IMPLICATIONS OF ADDING VITAMIN C TO PANCAKE MIX TO ENHANCE IRON ABSORPTION. Emily James 21 November 2005 F&N 453 Individual Project

Transcription

1 IMPLICATIONS OF ADDING VITAMIN C TO PANCAKE MIX TO ENHANCE IRON ABSORPTION Emily James 21 November 2005 F&N 453 Individual Project

2 ABSTRACT: This experiment studied the effects of replacing different amounts of the water element with grape juice in a fairly conventional recipe for pancakes. The three variable products of this experiment, A, B, and C were prepared using different amounts of grape juice made from frozen concentrate with ascorbic acid added. This experiment also studied the effects on the ph and the color of the pancake batter as the ratio of grape juice to water increases. Other evaluations of the products were made by 11 untrained, male and female panelists. The panel rated the products based on general appearance, taste and relative tartness. The purpose of this experiment was to determine whether or not a pancake product with Vitamin C added via grape juice would be acceptable to consumers. I. INTRODUCTION: Iron-fortified flour has practical use in common baked goods, such as commercial breads and cereals. Commercially, H 2 -reduced elemental iron powders are used to fortify cereal staple flours (Walter, 2004). Many fortified, ready-to-eat cereals contain at least 25 percent of the U.S. Adequate Intake for vitamin C (Mosure, 2004). A quick glance at nutrition labels, however, will show that most grain products used for cooking contain little to no vitamin C. Studies show that the bioavailability of iron increases when accompanied by ascorbic acid (K. Van Dyck et al, 1996; Mallory, 2003). If non-heme iron is to interact with its enhancer, ascorbic acid, it must be soluble (Walter, 2004). So, even though some whole-grain containing cereals contain 10 percent of the daily value of iron our bodies may not absorb that much due to two prime factors: the volume of

3 dissolved iron; and whether ascorbic acid, the absorption enhancer is present. The effects in children of iron deficiency can lead to serious heath problems, such as poor cognitive and motor development (Hashizume et al, 2004). The purpose of this experiment was to determine whether or not a pancake product with Vitamin C added via grape juice would be acceptable to consumers. The pancakes were prepared using all-purpose flour, whole wheat flour, and quick cooking oats. Together, these grain products contributed approximately 9.5 mg of iron. This experiment studied the effects of replacing different amounts of the water element with grape juice. The three variable products of this experiment were prepared using different amounts of grape juice made from frozen concentrate with ascorbic acid added. This experiment also studied the effects on the ph and the color of the pancake batter as the ratio of grape juice to water increases. II. METHODS: a. Overall Design The recipe for the control pancake product follows: 80 g quick cooking oats 8 g salt, divided 62 g all-purpose flour 3 g ground cinnamon 60 g whole wheat flour 0.4 g cream of tartar 55 g packed brown sugar 79 ml vegetable oil 7 g baking powder 2 eggs, beaten 30 g dry non-fat milk powder 235 ml water

4 The three variables, A, B, & C deviated from this recipe only in the amount of water/grape juice. Variable A replaced 25% of the water with grape juice resulting in ml water to ml grape juice. Variable B replaced 75% of the water with grape juice, resulting in ml water to ml grape juice. Variable C replaced all of the water with grape juice. b. Specific Procedures Trial one was prepared using the full recipe. For Trials two and three, rather than preparing the full recipe, only half the amount of each ingredient was used. Also, the grape juice was prepared from frozen concentrate and diluted with water. The grape juice in Trial 1 was mixed with 3 cans of water; however, to increase the concentration in later trials, Trials 2 & 3 were mixed with 1/3 less water. Except for the amounts made and the concentration of grape juice used, all three trials were prepared in the same manner. In a large bowl, the dry ingredients were mixed. The dry ingredients included the quick cooking oats, flour, whole wheat flour, brown sugar, baking powder, dry milk powder, salt, cinnamon, and cream of tartar. Beaten together in a small bowl were the vegetable oil and eggs. Then, 117.5mL of the water element was prepared for each sample. The control

