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The Effects of Adding: 1 The Effects of Adding Varying Amounts of Spinach to Boxed Brownies Adam Holley Jessica Kaag F&N 453 November 24, 2008 The Effects of Adding: 2 Abstract: Increasing the nutritional value of traditionally low nutrition foods has many benefits. The addition of spinach to traditional brownies may lend some answers to different ways that nutritional foods can be added to such products. In this experiment an attempt was made to incorporate nutritionally significant amounts of spinach into brownies while not creating changes in the attributes of flavor, texture, odor, and moisture content. It was found that the addition of nutritional ingredients is possible, but some changes in preparation and spinach processing may be required for desirable results. Introduction: There is a current trend in America that shows children are consuming less nutritionally dense foods. This lack of child nutrition is leading to health problems and chronic illnesses earlier in life than ever before. According to Krebs and colleagues, only 36 percent of children ages two to nineteen years of age are meeting their daily vegetable requirement of three to five servings. One of the main nutrients that children are becoming deficient in is iron. This is leading to anemia which can cause fatigue, loss of concentration, weakness, frequent colds and infections, and a pale complexion. A child can increase their iron intake by adding iron fortified cereals, meat, and leafy green vegetables to their diet (Harrar, 2005). Part of the problem with children's lack of vegetable intake is their dislike for vegetable's taste and texture. The idea for disguising vegetables in more kid-friendly foods is a strategy to get children to eat more vegetables. Many children will refuse to eat a serving of spinach, but will never turn down a brownie. By adding spinach to the brownie recipe, a child can eat a dessert without knowing that they are actually eating vegetables. According to Bessinger and The Effects of Adding: 3 colleagues, cannellini beans have been used in a similar manner. The cannellini beans were used to replace 25%, 50%, and 75% of the fat in the original recipe. After sensory tests using untrained panelists, it was found that 50% of the fat could be replaced with cannellini beans with little to no change in texture, taste, and flavor. By replacing 50 percent of the fat with pureed cannellini beans, the brownies had less fat and more nutrition than with the original recipe. Increasing your spinach intake can benefit adults as well as children. Spinach is high in many important nutrients such as vitamin K, vitamin A, manganese, folate, magnesium, iron, vitamin C, and many other nutrients necessary for human's health and well being. Spinach has even been shown to reduce risk for certain types of cancer (Esminger, 1986). Spinach has even been shown to reduce risk for certain types of cancer (Esminger, 1986). It has been shown to aid in the prevention of ovarian cancer, prostate cancer, and colon cancer. This is due to the antioxidants found in the spinach. Neoxanthin is a predominate carotenoid in leafy green vegetables such as spinach. This carateniod has been found to be a powerful antioxidant. It has been found to prevent the proliferation of prostate cancer cells (Asai 2004). With the preceding findings in mind, we will be setting the dependent variable as the quantity of spinach that can be added to brownies and still be undetectable by means of texture analysis using a Brookfield Texture analyzer, changes in water activity measured by a water activity meter, and through subjective panel rankings based on taste and moisture. The main concern with the outcome of this experiment is that the increased water content from the spinach will negatively affect the texture and overall quality of the brownies. This problem may be able to be avoided with further experimenting involving various fat content as well as spinach content. This would have to be tested in a separate experiment to allow for only one variable. The Effects of Adding: 4 This experiment will show if there is a possibility to increase the nutritional aspects of brownies while not sacrificing texture, flavor or moisture qualities typical of a traditional brownie. Methods: The brownies were prepared according to the box specifications and then each batch was separated into three equal portions. All ingredients were added in whole before dividing the test batch in to equal thirds. After the division of the batch, spinach was added to two of the thirds in the quantities of 284 and 369 grams