The Effects of Adding
Omega-3 Fatty Acids on the
Texture and Taste of
Chocolate Chip Cookies
Vindriani Lukito and Alexandra Arges
FN 453
Abstract:
Heart disease is on the rise, and omega-3 fatty acids are being promoted to help
increase HDL levels and lower one’s risk for cardiovascular disease. The aspiration was
to create a product that tasted delicious, but also helped consumers incorporate more
omega-3 fatty acids into their diet. Strawberry-flavored fish oil was infused into a
chocolate chip cookie. Then, the color, texture, and taste of the cookie were analyzed in
order to find the best amount of fish oil to add to a cookie without sacrificing palatability.
Four batches of cookies were made using the Toll House cookie recipe. Groups included
a control and groups with 10, 20, and 30 grams of fish oil added to the batter. Methods of
analysis included the Texture Analyzer, Hunter Colorimeter, and sensory evaluation
performed by untrained panelists. Texture analysis results showed an increase in hardness
at 10 grams compared with the control group, but a decrease in hardness when more oil
was added. Using the Hunter Colorimeter, a negative correlation between amounts of oil
added and lightness was found. Data collected from our sensory panelists found the
control group to be the softest cookie at a quantity of 3.14 out of 8 on a hardness scale.
Not surprisingly, they also found the control to be the sample they preferred. The control
group was preferred 100% over all of the other cookies. From the experimental groups,
the addition of 10 grams of fish oil to the cookies was the top choice. The experiment
found adding 10 grams of fish oil would be the best way to incorporate omega-3 fatty
acids into a common food without sacrificing palatability while also contributing to the
nutritional value of the food and the health of the consumer.
Introduction:
The main reason for conducting this experiment is that Americans have high rates
of heart disease, which can be lessened by incorporating more omega-3 fatty acids into
their diet. Americans consume a lot of fat, but not the right kind. According to Wolfson
in Technology Review (Wolfson 2004), adding docosahexaenoic acid (DHA) and
eicosapentaenoic acid (EPA) to foods can cleanse arteries. Omega-3 fatty acids are
essential nutrients, and the body cannot make them. Animal sources such as fish contain
both DHA and EPA, while plant sources only contain alpha-linolenic acid (ALA) and
must be converted to EPA and DHA before it can work its omega-3 magic. Therefore,
consumers must obtain them from food. Researchers have known about the vital role that
omega-3 fatty acids have in brain and retina development for a while. However, today,
they have been linked to help treat arthritis, colon and breast cancer, heart disease,
macular degeneration, depression, behavioral problems, and even Alzheimer’s disease
(Gatehouse 2009). The claims that omega-3 fatty acids might reduce depression and
behavioral problems come from the idea that a deficiency in omega-3 fatty acids might
inhibit transport of hormones, neurotransmitters, and nutrients across neurons (Gatehouse
2009). Furthermore, a study in the American Journal of Clinical Nutrition found that a
deficiency in omega-3 fatty acids contributed to 20.8% of all male mortality, and 32.5%
of female deaths. The lack of omega-3 was also associated with 28.4 % homicides, 27%
cardiovascular death, 65.5% postpartum depression, 98.5% depression, and 99.9% of
bipolar disorders (Gatehouse 2009).
Thus, the lack of consumption of omega-3 fatty acids must be compensated
somewhere. By adding this fat to cookies, a commonly consumed food, the health of
society might improve. According to the International Food Information Council, new
food and beverage products with omega-3 fatty acids added have come into the food
market because of the overwhelming health benefits associated with these fats. Examples
of foods that have added omega-3’s include salad dressings, sauces, baked good, cereals,
and baby food (IFIC 2008). Another way the food industry has tried to add more omega-3
fatty acids into food products is through injecting it into animal feed, so that their tissues
become enriched with the fat (IFIC 2008). The Food Industry is doing this because they
know how lucrative “health” products are for business. If they can get the consumer to
think buying their product will improve their health, the consumer is more willing to
spend money on food rather than medicine. Making a healthier cookie could help those
who like to eat cookies, although there is otherwise little nutritional value to them.
