RESEARCH
Department of Nutrition and Exercise Science
Bastyr University, December 4, 2012
Nutrition Differences and Customer Preference of Granola Bars
Prepared with Coconut Oil and Whole Eggs Compared to Safflower
Oil and Egg Whites
Ellen Freeman, Christy Goff, Cheryl Quinn, Danielle Taylor
ABSTRACT
The objective of this study was to develop and analyze a granola bar made with whole eggs and coconut
oil (experimental bar) compared to a granola bar made with egg whites and safflower oil (control bar) to
determine if a granola bar’s nutritional profile could be enhanced while maintaining consumer
acceptance. Nutrition analysis and consumer sensory score cards were used to compare the two bars
nutrition profile and consumer perception of flavor, texture, mouth feel, preference, and likelihood of
purchasing. Nutrition analysis of the two bars revealed that the experimental bar contained more
saturated fat, vitamin B12, folate, lutein and zeaxanthin but less vitamin E than the control bar. There
was no significant difference between the experimental and control bars in terms of flavor, texture, mouth
feel, preference or likelihood of purchasing. The results indicate that a granola bar could be developed
using whole eggs and coconut oil enhancing the nutrition profile, increasing the digestibility due to
medium chain triglycerides (MCT), and having an inverse relationship between consumption and
coronary heart disease while maintaining consumer acceptance and likelihood of purchasing compared to
a granola bar made with egg whites and safflower oil.
INTRODUCTION
High serum cholesterol levels have been
associated with increased risk of cardiovascular
disease (CVD) leading some health care
professionals to advise patients to limit their
consumption of eggs, a food high in dietary
cholesterol [1]. Although eggs, particularly egg
yolks, contain on average 185 mg of dietary
cholesterol, the change in serum cholesterol levels
depends on if an individual is a normal responder,
hypo-responder, or hyper-responder to dietary
cholesterol [2, 3]. If the person is a normal
responder, a 100 mg/d increase in dietary
cholesterol will only increase total cholesterol by
about 1% or 2.2 mg/dL. A hypo-responder would
have an increase in total cholesterol of less than
2.0 mg/dL while a hyper-responder would have an
increase in total cholesterol of more than 2.2
mg/dL. In addition to cholesterol, eggs also
contain vitamin E, vitamin B12, folate, and the
carotenoids lutein and zeaxanthin. On average it
is estimated that each egg yolk contains 292 g of
lutein, 213 g of zeaxanthin, 0.7 mg of vitamin E,
0.5 g of vitamin B12, and 23.5 g of folate [3].
Lutein and zeaxanthin filter high-energy blue
wavelengths of light and are antioxidants in the
eye. The amount of lutein and zeaxanthin in the
retina can be measured and it has been discovered
that an inverse relationship exists between the
density of the compounds in the retina and the risk
of age-related macular degeneration (AMD) and
cataracts [4]. Due to the other nutrients found in
eggs, specifically egg yolks, it has been suggested
that the benefits outweigh the potential adverse
effects from the dietary cholesterol [1].
Saturated fats, due to their influence on
cholesterol levels, have also been associated with
an increased risk of CVD [5]. Although an
association between saturated fats and increased
risk of CVD has been established, not all saturated
fats in foods are chemically equivalent. For
example, both animal products and coconut oil
contain saturated fats; however, animal products
contain mainly long chain fatty acids (LCFA)
which join together to form long chain
triglycerides (LCT) while coconut oil contains
medium chain fatty acids (MCFA) which join
together to form medium chain triglycerides
(MCT). The MCT are processed differently in the
body than LCT. Due to their smaller size, MCT
require fewer digestive enzymes to be broken
down into MCFA. The MCFA uniquely are
absorbed directly into the portal vein from the
intestines and travel to the liver to be used as fuel
for the body [6]. Due to the increased digestibility
of the MCT, they are used in the treatment of
absorptive
disorders
including
diarrhea,
steatorrhea, celiac disease, liver disease, and are
included in total perenteral nutrition (TPN) [7].
Clinical studies have shown that coconut oil,
although high in saturated fat, does not cause an
increase in cholesterol levels and can increase the
high density lipoproteins (HDL) overall reducing
the risk of coronary heart disease [8].
