The effect of adding Acai to brownies could reduce the risk of potential health problems

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1 Abigail Stevens and Laura Griggs F&N 453 Team Project Written Report The effect of adding Acai to brownies could reduce the risk of potential health problems Abstract: Acai is known to be rich in anthoycyanins and phenol content (Tonan, 2008). Acai contains a great deal of antioxidants that are very beneficial to one s health. It has been proven that the increased consumption of acai berries have had a positive effect on human diseases. It has also been a positive influence on esophageal and gastrointestinal cancers as well (Seeram, 2008). Adding acai berries to brownies could impact the quality and also provide health benefits to consumers. A sensory panel evaluated the qualities of the mouth feel, flavor, aroma, and appearance of the brownies after acai supplement powder and acai juice were added. The linespread apparatus and texture analyzer were also used in order to check the viscosity and texture of the additional acai. Three brownies were made using a Duncan Hines milk chocolate premade brownie mix. The first was a control, the second used a brownie mix with the addition of three grams of acai powder, and the third used a brownie mix with acai berry juice replacing the water the brownie mix called for. The viscosity of the batter was tested using a linespread apparatus. The Brookfield texture analyzer was used on the finished product to determine the change in force needed between the three variables. Results from the objective tests showed that the variable with the additional acai powder required more force using the texture analyzer and was the most viscous. The variable using the acai juice did not vary too greatly from the control in either the linespread or the texture analyzer. Subjective data showed that additional acai powder was comparable to the control in mouth feel and flavor. The results of this experiment therefore indicate that additional acai powder may be added without greatly changing the components of brownies. Introduction: The acai berry is native to Brazil, and has just become a popular food item in the last couple of years in other countries including the United States. It is highly perishable, but is full of excellent health and nutritional qualities. Acai is rich in anthoycyanins and phenol content. It was reported that it had higher antioxidant capacity than other rich anthocyanin fruits such as blueberries, blackberries, and cranberries (Tonan, 2008). It has been proven that the increased

2 consumption of acai berries have had a positive effect on human diseases such as cardiovascular and neurodegenerative diseases. It has also been a positive influence on esophageal and gastrointestinal cancers as well (Seeram, 2008). The acai berry has a different composition than most fruits. Acai pulp has a high nutritional value: lipids can account for up to 50% and proteins for about 10% of dry matter (Lichtenthaler, 2005). Antioxidants consumed through the diet have been believed to counteract free radicals in the body. Free radicals are consistently formed as byproducts of aerobic metabolism in the human body (Schauss and others 2006). The experiments done on acai have varied results on the actual antioxidant strength. However, in one study experimenters found acai to have greater antioxidant strength of approximately 10% more than low bush blueberries or cranberries on a dried weight basis (Hassimotto and others 2005). There are reactive oxygen s and reactive nitrogen s such as superoxide, hydroxyl radical, peroxyl radicals, nitric oxide, and peroxyl nitrite. These types of free radicals have been associated with many chronic and degenerative diseases including vascular diseases, diabetes, cancer, and overall aging. In another experiment, freeze-dried acai fruit pulp/skin powder has been shown to be extremely powerful in its antioxidant properties against superoxide by SOD assay. In that same study the reactive oxygen radicals were significantly inhibited even at low doses of freeze dried acai (Schauss and others 2006). The purpose of the experiment was to see the effects of additional acai to brownies that could create a product with added nutritional benefits and with minimal changes to the quality of the product. The independent variables were the control brownie which was a plain Duncan Hines brownie mix. The second variable was three grams of acai supplement powder added to the brownie mix. The third final variable was 52 grams of acai juice supplemented for the 52

3 grams of water the brownie mix originally called for. The dependent variables were the measurements recorded from the Brookfield Texture Analyzer and the linespread apparatus. The texture analyzer measured the texture of the baked brownie of all three variables. The linespread apparatus measured the viscosity of the brownie batters. Flavor, mouth feel, aroma, and appearance were the dependent variable recorded from the sensory panel. Methods: In this experiment three different types of brownies were made. The control brownie was a plain Duncan Hines cake mix brownie. The next variable was the same brownie mix only with 3 grams of acai berry supplement powder added to the mix. The third variable was the brownie mix with 52 grams acai berry juice which was supplemented for the water that the recipe had called for. Three trials were conducted. One trial was completed before the next trial began. Each trial called for the same recipe for each variable of brownie. The recipe is listed below. Control: 1 box Duncan Hines Milk Chocolate Brownie Mix 2 Eggs 112 g. oil Test Variable 1: with Acai Powder 1 box Duncan Hines Milk Chocolate Brownie Mix 2 eggs 112 g. oil 3 grams of Acai Max Blend Powder 59 g Water Test Variable 2: with Acai Juice 1 box of Duncan Hines Milk Chocolate Brownie Mix