According to research conducted by Dr. Ye at the Riddet Institute, adding fish oil
to processed cheese as compared to adding fish oil to a non-milk product allowed for less
oxidation. However, the newly fortified processed cheese still had a fishy taste. It was
found that making an emulsion with the milk and fatty acids allowed for better
fortification of omega-3 fatty acids (Ye 1093). This research shows that addition of fish
oil might not be favorable on the sensory level. Eating a healthy cookie would be ideal, as
long as it still tastes and feels like eating a cookie. Perhaps, emulsifying the fish oil with a
dairy product will help incorporate it better into the final product. According to the effect
of fatty acid addition on texture of the cheese, there were no changes in storage methods
or melt properties. This could have been due to the small droplets of fish oil added (Ye
1095).
It is important that the color, amount of chocolate chips, and the time of cookies
in oven be consistent. There should not be any other variables to play a part in the
experiment other than the amounts of fish oil. The Toll House Cookie recipe makes a
consistently uniformly textured cookie. Emulsifying cheese with fish oil has shown little
effect on the texture of the product (Ye 1093). While cheese and cookies are not the same
food, the hope is that adding fish oil will not change the texture of the cookie
dramatically. In order to find the right amount and effects of fish oil on chocolate chip
cookies, texture analysis, color analysis, and a sensory evaluation were conducted on
cookies with 10, 20, and 30 grams of added fish oil. The amount of oil added was the
independent variable, while texture, color, and sensory evaluation were the dependent
variables. The goal was to explore the effects of adding fish oil to cookies to create a
tasty product that had more nutritional value.
Methods:
The recipe used for this experiment was the Nestle Toll House Cookie recipe, in
which varying amounts of strawberry-flavored fish oil was added. The entire list of
ingredients for each batch can be found in Table 1 in the results section. First, flour,
baking soda, and salt will be combined in a small bowl. Next, butter, granulated sugar,
brown sugar, fish oil, and vanilla are beaten in a larger bowl or mixer. Each egg is added,
one at a time, beating the mixture after each addition. Then, the flour mixture is beaten in
for approximately three to five minutes or until a homogenous mixture. Finally, we add
chocolate chips to create a heterogeneous mixture. This recipe will be repeated four
times, for the control group and treatments 1-3, adding 0 grams of strawberry-flavored
fish oil, and then 10, 20, and 30 grams. After dropping teaspoons of dough on a pan, the
cookies will be baked in preheated 190.55 degrees Celsius for nine to eleven minutes or
until golden brown. They will be cooled on wire racks for approximately three minutes.
When making each batch of cookies, the temperature of the butter, eggs, and other
ingredients will be kept identical. Furthermore, the time spent beating the mixture making
it a homogenous mixture must be the same. Last, the size of the cookie must be kept
uniform so one cannot tell the difference between different batches. After the cookies
cooled, they were separated and analyzed by the Texture Analyzer, Hunter Colorimeter,
and a sensory panel. The objective tests were conducted repeated, three times on the same
day for three trials, while the sensory panel was conducted for three trials, trying to get as
many people as possible to take the sensory evaluation. Cookies were placed on white
paper plates with their identity concealed on the back of the paper plate. Panelists were
given the sensory evaluation to complete.
For the objective testing methods, texture and color were analyzed. The texture of
the chocolate chip cookie and fish oil variations was measured using the Texture
Analyzer located in Stone Hall. Samples from each of the four groups were left intact and
tested in three different trials. The procedure for using the Texture Analyzer can be found
in the Food Chemistry Laboratory Manual (Weaver and Daniel 2003). A one-inch
cylinder probe (p/1) was used at a test speed of 1.7 mm/s to measure force in
compression. The cookies tested using the Texture Analyzer were also used on the
Hunter Colorimeter. The Hunter Colorimeter was used to measure the color on the
outside of the chocolate chip cookie. The procedure for using the Hunter Colorimeter can
be found in the Food Chemistry Laboratory Manual (Weaver and Daniel 2003). Each
chocolate chip cookie in its entirety was placed on top of a piece of cellophane on top of
the machine. Three trials were conducted from three different cookies from every one of
the four groups. L, a, b values were recorded in the laboratory notebook.
Subjective testing involved a panelist of eight untrained individuals. The age and
sex of the panelists were kept anonymous. Samples were placed upon white plates with
only their random three-digit codes shown that only the researchers knew the identity of.
