The following is a research project on reducing the fat content of coleslaw. I worked on this project over nine weeks for a course called Experimental Food Science at Queens College. This project helped me discover my interest in product development. My group members and I spent alot of time working on our recipes and I'm proud of our results. In addition to this report, we had to present our findings to the class and create a poster display.
Sensory
Evaluation and Consumer Acceptability of Low Fat Coleslaw Prepared by
replacing mayonnaise with plain and Greek yogurts
AUDREY
LAHMAN, PROFESSOR SUNGEUN CHOI, DEPARTMENT OF FAMILY, NUTRITION AND
EXERCISE SCIENCES, QUEENS COLLEGE, CUNY, NY 11367
Abstract: Consumer preferences were analyzed in testing Coleslaw recipes formulated with variable amounts of fat content by replacing part or all of the mayonnaise with plain or Greek yogurt. The four recipes were evaluated by an untrained panel with 20 members (Average age 30, 4 Males:16 Females) and statistical analysis was done using one-way analysis of variance and a tukey test. None of the samples showed a significant difference for tanginess, sweetness or line spread. Yellowness was significantly higher in the mayonnaise sample while thickness was significantly higher for the 100% Greek yogurt sample in sensory evaluation. There was no significant difference in overall acceptance between the control mayonnaise based recipe and the 50/50 mayo/Greek yogurt recipe which contained 7 g of fat, less than half of the control’s 18 g of fat, which also decrease cholesterol and saturated fat levels. The 50/50 sample also contained more protein and calcium for fewer calories than the control. Successful formulation of a modified recipe decreasing fat and calories in Coleslaw is beneficial to preventing coronary heart disease and obesity in the population. Keywords: Coleslaw, Mayonnaise, Yogurt, Greek yogurt, Sensory Test, Line Spread Test
Introduction
Consuming
a diet high in full fat foods can lead to obesity which is linked to
many of the leading causes of death in the United States. More than
one third of Americans (around 78.6million people) are obese. (Ogden)
Coleslaw
is a fairly common side dish often served alongside sandwiches or
burgers. Coleslaw is traditionally made from cut up vegetables
covered in a mayonnaise based dressing. While the vegetables offer a
variety of beneficial nutrients, the mayonnaise in the dressing is
high in saturated fat and cholesterol.
Recently, researchers have
been working to find acceptable lower fat alternatives to products
like mayonnaise. One study tested mayonnaise made with soy milk
instead of egg. These scientists found that substituting some of the
egg (about 50%) with soy milk lowered the fat
content while still creating an acceptable product. (Rahmati) We
considered this method of combining ingredients in our research.
Another study tested Greek yogurt made with different types of animal
milks each at three different levels of fat. Researchers determined
that consumers are sensitive to milk from goat or sheep, but don't
seem to notice much of a difference between fat levels. They
concluded that reduced fat cows milk produced a healthier and
acceptable
Greek yogurt. (Atamian)
In our research we attempted to make a lower
fat coleslaw by replacing the mayonnaise with plain yogurt, fat free
Greek yogurt, and a combination of 50% mayo / 50% yogurt. We tested
for sensory factors like color, tanginess, sweetness, thickness and
acceptability. We also evaluated viscosity.
Methods
Ingredients
Three
modified coleslaw
recipes were compared to a control. Preliminary testing was done to
determine the optimal method
of mixing and what sensory
characteristics to
evaluate.
The
materials we used to make our coleslaw included: Packages
of Dole Classic Coleslaw Mix (Dole Fresh Vegetables
Inc. Monterey, CA), Fage Total Nonfat Greek Yogurt (Fage USA Dairy
Industry Inc. Johnstown, NY), Stonyfield Organic Plain Low Fat Yogurt
(Stonyfield Farm Inc. Londonderry,
NH
),
Hellmann's Real Mayonnaise (Unilever
US, Inc. Englewood
Cliffs NJ), Granulated Sugar (Domino Foods, Inc.Brooklyn, NY) and
McCormick Onion Powder (McCormick
& Company Inc. Sparks, MD).
We
determined that a serving size was ¼ cup and that the coleslaw
should be served chilled at 17C.
