Audrey Page Brooke Sacksteder Kelsi Buckley Title: The Effects of Black Beans as a Flour Replacer in Brownies Abstract: One serving of beans can provide 30% of an average adult s daily recommendation for fiber. Soluble fiber has been shown to help lower cholesterol and to help maintain blood sugar. Americans are not consuming enough fiber in their diets, beans are a cost effective way to add more fiber into the diet. This project examined the effect of replacing flour with different amounts of black beans and then examined the changes in appearance, taste, aroma, texture and color. A Texture Analyzer, Hunter Colorimeter and a taste panel were used to examine these changes in the brownies. The taste panel showed that the ½ black bean ½ flour recipe was the best liked. Therefore, this project evidenced that replacing flour with black beans was successful when replaced with ½ beans and leaving ½ of the flour in the original recipe. Introduction: Vegetables are foods of high nutrient density and relatively low energy content. In a study done to compare fresh, frozen, and canned vegetables in terms of nutrients per calorie and nutrients per penny, beans were concluded to be one of the lowest cost sources of potassium and fiber and provide the best nutritional value per penny. This study was conducted in an elementary school setting. While beans were categorized as one of the best nutritional values per penny, the children were consuming fewer beans than almost every other vegetable offered. A ½ cup of black beans counts as 1 ounce in the meat, poultry, fish, dry beans, and nuts or vegetables group. For a 2000 calorie diet, the daily recommendation is about 5 ½ ounces. Black beans are low in fat, cholesterol-free and provide 30% of the daily recommended amount of fiber in one serving. Black beans are a good source of B-complex vitamins, niacin, folate, magnesium, omega-3 fatty acids, calcium and soluble fiber. Soluble fiber has been known to help lower serum cholesterol and maintain blood sugar. Substituting black beans with flour in chocolate brownies is a way to increase bean intake amongst children and adults. Black beans are a good source of B-complex vitamins, niacin, folate, magnesium, omega-3 fatty acids, calcium and soluble fiber. Soluble fiber has been known to help lower serum cholesterol and maintain blood sugar. The latest USDA studies have places black beans at the top of the list of antioxidant-rich vegetables. Compared to red, brown, yellow and white beans; black beans are the highest in antioxidant content. One serving of black beans is equivalent to one serving of oranges. Beans rival many high antioxidant fruits such as cranberries, apples and grapes in their antioxidant content. Increased fruit and vegetable consumption has been associated with a reduced risk of mortality. In the past few years, more information has become available that concludes an increased consumption of antioxidants through fruits and vegetables will lead to a decreased risk of disease.
Substituting black beans with flour in chocolate brownies is a way to increase bean intake amongst children and adults. Ideally, if the experiment works, one brownie will provide an extra serving of vegetables through beans to the consumer. Brownies and other desserts are very popular amongst children and adults and would hopefully be appealing to eat. It is important that the black bean brownie have a similar texture to the control chocolate brownie. Since we will be using canned black beans they will have to be drained appropriately so that they do not add excess moisture to the brownie. It is very important that the finished product tastes good and is of similar consistency to a normal chocolate brownie. Methods: This project will test if drained black beans are a good flour replacer in chocolate brownies. The recipe that will be used is a simple chocolate brownie recipe from allrecipes.com. The ingredients are as follows: Ingredients (Control, 1 batch) 383.3 g (2c) sugar 229.5 g (1c) butter 55.6g (1/2c) cup cocoa powder 1 teaspoon vanilla extract 4 eggs 149.1g (1.5c) all-purpose flour ½ teaspoon baking powder ½ teaspoon salt The recipe will be made 1 batch at a time, each batch making about 20 brownies. When the time comes to mix the ingredients, they will be mixed in a room temperature bowl. The butter will be melted first, and then all of the ingredients will be added in order as stated above and stirred until the batter becomes a homogenous mixture. Once the mixture is ready, the batter will be poured into a 9 x 13 inch greased baking pan. The pan with the batter will be tapped against the counter to remove any possible air bubbles. Once this is done, the uncooked brownies will be allowed to bake in an already preheated oven at 350 F (177 C) for 25 minutes. This experiment will be started at 230pm on the Wednesday of our designated lab day. The brownies will be finished before lab is over, allowing volunteers in lab to be taste test subjects. The variables will be controlled by using the same utensils, same pan material for baking, and the same temperature of everything, an electric mixture to keep a consistent mixing speed, and the same baking time in the oven.
