The Effect of Adding Flaxseed to Oatmeal Chocolate Chip Cookies Rachel Hudson John Baccino Aashvi Patel NUTR 453 December 1, 2014
Abstract The addition of nutrient dense ingredients to commonly used foods is a popular trend in the food industry. The concept to increase nutrient adequacy is similar to the fortification of calcium in milk and orange juice. The goal is to take a food that does not contain particular ingredients and add something to increase the health benefits of that food. For example, flaxseed is a well-researched food and has been proven to produce a number of health benefits; however, how does the average individual incorporate this food into their diet? To help answer this problem, an experiment was conducted to determine if cookies made with flaxseed will have a desirable taste, texture and appearance. Flaxseed was added at two different concentrations 177.44 grams and 295.73 grams, respectively, to oatmeal chocolate chip cookies and compared to a control. Based on the average of the subjective data it was determined that the 295.73 grams (variation 2) flaxseed cookie produced a cookie very similar to the control. Therefore, the 295.73 gram flaxseed cookie has a high enough concentration of flaxseed to produce health benefits, and yet will still be desirable to consumers. Introduction Flaxseed is considered to be a highly beneficial superfood because it produces numerous health benefits beyond normal nutrition. One tablespoon of flaxseed contains 3 grams of polyunsaturated fat, 3 grams of fiber, flavonoids, and ligands. To analyze the benefits of flaxseed and the possibility of adding it to cookies, it is important to look at the health claims of the above nutrients. First, fiber has long been considered an important nutrient in the American diet; however, fiber is listed as a nutrient of key concern in the Dietary Guidelines for Americans. Moreover, fiber intake in the U.S. is consistently low with less than 10 percent of Americans meeting daily requirements (Clemens and colleagues 2012). Fiber alone has numerous health benefits including helping individuals maintain a healthy body weight by controlling hunger and increasing feelings of fullness. Fiber may also help to lower cholesterol by preventing bile recycling, promoting bile excretion, and using LDL cholesterol to help synthesize more bile. Finally, fiber has been linked to better control of blood glucose. In the article The Effects of Functional Fiber on Postprandial Glycemia, Energy Intake, Satiety, Palatability and Gastrointestinal Wellbeing: A Randomized Crossover Trial, increasing fiber intake by 10 grams significantly helped reduce blood sugar levels. The extra 10 grams of fiber added to bread produced an acceptable bread, but not a desired product (Yang and colleges 2014). With the main question being What products can you add fiber rich foods to without significantly compromising taste?. Polyunsaturated fatty acids, another key component in the flaxseed, is also associated with many important health outcomes. For example, according to the American Heart Association, intake of polyunsaturated fatty acids is associated with heart health and a reduced risk of disease. In the article Effects of Dietary Fatty Acids and Carbohydrates on the Ratio of Serum Total to HDL Cholesterol and on Serum Lipids and Apolipoproteins: A Meta-analysis of 60 Controlled Trials, it was found that replacing carbohydrate with polyunsaturated fatty acids not only reduced LDL cholesterol but also increased HDL cholesterol. This is of major concern because elevated LDL cholesterol is associated with atherosclerosis, while increased HDL is a negative risk factor for heart disease and can help eliminate cholesterol from arteries.
