The Effect of Blackstrap Molasses on Cookies 11/21/2011 FN 453 Written Report Hannah Abels, Shane Clingenpeel and Jennifer Smith
Hannah Abels Shane Clingenpeel Jennifer Smith The Effect of Blackstrap Molasses on Cookies Abstract Recent studies show the importance of antioxidants for disease and cancer prevention. With the average intake of sugar being 160 pounds a year for the average American, it is essential to get the optimal amount of nutrients and antioxidants through diet, furthermore sugar. Black strap molasses is a natural and common substitute for brown sugar and has a higher content of antioxidants compared to brown sugar, which is part refined sugar. Blackstrap molasses has higher nutritional benefits, reaching 14 20% of the daily value of the following nutrients: iron, potassium and calcium. By replacing packaged, brown sugar for black strap molasses and granulated, white sugar, it is assumed that the color, texture and taste preference will change depending on the independent variable while increasing the nutritional content as well. The independent variable is the amount of black strap molasses added to each recipe. Analyses of objective and subjective tests show that there is a significant difference in the texture and color but not for taste. Therefore, replacing brown sugar with black strap molasses will help one achieve their daily intake of iron, potassium and calcium and could potentially reduce the risk of cancer. Introduction According to the Environmental Magazine, Americans consume 160 pounds of sugar a year (Harris, 2001). With the high consumption of sweet products and low nutritional value in most sugars, American s health is an issue at hand. The high levels of sugar are resulting in increased health issues, including obesity, diabetes and heart problems. Brown sugar is a common ingredient in baked products.
A natural substitute for brown sugar, which contains increased nutritional benefits, is blackstrap molasses. Per tablespoon, blackstrap molasses contains 3.5 milligrams Iron, 170 milligrams Calcium, 500 milligrams Potassium and 0.4 milligrams Copper. The nutritional benefits of blackstrap molasses is equivalent to almost twenty percent of the Daily Value for Iron, seventeen percent of the Daily Value for Calcium and fourteen percent of the Daily Value for Potassium. Brown sugar, on the other hand, contains 1 milligram of Iron, 40 milligrams of Calcium, 290 milligrams of Potassium and 0.1 milligrams of Copper. A study by Phillips, Carlsen and Blamhoff, on the antioxidant content of substitutes for refined sugar, shows dark and blackstrap molasses have the highest antioxidant content of the sugars studied. The study used the ferric reducing ability of plasma (FRAP) to estimate the total antioxidant capacity. The FRAP of dark and blackstrap molasses was 4.6 to 4.9 mmol/100 grams, compared to brown sugars 0.2 to 0.7 mmol FRAP/100 grams. These results showed that substituting alternative sweeteners could increase antioxidant intake an average of 2.6 mmol/day, similar to the amount found in a serving of berries and nuts (Phillips, Carlsen and Blamhoff, 2009). The goal of this project is to increase nutritional content while providing a satisfying product by replacing packaged brown sugar with blackstrap molasses. The null hypothesis for this experiment is that the amount of black strap molasses will not have an effect on the color, texture and taste of the cookie. The independent variable is the amount of black strap molasses used in replacement of brown sugar. The dependent variables being measured include firmness, color, water activity and preference from the taste panel. Firmness, color and water activity are the objectively measured dependent variables and preference from the taste panel is the subjectively measured dependent variable. Methods
The design of this experiment was to substitute packaged brown sugar by black strap molasses and granulated sugar to use in a standard chocolate chip recipe, listed below. However, chocolate chips were not used when making the actual recipe because of inconsistency with the texture analyzer. The chocolate chips were not important for this experiment; therefore the results did not rely on the chocolate chips and were not seen as a necessity. There were three variables used in this experiment. The first being the light cookie with a ratio of.5 tablespoon:.5cup granulated sugar, the second being the medium with a ratio of 1 tablespoon:.5 cup granulated sugar and the third being the dark with a ratio of 1.5 tablespoons:.5cup granulated sugar. All three trials were baked three separate times for consistency. The cookie recipe was baked at 177 degrees C (350 degrees F) in a conventional oven; all trials were baked in the same oven with the same baking time of ten minutes and cooled for 15 minutes before taking the results for the Hunter Colorimeter, Texture Analyzer, Water Activity Machine and Taste Panel. Materials and Preparation In a mixing bowl, mix together flour, baking soda and salt. In a separate bowl, cream together butter, brown sugar and white sugar, add egg and extracts. Gradually, stir in the dry mixture to the wet mixture. Drop by melon baller on ungreased baking sheet and place on the center rack of the oven. Preheat oven to 177 degrees C Bake time: 10 12 minutes Yields: 18 cookies Ingredients: 150 g White sugar 113 g Butter 2 large Eggs
2.46 ml Vanilla Extract 1.23 ml Almond Extract 140.6 g All Purpose Flour Variations 2.3 g Baking Soda 1.5 g Salt For light: 10.75 g Blackstrap Molasses For medium: 21.5 g Blackstrap Molasses For dark: 32.25 g Blackstrap Molasses Objective Analysis Brookfield Texture Analyzer The Brookfield Texture Analyzer was used to determine the force in compression or tension interactions for the baked goods. Approximately one half of a cooled cookie was placed underneath the appropriate probe. Results were read and recorded for each trial. Water Activity System The Water Activity System was used to detect the condensation temperature related to moisture of each trial. Approximately one fifth of a cooled cookie was placed in a plastic, disposable cup and placed in the water activity machine. Results were read and recorded after 5 minutes. Hunter Colorimeter The Hunter Colorimeter was used to measure the color of the cooled cookies. By placing a whole cookie into a petri dish and placing it on the measuring port, the color of each trial was determined and recorded.