4 2 eggs 112 gm oil 52 g. Acai Juice blend Preheat oven to 177 degrees Celsius. All the ingredients were placed in a bowl. The contents were stirred with a spoon until well blended about fifty strokes. After the brownie mixtures were made, the viscosities of the batter were then tested by using the linespread apparatus. Fifty-five grams of the mixture was used and measured after a time period of five minutes. The brownie mixture was then placed in a greased cm by cm pan and cooked for 25 minutes. After the brownies were baked and cooled, the brownies were cut from the very center with edges being avoided for more accurate results. The texture was then analyzed using the Brookfield Texture analyzer. The setting was on a Cake setting using the round cylinder tip. The data was then collected for each brownie of each variable. The brownies were then evaluated by a sensory panel using the following score card. Please circle the option you feel most appropriate for each variable of for each of the senses. Mouth feel: Variable 379 Variable 852 Variable 603 Like extremely Like extremely Like extremely Like very much Like very much Like very much Like moderately Like moderately Like moderately Like slightly Like slightly Like slightly Neither like nor dislike Neither like nor dislike Neither like nor dislike Dislike slightly Dislike slightly Dislike slightly Dislike moderately Dislike moderately Dislike moderately Dislike very much Dislike very much Dislike very much Dislike extremely Dislike extremely Dislike extremely

5 Flavor: Variable 379 Variable 852 Variable 603 Like extremely Like extremely Like extremely Like very much Like very much Like very much Like moderately Like moderately Like moderately Like slightly Like slightly Like slightly Neither like nor dislike Neither like nor dislike Neither like nor dislike Dislike slightly Dislike slightly Dislike slightly Dislike moderately Dislike moderately Dislike moderately Dislike very much Dislike very much Dislike very much Dislike extremely Dislike extremely Dislike extremely Aroma: Variable 379 Variable 852 Variable 603 Like extremely Like extremely Like extremely Like very much Like very much Like very much Like moderately Like moderately Like moderately Like slightly Like slightly Like slightly Neither like nor dislike Neither like nor dislike Neither like nor dislike Dislike slightly Dislike slightly Dislike slightly Dislike moderately Dislike moderately Dislike moderately Dislike very much Dislike very much Dislike very much Dislike extremely Dislike extremely Dislike extremely Appearance: Variable 379 Variable 852 Variable 603 Like extremely Like extremely Like extremely Like very much Like very much Like very much Like moderately Like moderately Like moderately Like slightly Like slightly Like slightly Neither like nor dislike Neither like nor dislike Neither like nor dislike Dislike slightly Dislike slightly Dislike slightly Dislike moderately Dislike moderately Dislike moderately Dislike very much Dislike very much Dislike very much Dislike extremely Dislike extremely Dislike extremely Discussion: Once the data was collected, it was put into graphs and tables to compare and analyze the results. When reviewing the results of the linespread apparatus, it is clear that the addition of the acai powder and acai juice did affect the viscosity of the batters (see Table 1 and Figure 1). The averages of the results show that the batter with the additional acai powder was the most viscous.

6 The variation with the addition of the acai juice was overall the second most viscous. The control brownie batter showed the least amount of viscosity. Secondly, the results of the texture analyzer were reviewed (see Table 2 and Figure 2). When looking at the average of the three trials, the addition of the acai powder resulted in the greatest force necessary to penetrate the brownie. This was to be expected because the brownie contained more dry ingredients. The more dry ingredients affected the texture of the brownie. The brownie with the addition of acai juice required the second greatest force. The force required was not a great deal more than that of the control. The slight difference could be due to the fact that the acai juice is more viscous than the water it replaced. The control brownie required the least amount of force in reference to the variables. Overall, the important information data obtained from this test was that the additional acai powder did require more force, but not a great deal. Additional acai juice required even a smaller amount more of force than the control. Acai powder or juice could be added without much affect to the texture of the brownie. Next, the results of the subjective tests were averaged and reviewed. The panelists were asked to taste and rank the mouth feel, flavor, aroma, and appearance of the three brownies. Phrases were provided for the panelists to circle. The results for each trial were averaged (See graph 3 for the coding values). The control ranked higher than the other two variable brownies in mouth feel and aroma. The brownie with the additional acai powder was only a tenth of a point lower than the control with regards to mouth feel. The control brownie and the brownie containing the three grams of acai powder ranked evenly in flavor. This is important because the panelist enjoyed the flavor of the brownie that contains additional health benefits with the

