The Effect of Full Fat Soy Protein Flour on the Texture, Moisture and Color of Cheesy Bread

Transcription

1 The Effect of Full Fat Soy Protein Flour on the Texture, Moisture and Color of Cheesy Bread Nutrition 453 Research Project Jennifer Addison, Kelly Gates &Tracey Ropp 11/19/2012

2 Table of Contents Abstract.. 2 Introduction Methods Work Plan Recipe and Procedures Control Variable: 100% Enriched White Flour Variable 1: 100% Soy Flour Variable 2: 50% Soy Flour & 50% Enriched White Flour Variable 3: 25% Soy Flour & 75% Enriched White Flour Object Test Procedures Water Activity Hunter Calorimeter Texture Analyzer Subject Test Procedures Point Hedonic Scale Results Water Activity Hunter Calorimeter Texture Analyzer Discussion Results Take Home Message Future Work References Appendix

3 Abstract: Since Americans eat a high amount of baked goods, specifically breads, adding soy protein to cheesy bread can improve health benefits to a popular product. Osteoporosis and cardiovascular disease are both prevalent and on the rise in the United States population. Osteoporosis affects over four and a half million post menopausal women in the United States as of today. On the other hand, cardiovascular disease is the number one killer of men and women in America. Cheesy bread was tested with varying levels of full fat soy protein flour and enriched white flour and tested on moisture, texture and color to determine overall consumer preference. With the substitution of soy protein flour in cheesy bread, it can enhance health benefits to combat these two diseases. The data shows no significant difference in color, texture and moisture between variables making this product viable for consumers to combat the risk of cardiovascular disease and osteoporosis. Introduction: The purpose of testing the effects of soy flour on cheesy bread is to determine the level of soy that can be added without effecting flavor, texture, moisture and color in the product while also improving the nutritional value. The problem with the original cheesy bread product is that it contains unbleached white flour which is considered a refined grain. Refined grains lack calcium and protein which are important aspects of any healthy diet. By replacing the unbleached flour with full fat soy flour, the cheesy bread has added calcium and protein incorporated into it. The independent variable for this experiment was the amount of full fat soy protein flour and the dependent variables were color, texture and moisture. Soy protein was found to be a better protein source in the diet than animal protein because it lacks cholesterol that the animal sources have. Cholesterol is a component to high LDL levels that leads to cardiovascular disease. Replacing meat protein with soy protein in the diet can also reduce weight, which is also another leading factor of cardiovascular disease. Soy protein also contains soy isoflavones. These are important to cardiovascular health because they dilate the arteries lowering cholesterol and the condition of hypercholesteroldemia, which is the diagnosis of high cholesterol. With the dilation of the arteries, the blood can flow more freely, thereby reducing hypertension in individuals that consumed soy protein. Like most foods, in the studies, soy protein had the most effect on individuals that had a poor diet and changed to a better diet and exercise. With the incorporation of soy flour it provides these added nutrients which are needed to abate osteoporosis, cardiovascular disease and other chronic diseases related to calcium and protein intake (Sacks, 2006). 2

4 Osteoporosis affects 4.5 million post menopausal women in the United States as of 2012 (Centers for Disease Control, 2012). Low estrogen levels in postmenopausal women dramatically inhibit bone health. The best way to improve bone health at this point is from dietary sources. The consumption of soy products have shown to improve bone markers in bone in women that are postmenopausal. The best results came when the consumption of soy products had been taking throughout long periods of time such over the span of years. Soy protein in menopausal and postmenopausal women helped improved the markers of bone health in the fact it prevented the annual bone loss. Soy isoflavones partake in the metabolism of sex hormones such as estrogen (Lanou, 2011). Estrogen plays a key role in bone health by stimulating osteoblasts in bones which combats osteoporosis. The soy isoflavones can also contain cholesterol lowering properties as well as anticarcinogenic effects. In combination with other dietary factors, soy protein aids in the rebuilding of more bone (Bawa,2010). Cardiovascular disease is the number one killer in men and women; the level of mortality is over one million people each year (Sacks, 2006). Cardiovascular disease can come from obesity, high carbohydrate levels, high blood pressure, diabetes and high LDL levels. Soy protein has been show to improve the status of all of the health risks and lower the potential risk of coronary heart disease. High dietary ingestion of meat proteins has been correlated with high rates of obesity in individuals. It has been show that switching to a diet that is based on soy protein that weight will decrease, and therefore the rate of obesity, which will decrease risk factors for coronary heart disease. Soy protein lowers the level of carbohydrates ingested because the protein is plant based. Even though animal protein diets are lower in carbohydrates, they contain other factors, such as cholesterol, that can contribute to cardiovascular disease. Animal proteins also contribute to high blood pressure. Since animal proteins contribute to plaque build up in the arteries, it s harder for the blood to move through and therefore pushes against the artery walls. Soy protein actually reduces blood pressure instead of contributing to factors that create high blood pressure. Even though there is no connection between protein status and type two diabetes, it has been shown that ingestion of soy protein aids in insulin crossing the intracellular membrane. In this experiment, the combination of soy protein and carbohydrates would be a good combination for diabetes because of the carbohydrates for the glucose and the soy protein with the insulin. Even though it is not a significant amount, soy protein does lower LDL levels, but it does not have an effect on other lipoproteins in the blood. Even with the limited reduction in LDL levels, coronary heart disease can still be reduced (Clifton, 2011). 3