Due to the discussed benefits of whole eggs,
including the yolk, and coconut oil above, an
experiment was conducted to determine if an
energy bar could be made with both ingredients to
increase the bar’s nutritional profile while
maintaining or improving consumer acceptability
compared to a control energy bar. It was
hypothesized
that
an experimental
bar
manufactured with both whole eggs and coconut
oil would have an increased nutrition profile
evident by nutrition analysis, receive equal
sensory analysis scores for flavor, texture, and
mouth feel, and receive equal or increased
customer preference and likelihood of purchase
scores compared to a control bar.
The
independent variable of the experiment is the
energy bar with two conditions: the experimental
bar and the control bar, while the dependent
variable of the experiment is the consumer
evaluation of flavor, texture, mouth feel,
preference, and chance of purchasing the
experimental bar compared to the control bar. The
intention of the experiment was to determine if a
bar can be made more nutritional but still be as
acceptable to the consumer in flavor, texture,
mouth feel, preference, and likelihood of
purchasing compared to the control product. It
was predicted that by substituting coconut oil for
safflower oil and whole eggs for egg whites the
experimental bar will be higher in vitamin E,
vitamin B12, folate, lutein, and zeaxanthin, the
sensory analysis scores of flavor, texture, and
mouth feel would be similar between the two bars,
and the consumer preference and likelihood of
purchasing would be similar or improved
compared to the control bar.
METHODS
In order to accurately test the hypothesis, the
baking of the bars and the preference testing
followed a very specific sequence of steps and
was designed to ensure the least amount of bias
and/or error. In order to do this, one researcher
was chosen to bake both bars so that technique of
measuring, mixing and cutting were analogously
applied between the two variations. Then, the
control recipe was modified to include the health
promoting ingredients. Coconut oil was directly
substituted for safflower oil and 4 whole eggs for
5 egg whites respectively. The materials used
along with the control recipe and test recipe
modifications are shown in Table 1.
Once the recipe had been appropriately modified,
each step was strictly followed with similar
technique for both variations. Although the
researcher was not blinded to the identity of the
experimental bar when preparing the ingredients,
there were no incentives to the baker for making
one more palatable than the other. Therefore, the
only modification made was the substitution of
ingredients. All steps of baking are outlined in
table 1 as well. Upon completion of cutting and
properly storing the bars overnight, a qualitative
sensory analysis was performed by subjects who
attend Bastyr University as they passed by a table
offering the bar samples outside the University
Cafeteria.
BASTYR UNIVERSITY, FOOD SCIENCE BAR PROJECT 2
Table 1. The control recipe and test recipe modifications
BASIC Energy Bar Materials and Recipe
(Experimental bar modifications indicated in red and in parenthesis)
Ingredients
o
o
o
o
o
o
o
o
o
o
o
1 pound rolled oats
1 cup shredded, unsweetened coconut
1/2 cup sliced toasted almonds
2 tablespoons toasted sesame seeds
1/2 teaspoon coarse salt
1/2 cup golden raisins
1/2 cup dried cranberries
1/2 cup safflower oil (1/2 cup melted coconut oil)
2/3 cup honey
1 teaspoon pure vanilla extract
5 egg whites (4 whole eggs)
Directions
1. Preheat oven to 350 degrees with rack in center position. Line a 9-by-13-inch baking dish with
parchment and lightly oil.
2. In a large bowl, toss together the oats, coconut, almonds, sesame seeds, salt, and dried fruit.
Separately whisk together the oil (coconut oil), honey, 1/3 cup water, vanilla, and egg whites
(eggs); stir into the oat mixture.
3. Spread the granola in the baking dish and pack firmly. Bake for one hour, or until golden on top
and along the edges. Cool completely. * Both bars were removed from the oven at 53 minutes
4. Remove cooled granola to a cutting board. Cut in half lengthwise, and then cut crosswise into 1
1/2-inch-wide bars. Store in an airtight container.
Recipe from Martha Stewart Living
The scorecards shown below in Table 2 were
filled out by 25 randomly selected participants
who willing chose to participate and were either
students or faculty of the institution. None of the
participants were screened for tasting deficits,
health concerns, or lifestyle standards. Once the
scorecards were completed by 25 participants,
they were analyzed by a fellow researcher blinded
to which scorecards correlated with which bar as
well as the methods of the bar preparation.