7 additional acai powder equally to the control brownie. Appearance was ranked highest among the brownie containing the additional acai juice (See graph 3 and table 3). Sources of error could have been when using the linespread apparatus. When determining the points of movement in the pan, it was often hard to be exactly precise. After completing all three trials, it was noticed that the brownies from trial one varied from the other two. Brownies from trial one were different in color, the way they baked, and overall texture before and after baking. This was proven by the results from the linespread apparatus and the texture analyzer. For future experiments, the Brookfield Viscometer would be more accurate to measure the viscosity than the Linespread Apparatus. More acai powder or more acai juice could be added to variables in the future. This would add more health benefits because of the higher amount of antioxidants. There would also be more difference between the variables. It would be interesting to determine the maximal amount of acai one can add before making the quality of the brownie decrease tremendously. Results: Table 1: The Effect of the Addition of Acai Powder and Acai Juice on the Viscosity (mm) of the Brownies as Measured by the Linespread Apparatus: Variable 379 (control) Variable 852 (addition of acai powder) Variable 603 (addition of acai juice) Trial Trial Trial Average Standard Dev

8 Table 2: The Effect of the Addition of Acai Powder and Acai Juice on the Texture (g) of the Brownies as Measured by the Texture Analyzer: Variable 379 (control) Variable 852 (addition of acai powder) Variable 603 (addition of acai juice) Trial Trial Trial Average Standard Dev Table 3: The Average of the Effect of the Addition of Acai Powder and Acai Juice on the Mouth Feel, Flavor, Aroma, and Appearance of the Brownie as Measure by Subjective Tests* from All Three Trials: Variable 379 (Control) Variable 852 (Addition of Acai Powder) Variable 603 (Addition of Acai Juice) Mouth feel Flavor Aroma Appearance (* 9= Like Extremely, 8=Like Very Much, 7=Like Moderately, 6=Like Slightly, 5=Neither Like Nor Dislike, 4=Dislike Slightly, 3=Dislike Moderately, 2=Dislike Very Much, 1=Dislike Extremely)

9 Linespread (mm) 10 Millimete Trial 1 Trail 2 Trial 3 Average Variable 379 (control) Variable 852 (addition of acai powder) Variable 603 (addition of acai juice) Trials Figure 1: The Effect of the Addition of Acai Powder and Acai Juice on the Viscosity (mm) of the Brownies as Measured by the Linespread Apparatus Texture Analyzer (g) 250 Grams Variable 379 (control) Variable 852 (addition of acai powder) Variable 603 (addition of acai juice) 0 Trial 1 Trail 2 Trial 3 Average Trials Figure 2: The Effect of the Addition of Acai Powder and Acai Juice on the Texture (g) of the Brownies as Measured by the Texture Analyzer

10 Subjective Data Mouth feel Flavor Aroma Appearance Variable 379 (Control) Variable 852 (Addition of Acai Powder) Variable 603 (Addition of Acai Juice) Figure 3: The Average of the Effect of the Addition of Acai Powder and Acai Juice on the Mouth Feel, Flavor, Aroma, and Appearance of the Brownie as Measure by Subjective Tests from All Three Trials.

11 References: Hassimoto NM, Genovese MI, Lajolo FM Antioxidant Activity of Dietary Fruits, Vegetables, and Commercial Frozen Fruit Pulps. Journal of Agriculture and Food Chemistry 53(8): Lichtenthaler R Total Scavenging Capacities of Euterpe oleracea Mart (Acai) fruits. International Journal of Food Sciences and Nutrition 56(1): Schauss AG, Wu X, Prior RL, Ou B, Huang D, Owens J, Agarwal A, Jensen GS, Hart AN, Shanbrom E Antioxidant Capacity and Other Bioactivities of the Freeze-Dried Amazonian Palm Berry, Euterpe oleraceae Mart. (Acai). Journal of Agricultural and Food Chemistry 54(22): Seeram NP Berry Fruits: Compositional Elements, Biochemical Activities, and the Impact of Their Intake on Human Health, Perfomance, and Disease. Journal of Agriculture Food Chemistry 56(3): Tonan RV Influence of process conditions on the physiochemical properties of acai (Euterpe oleraceae Mart) powder produced by spray drying. Journal of Food Engineering 88(3):