respectively. The recipe in metric units is as follows: • 595 gram Box Duncan Hines Chewy Fudge Brownie Mix • 114 grams of egg • 59.25 mL water • 109 mL oil • 0 gram control, 284 grams, or 368.55 grams of Frozen Spinach (thawed and excess moisture drained off) • 22.9x12.7x7.6 cm baking pan Remove the spinach from the freezer. Let it thaw completely. Squeeze out the remaining moisture in the spinach and then set it aside. Set oven to 177 C. In a large bowl, add brownie mix, oil, water, egg, and spinach and then mix using a spoon until combined. Spray a 22.9x12.7x7.6 cm baking pan with cooking spray. Pour brownie batter into the pan and spread it evenly. Place in the pre-heated oven for 36 minutes. Remove them from the oven and then place on a rack to cool. Once cooled, cut into equal sized samples and served. The Effects of Adding: 5 The spinach that was used was packaged frozen chopped spinach. Before being added to the samples, the spinach was defrosted and drained through cheese cloth and the access moisture was squeezed out. To ensure equal moisture in all samples, the spinach was drained all at one time in the same batch. This way there was an equal amount of pressure applied and an equal amount of moisture was removed from all samples. After the addition of the spinach to the two samples, the samples were placed in separate 22.9x12.7x7.6 cm baking pans. All three samples were baked simultaneously in the same oven at 177oC rotating positions three times to ensure that any oven variation is accounted for. The samples spent a total time of 36 minutes in the oven. This procedure was completed a total of three times to create triplicate test batches for evaluation. Once baking was complete for each test batch, the samples were cooled to room temperature at 25 degrees C. Once at the desired temperature, texture analysis and water activity tests were completed. The texture analysis was completed using a Brookfield Texture Analyzer. The machine was equipped with a conical probe at a penetration speed of 0.5 mm per second and a force of 0.588 N. The texture analysis was undergone to observe any changes that may occur when spinach was added to the brownies. These changes in texture may be related to moisture content and the presence of the leafy green to the tested samples. To ensure accuracy, only center portions of the brownies were analyzed to decrease results representing the hardened edges of the samples that were closer to the sides of the baking pan. The water activity was taken using a water activity meter that was calibrated to zero before each test. Water activity was measure to find the optimum amount of spinach that can be added to the mix without changing the water activity qualities of a traditional brownie. The water activity will show the changes in available moisture in each sample of the brownies. To ensure accurate results, it is imperative that all The Effects of Adding: 6 samples produced were baked for the same amount of time and in the same oven positions. Subjective results were taken to ensure that the spinach additions did not produce any exceedingly undesirable flavors or textures. Samples were given using the randomization method. Each sample was given a random three digit number. From these samples, 50 participants of varying backgrounds were asked to rate the samples texture, flavor, odor, color, and overall appeal using a nine point hedonic scale. A representation of the sensory scorecard that was used in our experimentation can be viewed on the following page. Tables three, four and five show the results from the subjective testing of our samples and the correlating sample numbers that were presented in the sensory scorecard. The Effects of Adding: 7 Sensory Evaluation for Brownies (Please check the box that applies for each sensory attribute (Texture, Flavor, Odor, Color, and Overall Appearance) for each sample) Sample 152 Dislike Extremely Dislike Very Much Dislike Moderately Dislike Slightly Neither like nor Dislike Like Slightly Like Moderately Like Very Much Like Extremely Dislike Very Much Dislike Moderately Dislike Slightly Neither like nor Dislike Like Slightly Like Moderately Like Very Much Like Extremely Dislike Very Much Dislike Moderately Dislike Slightly Neither like nor Dislike Like Slightly Like Moderately Like Very Much Like Extremely Texture Flavor Odor Color Overall Appeal Sample 653 Dislike Extremely Texture Flavor Odor Color Overall Appeal Sample 457 Dislike Extremely Texture Flavor Odor Color Overall Appeal The Effects of Adding: 8 Results: Table 1: The Effect of Quantity of Spinach on the Texture (g) of Box Brownies as Measured by the Texture Analyzer