Lauren Paradiso, Ciara Seaver, Jiehao Xie
Abstract The amount of fat present in each pie crust had a big impact on the flavor, color and texture and overall affected the quality of each pie crust. In terms of flavor, color, texture and overall preference the 100% lard pie crust was favoured among the panel. The 50% lard, 50% inulin pie crust was liked overall but it lacked certain qualities that failed to meet the standards of the panel in terms of a paler color and slightly salty flavor. The 100% inulin pie crust was unsuccessful in mimicking the lard properties in terms of overall flavor, color, texture and quality. It was disliked the most among the panel and even though it may be regarded as the healthier option in terms of saturated fat content. Thus in substituting the lard out for a carbohydrate fat replacer called inulin was not a complete success. Introduction Pie crust are traditionally made with lard, this gives them a high fat content and that has made pies less favorable when it comes to healthy desserts. Our project was designed to make a more nutritional pie crust than a traditional recipe. Replacing varying levels of fat with a carbohydratebased fat replacer was done to achieve a healthier pie crust with the same texture. A carbohydrate-based fat replacer is best for baked goods because it works the best with keeping the same texture, flavor and appearance. To determine if changing the fat in a pie crust changes the flavor, texture, water activity or color the pie crusts were tested with sensory evaluation, (appendix 4) texture analyzer, water activity and hunter colorimeter. The purpose of this experiment was to determine if changing lard out for a fat replacer would have an effect on the quality of the pie crust. Methods Objectives: To create a pie crust with 50-100% fat replacement To not drastically alter the taste and texture of the pie crust To measure the difference in water activity between pie crusts To evaluate the difference in force to compress the pie crust using a knife probe with the texture analyzer To measure the difference in color between pie crusts To compare flavor, mouth feel and overall preference between the control and variable pie crusts using a hedonic and rating methods. Overall Design: This experiment compared objective and subjective evaluations of three different pie crusts, replacing lard with carbohydrate-based replacement, inulin. Objectively, the texture analyzer, water activity meter and hunter colorimeter were used, and subjective measures were analyzed. Specific tests are listed under Specific Procedure section under Method. Specific Procedure: Paradiso, Seaver, Xie 1
Prepare three different pie crusts using the recipes and general procedural shown below. Test the brownies by using a Stable Micro System Texture Analyzer with knife probe using the setup for crackers, which include, PreTest Speed: 2mm/s, Test Speed: 5mm/s, Post Test Speed: 5mm/s, Rupture Test Distance: 1mm, Distance: 5mm, Force 2000g, Time: 5s, Count: 5. Test the pie crust samples at the bottom of the crust, avoiding the edge. Record the final peak of the texture profile analysis curve. Using the CX-2 Decagon Devices Water Activity System, measure the water activity of the pie crust samples. Again, we used the bottom of the pie crust to avoid inaccurate results. Last, by using the Hunter Colorimeter, which include LabScan XE, we obtained the last part of objective measurements. Proper instruction for use of these machines can be found in The Food Chemistry Laboratory Manual - a Manual for Experimental Foods, Dietetics, and Food Scientists (Weaver and Daniel, 2003). All objective measurements were recorded in a lab notebook or using form provided below. Recipe: Please refer to Appendix 1-3. This is a recipe online. Directions for making two variables are also attached in Appendices. Ingredients: (128g) 3 cups of All-purpose Flour (3g) ½ teaspoon Table Salt (45g or 22.5g) 1 or ½ cup of Lard (22.5g or 45g) ½ or 1 cup of Inulin (14.79g) 3 to 6 tablespoon of Water Control: Prepare the recipe following the general procedure below using no Inulin. Use (45g) 1 cup of lard. Variable 1: Prepare the recipe following the general procedure below using (22.5g) ½ cup lard and (22.5g) ½ cup Inulin. Variable 2: Prepare the recipe following the general procedure below using (45g) 1 cup Inulin. General Procedure: The procedure that was followed is given in Appendices 1-3. All preparation were completed in room temperature. Pie crusts cooled at room temperature for 10 minutes before objective and subjective tests. Additionally, all cooking utensils were kept at room temperature. Replication, Randomization, and Sampling: Paradiso, Seaver, Xie 2
