Running Head: FINAL REPORT 1

FINAL REPORT:

Effect of the Use of Gluten­Free Flours on the Consumer Acceptance, and Color of Sugar Cookies

Alyssa Snow Callahan Christina Fasulo

Cory Ruth Charles Hu Stull

Leanna Tu

NTRS 410 – Experimental Foods California State University, Los Angeles

April 21, 2015 Spring Quarter 2015

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Abstract

The purchase of gluten­free products is on the rise as consumers with Celiac

disease or gluten intolerance search for quality substitutions for baked goods. Cookies,

a favorite snack option, can be made using a variety of gluten­free flours. However,

when compared to conventional wheat flour cookies, gluten­free cookies may have

differing nutrient, flavor, and textural qualities and thus may be more or less accepted

by consumers. The objective of this experiment was to assess the color and sensory

characteristics of gluten­free sugar cookies made with different flour blends. The

independent variable was the type of flour blend. The control cookies were made with

all­purpose flour, one variation was made with a blend of 75% rice flour and 25%

almond flour, and a second variation was made with a blend of 50% rice flour and 50%

almond flour. The dependent variables, color and consumer acceptance, were

assessed with a colorimeter and nine­point hedonic scale, respectively. The null

hypothesis for this experiment was that there was no significant difference in color and

consumer acceptance between the variations and the control cookies. The alternative

hypothesis was that there was a significant difference in color and consumer

acceptance between the variants and the control cookies. Statistical analyses showed

significant differences in consumer acceptance (n=14) between the wheat­based

cookies and each of the two gluten­free cookies when the variants were considered

separately in paired t­tests; however, ANOVA tests showed no significant differences in

the means of all the variants when considered together. There were no significant

differences in any of the color values between the three cookie variants. Thus, we

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accept the null hypothesis in regards to the color of the cookie variants, and additional

work needs to be done to determine consumer acceptability of these cookie variants.

Overall, sugar cookies made with almond and white rice flour blends may be a

promising gluten­free cookie option.

Keywords: gluten­free, flour, cookies, sugar cookies, almond flour, rice flour

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Introduction

Due to the growing prevalence of people suffering from celiac disease and gluten

intolerance, the demand for gluten­free baked products is also increasing.

Unfortunately, gluten­free baking poses immense challenges for both technologists and

nutritionists, as gluten plays a key role in the structure and quality of the baked

products.

Literature Review

An experiment conducted by Kaur, Sandhu, Arora, and Sharma (2015) compared

buckwheat flour (BWF) biscuits made with and without various gums to white flour (WF)

biscuits. Panelists compared the quality and acceptability of BWF and WF biscuits using

a 9­point hedonic scale, where the score of 1 denoted “extremely disliking” and a score

of 9 denoted “extremely liking.” The results showed that WF biscuits were the most

acceptable when judged on sensory characteristics, whereas BWF biscuits without

gums were the least acceptable. However, biscuits made with BWF and added gums

showed significant improvement in color, appearance, and flavor, making the overall

acceptance of the biscuits made with modified BWF higher than those made with solely

BWF. The scientists attributed the low acceptance of BWF biscuits to the phenolic

compounds in the flour, including rutin, quercetin, and protocatechuic acid, which can

influence taste and color. In addition, the BWF biscuits exhibited different physical

characteristics than WF biscuits, such as lower moisture, decreased thickness, and

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increased fracture strength, which may have also influenced the texture and

acceptability.

Torbica, Hadnadev, and Hadnadev (2012) looked at the effect of using BWF in

cookies. In this experiment, combinations of BWF and rice flour (RF) at three ratios

(90:10, 80:20, and 70:30) were used in gluten­free cookies and then compared to 100%

WF cookies. The results showed that cookies made from BWF had a positive a* value,

indicating a more red color, whereas cookies made from wheat flour had a negative a*

value, indicating a more green color. In addition, BWF­formulated cookies had the

lowest l* value, meaning the darkest overall color, and WF­formulated cookies had the

highest b* value, meaning the most yellow in color. The flavor of gluten­free cookies

made with 10% and 20% BWF scored the highest in acceptability as evaluated by 10

trained panelists using a 9­point hedonic scale, even when compared to WF cookies.

The researchers predict this may have been caused by aromatic polyphenols in BWF,

which may have masked the neutral/bland flavor of the rice flour.