Table
1: Formulation for
Coleslaw
Samples
| Ingredients: |
Control: Mayo |
Plain Yogurt |
Greek Yogurt |
50/50 Mayo/Yogurt |
| Coleslaw |
14 oz |
14 oz |
14 oz |
14 oz |
| Sugar |
¼ cup (58 g) |
¼ cup (58 g) |
¼ cup (58 g) |
¼ cup (58 g) |
| Apple Cider Vinegar |
2 Tablespoons |
2 Tablespoons |
2 Teaspoons |
2 Teaspoons |
| Onion Powder |
½ teaspoon |
½ teaspoon |
½ teaspoon |
½ teaspoon |
| Salt |
¼ teaspoon |
¼ teaspoon |
¼ teaspoon |
¼ teaspoon |
| Pepper |
¼ teaspoon |
¼ teaspoon |
¼ teaspoon |
¼ teaspoon |
| Mayonnaise |
1 cup (236 g) |
N/A |
N/A |
½ cup (112 g) |
| Stonyfield Low Fat Yogurt |
N/A |
1 cup (270 g) |
N/A |
N/A |
| Fage 0% Fat Greek Yogurt |
N/A |
N/A |
1 cup (264 g) |
½ cup (130 g) |
Preparation
First,
we measured each ingredient in grams using a digital scale. We
prepared each sample by mixing the mayo or yogurt, sugar, vinegar,
onion powder, salt and pepper with an electric mixer at level 1 for
45 seconds. Then we poured the dressing mixture over the coleslaw mix
and tossed. The samples were refrigerated for 20 minutes before
serving and temperature was recorded at 17F.
The
electric mixer we used was a Black & Decker spatula smart heavy
duty power boost model.
Sensory
Evaluation
20
panelists from Queens College (4 males, 16 females, average age 30)
judged yellowness, tanginess, sweetness, thickness, and overall
acceptability on a 1-9 scale. (1 being weak and 9 being strong)
Sample size was 1 tablespoon placed in a Dixie cup. All four samples
were given a three digit code to number the dixie cups which were
placed on trays. Water was provided between samples.
Table
2: Sensory Characteristics Evaluated
| Sensory |
Attribute |
Definition |
| Appearance |
Yellowness |
Lower numbers mean “light yellow” |
|
|
and higher numbers mean “dark yellow” |
| Flavor |
Sweetness |
Tastes similar to sugar or honey, one of the basic flavors, |
|
|
weak means “bland” and strong means “very sweet” |
|
Tanginess |
Tang is a specific tart spicy flavor similar to zest or piquant, |
|
|
weak means “bland” and strong means “very tangy” |
| Texture |
Thickness |
Rate at which sample flows down the side of a tilted container, |
|
|
weak means “watery” and strong means “thicker” |
| Overall Acceptability |
Liking |
Overall consumer acceptability |
Objective
Evaluation
A
line spread test was done to evaluate our four samples of coleslaw
dressing for viscosity. This test was performed on the third lab day,
so we prepared new batches of dressings, the same way as the samples,
except that we didn't include the coleslaw vegetables. Line spread
tests were done three times for each formulation in order to get a
mean value. Each test was performed using 2 tablespoons of dressing.
Data
Analysis
Statistical
analysis will be performed using SPSS Statistics Processor, (2013,
IBM Inc., Armonk, NY). Analysis of variance was done as well a tukey
post-hoc test. To create nutrient fact labels, we used The Food
Processor program, version 10120, ESHA Research 2012.
Results
Sensory
Evaluation
Analysis
of data indicate that there is no significant difference (p <
0.05) between any of the coleslaw samples
for sweetness or tanginess. Yellowness was significantly higher in
the control mayonnaise coleslaw sample. Thickness was significantly
higher in the Greek yogurt sample. For overall acceptability there
was no significant difference between the control mayonnaise sample
and the 50/50 mayo/Greek yogurt sample. The panelists disliked the
Greek sample which earned the lowest mean values of 2.9 for
yellowness and 3.8 for overall acceptability. The Greek sample was
significantly thicker with a mean value of 7.1 (refer to table 3).
Tanginess
and sweetness might not be important characteristics of coleslaw
since the control mayo sample received the same score for tanginess
as the Greek sample. Panelists favored a less thick, more yellow
coleslaw sample.
The
control mayonnaise coleslaw sample was rated the highest for
yellowness which makes sense since Hellmann's Real Mayonnaise is made
with egg yolks that contain
carotenoids.
The
Greek yogurt coleslaw sample
was rated the thickest which makes sense the process of making Greek
yogurt involves extensive straining. Less liquid means a thicker
texture.
Overall
acceptability was not significantly different between the control
mayonnaise coleslaw sample and the 50/50 mayo/Greek yogurt sample.
They both had means of 6.4, indicating that the 50/50 sample is an
acceptable lower fat replacement for the mayo control sample.
Table
3: Sensory Attributes for Coleslaw Samples
(Mean + SD)
| Sensory Attributes |
Samples |
|
Control: Mayo |
Greek Yogurt |
Plain Low-Fat Yogurt |
50/50 (Mayo/Greek) |
| Yellowness |
5.0ᵇ + 2.0 |
2.9ª + 1.6 |
3.7ªᵇ + 1.5 |
3.8ªᵇ + 2.0 |
| Sweetness |
5.5ª + 1.9 |
4.9ª + 2.5 |
4.4ª + 2.0 |
5.9ª + 1.3 |
| Tanginess |
5.0ª + 2.0 |
5.0ª + 2.6 |
4.3ª + 2.2 |
4.6ª + 1.6 |
| Thickness |
6.2ªᵇ + 1.7 |
7.1ᵇ + 1.3 |
5.1ª + 1.7 |
5.7ª + 1.7 |
| Overall Acceptability |
6.4ᵇ + 1.8 |
3.8ª + 2.0 |
4.4ª + 1.5 |
6.4ᵇ + 1.7 |
Figure
1: Bar Graph for Sensory Attributes of Coleslaw
Samples
Objective
Analysis
In
the line spread test the analysis of the data resulted in
no significant difference
between samples. A
visible
difference was seen in the
thickness of the Greek yogurt sample. (Refer
to table 4 below) Greek
yogurt is made by straining liquids off of yogurt, so it makes sense
that it would have a thicker texture.