Subjective Analysis Sensory Evaluation Before tasting, please answer the following question Rate the samples in order of preference for COLOR. 1 being the one you prefer most and 3 being the one you prefer the least. 473 618 104 Please taste the samples in front of you and rank samples on overall liking. 618 104 473 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 No Preference No Preference No Preference 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 The water activity machine was used as an objective test with the cookies to measure the water activity. The results from the water activity machine are shown in Figure 1. The figure shows the average of the three trials for each cookie color with the error bars showing the standard deviation. The cookies with the least amount of blackstrap molasses had the highest average water activity with 0.549. The water activity decreased with the increase of blackstrap molasses. This is shown in Table 1 with the water activity as 0.525 in the cookies with the medium amount of blackstrap molasses and 0.496 in the cookies with the highest amount of blackstrap molasses. This information suggests that, on average, a higher amount of blackstrap molasses will result in a lower water activity. Water activity is important to measure since it affects other objective and subjective characteristics. Water activity determines microbial growth and enzymatic activity so a product with a lower water activity will have a longer shelf life. Enzyme activity does not occur in a product with a water activity less than 0.85 and microbial growth does not occur in a product with a water activity less than 0.8. Because the average water activity for the three variations of cookies is between 0.496 and 0.549, all of the variations will have a similar shelf life. Errors while using the water activity machine could include not measuring how much cookie was placed into each plastic, disposable cup. If a larger amount of one cookie was placed in the cup than another, it could give a higher or lower result from the water activity machine than the actual product. The texture analyzer was used to measure the force needed to break the outer layer of a cookie. The results from this testing is listed in Table 2. Initially, when using the recipe with chocolate chips, if the texture analyzer hit a chocolate chip in the cookie it required much more force than if a chocolate chip wasn t encountered. This reason was the cause for performing the testing again with the absence of the chocolate chips. Intuitively, the more blackstrap molasses being added should lead to a softer cookie because of the extra liquid that is being added. Interestingly, the medium cookies were the
softest and not the dark cookies. The light cookie needed an average force of 1730.167 grams of force to break the outer layer, but the medium and dark cookies needed 1182.167 and 1448.767 grams, respectively. This is illustrated in Figure 2. Table 2 also indicates that the light and medium average force values are statistically significantly different. When baking cookies in an oven, they tend to not cook evenly and therefore would cause the texture analyzer data to be quite different depending on where the probe strikes. The knife probe was used to compensate for this, but with the large standard deviations it seems as if it wasn t enough. For the future, other probes could be used in conjunction with the knife probe in order to find a more true value from the texture analyzer. The Hunter Colorimeter was used in this experiment to measure the variety of color in each trial. This was a direct measure of color. L, a, and b values were recorded which are common parameters for this machine and put into a graph and figure (3). By looking at the results, one would see that the light cookie, having a ratio of.5 tbsp. to.5 cups granulated sugar, had the highest values for all three parameters, L,a, and b. The results for the L value ranged from 22 to 31. L values measure the value of color on a scale of 0 100. Zero being the darkest and 100 being the lightest. This result was no surprise, considering the light cookie had the least amount of black strap molasses therefore, had the higher value. For the a values, which measures the hue, the light cookie had the highest average value where the dark cookie had the lowest value. For b values, which measures chroma, the light cookie was found to have the highest values, where the medium cookie had the lowest value. For values L and b, the light cookie had a significant increase in values when compared to the other cookies. For more consistent results, one should mix the cookie batter to make a homogenous mixture without large parts of molasses being clumped together, which could affect the results for this analysis. Also, making sure that the petri dishes are clean and without smudges would reduce error.