The three-digit codes for the samples were picked randomly. Individuals were asked to
complete the sensory evaluation, judging hardness from a Hedonic scale and preference
using a ranking test as shown below.
Sensory Evaluation
Please taste each sample in front of you
On the scale below please mark the line that best describe the texture of each chocolate
chip cookie.
247
703 531 379 Rank the samples in order of preference. 1 being the one you like the most and 4 being
the one you like the least.
247 _______
703 _______
531 _______
379 _______
Comments:
Discussion:
Americans consume chocolate chip cookies on a daily basis, which includes
consumption of cholesterol and low-density lipoproteins. In order to help increase heart
health and increase intake of high-density lipoproteins, strawberry-flavored fish oil was
added to the Tollhouse Chocolate Chip Cookie recipe to produce a healthier product.
Texture, color, and taste were analyzed to determine if the recipe would appeal to the
consumer. According to Table 2 and Figure 1, the control cookies were softest. Upon
addition of increasing amount of fish oil, the cookies got softer. According to Table 3, the
values for the control group versus the 10 gram group were statistically significant,
suggesting addition of a small amount of oil made the cookies harder at first. For groups
20 grams and 30 grams, the values obtained were not statistically different, suggesting
the addition of these quantities of oil were harder, but in between the texture of the
control group and experimental groups. For color, addition of oil created a darker cookie,
which can be seen by the decreasing values for L in Figure 3, 4, and 5. There was a
significantly statistical difference between the L-value obtained for the control group
versus the 10 gram group, suggesting perhaps experimental error. As we added more oil,
the cookies got darker. This could have been due to varying cooking times or varying
ovens. Overall, the control group was found to taste the best, appear the best, be the
lightest, and be the softest cookie overall. The control group was preferred 100% over all
of the other cookies. From the experimental groups, the addition of 10 grams of fish oil to
the cookies was the top choice. Data collected from our sensory panelists found the
control group to be the softest cookie at a quantity of 3.14 out of 8 on a hardness scale.
Varying values could be due to experimental errors such as differences in baking time,
variation in measuring each component of our recipe, use of different ovens, differences
in mixing time, and even differences in presenting the cookies to our sensory panel.
The food industry must appeal to the consumer in order to sell their products.
With the increase interest in eating healthy, consumers are more likely to buy products
with added health benefits. The problem lies in creating a tasteful and appealing product.
Another way to incorporate fish oil without consumers tasting that fishy taste is to
encapsulate the omega-3 fatty acids (Wolfson 27). This can help to hide the fishy flavor
and protect the fragile oils from breaking down. According to Linda Antinoro, adding
omega-3 fatty acids to foods only contributes a small amount to your daily need. It is
better to consume foods rich in omega-3 fatty acids than to eat fortified sources.
According to Karwe, omega-3 fatty acids are prone to auto-oxidation, are sensitive to air,
heat, light, and humidity, and generate off odors (Karwe 21). Higher moisture retention in
baked goods such as bread or cookies can increase the quality of processed food.
Furthermore, encapsulated fish oil allows the fish oil to be retained. The study conducted
at Rutgers found sugar cookies with added fish oil retained 70-90% EPA and DHA and
that the type of oven used did not affect retention (Karwe 62).
According to consumer preference, the cookie with 10 grams of added fish oil
would be the best to add in the making of a commercial cookie product that advertises
addition of omega-3 fatty acids. In the future, an experiment could be conducted where
encapsulated fish oil was used rather than strawberry-flavored as this threw off the
randomness of knowing which cookies had added fish oil. Furthermore, lower amounts of
fish oil could be added such as 5, 10, and 15 grams to see if there was any distinction.
Also, if the bioavailability of the omega-3 fatty acids in the cookies could be measured,
then the most beneficial quantity of oil to be added to cookies could be determined. The
idea that addition of antioxidants to the mixture could help stabilize the fatty acids in the
cookies could be tested. In the future, more sensory panelists could have been chosen to
increase statistical significance of values obtained.