This experiment was completed in triplicate. Each experiment was done three times to provide accuracy of results and eliminate the possible human error. Nine panelists were used per experiment to provide sufficient information on subjective tests for accurate results. Three pie crust samples were coded with three digit numbers in order to reduce bias from panelists. Sample 284 represented the control (all lard), sample 389 represented the 50% lard, 50% inulin pie crust, and sample 454 represented the 100% inulin pie crust. The samples were not listed orderly on the subjective tests. Panelists were given bottom side of crusts and tasted them in the order listed on subjective sensory evaluation sheet. They were asked to fill out the Sensory Evaluation Sheet as directed using the keywords provided on the sheet. In addition, they were also asked to rate the three pie crusts from the most preferred to the least preferred. Data was analyzed by GraphPad s software, Instat 3, using ordinary one-way ANOVA, standard parametric methods, P<0.05, and Turkey comparison post-test. Statistics were recorded for averages of the three trials only. Subjective Evaluation Sheet: Please refer to Appendix 4. Objective Evaluation Sheet: Pictures showing Appendix 1, 2 and 3 at stages of preparation, baking and cooling of the pie crusts. Picture 1: 50% inulin, 50% Lard pie crust after 30 minutes of baking at 425 degree Fahrenheit Paradiso, Seaver, Xie 3
Picture 2: All lard pie crust after 30 minutes of baking at 425 degree Fahrenheit Picture 3: showing the 100% lard pie crust after 10-12 minutes of baking with the beans Picture 4: starting from the left and following to the right; 100% lard pie crust, 50% inulin 50% lard pie crust and 100% inulin pie crust respectfully, after 30 minutes of baking and cooling. Paradiso, Seaver, Xie 4
Picture 5: Blind baking the 100% lard pie crust after 10-12 minutes using beans wrapped in aluminum foil. Results Table 1: Sensory taste results of pie crust All Lard 50/50 No Lard Like extremely 2 Like very much 3 2 Like moderately 6 2 2 Like slightly 2 4 Neither 1 2 2 Dislike slightly 2 4 4 Dislike very much 1 1 1 Dislike moderately 3 5 1 Dislike extremely 20 10 Table 2: Hunter parameters L a b Control 50.25 3.25ab 17.73 a 50/50 59.53 1.93a 15.88 b All replacer 56.38 5.71b 23.42 c Means in column not bearing the same letter are significantly statistically different (P< 0.05) Paradiso, Seaver, Xie 5
Table 3: Texture analyzer for varying pie crusts Control 498.67 a 50/50 928.83 b All 4052.45 ab Replacer Means in column not bearing the same letter are significantly statistically different (P< 0.05) Table 4: Water activity for varying pie crusts Control 0.3417 ab 50/50 0.6527 a All 0.5617 b Replacer Means in column not bearing the same letter are significantly statistically different (P< 0.05) Paradiso, Seaver, Xie 6
Paradiso, Seaver, Xie 7
Discussion Appendix 1, the traditional pie crust recipe was essentially the control in this experiment. All the ingredients were present to make a flawless and desirable pie crust. Fats play a major role in the flavor and richness of foods. The characteristics of lipids are important as they can determine specific properties of foods that are essential in food production. Although fats are regarded as being very important for achieving the desirable properties of baked goods, they can be seen in a negative light and an unhealthy choice when it comes to desserts. Seen in Table 1 the sensory taste perception of all three pie crusts varies in order of preference. Even though decreasing the saturated fat content in this traditional pie crust recipe may have made it a healthier option, it was not favored among our judging panel. Out of 20 people, 13 of them liked to extremely liked the all lard pie crust. The desired texture characteristics of a pie crust should be tender, flaky and slightly moist. The appearance of the base should be golden brown, crisp and have an uneven texture. The flavor of the crust should be slightly salty and mouth-watering. All of these characteristics can be seen in picture 2 which illustrates the pie crust freshly baked using no fat replacer. There is a big difference regarding taste and overall likeness seen in figure 1. The 50% lard, 50% inulin pie crust seems to be the second favorite pie crust regarding flavor and texture. Half the panel disliked this pie crust. 