5 variable required only water, 117.5mL. Sample A required approximately 30mL grape juice and 87.5mL water. For sake of time, these two elements were combined into one mixture totaling 117.7mL. The water element for Sample B was prepared similarly, using 87.5mL grape juice and approximately 30mL water. Before proceeding, a flat pan was greased with cooking spray and placed over medium low heat to allow pan to reach cooking temperature. Next, the wet and the dry ingredients were mixed together alternating the egg/oil mix and the water/grape juice mix. To ensure uniformity, the batter of the control and each variable was mixed until the same consistency was reached for all four samples. All samples were mixed for approximately 60 seconds, which allowed the oats mixture, egg/oil, and water/grape juice mixture to blend together creating a batter that was not too tough. For objective measurements, a small test sample of the batter of the control and each variable was set aside in a glass custard dish. Batter from each sample was poured ¼ cup at a time onto the prepared flat pan. It was important for the sake of consistency to measure the amount of batter used to make each pancake; the measurement remained the same for each sample within each trial. Each pancake sample was cooked approximately two minutes on the first side, then 90 seconds on the other. Samples were then presented to an individual, anonymous, untrained sensory evaluator who rated the products based on appearance, taste, palatability, and tartness. To control temperature of served pancakes each sample was served and evaluated

6 within 2 minutes of end cook time. No sample over two minutes old should have been evaluated. After the completion of the sensory portion of the experiment the objective measurements were begun using the previously set aside custard dishes containing the control and variables. The Hunter colorimeter was used to measure the color of the samples. Before testing, proper calibration of the colorimeter was required to standardize measurements. Data was relayed according to the common L, a, b Hunter parameters. The ph meter was used to determine the ph of each sample. The measurements taken from the colorimeter and the ph meter were recorded for further analysis. c. Sensory Evaluation Upon completion of cooking, the pancake products were presented to a sensory panel for evaluation. The panel consisted of 11 male and female, untrained, college students. The panel evaluated the pancake products by use of a structured descriptive test of tartness; general appearance; and an affective test, a nine point Hedonic Rating Scale. Participants were asked to complete this sensory evaluation scorecard: Sensory Evaluation Scorecard 1. Circle or provide a new descriptive term for your initial impression of appearance. Control: Flavorsome I would not eat that Mouth-watering Displeasing Revolting Desirable Interesting Appetizing Disturbing Disgusting

7 Variable A: Flavorsome I would not eat that Mouth-watering Displeasing Revolting Desirable Interesting Appetizing Disturbing Disgusting Variable B: Flavorsome I would not eat that Mouth-watering Displeasing Revolting Desirable Interesting Appetizing Disturbing Disgusting Variable C: Flavorsome I would not eat that Mouth-watering Displeasing Revolting Desirable Interesting Appetizing Disturbing Disgusting 2. Nine-point Hedonic Rating Scale Place a clear mark in one box per row. Sample Control A B C Extremely dislike Dislike very much Dislike moderately Dislike slightly Neither like nor dislike Like slightly Like moderately Like very much Like extremely 3. Rate samples (Control, A, B, & C) for tartness against the descriptive terms below. None Slight Moderate Strong Extreme III. RESULTS: Table 1.1 reports the measurements from the objective measurements. Trial 1 information is provided, but not included in the averages. Values from Trial 1 are not included in the averages because the formula differed from Trials 2 & 3. The grape juice was made from frozen concentrate. In order to increase the concentration of grape juice in the batter the grape juice was mixed with 1/3 less