Box Brownie Variable Average (g) Standard Deviation Range Control Box Brownies 33.0 4.5 28.7-37.7 Variable 1- 284 g Spinach Added 52.3 4.6 47.9-57.1 Variable 2- 369 g Spinach Added 43.5 11.9 29.9-52.3 Table 2: The Effect of Quantity of Spinach on Water Activity as Measured by the Water Activity System meter Box Brownie Variable Average Standard Deviation Range Control Box Brownies 0.600 0.07 0.546-0.683 Variable 1- 284 g Spinach Added 0.717 0.01 0.704-0.727 Variable 2- 369 g Spinach Added 0.833 0.02 0.821-0.851 Table 3: The Sensory Attributes of the Control Box Brownies (Sample 152) as Measured on a Hedonic Scale with 1 Being the Worst and 9 Being the Best Sensory Attribute Average Standard Deviation Range Texture 7.28 1.12 6.0-9.0 Flavor 7.87 1.25 6.0-9.0 Odor 8.10 1.11 5.0-9.0 Color 7.01 1.55 4.0-9.0 Overall 8.02 1.99 6.0-9.0 The Effects of Adding: 9 Table 4: The Sensory Attributes of the Brownie Variable with 284 g Spinach Added (Sample 653) as Measured on a Hedonic Scale with 1 Being the Worst and 9 Being the Best Sensory Attribute Average Standard Deviation Range Texture 4.78 1.98 2.0-6.0 Flavor 5.10 1.11 3.0-8.0 Odor 6.24 2.03 4.0-7.0 Color 6.06 1.25 3.0-7.0 Overall 5.13 1.99 2.0-7.0 Table 5: The Sensory Attributes of the Brownie Variable with 369 g Spinach Added (Sample 457) as Measured on a Hedonic Scale with 1 Being the Worst and 9 Being the Best Sensory Attribute Average Standard Deviation Range Texture 1.75 1.08 1.0-3.0 Flavor 2.83 1.12 1.0-4.0 Odor 4.14 1.75 1.0-6.0 Color 5.04 2.01 1.0-7.0 Overall 2.15 1.75 1.0-5.0 The Effects of Adding: 10 Table 6: Water Activity ANOVA AW Between Groups Within Groups Total Sum of Squares .081 .011 .093 df 2 6 8 Mean Square .041 .002 F 21.334 Sig. .002 Table 7: Texture Analysis ANOVA TA Sum of Squares df Mean Square F Between Groups 559.496 2 279.748 Within Groups 388.107 6 64.684 Total 947.602 8 Sig. 4.325 .069 60 50 Force (g) 40 30 20 10 0 Control 284 g Spinach Added 368 g Spinach Added Brownie Variation Figure 1: Average Grams of Force Required for Texture Analyzer to Penetrate Brownies at each Amount of Spinach The Effects of Adding: 11 0.9 0.8 Water Activity (aw) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 Control 284 g Spinach Added 368 g Spinach Added Brownie Variation Figure 2: Average Water Activity Measured in Brownies with Varying Spinach Levels 12 Hedonic Scale Rating (1‐9) 10 8 6 4 Control Brownies Brownies with 284 g of Spinach 2 Brownies with 369 g Spinach 0 Texture Flavor Odor Color Overall Sensory Attributes of Brownies Figure 3: Average Sensory Attributes of Box Brownies with Varying Levels of Spinach as Measured by Hedonic Scale The Effects of Adding: 12 Discussion: The health benefits of adding or increasing leafy green consumption in the daily diet is well documented and known. The objective of this experiment was to examine the possibility of masking the health benefits of such leafy green by adding them to well received brownies. With this tact, the addition of leafy greens to a child’s diet would be greatly increased. In looking at the effects of the addition of these greens, many attributes were analyzed. The main changes that were predicted to occur through the addition of spinach, our leafy green of choice, were thought to be observed in the texture, moisture content and sensory aspects of the brownies. The health benefits of spinach, when cooked and drained, stem from their being a good source of Niacin, and a very good source of Dietary Fiber, Protein, Vitamin A, Vitamin C, Vitamin E (Alpha Tocopherol), Vitamin K, Thiamin, Riboflavin, Vitamin B6, Folate, Calcium, Iron, Magnesium, Phosphorus, Potassium, Zinc, Copper and Manganese (nutritionData.com, 2008). With the standard serving size of this type of spinach being 180 grams the tested additions of spinach to the box brownies yield 42 grams of spinach per serving for the 284 g test and 55 g per serving for the 369 g test or 24% and 30% respectively of the regular spinach serving size. With this being noted, the amounts of spinach that were added to each sample add a significant amount of nutrition of a typical serving of brownies. In looking at the texture attributes of the brownies and how they may be effected by the addition of spinach in varying amounts, we expected to see no significant difference in the penetrating forced needed when measuring the brownies using a conical probe affixed to the Hunter Texture Analyzer. The data that was collected suggests that the most force needed for penetration was witnessed in the testing of the 284 g sample. The force required for the control sample was far less than the force required for the samples with the addition