Flavonoids, yet another beneficial compound in flaxseed, is becoming more researched for their antioxidant properties. Flavonoids are phenolic compounds found in a variety of plant compounds responsible for the yellow/red/blue pigmentation. In the article Flavonoids as Antioxidants, flavonoids serve a variety of functions, but their function as antioxidants and their ability to neutralize free radicals is of major concern. Because of their function as antioxidants, flavonoids may be able to reduce certain types of cancers. After discussing the benefits of flaxseed it is important to briefly discuss methods for the experiment and to determine what level of flaxseed should be added to cookies to produce the desired benefits. To determine an average fiber intake the Recommended Dietary Allowance average for males and females ages 19-50 was used. Although the ranges differ depending on age, gender, and other factors, the average recommended intake was a good starting point. According to the National institute of Medicine classifications, a food is to be considered a good source of fiber if it contributes 10% of your daily value of fiber. Therefore 3 cookies at 177.44 grams of flaxseed per batch contributes 3 grams of fiber per serving, and the 295.73 grams contributes 4.5 grams of fiber. Ideally, the larger intake of fiber is considered better but taste, texture, and appearance must also be considered. A required amount for polyunsaturated fatty acids and flavonoids was not determined because an RDA is not determined and it is not yet clear at which levels provide the ideal benefits. For the study, the goal was to determine if flaxseed can be added to cookies at high enough levels to produce health benefits and can still produce a desirable cookie. Flaxseed was added at two different concentrations of 177.44 grams and 295.73 grams. It was then determined if the addition will have a significant effect on taste, texture, and appearance. The three cookie samples (control, 177.44 grams and, 295.73 grams flaxseed) were prepared under similar conditions for three different trials. The cookies were analyzed using a texture analyzer, water activity system, and colorimeter. The texture analyzer was selected to determine if the trial cookies properties including hardness, fracturability, chewiness, and cohesiveness is similar to the control. Water activity was measured to determine the ratio of vapor pressure of water in the cookies to the vapor pressure of pure water at the same temperature. The colorimeter was used to measure the color of the different variations of oatmeal chocolate chip cookies. Finally, a subjective taste panel was used to determine desirability of the different cookies. Materials and Methods Hypothesis: Adding ground flaxseed creates the most desirable taste, color, and texture in oatmeal chocolate chip cookies. Null Hypothesis: Adding ground flaxseed will have no effect on texture, color, or taste in the oatmeal chocolate chip cookies. Objectives: To create a more desirable and nutritionally beneficial dessert, specifically oatmeal chocolate chip cookies, by adding ground flaxseed to the pre-cooked mixture.
Variables: The independent variable of our experiment is the amount of ground flaxseed added to each trial. For the first trial (390), no flaxseed will be added. For the second trial (712), ¾ cup of flaxseed will be added to the original recipe. For the third trial (487), 1 ¼ cups of flaxseed will be added to the original recipe. The dependent variables of our experiment are taste, color, and texture evaluation. Experimental Design: The overall design of this experiment is to use an original oatmeal chocolate chip cookie recipe and add varying amounts of ground flaxseed to gain a nutritional benefit. The amount of flaxseed added is based on determining the daily recommended amount of fiber and then setting a serving size. There will be a control which has no added flaxseed, Variation 1 which will have ¾ cup (177.44 g) added flaxseed, and Variation 2 which will have 1 ¼ cup (295.73 g) added flaxseed. There will then be two subjective tests of each trial and each variation within the trials. Finally, objective tests such as the Water Activity System, Hunter colorimeter, and Texture Analyzer were performed. Sample of Subjective sensory score cards: Please taste each sample in front of you. On the scale below, please make a mark on the line by the description that best fits each cookie sample. Rank the samples in order of preference, 1 being the one you like the most and 3 being the one you like the least: 390-- 712 487 Other comments:
Trial 1: 1. Gather all needed ingredients, measuring utensils, and supplies. 2. Set up/turn on all necessary equipment such as the water activity system, texture analyzer, and Hunter colorimeter. 3. Preheat oven to 325 degrees Fahrenheit. 4. Obtain a large bowl and cream together the butter, brown sugar, and white sugar until smooth. Beat in the eggs one at a time and stir in vanilla. Into this mixture; add flour, baking soda, and salt until just blended. Stir in the quick oats and chocolate chips. 5. Using a consistently sized tool, such as a small spoon, transfer equal amounts of the batter onto an ungreased baking sheet. 6. Place baking sheet in oven and bake for 12 minutes. (Make sure oven is fully preheated before cooking.) Turn the sheet and bake an additional 5 minutes. *note* place each trial variation in same oven and same place as other trials to eliminate all random variables. 7. Allow product to cool and place on properly labeled plates for testing. 8. Perform objective tests (Hunter colorimeter, Texture Analyzer, and Water Activity) and record data. 9. Perform subjective tests (Consumer Preference and Structured Ranking) and record data. Trial 2: 1. In a large bowl and cream together the butter, brown sugar, and white sugar until smooth. Beat in the eggs one at a time and stir in vanilla. Into this mixture; add flour, baking soda, and salt until just blended. Stir in the quick oats and chocolate chips. 2. Add 177.44 grams of flaxseed and stir until mixed thoroughly. 3. Using a consistently sized tool, such as a small spoon, transfer equal amounts of the batter onto an ungreased baking sheet. 4. Place baking sheet in oven and bake for 12 minutes. Turn the sheet and bake an additional 5 minutes. *note* place each trial variation in same oven and same place as other trials to eliminate all random variables. 5. Allow product to cool and place on properly labeled plates for testing. 6. Perform objective tests (Hunter colorimeter, Texture Analyzer, and Water Activity) and record data. 7. Perform subjective tests (Consumer Preference and Structured Ranking) and record data.