5 To measure the effects of soy flour on the product, objective and subjective methods were used. The objective methods used for this experiment were the Water Activity, Hunter Calorimeter and the Texture Analyzer. The Water Activity objective test was used to determine the moisture content of the cheesy bread. This test is based on the product s dew point and can affect the product s texture and shelf life (Daniel, 2012). The Hunter Calorimeter objective test provided results for the color or appearance of each of the variables through L, a and b values (Daniel, 2012). The color change could influence consumer preference so the addition of soy protein flour could affect the product s appearance and desirability. The Texture Analyzer is a direct texture measurement using force to cut, compress or puncture a given product (Daniel, 2012). The subjective method used for this experiment was the 9 Point Hedonic Scale; this is indicative of consumer preference. The consumers testing the different products compared each variable by texture, flavor and preference. The Hedonic Ranking ranges from dislike a product extremely (1) to liking a product extremely (9). The Maillard Browning Reaction will occur in the cheesy bread causing the bread to change color. This reaction occurs when amino acids and reducing sugars combine to yield a colored product when heat is applied. Temperature directly effects Maillard Browning; the higher the temperature, the more the color changes. During the cheesy bread experiment, the goal was not to induce or reduce Maillard browning because golden appearances are more appealing to consumers. Overly browned products are not attractive to consumers and may not be acceptable for purchase. During the Maillard Reaction, amino acids can be lost which affects the nutritional content of the product. Maillard Browning is beneficial for the appearance of the product to an extent; however, it can also decrease the nutritional value and may cause concern for mutagenic effects (Daniel, 2012). Methods: Three cheesy bread trials were conducted during this research project. The replication was done to ensure validity, precision and accuracy. Each of these trials contained four different variables of either full fat soy flour, enriched white flour or a combination of both. The soy flour in this experiment is the independent variable which is being substituted for various amounts enriched white flour. By using random, three digit, non consecutive numbers and not putting the samples in any specific order based on flour ratios or sample numbers, the cheesy bread trials decreased the levels of bias within this experiment. This experiment follows a specific process which was acquired from a family recipe. The cheesy bread control contained 192 grams of enriched white flour; while, the experimental trials included: 4

6 Variable 1: 100% Soy Flour grams of soy flour Variable 2: 50% Soy Flour & 50% Enriched Flour grams of soy flour 96 grams of enriched flour Variable 3: 25% Soy Flour & 75% Enriched Flour grams of soy flour 142 grams of enriched flour The work plan that was followed to prepare the recipe and to complete testing was: 1. Enter the lab and preheat the oven to 375 F. 2. Then prepare the bread by combing yeast, softened butter, sugar, salt, and warm milk in a mixing bowl. Then add half the flour being used for the variable. Mix together thoroughly then add water. Mix these ingredients together while slowly adding the remaining flour or soy flour. Knead until smooth on a lightly floured surface. Place the dough in a greased bowl, cover, and let rise in a warm place. Then place the dough in a nine inch greased cake pan and press the dough to the edges. Prick the dough with a fork and bake at 375 F for ten to fifteen minutes, or until golden brown. 3. Melt the butter and add to dry ingredients for the toppings to the melted butter. 4. After the bread has cooked, top with melted butter mixture and place back it back in the oven for three minutes or until cheese melts. 5. Remove the bread from the oven and cut into squares for the sensory test. 6. Use appropriate product size for the texture analyzer, Hunter calorimeter, and water activity machine. 7. Record the results. 8. Repeat steps 1 through 7 two more times for a total of three trials. 9. Clean up the lab area. Bread: 3.7 g active dry yeast ml of warm water 15 g of softened butter 8.5 g of sugar 1.5 g of salt ml of warm milk Varying amounts of flour/soy flour (see below) Toppings: 20 g of onion powder Recipe: 5