Results:
Table 1: Ingredients Used in Toll House Cookie Recipe
Amount (g)
Ingredient
281.25
All-purpose flour
4.6
Baking soda
4.75
Salt
227
Butter
150
Granulated white sugar
165
Packed brown sugar
4.2
Vanilla extract
2
Eggs
342
Nestle Toll House Semi-sweet chocolate morsels
Table 2: Results of Texture Analysis of Various Cookies
Sample ID
Group
TA 1 (g)
TA 2 (g)
TA 3 (g)
Avg. TA (g)
703
Control
409.7
192.2
312.6
304.8
247
10 g
1111.4
2352.8
2771.4
2078.5
531
20 g
940.3
1306.0
1141.5
1129.3
379
30 g
463.7
809.9
1034.4
769.3
Table 3: Effects of Addition of Different Amount of Fish Oil on Average Texture
Analysis
Controla
Texture
Analyzer 304.833 ± 108.958
10gb
20gc
30gd
2078.533 ± 863.317
1129.267 ± 183.157
769.933 ± 287. 505
*All variables are statistically significant Table 4: Hunter Colorimeter and Darkness of Cookies
Sample ID
Group
1
2
3
Avg.
703
Control
L=42.70
L=42.91
L=44.42
L=43.34
a=2.59
a=3.86
a=4.66
a=3.70
b=8.75
b=9.41
b=11.27
b=9.81
L=32.39
L=33.37
L=34.75
L= 33.50
a=5.98
a=6.00
a=6.92
a=6.3
b=6.73
b=6.73
b=7.52
b= 6.99
L=36.83
L=36.55
L=36.40
L=36.59
a=4.56
a=4.41
a=4.70
a=4.56
b=6.02
b=5.60
b=5.66
b=5.76
L=32.44
L=30.41
L=32.33
L=31.73
a=5.37
a=5.59
a=4.73
a=5.23
b=5.30
b=5.63
b=4.83
b=5.25
247
531
379
10 g
20 g
30 g
Table 5: Effect of Different Amounts of Fish Oil Added on Average Hunter Color
Values
10gb*
20gc
30gd
Controla
L value 43.343 ± 0.938
33.503 ± 1.186
36.593 ± 0.218
31.727 ± 1.142
a value
3.703 ± 1.044
6.300 ± 0.537
4.557 ± 0.145
5.230 ± 0.447
b value
9.810 ± 1.307
6.993 ± 0.456
5.760 ± 0.227
5.253 ± 0.402
*All variables are statistically significant Table 6: Average Texture and Ranking based on Sensory Evaluation
Sample Numbers
Average Texturea
Average Ranking
703 (Control)
3.14
1
247 (10g)
6.43
2
531 (20g)
6.86
3
379 (30g)
6.43
4
a
based on scale 1-9 with 1 being the extremely soft and 9 being extremely hard.
Figure 1: The Effects of Adding Different Amount of Fish Oil on the Texture
Analysis in 3 trials
Figure 2: The Effects of the Addition of Different Amount of Fish Oil on the
Average of the Texture Analysis
The Effect of Omega-3 Fatty Acids on
Color of Chocolate Chip Cookies
50
45
40
35
30
L-value
a-value
b-value
25
20
15
10
5
0
1
2
3
4
Groups With Varying Amounts
of Added Oil
Figure 3: The Effect of Omega-3 Fatty Acids on the Color of Chocolate Chip
Cookies
Lightness (L value) Compared
to Amount of Added Fish Oil
50
45
40
35
30
25
20
15
10
5
0
0
10
20
30
40
Fish oil added (g)
Figure 4: Comparing Lightness to Amount of Fish Oil Added to Cookies
Figure 5: The Effects of the Different Amounts of Fish Oil Added on Average
Hunter Color Values
Figure 6: Subjective Variables on the Texture of the Cookies
References:
Gatehouse, Jonathan. 2009. “The Cure for Everything.” Maclean’s 120 (3): 32-38.
International Food Information Council Foundation. 2008. “Functional Foods Fact Sheet:
Omega-3 Fatty Acids.” IFIC.
Karwe, Mukund V. 2004. “Fortification of Foods with Marine Omega-3 Fatty Acids:
Food Technology Issues.” Rutgers University.
Weaver, C and Daniel, J. 2003. The Food Chemistry Laboratory. Boca Raton: CRC
Press.137.
Wolfson, Wendy. 2004. “Fish-Oil Cookies.” Technology Review 107(7): 27.
Ye, A. and Cui, J. 2009. “Evaluation of Processed Cheese Fortified with Fish Oil
Emulsion.” Food Research International 42(8): 1093-1098.