The intention in using the following 5 sensory
analysis factors was to thoroughly assess the
palatability of a potentially healthier energy bar
compared to the control bar. Although our
preference testing participants were not
necessarily trained in sensory analysis taste
testing, many had presumably tasted a variety of
other energy bars and were well accustomed to
what flavors and textures would compel them to
buy another. Testing the bars among a population
that utilizes energy bars frequently was therefore
optimal for gaining insight into the marketability
of the new product.
As shown below, the score card tests 5 categories
of sensory characteristics upon a continuum of 9.
This structure of the scorecard was valuable in
determining the significance of the difference
between the two bars. Since customer acceptance
was the driving factor in formulating the
experimental bars, the scorecard was also tailored
to thoroughly evaluate whether or not the texture,
flavor and mouth feel were well tolerated enough
to warrant a purchase. The scorecard was filled
out for each tasted bar, requiring 2 scorecards per
panelist. The only difference in labeling between
the two was merely the color of the bar wrapper.
BASTYR UNIVERSITY, FOOD SCIENCE BAR PROJECT 3
Table 2. Example scorecard for energy bar
Continuum from 1-9
Variable
Flavor
Bland
1
8
Extremely
Sweet
9
8
Tough/hard
Crumbly
9
Mildly
Sweet
2
3
4
6
7
5
Texture
Light/Fluffy/Tender
1
Mouth
feel
Oily
Preference
LOVE IT
1
1
Chance of
Buying
I’m heading to
store now!
1
Chewy
2
3
4
5
6
7
Dry
Gritty
5
2
3
4
6
7
8
Dislike
Like it
2
3
4
5
6
7
8
9
8
I’d never pay
for this…
9
I might buy
2
3
4
5
9
6
7
RESULTS
Subjects were asked to use a hedonic scale of 1 to
9 points to assess their sensory perceptions,
preference, and chance of buying for each sample.
The resulting 25 scores of each sensory
characteristic for each bar were recorded. The
means and standard deviations for each
characteristic are presented in Table 3.
Table 3, all the means fell within the 4-6, equating
a moderate preference for the sensory
characteristics of the bars.
Although not
significant, the means were slightly higher in the
control bar than the experimental bar as shown in
Figure 1.
Statistical Analysis
A two-tailed related samples t-test of 25 samples
was used to calculate the significance of each
independent sensory score of customer
perceptions between the experimental and control
bar. Analysis of statistics were applied using a
minimum significant different test of alpha <0.05.
The resulting p-values determined that the two
bars were not significant in flavor, texture, mouth
feel, preference or chance of buying. As seen in
In addition, the nutritional profile was calculated
for each bar using the Self Nutrition Data database
to determine which bar contained more beneficial
nutrients. Information from Self Nutrition Data's
database comes from the USDA's National
Nutrient Database for Standard Reference [9]. The
experimental bar had more fat (14g vs. 10g),
protein (9g vs. 5g), lutein and zeaxanthin (1.2mcg
vs. 0.8mcg), vitamin B12 (0.5mcg vs. 0mcg) and
folate (30.7mcg vs. 12.7mcg) than the control bar
as seen in Table 4.
BASTYR UNIVERSITY, FOOD SCIENCE BAR PROJECT 4
Table 3: Mean, standard deviation, and p-values of the overall sensory characteristics in each bar on a
preference scale of 1-9, using a two-tailed related samples t-test.