7 113 g of butter 4 g of oregano 6 g of garlic salt 250 g of mozzarella cheese To make the bread combine the yeast, softened butter, sugar salt and warm milk into a mixing bowl; mix well. Then add half of the flour that is needed in the recipe. Mix together the ingredients slowly adding the warm water. Add the remaining flour to the mixture and continue to mix until all flour has been incorporated. Take the bread out of the bowl and knead on a lightly floured surface. Place the dough ball into a greased bowl and cover to let the dough rise. Make sure you place the bowl in a warm place to help the yeast. After the dough has risen, place the dough into a nine inch greased cake pan and press the dough to the edges. Prick the dough with a fork and back at 375 F for ten to fifteen minutes. While the dough is cooking, melt the butter for the topping and add the onion powder, oregano and garlic salt to the butter. Stir the seasonings together. Once the dough has cooked for the allotted amount of time take it out of the oven and brush the butter mixture over the bread. Add the mozzarella cheese on top of the bread and put it back into the oven for three minutes or until the cheese has melted. Each recipe contained a different amount of soy flour or bleached white flour. The control, sample 845, contained 192 grams of enriched white flour, then the three variables that were tested contained varying amounts of soy flour and white flour. Sample 439 contained grams of soy flour and no white flour. Sample 340 used 96 grams of white flour and grams of soy flour, giving this variable a 50/50 ratio of flours. The last variable was sample 237 which contained 142 grams of white flour and grams of soy flour which gave it a ratio of 75/25 white flour to soy flour. Once the cheesy bread was fully cooked, the objective and subjective tests were then carried out. The objective tests that were completed on the final product were the Texture Analyzer, Hunter Calorimeter and Water Activity. Each of these tests was used to test the texture, color and moisture content of the bread. The Texture Analyzer was used directly test the texture of each variable. Since soy protein flour was added to the bread, this test was used to determine its effects on the quality of the bread product. Each variable of cheesy bread was cut into sizable pieces and placed onto the platform of the machine. A metal probe then inserted itself into the bread to measure the texture of each variable. This data can be viewed in Table 2.1 and Figure 2. The Hunter Calorimeter was also used to determine the color of the sample which could affect a consumer s preference to the product. This test provided the L, a and b values to show color changes 6

8 between the variables. The bread was cut into small pieces and placed in a petri dish. The machine then tested each sample for the L, a and b value and then they were recorded. This data can be viewed in Table 3.1 through Table 3.3 and Figure 3 through Figure 5. The last objective test that was conducted was the Water Activity. This measurement can identify a product s texture and shelf life stability by measuring the moisture content of the product. For this test, the bread was cut into very small pieces and placed into small plastic containers. These containers were inserted into the machine and it read the water activity of each variable. The results were recorded and can be viewed in Table 1.1 and Figure 1. Subjective measurements were also taken for each trial and each variable. The 9 Point Hedonic Scale was used to determine texture, flavor and consumer preference. Panelists were asked to taste each variable and rank them on a scale from 1 to 9. The panelists were not aware of any changes to the bread and were to rank the samples according to texture, flavor and preference. All samples were randomly numbered with non consecutive numbers and no specific order of the product. This data can be viewed in Table 4.1 through 4.3 and Figure 6 through Figure 8. The following scorecard was used for the sensory analysis completed by random individuals. Cheesy Bread Scorecard (439) Texture: Soft, Chewy Hard, Dry Flavor: No Flavor Full Flavor Preference: Strongly Dislike Dislike Neutral Like Strongly Like (237) Texture: Soft, Chewy Hard, Dry Flavor: No Flavor Full Flavor Preference: Strongly Dislike Dislike Neutral Like Strongly Like 7

9 (845) Texture: Soft, Chewy Hard, Dry Flavor: No Flavor Full Flavor Preference: Strongly Dislike Dislike Neutral Like Strongly Like (340) Texture: Soft, Chewy Hard, Dry Flavor: No Flavor Full Flavor Preference: Strongly Dislike Dislike Neutral Like Strongly Like Results Three separate trials were completed using a control and three different variables with varying amounts of soy protein flour. Each of these trials was tested objectively and subjectively. The Hunter Calorimeter, Water Activity and Texture Analyzer were used to test the objective data and the 9 Point Hedonic Scale was used to test the subjective data. TABLE 1.1 Water Activity for All Trials with Average Activity and Standard Deviations Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average a a a a Standard Deviation

