Food Chemistry 453. Individual Project. November 20, By, Katie Flickinger

Transcription

1 Food Chemistry 453 Individual Project November 20, 2006 By, Katie Flickinger

2 The Effect of Omega-3 Fatty Acids on the Texture, Color, and Palatability of Macaroni and Cheese Abstract There have been no found articles in the scientific literature that show traces of scientists experimenting with adding omega-3 fatty acids to foods that don t already naturally contain them like fish. So, this experiment seeks to find an alternate food, (macaroni and cheese) to add omega three fatty acids to in order to provide consumers with the health benefits that are associated with consumption of these particular fatty acids, but without having to consume fish. The goal is to make this addition without negatively impacting or altering the texture, color/appearance, or taste of the macaroni and cheese. This will all be tested and evaluated through the use of objective and subjective testing. The following tests will be used: the texture analyzer, the hunter colorimeter, and the use of sensory surveys (a hedonic scale evaluation). Introduction Cardiovascular diseases (CVD) claim approximately 910,614 lives, which is 37.3% of all deaths, or one death out of every 2.7. These diseases are responsible for the largest percentage of death of Americans both male and female of any race or ethnic background. Deaths caused by CVD are also no longer confined to the elderly population; rather they are trans-generational. Clearly the incidence of cardiovascular disease is no small thing and it is not isolated to a particular group or segment of the population; it is a nation wide concern. Fortunately, science is studying and researching ways to decrease the prominence of CVD by reducing ones risk or risk factors.

3 According to scientists, one way to reduce several risk factors, and improve overall cardiovascular health (Dewailly and others 2001) is through the consumption of omega-3 fatty acids, which are found most readily in higher fat fish. Omega-3 fatty acids contribute to lowering the risk of cardiovascular disease by lowering plasma triglycerides, decreasing blood pressure, lowering platelet aggregation and inflammations as well as improving vascular reactivity (Breslow 2006). Additionally, these omega-3 fatty acids decrease risk factors like obesity, hypertension, glycohemoglobin, and ST-T segment changes in an ECG (Kris Etheron and others 2003). As previously mentioned one of the greatest sources of omega-3 fatty acids is fish. There is a large portion of the American population who does not eat fish, does not like fish, can not afford it, or simply has limited access and variety to it due to their geographic location. Therefore, the idea to incorporate omega three fatty acids into macaroni and cheese came about. Why macaroni and cheese? Macaroni and cheese was chosen because pasta is inexpensive and accessible. Moreover, pasta can serve as a safe alternative for pregnant women or young children who may be concerned with or sensitive to high mercury levels in fish. The purpose of this experiment is to create an inexpensive macaroni and cheese product with enough omega-3 fatty acids in it to help reduce the risk of cardiovascular disease while preserving the original flavor, color, and texture that is associated with macaroni and cheese. The independent variable is the presence of omega-3 fatty acids, and the dependant variables include texture, color, and palatability. The texture of the product will be tested using the texture analyzer. This device will be using the cone probe on the pasta setting. The main purpose of using the texture analyzer to test this product is to assure that it maintains the correct texture/mouth feel of macaroni and

4 cheese. A second factor that heavily determines a consumer s acceptance or rejection of the product is how it tastes. Thus a sensory taste panel will be sampling the macaroni and cheese and then evaluating it on a 9-point hedonic scale. Lastly, the color/appearance of the product will be tested using the hunter calorimeter. It is important that the color characteristic of macaroni and cheese is preserved in this experiment. This experiment will be conducted using a simple homemade KRAFT recipe for macaroni and cheese. The recipe will be made three separate times, each time having one pan of the control (no omega-3 fatty acids) and one pan of the variable (contains omega-3 fatty acids). After the product is made it will under go the tests described above. This will be repeated for each trial. In short, the objective of this experiment is to make and then test a macaroni and cheese product with an added health benefit of omega-3 fatty acids and evaluate it for taste, texture, and appearance to see if the product might be successfully consumed by the general public. Methods Making the Variables: This laboratory experiment will test whether or not the addition of omega-3 fatty acids to macaroni and cheese will affect the texture, color, or palatability of the food. Begin by acquiring all of the necessary ingredients needed to make macaroni and cheese (see recipe listed below). Once all of the necessary ingredients are gathered, preheat the oven to 375 degrees F (190 degrees C) so that it will be at the appropriate temperature once the macaroni and cheese is assembled. Next, take a pot and fill it with enough water to boil 2 cups of uncooked elbow macaroni. Once the water has reached rapid boil cook pasta for the amount of time listed on the package, 8-10 minutes. After the pasta has

