prepared; the first sample was control This descriptive scale was used for all other parameters.
(without inulin). Samples A, B, C and D contained 3,
3.5, 4 and 4.5% of added inulin, respectively. Physical, Statistical analysis: The data was analysed by using
chemical and sensory analyses were conducted. All the Statistical Package for Social Sciences (SPSS,
gluten-free samples were pre-backed, refrigerated and version15.0, 2007, Chicago, IL). One-way analysis of
baked. variance (ANOVA) test was performed to test
differences between blends followed by mean
Chemical analysis: Proximate chemical analysis separation using Duncan's Analysis. Findings with a p-
(moisture, protein, lipid, crude fibre and ash) was value of ≤0.05 were considered to be statistically
determined in duplicate for all gluten-free samples significant.
according to the AACC procedure (AACC, 2000).
Total carbohydrates were calculated by difference as RESULTS AND DISCUSSION
100-(protein+fat +moisture+ash+fibre).
Table 1 illustrates the chemical composition of
Physical analysis: Spread Factor. The AACC (2000) gluten free cookies; the data obtained suggested that the
was used to evaluate the cookies width, thickness and moisture content of a food is of great significance for
spread factor. Cookies width (W) was measured by many scientific, technical and economic reasons (i.e.,
placing six cookies edge to edge to get an average the lower the moisture content of the cookies, the better
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 Adv. J. Food Sci. Technol., 5(7): 866-870, 2013

Table 1: The Chemical composition of gluten-free cookies

Chemical parameters Control A B C D
Moisture 2.12± 0.04a 2.50±0.4a 2.78±0.4a 2.85±0.1a 2.94±0.3a
Protein 13.97± 0.1a 13.95±0.2a 13.93±0.3a 13.92±0.3a 13.91±0.2a
Fat 12.42± 0.2a 12.87±0.3a 12.67±0.2a 12.65±0.3a 12.61±0.3a
a a a a
Ash 1.88± 0.01 1.94±0.2 1.89±0.3 1.76±0.2 1.69±0.2a
Total carbohydrate 69.61±0.2a 68.74±0.3a 68.75±0.4a 68.81±0.3b 68.85±0.3a
Total dietary fibre 3.86±0.3c 11.77±0.3b 12.89±0.3ab 13.11±0.3ab 14.96±0.3a
Values are the average of two replicates ± the standard deviation; row values with the same letters are not significantly different (p≤0.05); Sample
A contain (3%) Inulin; Sample B contain (3.5%) inulin; Sample C contain (4%) inulin; Sample D contain (4.5%) Inulin

Table 2: Physical parameters of gluten-free cookies

Physical parameters Control A B C D
Width (mm) 17.2±1.05a 17.5±1.05a 17.5±1.02a 17.6±1.03a 17.8±1.08a
Thickness (mm) 3.98±1.09a 3.8±1.09a 3.8±1.03a 3.8±1.01a 3.6±1.07a
Spread factor 4.3±1.07a 4.6±1.01a 4.6±1.02a 4.63±1.01a 4.9±1.01a
Values are the average of two replicates ± the standard deviation; row values with the same letters are not significantly different (p≤0.05); Sample
A contain (3%) Inulin; Sample B contain (3.5%) inulin; Sample C contain (4%) inulin; Sample D contain (4.5%) Inulin