8 water. Disregarding information form Trial 1, as the batter formula included more grape juice the average L values decreased, and the average b values decreased. The average a values were all lower than the control; however the difference between variable and control decreased as the concentration of grape juice increased. Variable C, which contained the most grape juice in its formula, differed from the control values of L, a, and b by negative units, units, and -9.80, respectively. Also reported in Table 1.1 are the recorded ph values taken from samples of each batter. Except for Trial 1, as the batter formula included more grape juice the ph decreased. Table 1.1 Hunter colorimeter measurements for the control and each variable, as reported in L, a, and b values; the difference in L, a, b values between the control and each variable; and ph values for all samples. Trial Hunter Colorimeter ph Variation L a b Control Average A Average Difference B Average Difference C Average Difference Pancake products from trials 1, 2 &3 were rated by 11 untrained panelists. Ratings based on general appearance were made by having participants circle one descriptive adjective, which were provided, or provide their own word to describe the

9 sample. As seen in Table 2.1, the control product received only positive ratings. All variables received a range of positive and negative ratings, choosing from Appetizing to Disturbing. Table 2.1 The descriptive word ratings based on general appearance as rated by a panel of 11 participants. All trials are combined into one analysis and include only the descriptive words circled by panelists. Control Variable A Variable B Variable C Appetizing Appetizing (II) Appetizing (II) Appetizing Interesting (5) Mouth-watering Mouth-watering Desirable (III) Desirable (III) Interesting (III) Flavorsome (II) Flavorsome (II) Flavorsome (II) Displeasing (III) Interesting (III) Mouth-watering I would not eat that Displeasing (II) Interesting (III) Other: Not Flavorful Disturbing Displeasing Based on taste, Variable C received generally positive ratings. No sample appeared to be particularly favored by much degree. To group ratings into an interpretable format, a rating of Extremely dislike was equated to one point; a rating of Like extremely equated to nine points. The numeric value associated with the rating was then multiplied by the number of times a sample received that rating. Those multiples were then divided by nine to obtain an integer between 1 and 9. This was similar to calculating an academic grade point average. The control and Variable C ranked highest with an average rating of 8 points. Variable A ranked second highest, with an average rating of 7 points. Variable B ranked last, scoring only 6 out of nine points when averaged. Figure 2.1 displays these results. Table 2.2 The 9-point hedonic scale ratings based on flavor as rated by panelists. Samples Rating Control A B C Extremely dislike Dislike very much 1 Dislike moderately 1 1 Dislike slightly

10 Neither like nor dislike Like slightly Like Moderately Like very much Like extremely Average points Sample Control A B C Figure 2.1 Average points out of 9 possible received by each sample of pancake product. Panelists were asked to rank the relative tartness of products; reported in Table 2.3 are the results. The control was ranked most frequently at no tartness when compared to the other samples. Variable A was ranked most frequently at none-slight tartness. Variable B received an average rating of slight-moderate tartness with one outlier recorded at extreme tartness. Variable C was ranked most frequently at moderate-strong tartness. Table 2.3 The relative tartness rankings. Numerals in the table represent the number of times a variable received that particular position in the ranking. Relative Tartness Control A B C None Slight Moderate Strong 5 Extreme 1

11 IV. DISCUSSION: It has been well studied that the bioavailability of iron is enhanced with the presence of vitamin C, or ascorbic acid (Walter, et al, 2004). The purpose of this experiment was to determine whether or not a pancake product with Vitamin C added via grape juice would be acceptable to consumers. Based on the 11 panelists ratings, the sample containing the most grape juice received an average rating of 8 out of 9 in the 9-Point Hedonic rating scale. This is also the score most of the panelists gave to the control product. A rating of 8 out of 9 corresponds to the description Like very much. These results seem to conclude that a pancake product which was prepared substituting grape juice for water would be acceptable to consumers. Due to the low number of participating panelists skewed results may have been obtained. This experiment studied the effects of replacing different amounts of the water element with grape juice. It was concluded after Trial 1 that the concentration of grape juice should be increased in subsequent trials. To maintain the absolute amount of the water element used in preparation, the grape juice concentrate was diluted only 2/3 as much for Trials 2 and 3. This resulted in an increased concentration of sugar as well as ascorbic acid. The increase in sugar may have been the reason Variable C, which contained the most excess sugar, did not cook fully under the same conditions as other samples containing less or no juice. However, Variable C may have required a longer cooking time due to its placement on the cooking surface. A square flat pan was heated over a round