5 been cooked, drain well in a colander. While the macaroni noodles are draining, measure the remaining ingredients and begin to assemble them in a large mixing bowl. Measure 16 oz. of sour cream, 1-8oz. package of shredded cheddar cheese, 1 cup low fat cottage cheese, and ½ tsp. salt. Mix all ingredients lightly together until well mixed. Once the sour cream, cheeses and salt are mixed add macaroni noodles and stir until the noodles are well coated with the cream, cheese, and salt mix. After that, divide the mixture in half. Spoon one half of the macaroni and cheese mixture directly into a 2 quart casserole dish, then add 3 grams of omega-3 fatty acids to the other half, and then place into a 2 quart casserole dish. Crush 1 cup of corn flake crumbs and then mix with 1 Tbsp. melted butter. Sprinkle this on top of each dish. Place both dishes side by side on the middle rack of the oven. Keep the casserole dish with the control macaroni and cheese on the left side and the variable on the right side of the oven, so that each trial will be consistent. Bake at 375 degrees for 30 minutes. Upon completion of baking set dishes on top of a cooling rack and let them cool before starting tests. Note that all of the above values listed were listed in non metric units in order to best replicate that of a household kitchen. Kraft Macaroni and Cheese: (amounts listed for one trial only) 2 cups (248.0g) elbow macaroni 16 oz. (497.7g) sour cream 1 package, 8oz. (248.0g) sour cream 1 cup (124.4g) low fat cottage cheese ½ tsp. (2.49g) salt 1 cup (124.4g) corn flakes 1 Tbsp. (15.6g) melted butter

6 3 grams omega-3 fatty acids (variable version only) cook macaroni as directed on package; drain return to pan. add sour cream, cheeses and salt; mix lightly spoon into 2-qt. casserole. top with corn flakes; drizzle with butter bake at 375 degrees F (190 degrees C) for 30 minutes Measurements: For the subjective measurements, the scorecard below should be used and each sample labeled with a three digit random number. Each sample has a separate sheet so each subject who completed the sensory evaluation filled out two sheets, one for the control and one for the variable. New three digit random numbers were generated for each trial done so that the subject who test do not become familiar with the numbers and choose on number set automatically as a favorite. Having the same subjects taste for each trial will improve consistency, but that is often difficult. A diverse population can also improve sampling results. Sensory Score Card: Product Name Date Please evaluate the product by tasting it, and then marking on the 9 point hedonic scale you feelings towards it. like extremely (9) like very much (8) like moderately (7) like slightly (6) neither like nor dislike (5)

7 dislike slightly (4) dislike moderately (3) dislike very much (2) dislike extremely (1) The objective tests preformed were the texture analyzer test and the hunter colorimeter test. Testing was preformed using the cone probe of the texture analyzer to measure the toughness of the macaroni noodles. The texture measurements were measured in the center of a noodle taken from the middle of the macaroni and cheese dish. The second objective test done used the hunter colorimeter which is an instrument which sees color in that same fashion as the human eye. It is a direct measure of the color/appearance of a food sample. The machine was first standardized, and then calibrated. The L, a, and b values were measured for one variable at a time. This was done by scooping a spoon full of macaroni from the center of the macaroni dish into a clear Petri dish, filling the Petri dish completely, so there were no major gaps between the noodles. All of the samples for the objective tests were taken from the middle of the pan, in order to establish some consistency, as well as stay away from the edges which may have been better cooked than the rest of the macaroni and cheese. Discussion Calculations: Standard Error of the Mean= The standard deviations of the sample in a frequency distribution, obtained by dividing the standard deviation by the total number of cases in the frequency distribution. Sources of Error:

8 Some sources of error from the subjective measurements vary from error existing to being non existent. It is very difficult when doing a subjective tests because it is so dependant on the individual and their personal taste preferences, their feelings towards tasting the samples, the environment in which the sensory test is occurring, and the degree to which they are hungry. Also, what tastes good to one subject may not taste good to another subject. If the same subjects are used to taste all of the samples then some consistency may emerge. Another source of error could result from selection bias. If one looks more appetizing to the subject than another sample, the better looking one may be chosen for better taste, simply because it looks more appealing. There are two categories of error when performing objective tests. Objective tests can show sources of error caused by the operator of the equipment, or from the instruments themselves. Error caused by the operator of the equipment is usually due to carelessness or rushing, and can typically be eliminated or at least minimized. These errors can be eliminated or drastically minimized by carefully following the step by step operating instructions for the particular instrument. Errors caused by the instruments themselves can be lessened by calibrating/standardizing the instrument between each test. Take Home Message: The addition of omega-3 fatty acids to macaroni and cheese did not change/effect the texture of the product much, if at all. The differences in values taken from the texture analyzer are minimal. The values stayed fairly consistent among all three trails for both the control and the variable. The results/values from the hunter colorimeter were very similar between the control and variable macaroni and cheese dishes within each trail, but they varied more significantly between trails, especially between trial one and then trials