10 Water Activity (grams) Water Activity ± ± ± ± % Soy 75% White, 25% Soy Control 50% Flour, 50% Soy Cheesy Bread Sample Average FIGURE 1 This figure shows the results of the water activity for all variables by using the average of all three trials. The standard deviations are also represented on this figure. TABLE 2.1 Texture Analyzer for All Trials with Average Texture and Standard Deviations Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average 51.7 a a a a Standard Deviation Texture Analyzer (grams) ± Texture Analyzer ± ± ± % Soy 75% White, 25% Soy Control 50% Flour, 50% Soy Cheesy Bread Variable Average FIGURE 2 This figure shows the results of the texture analyzer for all variables by using the average of all three trials. The standard deviations are also represented on this figure. 9

11 TABLE 3.1 Hunter Calorimeter L Values for All Trials with Standard Deviations Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average a a a a Standard Deviation L value Hunter Calorimeter L Values ± ± ± ± % Soy 75% Flour, 25% Soy Control 50% Flour, 50% Soy Cheesy Bread Variable Average FIGURE 3 This figure shows the results of the hunter calorimeter L values for all variables by using the average of all three trials. The standard deviations are also represented on this figure. TABLE 3.2 Hunter Calorimeter a Values for All Trials with Standard Deviations Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average a a a 5.51 a Standard Deviation

12 a Values Hunter Calorimeter a Values % Soy 75% Flour, 25% Soy Control 50% Flour, 50% Soy Cheesy Bread Variable Average FIGURE 4 This figure shows the results of the hunter calorimeter a values for all variables by using the average of all three trials. The standard deviations are also represented on this figure. TABLE 3.3 Hunter Calorimeter b Values for All Trials with Standard Deviations Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average a ab ab b Standard Deviation b Values Hunter Calorimeter b Values 100% Soy 75% Flour, 25% Soy Control 50% Flour, 50% Soy Cheesy Bread Variable Average FIGURE 5 This figure shows the results of the hunter calorimeter a values for all variables by using the average of all three trials. The standard deviations are also represented on this figure. 11

13 TABLE Point Hedonic Scale Rating for All Trials on Texture Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average 3.27 a 4.93 a 3.93 a 3.67 a Hedonic Scale Ranking Texture 100% Soy 75% White /25% Soy Control 50% White/50% Soy Cheesy Bread Variable Average FIGURE 6 This figure shows the results of the 9 Point Hedonic Rating Scale texture values for all variables by using the average of all three trials. TABLE Point Hedonic Scale Rating for All Trials on Flavor Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average 6.9 a 3.93 a 5.3 a 6.33 a 12

14 Flavor Hedonic Scale Ranking % Soy 75% White /25% Control Soy Cheesy Bread Variable 50% White/50% Soy Average FIGURE 7 This figure shows the results of the 9 Point Hedonic Rating Scale flavor values for all variables by using the average of all three trials. TABLE Point Hedonic Scale Rating for All Trials on Preference Control 100 % Soy 50% White 50% Soy 75% Soy 25 % White Trial Trial Trial Average 7.33 a 2.7 a 5.6 a 6.83 a Hedonic Scale Rnaking Preference 100% Soy 75% White /25% Soy Control 50% White/50% Soy Cheesy Bread Variable Average FIGURE 8 This figure shows the results of the 9 Point Hedonic Rating Scale flavor values for all variables by using the average of all three trials. 13