A study from Liu and others (2015) also experimented with substituting white rice

and brown rice flours for wheat flour. Two of the factors that were evaluated included

color, which is an important factor in determining the acceptability of cookies, and

textural properties, which contribute to the eating quality of cookies. The color of the

cookies was measured by using a colorimeter (CR­10, Konica Minolta Sensing Inc.,

Osaka, Japan). Hardness, a textural property, of the baked cookies was measured by

using a texture analyzer (TA­XT2, Stable Micro Systems, Surrey, UK). The color of the

white rice and brown rice cookies appeared similar to that of the wheat cookies, but

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hardness decreased substantially from 2,240 grams in the control wheat cookies to 463

grams with 100% white rice flour and 774 grams with 100% brown rice flour. The

researchers concurred that this softening was primarily due to the reduction of gluten,

as lower amounts of gluten inhibit the formation of the gluten matrices that provide the

hardness and structure of cookies (Liu 2015).

Research from Apotiola and Fashakinly (2013) also evaluated the effects of

using flour blends including wheat, soybean, and yam flour in baking cookies. The

physical tests showed that as the wheat content of the flour used decreased, the protein

content of the cookies increased and the carbohydrate content decreased. In addition,

when the cookies were evaluated on crispiness, color, taste, texture, and overall

acceptability based on a 9­point hedonic scale, the cookies made from a higher content

of wheat flour were most acceptable. The control cookies made entirely from wheat flour

scored the highest for color and overall acceptability, while the cookies made from

mostly wheat flour (80% wheat with only 10% yam flour and 10% soybean flour) scored

the highest for crispiness, taste, and texture. However, in other cookie formulations with

lower wheat flour content and more yam and soybean flour, all of the measures of

acceptability gradually decreased.

Another gluten­free flour substitute, coconut powder, is rich in fiber, vitamins, and

minerals, making it a viable and nutritional substitute. In a study by Dhankar (2013) that

substituted coconut powder for wheat flour in cookies, panelists evaluated the cookies

on a 9­point hedonic scale. Based on ANOVA testing, coconut cookies received an

overall acceptability score of 7.33 ± 0.70, compared to the control wheat cookies that

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received a score of 6.85 ± 0.64 (Dhankar 2013). However, there were many variables

involved in the formulation of the coconut cookies, as Dhankar omitted shortening

because of the high fat content of coconut powder, added egg as a tenderizing agent,

and added gums for binding. These additional modifications to the cookie recipe may

have affected the final product, leading to higher acceptability, and may not be

attainable in an experiment only modifying a single variable.

Millet, a staple grain in Africa, has a high nutritional value and many potential

health benefits. To examine the effects of millet flour on the characteristics of cookies,

Rai and others (2014) compared cookies made with wheat flour with six 50:50 ratio flour

blends of rice/maize, rice/sorghum, rice/pearl millet, maize/sorghum, maize/pearl millet,

and pearl millet/sorghum. Each cookie was then weighed and measured to obtain its

width, thickness, spread ratio, and peak force. In addition, panelists used a 9­point

hedonic scale to assess the cookies’ acceptability. The data was then analyzed with

ANOVA using randomized design. Overall, the gluten­free cookies had a higher

nutritional value than the control cookies, with the pearl millet/sorghum flour blend

cookies having the highest amount of protein and the cookies made with maize flour

having the highest levels of fiber. The panelists found the pearl millet/sorghum flour

blend cookies to have the best texture and flavor, as well as the highest overall

acceptability. In addition, the cookies made from sorghum flour scored high levels of

acceptability, but had a more fragile texture than the wheat cookies and a lower spread

ratio than the rice/maize flour blend cookies. Altogether, the gluten­free cookies were all

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deemed acceptable by the panelists, and the pearl millet/sorghum flour blend cookies

were rated even higher than the wheat­based cookies.

A study by Emmanuel and Sakey (2013) evaluated the effects of millet flour on

sponge cake. They created 11 samples, varying the ratio of wheat and millet flour, to

incrementally decrease the amount of wheat flour and increase the amount of millet

flour. The study used an untrained panel to conduct sensory assessments and use a

9­point hedonic scale to evaluate visual puffiness, appearance and color, smell and

aroma, taste, overall texture, moistness, and overall liking. The panel gave the highest

ranking of appearance and color to the cake made solely from wheat flour, while the

cake made from a blend of 20% wheat and 80% millet flour scored the lowest. There

was no observable pattern in the color rankings, assessed visually by the researchers.