9 two and three. Trial one came out of the oven rather well done, almost burnt, due to the buttered corn flake topping. Because a burnt product is not desirable, the buttered corn flake topping was left off for the subsequent trials. The sensory tests showed that this product was not extremely desirable. The majority of the subjects did not care for the control or the variable product. Future Experiments: In the future, a different recipe might be suggested to use in place of the macaroni and cheese recipe used in this experiment, due to the lack of popularity among sensory test subjects. A different recipe may impact and/or improve the taste of the macaroni and cheese. Additionally, for future experiments a larger group of sensory tasters should be used in order to get a better idea/more accurate picture of how the samples were liked or disliked. The general trend however was that the macaroni and cheese was rated as fair. This may have been due to some flavors coming out Results The average results of the texture analyzer (Table 1.1, Figure 1.1) show that there was no significant difference in the texture, or toughness of the macaroni and cheese containing the omega-3 fatty acids compared to the macaroni and cheese that was made without the addition of omega-3 fatty acids. There was only a N difference between the two values. The result for the hunter colorimeter are listed, averaged, and illustrated in Table 2.1 and Figures These results show a very slight difference in the L, a, and b values between the control and the variable results. Thus, it does not appear that the addition of omega-3 fatty acids affects the color/appearance of the

10 macaroni and cheese. Thus far, the objective test results from the texture analyzer and the hunter colorimeter do not disprove the null hypothesis; the addition of omega-3 fatty acids has no effect on the texture, color, or palatability of the macaroni and cheese. Moving on, however to discuss and evaluate the sensory hedonic scale results, as depicted numerically and graphically in Table 3.1 and Figure 3.1 and 3.2. These results also show little variation in likes and disliked in taste between both the control and the variable macaroni and cheese dishes. When the overall averages are compared between the control and the variable macaroni and cheese, the macaroni and cheese with the added omega-3 fatty acids was surprisingly preferred to the macaroni and cheese dish containing no omega-3 fatty acids. This may be due to a poorly chosen macaroni and cheese recipe, or due to an untrained to semi trained sensory panel. More sensory panelists should be used in order to see how the distribution changes or shifts. The null hypothesis states that the palatability of the food should not change with the addition of the omega-3 fatty acids; however this experiment disproves the null. For this particular experiment, the addition of omega-3 fatty acids enhanced the taste of the macaroni and cheese. Table 1.1 Texture Analyzer Penetration Force Trial 1 Penetration Force Trial 2 Penetration Force Trial 3 Penetration Force Average Control N N N N Variable N N N N

11 Figure Force (N) Omega-3 Fatty Acids (grams) Grams of Omega-3 Fatty Acids vs. Force Table 2.1 Control Variable Hunter Colorimeter Trial 1 Trial 2 Trial 3 Average L a b L a b Figure 2.1

12 61.5 Average L value Omega-3 fatty Acids (grams) Grams of Omega-3 Fatty Acids vs. Average L Value Figure Avergae a Value Omega-3 Fatty Acids (grams) Omega-3 Fatty Acids vs. Average a Value Figure 2.3

13 Average b Value Omega-3 fatty Acids (grams) Grams of Omega-3 Fatty Acids vs. Average b Value Table 3.1 Hedonic Rating Like Extremely (9) Like Very Much (8) Like Moderately (7) Like Slightly (6) Neither Like nor Dislike (5) Dislike Slightly (4) Dislike Moderately (3) Dislike Very Much (2) Dislike Extremely Control 1 Control 2 Control Control Variable Variable Variable Variable 3 Average Average

14 (1) Figure 3.1 Average Hedonic Rating Hedonic Scale Hedonic Rating Averages vs. Hedonic Scale teal = control violet = variable Figure 3.2 Omega-3 Fatty Acids vs. Sensory Hedonic Average Sensory Hedonic Average control variable 0 3 Omega-3 Fatty Acids (grams) References Breslow, Jan L n-3 Fatty Acids and Cardiovascular Disease. American Journal of Clinical Nutrition. Vol. 83 (6):

15 Dewailly, Eric, Carole Blanchet, Simone Lemieux, Louise Sauve, Suzanne Gingras, Pierre Ayolte and Bruce John Hulub n-3 Fatty Acids and Cardiovascular Disease Risk Factors among the Inuit of Nunavik. American Journal of Clinical Nutrition. Vol 74 (4): Harper, Charles R. MD, Terry A. Jacobson, MD The Fats of Life: The Role of Omega-3 Fatty Acids in the Prevention of Coronary Heart Disease. Archives of Internal Medicine. Vol. 161(18): Kris-Etherton, Penny M, William S. Harris, Lawrence S. Appel, and the AHA Nutrition Committee Alteriosclerosis, Thrombosis and Vascular Biology. Journal of the American Heart Association. Vol. 23: Kris-Etherton, Penny PhD, RD, William S. Harris, Phd, Laurence J Appel, MD, MPH. Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease. Circulation. AHA Scientific Statement Uauy, Ricardo, MD, PhD, and Alfonso Valenzeula PhD Marine Oils: The Health Benefits of n-3 Fatty Acids. Nutrition. Vol. 16 (7-8):