Figure
2: Averages of Line spread Test
Table
4: Line Spread Tests (Mean + SD)
| Line Spread Test |
Control: Mayo |
Plain Yogurt |
Greek Yogurt |
50/50 (Mayo/Greek) |
| Averages of 3 Trials |
3.81ª + 0.43 |
4.1ª + 0.05 |
2.7ª + 0.06 |
4.26ª + 0.01 |
| * Mean + Standard Deviation of 3 trials (12 measurements) |
| *Four values were obtained from each individual line spread test, measured in centimeters |
| * Means with the same superscripts indicate no significant difference (Tukey test, p<0.05) |
Figure
3: Nutrition Facts
 |
| Control: Mayo Sample |
 |
| Greek Yogurt Sample |
 |
| Plain Yogurt Sample |
 |
| 50/50 Mayo/Greek Sample |
Nutrient
Analysis
Greek
yogurt has calcium and protein with no cholesterol or fat making our
Greek yogurt coleslaw the healthiest sample. It was chosen for the
50/50 mayo/Greek sample for its nutritional benefits. By replacing
50% of the mayonnaise with Greek yogurt, the 50/50 sample has almost
half the calories, fat and cholesterol of the control mayo sample.
The 50/50 sample also contains protein that the control did not.
The
Greek yogurt sample was the healthiest
option. It fulfills FDA requirements to be labeled as low calorie,
fat free and cholesterol free. It
contained only 21% of calories of the mayo control sample.
The
50/50 mayo/Greek sample meets FDA standards to be labeled as a
reduced fat, reduced calorie and reduced cholesterol product. It
contained only 39% of the fat of the mayo control sample and only 53%
of the calories.
The
control recipe contained 18g of fat, 2.5 of those grams were from saturated
fat. The 50/50 sample contained only 39% of the fat. The plain yogurt
sample contained 33% while the Greek sample contained 0% of the fat
of the control mayonnaise sample.
Conclusion
This
study demonstrated that low and reduced fat versions of coleslaw can
be created that still fulfill certain sensory characteristics and are
overall acceptable to consumers. The control mayonnaise sample was
equally acceptable and showed no significant difference to the 50/50
mayo/Greek yogurt sample.
We initially hypothesized that using yogurt
by itself to replace mayonnaise would result in noticeable flavor
differences, however no significant differences were found for
sweetness or tanginess between samples which seemed to indicate that
flavor was not an important factor for overall acceptability.
With
the right ratio of 50% mayonnaise and 50% Greek yogurt, we were able
to create a product that contained the nutritional benefits of the
yogurt while adequately meeting sensory characteristics needed for
consumer acceptability.
This healthier version of coleslaw should be
incorporated
into restaurant
menus to provide a delicious yet healthier option to traditional
coleslaw. More research should be done on the exact ratios of
mayonnaise to Greek yogurt for
replacing mayonnaise in other recipes. Sensory analysis performed
with a larger panel would also produce more statistically
significant results.
The
line spread test may have been flawed. The plain yogurt sample
appeared much more liquidy than the others. In our test, we may have
taken a scoop that somehow more viscous than the sample overall. Our
sensory results revealed that texture was an important factor in
consumer acceptability so further studies on viscosity should be
done.
Acknowledgments
Ingredients
and equipment provided by the FNES department at CUNY Queens College, 65-30
Kissena Boulevard, Flushing,
NY 11367.
The experiments were performed with the help of Eguono Evwiehor, Stephanie Honeywell and Jacqueline Lofters.
References
Ogden,
Carroll,
Kit
&Flega.
Prevalence
of Childhood and Adult Obesity in the United States, 2011-2012. The
Journal of the American Medical Association.
311(8),
806-814.
Rahmati,
Kobra. Mazaheri, Teherani, Mostafa. Daneshvar, Kazem. Soy milk as an
emulsifier in mayonnaise. Journal of Food Science and Technology.
51(11), 3341-3347.
Atamian,
Olabi, Baghdadi, Omar, & Toufeili(2014). The characterization of
the physiochemical and sensory properties of full-fat, reduced-fat
and low-fat bovine, caprines and ovine Greek yogurt. Food Science
& Nutrition. 2(2), 164-173.