Once the product is finished, the product will be tested for texture using a texture analyzer, color, and taste. A sensory evaluation will also be done with a taste panel (see attachment). Replications: The experiment will be carried out through three different trials. Each trial will have each of the three different bean and flour ratios. The sample containing no beans will be the control. Each trial will be tested using a taste panel, the Texture Analyzer, and the colorimeter to measure dependent variables. In each trial, the same oven was used at the same set temperature cooking all three samples at a time. Measurements: Subjective: Subjects will use a hedonic ranking scale to evaluate taste, aroma, appearance and overall liking. The goal of these subjective tests is to have high evaluations of each characteristic in the mostly black bean brownies. Objective: To produce a brownie that has a similar texture and color throughout the variable changes utilizing a texture analyzer and a colorimeter. Discussion: The three variations were evaluated for overall liking, aroma, appearance and taste. A texture analyzer and colorimeter were also tested on each sample. These results are summarized in the tables below. From the data shown in tables 1.1, 1.2 and 1.3, the ½ black beans and ½ flour recipe was the most well liked according to the taste panel. The control and the all bean recipe were both ranked the same (3.3 out of 9) for overall liking. The most like appearance was for the control and the all bean recipe. The taste panel rated the ½ black beans and ½ flour recipes as the best tasting brownie. The control was rated the least liked for taste. This is a surprising result since flour is what most of the taste panel is used to and would expect from a brownie. The aroma was best in the all black bean brownie and was the least liked in the ½ flour recipe. The three variations were analyzed utilizing a texture analyzer and a colorimeter. The texture analyzer was used to determine the texture of the brownie variations. Each variation had three trials and each trial was tested. The texture analyzer used the cone probe and was set to the cake setting. In table 1.4, it can be seen that Sample 764 had the most consistent results with each trial having the force of compression of at least 20.0g. This could be an influence on the subjective measurement for overall liking seen in tables 1.1, 1.2, and 1.3. It was noted that with each sample, that one trial always measured higher than the other two. Figure 2.5 displays that the control, sample 538, required the largest force of compression with an average of 42.8g, relating to the denseness of the brownie.
The colorimeter measures the color of each variation. The colorimeter reports color in a variety of ways, including L*, a*, and b*. The parameter L* is the lightness component, ranging from 0-100, and parameters a* (green to red) and b* (blue to yellow) are known as the two chromatic components, which range from -120 to 120 (Leon 2005). This information has been summarized in table 1.4. It can be seen that each one of the variations had low L* parameters, which is typical when producing a brownie. The a* parameter for the control (sample 538) had higher values than sample 627 and sample 764. The b* parameter for each sample was toward the lower end of the range. Table 1.4 also demonstrates that sample 538 had the highest values overall with each parameter, while sample 764 had the lowest values. These results were seen when the product was made and the color of sample 764 was the darkest. Sources of Error: Due to the test asked for subjective measurements, there is a large room for error and biases. Individuals will rate dependent on what they have consumed already, the setting, food preference and their mood at the time. With each variation producing an outlier in the texture analysis, the operation of the analyzer could be an influence on the results. Results: Overall liking is on a scale of 1-9, 1 being the most liked and 9 being the worst. Appearance, taste and aroma are shown on a (1-3) scale. 1 being the best liked, and 3 being the worst. Table 1.1: Subjective Test on Overall Liking, Appearance, Taste and Aroma in a Brownie Containing all Flour Control Overall Liking Appearance Taste Aroma 1 2.6 1.4 1.8 2 2 3.2 1.6 1.8 1.5 3 4 2.5 2.4 2.1 Average 3.3 1.8 2.0 1.9 Table 1.2 Subjective Tests on Overall Liking, Appearance, Taste and Aroma in a Brownie Containing Half Flour and Half Black Beans 1/2 Flour 1/2 Black Beans Overall Liking Appearance Taste Aroma 1 2.8 2.4 2.2 1.8 2 2.5 2 1.6 1.7 3 3.8 2 1.9 2.4 Average 3.0 2.1 1.9 2.0