*note* subjective tests were performed outside of class with random subjects for this trial Trial 3: 1. In a large bowl and cream together the butter, brown sugar, and white sugar until smooth. Beat in the eggs one at a time and stir in vanilla. Into this mixture; add flour, baking soda, and salt until just blended. Stir in the quick oats and chocolate chips. 2. Add 295.74 grams of flaxseed and stir until mixed thoroughly. 3. Using a consistently sized tool, such as a small spoon, transfer equal amounts of the batter onto an ungreased baking sheet. 4. Place baking sheet in oven and bake for 12 minutes. Turn the sheet and bake an additional 5 minutes. *note* place each trial variation in same oven and same place as other trials to eliminate all random variables. 5. Allow product to cool and place on properly labeled plates for testing. 6. Perform objective tests (Hunter colorimeter, Texture Analyzer, and Water Activity) and record data. 7. Perform subjective tests (Consumer Preference and Structured Ranking) and record data. *note* subjective tests were performed outside of class with random subjects for this trial 8. Clean area, put away all items, and turn off any machines used. *note* all trials were performed on the same day and methods reflect that Recipe: The original recipe reads as follows: - ¾ cup and 1 tablespoon and 2 teaspoons butter, softened (195 g) - ¾ cup and 1 tablespoon and 2 teaspoons packed light brown sugar (190 g) - ¼ cup and 3 tablespoons white sugar (85 g) - 1 ¾ eggs - 1 ¾ teaspoons vanilla extract (9 ml) - 1 cup and 1 tablespoon all-purpose flour (135 g) - ½ teaspoon baking soda (2 g) - ¾ teaspoon salt (5 g) - 2 ½ cups and 1 tablespoon quick-cooking oats (210 g) - ¾ cup and 1 tablespoon and 2 teaspoons semisweet chocolate chips (145 g) Modifications: - Ground flaxseed (295.73 and 177.44 g)
Discussion The texture analyzer was used to determine the texture differences caused by the addition of flaxseed to the oatmeal chocolate chip cookies. The cone probe that was used was set at cookies. The breaking forces of each sample can be found in Table 1 and Figure 1. As seen in the data, sample 390, which was the control, had an average breaking force of 178.96 grams, sample 712 had an average breaking force of 185.08 grams, and sample 487 had an average breaking force of 235.8 grams. The control sample containing no flaxseed had the lowest breaking force. This shows that flaxseed does have an effect on texture. The sample containing the highest amount of flaxseed had the highest average breaking force, which further confirms that the amount of flaxseed that the oatmeal cookie contains, the more force needed to break into the cookie. According to the ANOVA testing, the p value is considered not significant. This means that none of the texture analysis values are that different. This does not correspond to the interpretation of the results because this means that flaxseed has no effect on the texture of the cookie. This may be due to the experimental error that may have been caused during the measurement of the breaking force of the cookies. The Hunter Colorimeter was used to measure the color of the different variations of oatmeal chocolate chip cookies. The data obtained from the Hunter Colorimeter can be found in Table 2 and Figure 2. The L values of the Hunter Colorimeter represent the whiteness and darkness of the sample. The scale is set ranging from 100 to 0; 100 being white and 0 being black. The a values refer to the ranking of color on a scale from green to red. Negative a is mostly green and positive a is mostly red. The b value represents color as either blue or yellow. If the value is negative, the color is blue, and if the value is positive, the color is yellow. As seen by the results, for each of the three trials for the L value, the averages were greater than 30. This shows that the color of the samples was closer to black than they were to white. The darkest of the cookies was the control, but in the pictures of the oatmeal cookies found in the appendix, the control cookies containing no flaxseed were the lightest in color. The results of the Hunter Colorimeter are not consistent with the subjective results of the cookies. This could have been due to errors in the calibration of the machinery or other experimental errors. The samples