100% inulin pie crust had no lard present may be seen as the healthier option in terms of the saturated fat content of the pie crust however it was un-favored the most by our panel. 8/10 panelists said they disliked or extremely disliked this crust and one of the comments suggested that the texture of this pie crust was too hard and inedible. One comment mentioned in our results after the sensory test was that the 50% lard, 50% inulin pie crust had a slight salty after taste. This may be down to inaccurate measurements of salt in each recipe as the same amount was intended to be used for each pie crust. The measurement of lightness represented by L* value, shows the least amount of light at L* = 0, and the brightest white at L* = 100. The value found in the all lard pie crust was an L* value of 50.25. Fat contributes to the color of a pie crust overall giving it a dark, golden brown color. The reduced fat recipes used have a higher L* value which indicates that the less fat used the lighter/paler the pie crust will become which can be seen in picture 1. The 50% lard, 50% inulin pie crust had the highest L* value at 59.53 which could suggest that this was because of a mixed fat and carbohydrate content of inulin and lard. The overall color of the pie crust is affected by the fat content and suggests that this is one characteristic that isn t quite matched by the carbohydrate-based fat replacer as it produces a much paler pie crust compared to the recipes using saturated fat in the form of lard. The desired golden brown color is lost.. The texture is what defines a good pie crust; it should be flaky, light and crumble in your mouth. The more inulin used in the recipe, the more tough and inedible the pie crust became. As seen in Table 3 the texture for a normal pie crust with no inulin present was found to be 498.67 a. The amount of force used to analyze the texture of the pie crust seems to increase dramatically as the amount of fat replacer used increases which is an undesirable property. This highlights that lard, the fat plays a major role in the texture of the pie crust. One variable that didn t fluctuate a lot was the amount of water activity in each of the pie crusts. Appendix 2 and 3 had similar water activity values shown in table 4; at 0.5617 b and Paradiso, Seaver, Xie 8
0.6527 a respectfully. These values are close to the original pie crust with no fat replacer used at 0.3417ab. In terms of color, egg yolk is traditionally used to make the final pie crust shiny and golden brown assisting in Millard browning of the pie crust. Egg yolk contains an emulsifying agent, lecithin which aids in the overall appearance of the pie crust sealing any cracks that formed during baking. One problem that was encountered was the base of all the pie crusts turned slightly soggy after blind baking which can be seen in picture 3. Brushing a thin layer of egg yolk over the base can also help prevent this from occurring and overall enhance the texture of the pie crust. Potentially using an egg yolk on all three pie crusts could have amended some of the qualities that the 50% lard, 50% inulin pie crust and 100% inulin pie crust were lacking in regards to overall appearance, texture and flavor. Paradiso, Seaver, Xie 9