Overall acceptability of the cakes increased as the ratio of wheat flour to that of millet

flour decreased up to the flour made from 60% wheat and 40% millet flour. However,

when more than 40% of the flour was millet flour, the acceptability was lower. The most

preferred product was the sponge cake made from 60% wheat flour and 40% millet

flour, which underscored the fact that the optimum formulation of flours in baked goods

may be a ratio between several types of flours.

Another flour combination of interest arises from a study from Bhaduri (2013), in

which muffins made from combinations of rice and quinoa flour were examined and

compared to muffins made solely with wheat flour. The muffins were tested on physical

properties including hardness, springiness, gumminess, chewiness, and viscosity, as

well as subjective measures, like flavor, appearance, texture, sweetness, and overall

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acceptability, using a 9­point hedonic scale. The study found that muffins made with

100% rice flour and a mixture of 75% rice flour and 25% quinoa flour were most

acceptable due to the low viscosity, light color, and weak flavor of rice flour, which

contributed to an airy texture, pleasing color, and sweet flavor. As the content of quinoa

flour increased to replace rice flour, the resulting muffins became less acceptable, as

quinoa flour exhibited a darker color, bitter taste, and hard, gummy texture.

A study by Man and others (2014) examined also flour combinations that

included rice flour to develop acceptable gluten­free pastries. This study examined the

effects of combinations of maize flour, rice flour, and cornstarch on properties of

pastries, as compared to a control made of wheat flour. The results demonstrated that

the pastry made from a combination of 20% maize flour, 16% rice flour, and 64%

cornstarch had the highest level of acceptability based on a 9­point hedonic scale and

exhibited comparable physicochemical properties, such as thickness, moisture, and

specific gravity, to the control pastry.

Other gluten­free flour combinations of note were tested by Breshears and others

(2013) in a study to assess the acceptability of gluten­free breads made with either

amaranth or Montina™ flour, a dietary staple of Native Americans, compared to a

commercial gluten­free bread. Amaranth or Montina™ flour was substituted at 20% of

the total flour weight in a standardized gluten­free bread recipe that also utilized white

rice flour, potato starch, tapioca starch, soy flour, and guar gum. A 9­point hedonic scale

was used to evaluate appearance, texture, flavor, tenderness, and overall acceptability

among 222 untrained participants, some of whom typically eat a gluten­free diet and

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some of whom have an unrestricted diet. The results showed no significant differences

in acceptability of the amaranth flour gluten­free bread and Montina™ flour gluten­free

bread between both usual gluten­free and unrestricted participants. However, there

were significant differences between the two developed breads (amaranth and

Montina™ flours) compared to the commercial gluten­free bread. The commercial

gluten­free bread was preferred over either developed bread, and the Montina™ flour

bread was preferred over the amaranth flour bread. Researchers also visually evaluated

the color of the breads. The amaranth bread was slightly more yellow compared to the

commercial gluten­free bread, and resembled white bread. The Montina™ bread had

black particles dispersed throughout, making it look like multi­grain bread. While the

nutrient density of the breads made from amaranth and Montina™ flours were higher,

the low overall acceptability of these breads indicate that it may be advantageous to

conduct further research to develop acceptable nutrient­dense gluten­free baked goods.

Objectives

The objective of this experiment was to evaluate the sensory and color

characteristics of gluten­free sugar cookies. The above review examined some of the

positives and negatives of using various flours to make gluten­free baked products.

Because of the information found above, as well as additional informal research via the

Internet and personal experiences with baking gluten­free products, we chose to test

blends of rice flour and almond flour. The control cookies were made with all­purpose

flour, while the variants were made with a 75%­25% blend of rice flour and almond flour

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and a 50%­50% blend of rice flour and almond flour. The color and overall liking was

assessed in a group of 15 untrained individuals.

Hypothesis

The null hypothesis of the experiment stated that there would be no significant

differences in color or consumer acceptance among all variants, including the control.

The alternative hypothesis stated that there would be significant differences in color or

consumer acceptance for all the variants, including the control.

Materials and Methods

All recipe ingredients for the three variants were procured from local grocery

stores. These ingredients are listed in Table 1 of the “Cookie Preparation” section of this

paper. The equipment for both objective evaluation (color) and sensory evaluation were

available in the laboratory, and were used during this experiment. This equipment is

listed in the color and sensory evaluation sections of the Methods, respectively. The

experiment was conducted on May 5, 2015; the entire experiment, with all appropriate

controls and variants, was replicated on May 12, 2015 to obtain a larger pool of data.