the storage stability). The mean values for moisture this increases the risk of a variety of diseases. The
content (Table 1) showed statistically non-significant serving size of this product is two pieces (each is 17g)
(p>0.05) variations among all sample cookies and since the Reference Amount Customarily Consumed
ranged from 2.12±0.04 to 2.94±0.3%. (RACC) for cookies is 30 g. Therefore, each serving
Means for protein content of all sample cookies size of this product would provide approximately 6 g of
illustrated a non-significant (p>0.05) effect of the fibre with a 4.5% inulin addition level. Accordingly,
addition of inulin; the crude protein content ranged this product is considered rich in fibre for CD patients.
from 13.91±0.2to 13.97±0.1in all cookies (Table 1).The Table 2 shows the physical parameters of gluten-
means for fat content of cookie samples (Table 1) free cookies. The data obtained suggest that the mean
showed non-significant differences with ranges from values for the width (diameter) of all types of cookies,
12.42±0.2 to 12.87±0.3%.
which ranged from 17.2±1.05 to 17.8±1.08 mm had a
Ash content in a food substance indicates inorganic
non-significant impact on this trait. Mean values for
remains after the organic matter has been burnt away.
thickness of all types of cookies are shown in Table 2.
The mean ash content values of all types of cookies are
given in Table 1. Ash content varied (non-significantly) The thickness of cookies ranged from 3.6±1.07 to
from 1.69±0.2to 1.94±0.2% in all cookies. 3.98±1.09mm. Spread factor indicates the ratio, which
The means for total carbohydrate content of all depends upon the values of width and thickness. Means
types of cookies in Table 1 show that total carbohydrate for spread factor revealed (Table 2) non-significant (p >
content in different cookies ranged from 68.74±0.3to 0.05) differences among all types of cookies. The
69.61±0.2%. spread factor of cookies ranged from 4.3±1.07to
The means for crude fibre of all types of cookies 4.9±1.01; these values are in agreement with the
(Table 1) showed that fibre content ranged from acceptable range reported in the literature. Having no
3.86±0.3 to 14.96±0.3%. In relation to dietary fibre significant difference between samples indicated that
content, as expected, it was noticed that as the addition the addition of inulin had minimal effects. Moreover,
of inulin increased, so did the fibre content. Moreover, no changes in these physical parameters were desirable
there was a significant difference (p≤ 0.05) among the because otherwise, the chewing and final shape of the
samples, where sample D (4.5% inulin) showed a cookies would have been changed and thus, not
significant increase in this component while the control appealing to CD patients. Spread factor and size of the
exhibited the lowest fibre content. It has been shown cookies depends on particle size and moisture content
that fibre deficiency is common in gluten-free diets of flour (Gaines and Donelson, 1985).The present study
because gluten-free products are generally not enriched revealed that the addition of inulin had no adverse
or fortified and are frequently made from refined flour effects on the physical parameters of cookies.
or starch. The recommended daily intake for total fibre The effects of gluten free cookie formulation on
for adults aged 50 years and younger is 38 g for men colour measurements were performed and presented in
and 25 g for women, while for men and women over 50 Table 3. Namely, the top and bottom surface colour of
years, it is 30 and 21 g of fibre per day, respectively baked cookiesarevery important parameters in the
(Stojceska et al., 2010). The typical diet of the coeliac initial acceptability of products tested by consumers
does not always deliver the recommended 20 to 30 g of (Zucco et al., 2011). According, to Chevallier et al.
dietary fibre per day. Adults diagnosed with CD have a (2000) cookie colour surfaces occur as a result of non-
lower intake of fibre when compared to a control group enzymatic browning (Maillard reactions) between
of individuals on a normal diet (Grehn et al., 2001) and reducing sugars and amino acids as well as from starch
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Table 3: Colour characteristics of gluten free cookies

Colour parameters Control A B C D
L* 72.20a 72.02a 71.00a 71.00a 70.10a
a* -2.98a -2.94a -2.90a -2.89a -2.87a
B* 35.80a 35.83a 35.85a 35.87a 35.90a
Row values with the same letters are not significantly different (p≤ 0.05); Sample A contain (3%) Inulin; Sample B contain (3.5%) inulin Sample
C contain (4%) inulin; Sample D contain (4.5%) Inulin