could also have been placed incorrectly on the measuring port of the machine. The a and b values of each of the variations were positive, showing that the color results were closer to red and yellow, rather than blue and green. According to the p values of the L parameter, the p values are not considered significant. This means that there is no difference between the L values of the cookies. The ANOVA testing data shows that there is no difference in the darkness and lightness of the cookies, however the subjective data clearly shows that there is a color difference between the cookies. The p values of the a parameter are considered very significant. This means that there is a color difference of green to red for the different cookies. The p values for the b parameter is considered not significant meaning that there is no difference between the blue to yellow colors of the different variations of cookies. Water activity is used to measure the ratio of vapor pressure of water in a compound to the vapor pressure of pure water at the same temperature. The average water vapor of each variation was measured and is shown in table 3 and figure 3. According to the results, variation 1 (containing the lesser amount of flaxseed) had an average water activity level of 0.746, which was the highest water activity out of the three variations. Variation 2 (containing the highest amount of flaxseed) had the lowest average water activity with a value of 0.396. The results are inconsistent with the subjective tests of the variations of
cookies. According to Figure 3, the data in the graph shows that the cookies with the lesser amount of flaxseed had the highest water activity. This could be because the more flaxseed added, the drier the product became. However, we are not sure why the control had a lower water activity than variation 1. This could be due to a variety of sources including experimental error or incorrect sample size. According to the ANOVA testing results, the p value is considered very significant, meaning that the water activity of each cookie is different from one another. This supports the fact that the water activity decreases as flaxseed is added to the cookies. According to the participants preference of cookies, the highest preferred cookies were both the control and variation 2. The same number of people preferred the cookies that contained zero flaxseed as the cookies that contained the most amount of flaxseed. A consumer scale was used to rank the cookies based on texture and crunchiness. Overall, the participants ranked the control cookies as the most chewy/soft, and the cookies with the lesser amount of flaxseed as the crunchiest. This did not fit in with our results from the texture analyzer, since it was recorded that the cookie with the most amount of flaxseed was the hardest to break through, therefore the crunchiest. Suggestions for future work would be to add more flaxseed to variation 2 to see if there would be a significant difference between the two variations of cookies containing flaxseed. Another suggestion would be to experiment with different types of cookies or other desserts to determine if the experiment produces desirable results between the control and the cookies with added flaxseed. The oatmeal and chocolate chips may have had contributing factors to the texture, color and water activity Conclusion The null hypothesis was rejected after thorough analysis of the data. The more flaxseed added to the different variations, the more force was required to break through the cookie. According to our results, the data corresponding to the water activity did not support the hypothesis since there was no obvious pattern to the results. The addition of flaxseed had little effect on the taste of the cookies. Participants equally preferred both the control cookie (containing no flaxseed), and variation 2 (containing the most amount of flaxseed). According to a study done by Mercier et al., the results found by the researchers were similar to the ones found in this experiment. The researchers found that adding flaxseed to cookies decreases the water activity levels, increases the force required to break the cookie, and increased the darkness of the cookie. Our results were similar except for the discrepancies in the data for the water activity level.