References Center for Disease Control and Prevention. 2014 Obesity and Overweight. Journal of American Medicine. National Health and Nutrition Examination Survey. 1999-2000 Intake of Calories and Selected Nutrients for the United States Population. U.S. Department of Health and Human Services. O Brien, C.M. 2003 Evaluation of the effects of fat replacers on the quality of wheat bread. Journal of Food Engineering, Vol. 56, pg 265-267. Voragen, AG. 1998 Technological aspects of functional food-related carbohydrates. Trends in Food Science & Technology, Vol. 9, pg 329-335. Zoulias, E.I. 2002 Textural properties of low-fat cookies containing carbohydrate- or protein-based fat replacers. Journal of Food Engineering, Vol. 55, pg 337-342. Appendices Appendix 1: Control pie crust recipe Appendix 2: 50/50 pie crust recipe Appendix 3: Fat replacer pie crust recipe Appendix 4: Sensory evaluation sheet Appendix 5: Lab papers Paradiso, Seaver, Xie 10
Appendix 1 Taken from tasteofhome.com Control Pie Crust Recipe Flour 128 grams Salt 3 grams Lard 45 grams Water 14.79 grams Preheat oven to 425 degree Fahrenheit. The dry ingredients must all be mixed into a bowl together (flour and salt) when they are thoroughly mixed the lard must be cut into the dry ingredients using a pastry blender. Once this mixture has been mixed together and they are in pea sized particles sprinkle with water a little bit at a time. Mix this with a fork till the flour is moisture. Press into a ball and chill for 30 minutes. Then press out onto a floured surface. Roll out to the desired size that will fit in the 8 inch pie pan, avoid using too much extra flour to decrease the chances of this changing the texture of the crust. Place the crust in the pan prick with flour and line with foil and pour beans into the crust to stop the crust from rising. Decrease the oven temperature to 400 degrees Fahrenheit and bake for 10-12 minutes or until the edge of the crust starts to turn golden. Remove the foil and beans and cook for an additional 15 minutes. Recipe from http://www.tasteofhome.com/recipes/mom-s-lard-pie-crust Paradiso, Seaver, Xie 11
Appendix 2 50/50 Pie Crust Recipe Flour 128 grams Salt 3 grams Lard 22.5 grams Inulin 22.5 grams Water 20 grams Preheat oven to 425 degree Fahrenheit. The dry ingredients must all be mixed into a bowl together (flour and salt) when they are thoroughly mixed the lard and fat replacer must be cut into the dry ingredients using a pastry blender. Once this mixture has been mixed together and they are in pea sized particles sprinkle with water a little bit at a time. Mix this with a fork till the flour is moisture. Add more water as necessary as seems fit. Press into a ball and chill for 30 minutes. Then press out onto a floured surface. Roll out to the desired size that will fit in the 8 inch pie pan, avoid using too much extra flour to decrease the chances of this changing the texture of the crust. Place the crust in the pan prick with flour and line with foil and pour beans into the crust to stop the crust from rising. Decrease the oven temperature to 400 degrees Fahrenheit and bake for 10-12 minutes or until the edge of the crust starts to turn golden. Remove the foil and beans and cook for an additional 15 minutes. Paradiso, Seaver, Xie 12
Appendix 3 Fat Replacer Pie Crust Recipe Flour 128 grams Salt 3 grams Inulin 45 grams Water 30 grams Preheat oven to 425 degree Fahrenheit. Add all dry ingredients into the bowl, this includes the inulin, add water. More water will be added later. Once this mixture has been mixed together and they are in pea sized particles sprinkle with water a little bit at a time. Mix this with a fork till the flour is moisture. Press into a ball and chill for 30 minutes. Then press out onto a floured surface. Roll out to the desired size that will fit in the 8 inch pie pan, avoid using too much extra flour to decrease the chances of this changing the texture of the crust. Place the crust in the pan prick with flour and line with foil and pour beans into the crust to stop the crust from rising. Decrease the oven temperature to 400 degrees Fahrenheit and bake for 10-12 minutes or until the edge of the crust starts to turn golden. Remove the foil and beans and cook for an additional 15 minutes. Paradiso, Seaver, Xie 13
Appendix 4 Sensory Evaluation Please taste the samples in front of you and determine your preference 389 284 454 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 Neither Neither 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 Rank the samples in order of preference. 1 being the one you like the most and 3 being the one you like the least. Comments: 284 389 454 Paradiso, Seaver, Xie 14