Table 4: Sensory evaluation of gluten-free cookies

Attributes Control A B C D
Texture 5.10±1.16a 5.25±1.16a 5.63±1.21a 5.74±1.12a 5.80±1.17a
Aroma 5.54±1.3a 5.01±1.28a 5.45±1.14a 5.22±1.15a 5.78±1.16a
Flavour 5.62±1.5a 5.14±1.09a 5.44±1.14a 5.56±1.04a 5.88±1.02a
Softness 5.41±1.4a 5.54±1.4a 5.21±1.4a 5.10±1.4a 5.32±1.4a
Overall impression 5.840±1.07a 5.80±1.09a 5.78±1.21a 5.71±1.16a 5.98±1.04a
Average of 50 judgments. Hedonic Scale: (7) Like extremely; (6) Like very much; (5) Like moderately; (4) Neither like nor dislike; (3) Dislike
moderately; (2) Dislike very much; (1) Dislike extremely; The samples (mean±standard deviation) followed by the same letter (same row), not
significantly different (p≤ 0.05); Sample A contain (3%) Inulin; Sample B contain (3.5%) inulin; Sample C contain (4%) inulin; Sample D
contain (4.5%) Inulin

dextrinisation and sugar caramelisation. The lightness inulin to white bread as a substitute for fat does not
(L*), redness (a*) and yellowness (b*) values of gluten- affect its sensory characteristics (Lajolo and Menezes,
free and control cookies suggest the following ranges of 2006). In summary, different concentrations of inulin
cookie colour: L* = 70.1 to 72.2, a* = -2.87 to -2.98 do not compromise the sensory characteristics of the
and b* = 35.8 to 35.9. There was no significant product nor its acceptance by consumers.
(p>0.05) difference between all of the cookie samples;
these results agreed with those obtained by Mandala CONCLUSION
et al. (2009), who reported that no significant difference
in crust colour was observed for inulin addition at 3% The results obtained in this study demonstrated that
in freshly baked breads. From the results it can be seen the addition of dietary soluble fibre (inulin) at different
that the increased addition of inulin reduced the concentrations did not compromise the sensory
lightness, which confirmed that reported by Morris and characteristics of the product nor its acceptance by the
Morris (2012), who indicated a darker crust colour for consumers. This product is considered a rich source of
all levels of addition (2.5, 5 and 7.5%) and 2 types of fibre due to the two main ingredients: lupine and added
inulin. An enhancement of bread crust coloration was inulin. Therefore, it helps to meet consumer
also reported for breads prepared with as little as 3% requirements for fibre (38 g for adult men and 25g for
and up to 10% inulin. These darker colours have been adult women). Enhancing the fibre value of gluten-free
explained by a greater number of reducing ends cookies provides health benefits, including a reduction
involved in a Maillard reaction. Shorter chain inulin in the bowel transit time, prevention of constipation,
results in even darker colour, as it possesses a higher reduction of the risk of colorectal cancer and lowering
proportion oflow molecular weight fructans (Peressini
of blood cholesterol. Similarly, the health benefits of
and Sensidoni, 2009). A slight change in colour was
inulin include an increase in mineral absorption (Ca and
favourable to maintaining the original, colour of the
Mg), a decrease in triglyceridaemia, production of
cookies that is deemed acceptable for consumers.
short-chain fatty acids, a lowering of the risk of colon
Sensory evaluation results of gluten-free cookies
are presented in Table 4.These results showed that the cancer and irritable bowel syndrome and promotion of
most influential descriptors concerning gluten-free the growth of beneficial gut microflora Finally,
cookie evaluation were: texture, aroma flavour and considering the prebiotic action, the use of inulin
overall impression, in which all attributes score represents an important technological alternative.
between 5 and 6 from like moderately to like very Therefore, the developed product attends to the demand
much. This indicated that no adverse effects of the of practicality expected by the consumers. Developing
addition of inulin exist and that the addition might these high nutritional gluten-free cookies helps to create
actually improve the sensory attributes; sample D (4% a major opportunity for food producers to provide more
inulin) yielded the highest score. The addition of these healthy dietary fibre-enriched products, which are
fructans (inulin) is promising as they do not alter the currently lacking in the gluten-free market.
appearance or flavour of foods, which agrees with the
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