of spinach, by an The Effects of Adding: 13 average of 14.9 g of force. Therefore, there was a significant difference between all test samples as indicated in Table 6. When the samples were inspected, the causation for the unexpected texture results became evident. In the preparation of the spinach for this experiment, the chop of the spinach was large. In this test, the consistency of the spinach in the sample played a large role in the outcome of the texture analysis. A consideration of future testing would be to uniformly puree the spinach prior to its addition to the brownies. This application will also show merit with the analysis of sensory panel data. The other attribute of the brownies for objective consideration when adding in spinach was the final product water activity. Analysis of the water activity will show how the addition of spinach changes the available water in the prepared samples. Some implications of an increase in water activity are viable in the possibility of a decrease in prepared product shelf life. With an increase in available water, the possibility of microorganism growth also increases. This increase in water activity, if observed, can be decreased by a longer baking time or decreasing the liquids that are added in preparation when spinach is applied to the recipe. As expected, there was a positive and significant correlation to the amount of spinach that was added and the water activity of the end products. Because of this increase in the water activity, the moisture of the brownie was higher which may lead to an increased possibility of microbial growth, staling, and an overall decrease in the shelf life of the brownie product. After this analysis, omitting the water required in the recipe when adding the samples should be explored as a possible way of decreasing the water activity of the final baked product. The lengthening of the baking time was not recommended due to the possibility of increasing the dryness of the samples on the outside to ensure that the middle of the samples has had the correct amount of water removed. The Effects of Adding: 14 Along with mechanical analysis of the samples, subjective testing was observed in the areas of texture, flavor, odor, color, and overall liking of the samples. All of the samples were allowed to cool before subjective testing was done. This cooling decreases the spinach odor and flavor and allows it to be masked by the chocolate in the brownies. The original idea was that the 284 g sample would produce similar results to the control brownies. However, an inverse relationship was observed between the amount of spinach added to the samples and all of the sensory evaluation scales. With this in mind, the idea that was previously presented about decreasing the cut of the spinach to a puree once again becomes a factor. Analysis of the data shows texture to be least desirable attribute of the spinach added brownies when compared to the control. The odor, while still an issue, was the most similar attribute when compared to the control samples. With this being said, another masking technique, in addition to brownie cooling, would be to add in another flavoring from the leafy green, mint. By decreasing the cut size to a puree we believe that the texture distaste would be decreased within the subjective tests. The odor issue can be dampened by the addition of mint as a masking olfaction attribute. We also believe the addition of mint to the sample would also bolster the flavor profile of the spinach added samples in the same way it would aid the olfactory sensory data. The Effects of Adding: 15 References: Asai A, Terasaki M, Nagao A. An epoxide-furaniod rearrangement of spinach neoxanthin occurs in the gastrointestinal tract of mice and in vitro: formation and cytostatic activity of neochrome stereoisomers. Journal of Nutrition. 2004; 134(9):2237-2243. Bessinger, C., Szafranski, M., and Whittington, J. A., Pureed Cannellini Beans Can Be Substituted for Shortening in Brownies. Journal of the American Dietetic Association 105(8):1295-1298 (2005). Ensminger AH, Esminger M. K. J. e. al. Food for Health: A Nutrition Encyclopedia. Clovis, California: Pegasus Press; 1986. PMID:15210. Harrar, SarA N., Popeye’s Prescription. Prevention 57(11):127-128 (2005). Krebs-Smith SM, Ballard-Barbash R, Cleveland LE. Food intakes of US children and adolescents compared with recommendations. Pediatrics 100(3):323-329 (1997). NurtitionData: Know What You Eat. 2008. Spinach, cooked, boiled, drained, without salt. CondeNet Inc. Available from: http://www.nutritiondata.com/facts/vegetables-andvegetable-products/2627/2. Accessed: October 12, 2008.