Results Table 1: Texture Analyzer readings for the required breaking force of variations of the oatmeal cookies Trial Control Variation 1 Variation 2 Trial 1 272.7 258.7 248.2 Trial 2 181.3 201.7 199.2 Trial 3 82.87 94.83 260 Average 178.96 185.08 235.8 Standard Deviation 94.93 83.19 32.24 Figure 1: Texture Analyzer readings reported as an average of breaking forces
Table 2: Hunter Colorimeter values for three variations of oatmeal chocolate chip cookies Control Var. 1 Var. 2 L a b L a b L a b Trial 1 32.96 10 23.6 33.12 13.39 25.02 34.64 11.73 24.77 Trial 2 39.21 11.06 29.24 31.7 12.37 23.44 33.72 10.96 23.14 Trial 3 35.4 11.3 24.76 32.46 13.62 24.56 33.1 11.74 23.83 Ave 35.86 10.79 25.87 32.43 13.13 24.34 33.82 11.48 23.91 SD 3.15 0.69 2.98 0.711 0.665 0.813 0.77 0.447 0.818 Figure 2: Hunter Colorimeter values, reported as averages, of the three variations
Table 3: Water activities for the three variations of oatmeal chocolate chip cookies Trial Control a w Variation 1 a w Variation 2 a w Trial 1 0.387 0.833 0.392 Trial 2 0.524 0.824 0.407 Trial 3 0.527 0.582 0.388 Average 0.479 0.746 0.396 Standard Deviation 0.08 0.142 0.01 Figure 3: Water activities, reported as averages, of three variations of oatmeal chocolate chip cookies
Table 4: Ranking based on preference of the oatmeal chocolate chip cookies on a scale of 1 to 3 Variation Ranking 1 2 3 Control 7 9 2 Variation 1 3 7 8 Variation 2 7 2 9 Figure 4: Number of participants who preferred each variation the most
Figure 5: Structured ranking based on texture of the oatmeal chocolate chip cookies
References American Heart Association. Accessed November 24, 2014. Polyunsaturated Fats. Dallas, TX: Available from: http://www.heart.org/heartorg/gettinghealthy/nutritioncenter/healthyeating/polyunsaturated- Fats_UCM_301461_Article.jsp. Accessed November 24, 2014. Clemens R, Kranz S, Mobley AR, Nicklas TA, Raimondi MP, Rodriguez JC, Slavin JL, Warshaw H. 2012. Filling America's fiber intake gap: summary of a roundtable to probe realistic solutions with a focus on grain-based foods. Journal of Nutrition 142(7): 1390-1401. Mensink RP, Zock PL, Kester AD, Katan MB. 2003. Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. Am J Clin Nutr. 77(5): 1146-55. Mercier S, Villeneuve S, Moresoli C, Mondor M, Marcos B, Power KA. 2014. Flaxseed-Enriched Cereal- Based Products: A Review of the Impact of Processing Conditio. Comprehensive Reviews in Food Science and Food Safety. pp 400-412. Pietta PG. 2000. Flavonoids as antioxidants. J Nat Prod. 63(7):1035-42. United States Department of agriculture. Accessed November 24, 2014. Dietary Guidelines for Americans, 2010. Washington, D.C.: Office of Disease Prevention and Health Promotion. Available from http://www.health.gov/dietaryguidelines/2010.asp. Acesssed November 24, 2014. Weaver, C.M., Daniel, J.R 2003. The Food Chemistry Laboratory, 2 nd edition. CRC Press LLC. Boca Raton, FL. 137. Yuan JY, Smeele RJ, Harington KD, van Loon FM, Wanders AJ, Venn BJ. 2014. The effects of functional fiber on postprandial glycemia, energy intake, satiety, palatability and gastrointestinal wellbeing: a randomized crossover trial. Journal of Nutrition 13(76): 1186-91.
Appendix Figure 6: Trial 1- Control Figure 7: Trial 1- Variation 1 Figure 8: Trial 1- Variation 2
Figure 9: Trial 1- Comparison of each variation Figure 10: Trial 2- Control Figure 11: Trial 2- Variation 1
Figure 12: Trial 2- Variation 2 Figure 13: Trial 2- Comparison of each variation Figure 14: Trial 3- Control
Figure 15: Trial 3- Variation 1 Figure 16: Trial 3- Variation 2 Figure 17: Trial 3- Comparison of each variation
Figure 18: Example of baked Control Figure 19: Example of baked Variation 1 Figure 20: Example of baked Variation 2
Figure 21: Comparison of each baked variation Figure 22: Final baked products ready to be sampled and subjectively tested
Figure 23: ANOVA testing for Texture Analysis Figure 24: ANOVA testing for Hunter Colorimeter L values
Figure 25: ANOVA testing for Hunter Colorimeter for a values Figure 26: ANOVA testing for Hunter Colorimeter for b values
Figure 27: ANOVA testing for Water Activity