A. Cookie Preparation

Refer to Attachment 2 in the Appendix for the adapted recipe with original

measurements and Attachment 4 for Nutrition Label information. All of the

ingredients listed below were converted to grams using ESHA Food Processor

(Version 10.11 ESHA, Salem, OR, USA) from the standard recipe in the

Appendix as Attachment 2. The first step of cookie preparation was to weigh out

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each ingredient for all three variants according to Table 1 (below). The oven was

preheated to 375°F with rack in third position from the top. The dry ingredients,

including the flour or flour mix, baking soda, and baking powder were combined.

In a separate bowl, the butter and sugar were created together. Then, egg and

vanilla were added to the batter and beaten together. The dry ingredients were

added gradually while continuing to mix the batter until they were fully

incorporated. Teaspoons of dough were rolled into balls and put on ungreased

cookie sheets. The cookies then baked in the oven for 8 to 10 minutes, or until

golden. The cookies sat on cookie sheet for two minutes before they were

removed to cool completely on wire racks until they reach room temperature.

Once the cookies were cooled, sensory and objective evaluation tests were

performed.

Table 1: Sugar Cookie Formula

Ingredients (g) All­Purpose White Flour

75/25 Flour Blend (75% Rice Flour,

25% Almond Flour)

50/50 Flour Blend (50% Rice Flour, 50%

Almond Flour)

Control Variant 1 Variant 2

All­Purpose White Flour 220.67 0 0

Rice Flour 0 196.75 135.48

Almond Flour 0 46.49 96.03

Baking Soda 2.95 2.78 2.87

Baking Powder 1.60 1.51 1.56

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Unsalted Butter 145.85 137.17 141.68

White Granulated

Sugar 194.13 182.58 188.58

Large Egg 32.10 30.19 31.18

Pure Vanilla Extract 2.70 2.54 2.62

TOTAL 600.00 600.00 600.00

Objective Evaluation

Color: CIELab color was measured using a Minolta Chroma Meter (Model

CR­410, Konica Minolta Sensing Americas, Inc., Ramsey, NJ, USA), which was

calibrated using a Minolta white calibration plate No. 17333240 for

CR­200/CR­300/CR400 with 2° OBSERVER to measure lightness (L*), red/green (a*),

and yellow/blue (b*) color values. Readings were collected from the center of each

sample. A total of two (2) samples of the cookies were randomly chosen per variant (3).

Sensory Evaluation

Acceptability: Fourteen untrained panelists assessed and recorded the

acceptability of the cookies by selecting a category on a 9­point hedonic scale that

ranged from ‘extreme like’ to ‘extreme dislike’ (Refer to Attachment 1 in the Appendix).

The data helped to evaluate the overall acceptability of the cookie variants.

Statistical Analysis

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An analysis of variance (ANOVA), descriptive statistics, and t­tests were

performed using Microsoft Excel (Microsoft Excel 2011, Version 14.0.2, Redmond, WA

USA) and StatPlus (StatPlus:mac, AnalystSoft, Walnut, CA USA). Data from both

experimental replicants was combined for the analyses.

RESULTS AND DISCUSSION

The results of the consumer acceptance tests and color evaluations are shown

as follows in Table 2.

Table 2: Means ± Standard Deviations (SD) of Sugar Cookie Results for Consumer Acceptance and Color

Variation Hedonic Score1

Color (L*)2 Color (a*)2 Color (b*)2

Control:

All­Purpose Flour

7.33 + 1.75a

74.60 + 1.89a

­0.87 + 0.24a

21.25 + 2.42a

Variant 1 (V1):

75/25 Blend (75% Rice Flour and 25% Almond

Flour)

6.19 + 2.08b

73.76 + 6.47a

­1.42 + 1.46a

19.85 + 2.40a

Variant 2 (V2):

50/50 Blend (50% Rice Flour and 50% Almond

Flour)

6.56 + 1.76b

73.91 + 5.49a

­1.61 + 0.87a

20.71 + 2.63a

1 Means±SD of 2 replicants; 14 judges per variant within replicant one and 13 judges per variant within replicant two. 2 Means±SD of 2 replicants; 2 readings per variant within each replicant. ab Means within the same column with the same letter are not significantly different (p>0.05).

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Sensory Evaluation

A 9­point hedonic scale was used to assess overall acceptability of each type of

cookie. The data collected from the hedonic scale ballots on 05/05/15 and 05/12/15 was

combined in Table 2, which displays the means + SD for each cookie variety. From

these descriptive statistics, we can see that mean acceptability was highest for the

control cookies (7.33 + 1.75) and decreased with the 50/50 blend (6.56 + 1.76) and the

75/25 blend (6.19 + 2.08). Table 2 also indicates whether means between the variants

were significantly different or not—this information was taken from p values from the

paired two­sample t­tests.