The heart of this experiment was in the hands of the sensory panel. Table 5 shows the results of the sensory question for color preference. The range on this question was 1 to 3, where 1 meant the most preferable and 3 being the least preferable. Table 5 shows that the cookie with the least amount of blackstrap molasses had the most preferential rating with an average vote of 1.27, whereas the medium cookie only received a 2.18 rating on average. Also, from Table 5, the light cookie was rated the better colored cookie 9 out of 11 times. Clearly this shows that blackstrap molasses has an overall negative effect of color of the cookie and the null hypothesis does not hold true. For the hedonic testing, each panelist was asked to rank their taste preference for each cookie. Table 4 contains the results from this testing. There was a lot of variation for taste preference in this test, but some noteworthy observations can be made here. First, only one panelist actually disliked one of the cookies, so all of the cookies taste pretty good. Secondly, the average rating for each cookie is very close to each other. This shows that there isn t much of a taste preference, so the null hypothesis is satisfied. The taste is not affected enough by the concentrations of blackstrap molasses used in this experiment. Conclusion The null hypothesis of this experiment states that the amount of blackstrap molasses does not have an effect on the color, texture and taste of the cookie. The results from this experiment show the null hypothesis is true for taste but the color and texture are affected by the amount of blackstrap molasses. Due to the increase in antioxidants, Iron, Calcium and Potassium from blackstrap molasses, this experiment shows that substituting blackstrap molasses for brown sugar could be used in products for increased health benefits. For future work, the blackstrap molasses could be compared to dark brown sugar instead of light brown sugar to measure the change in taste, texture and color. Also, larger taste panels could be used to have a better idea of taste preference across the population.
Results Objective Testing Table 1: Water Activity Results, Averages and Standard Deviation Water Activity Light Medium Dark Trial 1 0.57 0.483 0.492 Trial 2 0.542 0.537 0.478 Trial 3 0.536 0.556 0.518 Average 0.549333 0.525333 0.496 Standard Deviation 0.018148 0.037873 0.020298 Water Activity 0.58 0.56 0.54 0.52 0.5 0.48 0.46 0.44 0.42 Water Activity Values Light Medium Dark Cookie Color Aw Figure 1: Water Activity Comparison of Averages
Table 2: Texture Analyzer Results, Averages and Standard Deviation Force (g) Light Medium Dark Trial 1 1913.5 1270.2 1552.6 Trial 2 1631.4 1254.2 1347.3 Trial 3 1645.6 1022.1 1446.4 Average 1730.167 a 1182.167 b 1448.767 ab Standard 158.93 138.8525 102.6705 Deviation Averages not bearing the same superscript are statistically significantly different, p < 0.05. Force in Grams 2000 1800 1600 1400 1200 1000 800 600 400 200 0 Texture Analyzer Values a ab b Light Medium Dark Cookie Color TA Figure 2: Texture Analyzer Comparison of Averages Table 3: Hunter Colorimeter Averages and Standard Deviation Average Hunter Values L a b Light 31.44 b 11.26 14.40 d Std Dev 2.27 0.09 1.09 Medium 22.84 a 9.62 9.70 c Std Dev 0.59 0.11 0.20 Dark 24.26 a 8.63 10.54 c Std Dev 0.84 0.84 0.14 Averages not bearing the same superscript are statistically significantly different, p < 0.05.
Hunter Colorimeter Values 40.00 35.00 b 30.00 Hunter Colorimeter Value 25.00 20.00 15.00 10.00 a a d c c Light Medium Dark 5.00 0.00 L a b Hunter Colorimeter Parameter Figure 3: Hunter Colorimeter Comparison of Averages
Subjective Testing Table 4: Sensory Results for Taste Preference and Averages on a Hedonic Scale Hedonic Cookie Data Test # Light (473) Medium (618) Dark (104) 1 8 8 9 2 8 3 6 3 8 8 5 4 7 8 9 5 7 8 6 6 6 6 5 7 7 8 8 8 9 8 7 9 7 8 9 10 7 7 8 11 8 7 6 Average 7.45 7.18 7.09 Table 5: Sensory Results for Color Preference and Averages Test # Light (473) Color Cookie Data Medium (618) Dark (104) 1 1 3 2 2 1 3 2 3 1 2 3 4 1 2 3 5 1 2 3 6 1 2 3 7 1 2 3 8 1 2 3 9 3 2 1 10 2 1 3 11 1 3 2 Average 1.27 2.18 2.55
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