12 stove top surface. It may have been that the quarter of the flat pan which was used to cook Variable C was not heated properly due to the conflicting geometries. This experiment also studied the effects on the color of the pancake batter as the ratio of grape juice to water increased. There are delta values L, a, and b associated with the Hunter L, a, b color model (HunterLab, 1996). These values indicate how much a standard and sample differ from one another in L, a, and b. The differences can be reported in positive or negative values using a simple formula: L difference = L sample - L standard Positive L difference means the sample is lighter than the standard; negative L difference means, the sample is darker than the standard. Similarly, a positive a difference means the sample is redder than the standard; negative a difference means the sample is greener. A positive b difference means the sample is more yellow; a negative b difference means the sample is bluer (HunterLab, 1996). From the results it can be concluded that Variable C, the pancake product with the most grape juice, differed from the control in that it was darker, greener, and bluer than the control. An important source of error here would be whether or not the samples were representative of their variable. Samples should have been taken from thoroughly mixed batter to ensure uniform color. This experiment tested the ph of the pancake batters and found that the average ph decreased as grape juice concentration increased. It was concluded that the decrease in ph was due to the ascorbic acid from the juice. The decrease in ph was perceived by some panelists who ranked Variable C as being the most tart of

13 all the samples. This ranking, however, could be flawed in that panelists knew which sample contained the most ascorbic acid. The pancake product samples were darker in appearance as grape juice concentration increased. The panelists may have assumed the correct response would be to rate Variable C as most tart. To attempt to eliminate this bias samples panelists could have been asked to be blindfolded. Overall, the replacement of grape juice for water in a conventional pancake recipe produces a significantly different product, but seems to remain appealing to consumers. The implication of adding vitamin C to pancake mix to enhance iron absorption could have a place in commercial manufacturing. As an added draw, consumers would be interested in the health claim of such a product. Of course, tests would be required to determine if the bioavailability of the iron present in the flour was actually increased by this method of vitamin C supplementation. Suggestions for future projects include use of other sources of ascorbic acid to increase bioavailability of iron from iron-fortified flour; varying the amount of sugar used to determine if that may contribute to an increased necessary cook time. Another objective test which could have been performed was testing the water activity of the baked products. One last suggestion would be to test the freeze/thaw stability of a pancake product with increased grape juice content. The reason for suggesting such an idea stems from the abundant consumption of frozen breakfast foods by this on-the-go nation.

14 V. REFERENCES: Delicious Pancakes. (2005). Retrieved September 23, 2005, from Hashizume, M., Shimoda, T., Sasaki, S., Kunii, O., Caypil, W., Dauletbaev, D., & Chiba, M., Anemia in relation to low bioavailability of dietary iron among school-aged children in the Aral Sea region, Kazakhstan. Intern J of Food Sci and Nutr: 55, HunterLab Insight on Color: Hunter Lab Color Scale. Applications Note: 8, 1-4. Mallory, M. A., Sthapanachai, C., Kowdley, K. V., Iron overload related to excessive vitamin C intake. Am Inter Med: 139, Mosure, J. (2004). Ascorbic Acid. Retrieved September 23, 2005, from Van Dyck, K., Tas, S., Robberecht, H., & Deelstra, H., The influence of different food components on the in vitro availability of iron, zinc and calcium from a composed meal. Intern J of Food Sci and Nutr: 47, Walter, T., Pizarro, F., Abrams, S. A., Boy, E., Bioavailability of elemental iron powder in white wheat bread. Eur J of Clin Nutr: 58,