ANOVA is used to see whether there are statistical differences between the

means of three or more groups. Based on this analysis (p = 0.08), there was no

significant difference in consumer acceptability when all three sugar cookie varieties

were analyzed together. If this was the only statistical test conducted, we would accept

the null hypothesis (that there are no significant differences between the control and two

variants) for consumer acceptability.

However, further analysis was conducted. Paired two­sample t­tests were

conducted in which the means between only two types of cookies were compared at a

time. The t­test comparing the means of the control cookies and the 75/25 blend as well

as the t­test comparing the means of the control cookies and the 50/50 blend resulted in

p values less than 0.05. This indicated that there was a significant difference in

consumer acceptability between the control and each variant when the variants were

considered separately. However, the t­test comparing the means of the 75/25 blend and

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the 50/50 blend resulted in p>0.05, meaning there was no significant difference in

acceptability between the two variants. The t­test results show that the panel gave

significantly lower scores for both of the variants when compared to just the control

cookies, but the acceptability was not significantly different between the two variants.

Based on the t­tests for consumer acceptability alone, we would reject the null

hypothesis and accept the alternate hypothesis—there were significant differences

between the control and the 75/25 blend as well as between the control and 50/50

blend.

The results from ANOVA, paired t­tests, and previous studies indicate a need for

future testing to determine whether there is truly a difference in consumer acceptability

when substituting various proportions of white rice flour and almond flour for all­purpose

white flour in sugar cookies.

The literature reviewed reveals mixed results for the acceptability of gluten­free

baked products made with rice flour. Results similar to our experiment were found in a

study by Apotiola and Fashakinly (2013), which found that the control cookies made

entirely from wheat flour scored the highest for overall acceptability compared to

gluten­free blends. However, Torbica, Hadnadev, and Hadnadev (2012) found opposite

results. They found that gluten­free cookies made with a 90:10 and 80:20 blend of

buckwheat flour to rice flour scored the highest in acceptability as evaluated by 10

trained panelists using a 9­point hedonic scale, even when compared to WF cookies.

Man and others (2014) also examined flour combinations that included rice flour to

develop acceptable gluten­free pastries. They demonstrated that the pastry made from

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a combination of 20% maize flour, 16% rice flour, and 64% cornstarch had the highest

level of acceptability. Their gluten­free blend that included rice flour ranked higher on

the hedonic scale than white flour recipes.

Thus, the existing literature has mixed conclusions on the acceptability of

gluten­free baked goods made with rice flour—some studies showed that the blends

containing rice flour had higher acceptability compared to non­gluten­free controls, but

other studies demonstrated the opposite. None of the reviewed studies examined the

effects of almond flour on overall acceptability of gluten­free baked goods. However,

these two flours are commonly sold at health­food supermarkets and thus it is

imperative to evaluate their usage in gluten­free baking. Our study, then, sheds light on

the acceptability of these products, although further testing is necessary for conclusive

results.

Measurement of Color

Color measurements were obtained from two randomly chosen sample sugar

cookies of the control cookie and the two variants (V1, the 75/25 flour blend and V2, the

50/50 flour blend). Measurements were taken by placing the Minolta colorimeter over

the top of the middle of the cookie. According to the CIELab Color system, the L* values

measure lightness on a scale from 0­100, with 0 indicating a dark, black color and 100

indicating a light, white color. The control, Variant 1, and Variant 2 had relatively high

average L* values (74.60, 73.75, and 73.91, respectively), which indicates that all

cookies tested exhibit a light color. There were no significant differences (P>0.05) in the

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L* values between any two variants, so we accepted our null hypothesis in terms of

lightness of color.

This finding mirrors the findings from a study by Torbica, Hadnadev, and

Hadnadev (2012), which found that L* values did not differ significantly when measuring

the upper surface of cookies made of wheat flour as compared to cookies made of

varying mixtures of rice and buckwheat flours. Similarly, in research from Bhaduri

(2013), the L* values of muffin crusts did not differ significantly between muffins made

with 100% wheat flour, 100% rice flour, a mixture of 75% rice flour and 25% quinoa

flour, and a mixture of 50% rice flour and 50% quinoa flour. However, research from

Chung et al. (2014) found that L* values of cookies differed significantly when white rice

flour was either fully or partially substituted for wheat flour. In these cookies, the L*

values were larger in the cookies made with white rice flour, indicating that the cookies

were lighter in color than the wheat­based cookies.