Table 1.3 Subjective Tests on Overall Liking, Appearance, Taste and Aroma in a Brownie Containing all Black Beans and No Flour All Black Beans Overall Liking Appearance Taste Aroma 1 2.2 2.2 2 2.2 2 4 1.7 2.5 1.8 3 3.6 1.5 1.6 1.5 Average 3.3 1.8 2.0 1.8 Figure 2.1: Subjective Measures of Overall Liking Overall Likeness of Brownies for Three s of Three Different Variables of Brownies Likeness Score 5 4 3 2 1 0 1 2 3 Average All Black Bean (764) Half and Half (627) Control (538) Figure 2.2: Subjective Measures of Appearance Appearance Scores for Three s of Three Variables of Brownies Appearance Score 3 2.5 2 1.5 1 0.5 0 1 2 3 Average All Black Bean (764) Half and Half (627) Control (538)
Figure 2.3: Subjective Appearance for Taste 3 2.5 Taste Scores for Three s of Three Variables of Brownies Taste Score 2 1.5 1 0.5 0 1 2 3 Average All Black Bean (764) Half and Half (627) Control (538) Figure 2.4: Subjective Appearance for Aroma 3 Aroma Scores for Three s of Three Variables of Brownies Aroma Scores 2.5 2 1.5 1 0.5 0 1 2 3 Average All Black Bean (764) Half and Half (627) Control (538)
Table 1.4: Forced measured by the Texture Analyzer and Color Measured by a Colorimeter on Three Variations of Brownie Texture Analyzer (Cone Probe and Cake Setting) Colorimeter Control 1 36.1g L=5.52, a=12.86, b=3.68 538 2 33.5g L=7.08, a=13.93, b=4.72 3 59.0g L=5.27, a=12.77, b=3.51 One Half 1 24.9g L=3.53, a=9.21, b=2.36 627 2 41.9g L=2.42, a=6.67, b=1.61 3 31.6g L=6.05, a+13.73, b=4.04 Full 1 22.0g L=.60, a=1.75, b=.40 764 2 29.5g L=.70, a=2.05, b=.46 3 23.0g L=.72, a=2.12, b=.48 Figure 2.5: Force Measured by Texture Analyzer Texture Analyzer (g) for Three s of Three Diferent Variables of Brownies Texture Analyzer (g) 70 60 50 40 30 20 10 0 1 2 3 Average All Black Bean (764) Half and Half (627) Control (538)
References: Bennink M. (2002) Consumption of Black Beans and Navy Beans (Phaseolus vulgaris) Reduced Azoxymethane-Induced Colon Cancer in Rats, Nutrition & Cancer, Vol.44, No. 1: pg 60-65. Drewnowski A, Rehm CD (2013) Vegetable Cost Metrics Show That Potatoes and Beans Provide Most Nutrients Per Penny. PLoS ONE 8(5): e63277. "Food In The News." Medical Update 30.7 (2005): 4. Corporate ResourceNet. Web. 23 Sept. 2013 Lee SI, Kim SD, Lee YK, Kim MJ, Lee IA, Choi J, Suh JW. (2013) Dietary effects of black bean fermented by Monascus pilosus on body weight, serum lipid profiles and activities of hepatic antioxidative enzymes in mice fed high fat diets. Korean J Nutr., Vol. 46, No.1: pg 5-14. **This article is in Korean but it was a link to the original pdf from the English translation. Leon K., Mery D., Pedreschi F. 2005. Color measurement in L*a*b* units from RGB digital images. Journal of Food Engineering. Quick and Easy Brownies Recipe - Allrecipes.com. (n.d.). Allrecipes - Recipes and cooking confidence for home cooks everywhere. Retrieved September 22, 2013, from http://allrecipes.com/recipe/quick-and-easy-brownies
Sensory Evaluation: Aroma Rank the three samples (1 3) based on the aroma of brownie 1=Best Aroma, 3= Worst Aroma 627 538 764 Appearance Rank the three samples (1 3) based on the physical appearance of brownie 1=Most Appealing, 3= Least Appealing 627 538 764 Taste Rank the three samples (1 3) based on the taste of brownie 1=Best Taste, 3= Worst Taste 627 538 764
Sensory Evaluation: After tasting, smelling, and observing the brownie please mark your overall liking on the scale below for each sample. 627 Like extremely Like very much Like moderately Like slightly Neither like nor dislike Dislike slightly Dislike moderately Dislike very much Dislike extremely 538 Like extremely Like very much Like moderately Like slightly Neither like nor dislike Dislike slightly Dislike moderately Dislike very much Dislike extremely 764 Like extremely Like very much Like moderately Like slightly Neither like nor dislike Dislike slightly Dislike moderately Dislike very much Dislike extremely