15 Discussion The purpose of this research project was to test the effects of soy flour on cheesy bread to determine the level of soy that can be added without effecting flavor, texture, moisture and color in the product while also improving the nutritional value. Through three trials, overall it was found that the cheesy bread contained no significant difference between the amount of moisture and texture of the variables despite the levels of soy protein flour added. The b value of the Hunter Calorimeter was found to be significantly difference because the P value is less than 0.01 when comparing the 100% soy flour to the 50% white flour and 50% soy flour. This indicates that there is no possibility that the outcome was by chance. Figure 5 and Table 3.3 show this data. It was found that when full fat soy protein flour replaced the enriched white flour by half or more, the overall consumer ratings decreased dramatically. The panelists preferred the control overall; however, the 75% enriched white flour and 25% full fat soy protein flour was found to be very close to the control in preference, texture and moisture. The 100% full fat soy protein flour variable was the least preferred, had the lowest texture and flavor ratings. Figure 6 through Figure 8 show these results. The panelists overall chose the control to be the most desirable product with the 100% full fat soy protein flour variable to be the least desirable product. The appearance of the dough before baking was very dry, crumbly and grainy compared to the soft, smooth and doughy feel of the control. The dough of the 100% full fat soy flour did not rise or expand while the control and other two variables did. In respect to the 75% enriched white flour and 25% full fat soy protein flour and the 50% enriched white and 50% full fat soy protein flour, both of the variables had some similar qualities to the control dough, however, the 50%/50% had more similarities to the 100% full fat soy protein flour. Both of these variables did however expand and rise before baking and had a better overall appearance than the 100% full fat soy protein flour. The Water Activity, shown in Table 1.1 and Figure 1, shows there are no significant differences between the control and the variables. This shows positive results for substituting full fat soy protein flour for enriched white flour because the level of water activity did not change. This means the moisture content did not change between variables. The Texture Analyzer results can be viewed in Table 2.1 and Figure 2. The data collected and ran in the SPSS program did not show any significant differences between the variables. The Hunter Calorimeter, which can be viewed in Tables 3.1 through 3.3 and Figure 3 through Figure 5 shows the objective data results. The Hunter Calorimeter is measured with the L, a and b values. The b value, showing the blue and yellow colors, showed one significant difference between the 100% full fat soy protein flour and the 50% full fat soy protein flour and 50% 14

16 enriched white flour. The more positive the value, the more yellow the product which indicates a difference in the product s yellowing color between these two variables. The L and a values showed no significance between the variables. The overall conclusion from this research study is that replacing full fat soy protein flour with enriched white flour up to 50% will produce a similar, healthier product based on subjective data and literature reviews. The SPSS data showed no significant difference between the control and the variables used except for the Hunter Calorimeter b value data between the 100% full fat soy protein flour and the 50% full fat soy protein flour and 50% enriched white flour. Although the data does not indicate this, the products did differ in texture and color especially between the control and the 100% full fat soy protein flour. In closing, the data shows no significant difference in color, texture and moisture between variables making this product viable for consumers to combat the risk of cardiovascular disease and osteoporosis. During replication of this research project, there a few corrections that would need to be applied to decrease the chance of error. These errors were found after the completion of all three trials and after all data had been collected and analyzed. By using more panelists, the standard deviation could be lowered and more panelists would be used which would broaden the variety of taste preferences. For future objective testing, the product should not be tested with the toppings on the bread. Since the full fat soy protein flour was only added to the bread itself and not the toppings, the bread should be the only piece of the product that is tested. The toppings should still be added for the subjective testing since the product is cheesy bread. Each trials subjective and objective data should be collected at the same time instead of waiting until the following day due to properties of the food changing from cooling back to heating. References Daniel J Food Chemistry Lecture Notes volume 5.0: Bawa S The Significance of Soy Protein and Soy Bioactive Compounds in the Prophylaxis and Treatment of Osteoporosis. Journal of Osteoporosis article ID , 8 pages. Center for Disease Control Calcium and Bone Health. Web. Clifton, Peter M Protein and Coronary Heart Disease: The Role of Different Protein Sources. Current Atherosclerosis Reports. 15

17 Ivanovski B, Seetharaman K, Duizer LM Development of Soy Based Brad with Acceptable Sensory Properties. Journal of Food Science 71: Kenny AM, Mangano KM, Abourizk RH, Bruno RS, Anamani DE, Kleppinger A, Walsh SJ, Kerstetter JE Soy Proteins and Isoflavones Affect Bone Mineral Density in Older Women: a Randomized Controlled Trial. American Journal of Clinical Nutrition, 90: Lanou AJ Soy Foods: Are They Useful for Optimal Bone Health? Therapeutic Advances in Musculoskeletal Disease. Web. Sacks, Frank, Lichtenstein, Horn, Harris, Kris Etherton, Winston Soy Protein, Isoflavones, and Cardiovascular Health: An American Heart Association Science Advisory for Professionals from the Nutrition Committee. Journal of the American Heart Association 1044th ser Appendix: I. Maillard Browning Chemistry (Weaver and Daniel, 2003) 16

18 II. Photographs of the Control, 100% Soy Flour, 75% White Flour and 25% Soy Flour, 50% White Flour and 50% Soy Flour. Control Variable 50% White Flour, 50% Soy Flour 75% White Flour, 25% Soy Flour 100% Soy Flour 17