When measuring red and green hues, a negative a* value indicates a green

color, while a positive a* value indicates a red color. The mean a* values of the control,

Variant 1, and Variant 2 were all negative (­0.87, ­1.41, and ­1.61, respectively),

therefore indicating a slightly green color. There were no significant differences (P>0.05)

in the a* values between any two variants, so we accepted our null hypothesis in terms

of the green/red hue.

This data on a* values aligns with the findings from Bhaduri (2013) on muffin

crusts, as the a* values did not differ significantly in muffins made of 100% wheat flour

and 100% rice flour muffins, although this was not true in some of the muffins made with

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combinations of rice and quinoa flour. The study from Chung et al. did find significant

variations in the a* values between cookies made of 100% wheat flour and 100% white

rice flour. However, some of the cookies made of a combination of white rice and wheat

flour did not have a significantly different a* value compared to the 100% wheat cookies.

In both of the aforementioned studies, any significant differences showed that the baked

goods made with wheat flour had lower a* values than the gluten­free versions,

indicating that the wheat products were more green in color. Research from Torbica,

Hadnadev, and Hadnadev (2012) also found significant differences in a* values when

looking at the upper surface of cookies made with combinations of rice and buckwheat

flour as compared to wheat flour. Yet, the cookies made with buckwheat and rice flour

had smaller a* values than the wheat cookies, indicating that the gluten­free cookies

were more green in this case.

When measuring blue and yellow hues, a negative b* value indicates a blue

color, while a positive b* value indicates a yellow color. The mean b* values of the

control, Variant 1, and Variant 2 were all positive (21.25, 19.84, and 20.71, respectively)

thus indicating that all cookies are yellow in color. There were no significant differences

(P>0.05) in the b* values between any two variants, so we accepted our null hypothesis

in terms of the blue/yellow hue. In summary, the control and two variations of sugar

cookies were light in tonal quality, while mildly green and very yellow in terms of hue.

Research findings show much more significant differences in b* values than was

found in our study. The study by Bhaduri (2013) showed that the b* values of muffin

crusts did not vary significantly between muffins made of wheat flour, 100% quinoa

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flour, and 50% quinoa flour and 50% rice flour. The muffins made with 100% rice flour

had a significantly larger b* value, indicating that these muffins appeared more yellow in

color. In contrast, the research from Chung et al. found that cookies made with 100%

wheat flour had higher b* values than cookies made with 100% white rice flour.

However, if the rice flour was mixed with wheat flour at all (even 30% wheat flour and

70% white rice flour), there were no significant variations in the b* values between

cookies made of 100% wheat flour and cookies made with mixtures of wheat and white

rice flour. The study from Torbica, Hadnadev, and Hadnadev (2012) also showed

significant differences in b* values when looking at the upper surface of gluten­free and

wheat­based cookies, as all cookies made from combinations of rice and buckwheat

flour had significantly smaller b* values than the wheat cookies, indicating that the

wheat cookies were more yellow.

Nutrition Information

Table 3: Nutrition Facts for the Variations of Sugar Cookies

The ESHA analysis (Table 3) listed above demonstrates the nutritional

information for the control sugar cookie and the two variants. It shows that the control

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shares more similarities with Variant 1 than Variant 2 in terms of calorie amount, total

fat, total carbohydrate, fiber, sugar, and protein content. There is a difference of only 10

calories and 1 gram of fat between the control and Variant 1. Additionally, the control

has an additional 1 gram of sugar compared to Variant 1. Variant 2, on the other hand,

has the same caloric content as Variant 1, but with a 2 gram disparity in both total fat

and total carbohydrate content, as well as a 1 gram difference in fiber. Variant 2 also

had 1 more gram of protein than the control cookie. This clearly demonstrates that when

creating a gluten­free sugar cookie, the product is extremely similar in nutritional value

to that of a regular wheat­flour sugar cookie. However, when examining small

differences, the flour ratio of 75% rice flour and 25% almond flour is slightly nutritionally

superior to a cookie made with 50% almond flour and 50% rice flour.

CONCLUSION AND FUTURE WORK

The growing prevalence of people suffering from celiac disease and gluten

intolerance along with novel research showing the detrimental effects of gluten proteins

on various body systems will ensure that gluten­free products will remain a popular food

movement despite a decrease in the number of people who associate gluten­free with

health. This is why continued research into gluten­free products should continue despite

the many challenges gluten free baking poses for technologists and nutritionists.