Control Bar
Altered Bar B P-value (alpha <0.05)
A
Flavor
4.56 (1.55)
4.52 (1.29)
0.922
Texture
5.44 (1.42)
5.12 (1.51)
0.200
Mouth feel
5.08 (1.68)
4.72 (1.51)
0.185
Preference
4.72 (1.88)
4.56 (1.96)
0.701
Chance of buying
5.12 (1.83)
4.64 (2.10)
0.218
Figure 1: The means of each sensory characteristic for the control bar (blue) and the experimental bar
(red). All the means fell between 4-6 on the sensory continuum
Average means of sensory characteristics in the
control and experimental bars
6
5
4
3
2
1
0
Control Bar
Experimental bar
Table 4: Nutrition comparison of the control and experimental bar calculated in Self Nutrition Data
database [9]
Serving Size
Total Fat
Saturated Fat
Monounsaturated
Polyunsaturated
Trans fat
Cholesterol
Total Carbohydrate
Protein
Vitamin E
B12
Lutein & Zeaxanthin
Folate
Control Bar
66g
10g
2.8g
2.2g
4.2g
0g
0mg
28g
5g
2.3mcg
0mcg
.8mcg
12.7mcg
Experimental Bar
66g
14g
7g
3.3g
1.6g
0g
164mg
29g
9g
1.2mcg
.5mcg
130mcg
30.7mcg
BASTYR UNIVERSITY, FOOD SCIENCE BAR PROJECT 5
CONCLUSIONS
This study demonstrated that a granola bar made
with whole eggs and coconut oil (experimental
bar) compared to a granola bar made with egg
whites and safflower oil (control bar) could
increase digestibility and nutritional content
without any difference in customer perception in
flavor, texture, mouth feel, preference or
likelihood of purchasing. The null hypothesis was
retained indicating there was no significant
difference in the mean values of customer
perception in flavor, texture, mouth feel,
preference or likelihood of purchasing between
the two bars, confirming the testers hypothesis. It
was predicted that by substituting coconut oil for
safflower oil and whole eggs for egg whites that
the experimental bar would be higher in
nutritional value, specifically for vitamin E,
vitamin B12, folate, lutein, and zeaxanthin.
Nutritional analysis confirmed that the
experimental bar created contained higher levels
of vitamin B12, folate, lutein and zeaxanthin,
however the level of vitamin E decreased (Table
4). As a trade off for the higher level of these
vitamins and minerals, the levels of saturated fat
and cholesterol were higher in the experimental
bars due to the use of whole eggs and coconut oil
as compared to safflower oil and egg whites.
The results of this study indicate that the snack
market could offer a granola bar naturally higher
in vitamin B12, folate, lutein and zeaxanthin that a
customer is equally likely to buy without a
difference in perception of flavor, texture, mouth
feel or preference. Although research indicates
that lutein and zeaxanthin are antioxidants for the
eye and higher densities of these may be inversely
related to the risk of age related macular
degeneration and cataracts [3,4], the Institute of
Medicine has determined that, at this time, this
evidence is not strong enough to conclude the
impact these nutrients may have on chronic
disease. The results observed in carotenoid
studies may be due to other substances found in
carotenoid rich food, or to other consumption and
behaviors that may be associated with the
increased consumption of such nutrients [10].
The use of coconut oil and whole eggs also
resulted in a higher saturated fat content, which
may be a concern to consumers due to previous
popular information relating saturated fat to an
increased risk of heart disease. Contrary to this
thought, a 20 year follow up of The Nurses’
Health Study of 121,000 women comparing the
calorie for calorie energy obtained from saturated
fat as compared to carbohydrates indicated that
saturated fat was non-significant in relation to the
risk of developing coronary heart disease (CHD)
and that trans-fat was most strongly related to a
greater risk of CHD [11].
Possible errors that may have been introduced into
this experiment include bias due to the origin of
the population of testers. It is conceivable that the
population of Bastyr students may not adequately
represent the population of potential consumers of
granola bars. In addition, the students and facility
testing the bars were selected by who walked by
the table at the time of sampling and therefore was
not optimally randomized. As a result, the
participants may not have represented the
university population thus skewing the results.
Another factor affecting the results was that the
sample size of 25 was relatively small. A larger
sample size would have increased the power of
the experiment minimizing the probability of
accepting the null hypothesis when it was indeed
false.
Further steps for continuing investigation could
include experimenting with the quantity of eggs
and coconut milk in the bars as well as the
cooking times and temperatures with the objective
of creating a bar with higher levels of carotenoids
that would be preferred over the control bar. The
addition of carotenoid containing powdered
greens could also be considered for bar additions.
In addition to the study of nutrient content and
customer preference, the cost of creating a more
nutrient dense product would also require market
study.
BASTYR UNIVERSITY, FOOD SCIENCE BAR PROJECT 6
References
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%20CHAIN%20TRIGLYCERIDES%20%28MCTs%29. Accessed November 28, 2012.
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2012.
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10. Oh K, Hu FB, Manson JE, et al. Dietary fat intake and risk of coronary heart disease in women: 20 years of follow-up of the nurses’
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11. Institute of Medicine. DRI dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. National Academy Press
Washington, D.C. website. http://books.nap.edu/openbook.php?record_id=9810&page=R1. 2000;325-382. Accessed November 29,
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BASTYR UNIVERSITY, FOOD SCIENCE BAR PROJECT 7