In addition to an all­purpose flour control sugar cookie, two gluten­free sugar

cookie products were developed through the course of this experiment: one made with

75% rice flour and 25% almond flour and the other made with 50% rice flour and 50%

almond flour. A 9­point hedonic scale was utilized to assess consumer acceptability,

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and analysis demonstrated that while no significant difference was seen when all three

cookie types were considered together, when considered in paired t­test there were

significant differences between the control and 75/25 cookies as well as the control and

50/50 cookies. According to the paired t­test analysis, we reject the null and accept the

alternate hypothesis—there was a significant difference in consumer acceptance

between the control and each variant when considered separately (the consumers liked

the control more than either variant). A Minolta colorimeter was used to assess color;

the cookies were light in tone, mildly green, and markedly yellow. Statistical analyses

showed that there were no significant differences in any of the color values, so the null

hypothesis was accepted in terms of color data.

Our gluten­free sugar cookie formulations using various ratios of rice flour and

almond flour produced products that, although similar in color to the control cookies,

were slightly less liked by the consumer panel compared to the control cookies. The

nutritional content of all three variants are comparable. Thus, improving the acceptability

of these gluten­free alternatives is the primary aim of further work. This study only

manipulated the type of flour blend used and all other variables and ingredients were

left constant. There are limitations to this approach which are discussed below.

Our preliminary study in developing a novel gluten free sugar cookie using

blends of rice and almond flour had several flaws which would need to be addressed in

order to improve validity and accuracy of results. Various testing protocols conducted

did not comply with food industry standards for sensory evaluation. Among these was

the application of the 9­point­hedonic scale for customer acceptance of our cookie

FINAL REPORT 23

variants. Our testing protocol utilized subjects repeatedly over several trials which in

turn “trained” the panelists not only in the testing protocol but also allowed them to

associate physical cues such as thickness, color, brittleness and size with the different

cookie variants. This may have influenced the sensory evaluation and consumer

preference values. Future work should utilize a large population of untrained panelists.

Another issue which needs to be addressed is variations in cookie size. Due to

the physical properties of gluten in the physical shape of cookies, gluten free alternates

often have a greater spread. Left uncontrolled, tested variants of cookies may have

different shapes and sizes which may also influence sensory evaluation. In the future,

cookie size should be a controlled variable.

Future studies should also utilize a testing environment that complies with The

American Society for Testing and Materials: Sensory Evaluation testing protocols.

These include enforcing an environment whereby panelists may not interact or

communicate with one another. In addition, samples to be evaluated should be

prepared away from the testing area to avoid possible aroma or visual cues from

influencing the participants.

Finally, additional recipe modification maybe necessary to accommodate for the

lack of gluten proteins in GF baked products. Other publications have noted increased

consumer acceptance when gums and starches were added to the GF flour products as

these carbohydrates aid in the structural lattice of the baked product, providing a texture

and mouthfeel more similar to products containing gluten. Future modifications should

include the incorporation gums and starches into gluten­free sugar cookies.

FINAL REPORT 24

References

AllRecipes.com. Easy Sugar Cookies. Available from:

http://allrecipes.com/recipe/easy­sugar­cookies/. Accessed April 15, 2015.

Apotiola ZO, Fashakinly JF. 2013. Evaluation of Cookies from (Wheat, Yam, and

Soybean) Blend. Food Sci Qual Management 14: 11­16. Available from:

http://www.iiste.org/Journals/index.php/FSQM/article/view/5159. Accessed 2015

April 17. *Alyssa Snow Callahan

Bhaduri S. 2013. A Comprehensive Study on Physical Properties of Two Gluten­Free

Flour­Fortified Muffins. J Food Process Technol 7(4):251. doi:

10.4172/2157­7110.1000251. *Alyssa Snow Callahan

Breshears KL, Crowe KM. 2013. Sensory and Textural Evaluation of Gluten­Free Bread

Substituted With Amaranth and Montina™ Flour. Journal of Food Research 2(4):

1927­0895. doi: 10.5539/jfr.v2n4pl. *Leanna Tu

Chung, H. J., Cho, A. Lim, S. 2014. Utilization of germinated and heat­moisture treated

brown rices in sugar­snap cookies. LWT ­ Food Science and Technology 57

(2014) 260e266. http://dx.doi:10.1016/j.lwt.2014.01.018. *Christina Fasulo

Dhankhar, P., 2013. A Study on Development of Coconut Based Gluten Free Cookies.

International Journal of Engineering Science Invention ISSN (Online): 2319 –

6734, 2 (12),10­19. Available from:

http://www.ijesi.org/papers/Vol%202%2812%29/Version­1/B021201010019.pdf.

Accessed 2015 April 16. *Christina Fasulo

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Emmanuel K, Sakey AS. 2013. Nutritional and Sensory Analysis of Millet Based Sponge

Cake. International Journal of Nutrition and Food Sciences 2(6): 287­293. doi:

10.11648/j.ijnfs.20130206.14. *Leanna Tu

Kaur, M., Sandhu, K., Arora, A., & Sharma, A. 2011. Gluten free biscuits prepared from

buckwheat flour by incorporation of various gums: Physicochemical and sensory

properties. LWT ­ Food Science and Technology, 62, 628­632.

doi:10.1016/j.Jwt.2014.02.039. *Charles Stull

Man S, Paucean A, Muste S, and Pop A. 2014. Studies on the Preparation of Aglutenic

Foam Type of Pastry Product Using Different Flour Combinations. Bulletin

UASVM Food Science and Technology 71(2): 217­218. doi:

10.15835/buasvmcn­fst:10798. *Cory Ruth

Rai S, Kaur A, Singh B. 2014. Quality Characteristics of Gluten Free Cookies Prepared

from Different Flour Combinations. J Food Sci 51(4): 785­789. doi:

10.1007/s13197­011­0547­1. *Cory Ruth

Sloan, E.A. 2015. The Top Ten Food Trends. Food Technology 69(4): 24­40.

Torbica, A., Hadnadev, M., & Hadnadev, T. 2012. Rice and Buckwheat flour

characterization and it's relation to cookie quality. Food Research International,

48, 277­283. doi:10.1016/j.foodres.2012.05.01. *Charles Stull

Appendix Attachment 1: Scorecard

ACCEPTABILITY TEST FOR GLUTEN­FREE SUGAR COOKIES

FINAL REPORT 26

You may rinse your mouth with water at any time during the test if you need to. Please taste the samples according to the 3­digit random code provided on the samples and the ballot. You may not go back and re­taste the samples. No talking during sensory testing. Check the box that best describes your overall opinion of each sample

3­Digit Sample Numbers

________

________

________

(9) LIKE EXTREMELY

(8) LIKE VERY MUCH

(7) LIKE MODERATELY

(6) LIKE SLIGHTLY

(5) NEITHER LIKE NOR DISLIKE

(4) DISLIKE SLIGHTLY

(3) DISLIKE MODERATELY

(2) DISLIKE VERY MUCH

(1) DISLIKE EXTREMELY

FINAL REPORT 27

Appendix Attachment 2: Original Recipe Ingredients: 2 3/4 cups all­purpose flour 1 teaspoon baking soda 1/2 teaspoon baking powder 1 cup unsalted butter, softened 1 1/2 cups white granulated sugar 1 egg 1 teaspoon pure vanilla extract Directions:

Preheat oven to 375 degrees F (190 degrees C). In a small bowl, stir together

flour, baking soda, and baking powder. Set aside.

In a large bowl, cream together the butter and sugar until smooth. Beat in egg

and vanilla. Gradually blend in the dry ingredients. Roll rounded teaspoonfuls of dough

into balls, and place onto ungreased cookie sheets.

Bake 8 to 10 minutes in the preheated oven, or until golden. Let stand on cookie

sheet two minutes before removing to cool on wire racks.

Makes 4 dozen.

This recipe was adapted from “Easy Sugar Cookies” which can be accessed at

AllRecipes.com. Easy Sugar Cookies. Available from:

http://allrecipes.com/recipe/easy­sugar­cookies/. Accessed April 15, 2015.

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Appendix Attachment 3: Budgetary Estimate

The budget is summarized below in Table II.

Table II: Estimating Totals for Cookie Budget and Amounts for Market Order

Ingredients Total Amounts Needed Amount (g)

Cost per ingredient per team ($)

All­Purpose White Flour

220.67 0.72

Rice Flour 332.23 3.18

Almond Flour 142.52 5.87

Baking Soda 8.60 0.02

Baking Powder 4.67 0.12

Unsalted Butter 424.70 7.17

White Granulated Sugar

565.29 1.83

Large Egg 93.47 1.43

Pure Vanilla Extract

7.86 0.31

Total 20.34

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Appendix Attachment 4: Nutrition Labels

Control

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75/25 Flour Blend

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50/50 Flour Blend