The Effect of a Carbohydrate-Based Fat Replacer in Thousand Island Salad Dressing. By: Rachel Kroll

Transcription

1 The Effect of a Carbohydrate-Based Fat Replacer in Thousand Island Salad Dressing By: Rachel Kroll

2 Abstract: The typical American diet is low in fruits, vegetables, and whole grains but high in saturated fat, salt and sugar (Meadows, 2005). Thus, obesity and related diseases such as cardiovascular heart disease and Type 2 Diabetes are problematic in epidemic proportions in the United States. The use of fat replacers in foods we commonly eat can help reduce risk factors for these diseases. The carbohydrate-based fat replacer, Oatrim, was used to replace fat in the form of mayonnaise in Thousand Island Salad Dressing recipes. Three salad dressings were prepared including the control which contained 2 cups of Real Hellmann s Mayonnaise. One variable replaced 1 cup of mayonnaise with 1 cup Oatrim gel while the other variable replaced 2 cups of mayonnaise with 2 cups Oatrim gel. The Oatrim gel was prepared by mixing Oatrim powder with water in a 3:1 water to Oatrim ratio. Subjective results from a total of 21 sensory panelists found the full fat salad dressing to be most desirable in flavor, texture, and mouthfeel and the fully substituted variable to be least desirable in flavor, texture, and mouthfeel. Objective results from the Brookfield viscometer found the control recipe to be the thinnest, runniest product with lowest viscosity and the 50% substituted salad dressing to be the most viscous, thickest product. In addition, results from the Bostwick consistometer showed the full fat recipe to travel the farthest distance in centimeters in a 2 minute time period while the fully substituted variable flowed the least distance in a 2 minute time period. In conclusion, while replacing fat in recipes is ideal for reducing the risk of diseases such as obesity and cardiovascular heart disease, the functionality of fats in foods often cannot be duplicated. Viscosity, flavor, texture, mouthfeel, and overall palatability of Thousand Island Salad Dressing were compensated when fat in the recipe was replaced with Oatrim gel.

3 I. Introduction Americans today consume diets too low in foods such as fruits, vegetables, and whole grain products while consuming too much salt, sugar, and saturated fat. As a result, our country is facing an epidemic of obesity and ever increasing risks for cardiovascular heart disease, atherosclerosis, Type 2 Diabetes, and even certain cancers (Meadows, 2005). Increases in portion sizes and decreases in physical activity seem to be the major role players in the obesity epidemic we face (Nestle, 2003). Part of the problem is contributed to the excess consumption of fat in the diet. Fat provides us 9 kilocalories per gram consumed as compared to the 4 kilocalories found in one gram of either protein or carbohydrate. Therefore, Americans now consume more energy dense foods than ever before which provide more Calories but not necessarily more nutrients. In an effort to curtail the ill effects of consuming too much fat in the diet, research is being done to use fat replacers in foods. This study takes a look at the functionality of fat in Thousand Island Salad Dressing by replacing the fat in the recipe with a carbohydrate-based fat replacer called Oatrim. The goal when using a fat replacer is for it to contribute everything fat does, but without the calories, saturated fat, and cholesterol (Kurtzweil, 2005). This can be hard to do because fat serves several functions in foods which include establishing texture, contributing flavor, and even influencing the order that different components of flavor are released in our mouth. Additionally, in emulsified form fat provides the velvety smoothness in a product such as the mayonnaise used in this study. Fats provide a sensation of moistness and are a valued ingredient because of the mouthfeel contributions they make (Charley & Weaver, 1998). Fat also serves several functions in our body that include carrying the fat-soluble vitamins A, D, E, and K. Fats provide us with essential fatty acids and they help us feel full after we eat them

4 (Kurtzweil, 2005). Although fats serve several purposes in foods and our bodies, eating them in excess are where all the problems begin. Therefore, we use fat replacers such as Oatrim in an attempt to maintain the functional properties of fats in foods without giving us the ill-effects true fat does. Maltodextrins are one group of fat replacers that includes Oatrim. Oatrim consists of maltodextrins from whole oat starch combined with the viscous beta-glucans found in the oat grain (Charley & Weaver, 1998) Mixing Oatrim in its powder form with water in a one to three ratio yields a thick gel. This gel, at only one kilocalorie per gram (as compared to nine in a gram of fat) can then replace fats and oils in recipes in a one to one ratio. Oatrim is suggested to replace anywhere from 50%-100% of fats and oils in recipes we use everyday ( 1993). Oatrim has been found to be nutritionally sound because of the soluble beta-glucans and maltodextrins it contains. Consuming Oatrim has been associated with health benefits related to disease control, glucose and insulin responses, and weight control (Inglett, 1997). A human study of Oatrim was conducted in the early 1990s. The participants not only liked the food containing Oatrim but they also had a substantial drop in their bad cholesterol, LDL, without dropping their good cholesterol, HDL. Additionally, their ability to process sugar after a meal greatly increased. Since Oatrim is high in beta-glucans, diabetic subjects in another study showed lowered blood glucose levels along with lowered insulin responses (Hallfrisch, J. et al., 2002). Another surprise discovered during this study was that most of the subjects lost weight even when the diets were carefully planned to have the subjects maintain their weight. It was concluded that Oatrim could maintain satiety and lower total calories simultaneously (McBride,1993)!

5 Products with Oatrim have been found to be comparable to their full fat counterparts in appearance, taste, and texture (McBride, 1993). The purpose of this project was to determine the functionality of a carbohydrate-based fat replacer in everyday recipes. Mouthfeel, texture, and flavor were evaluated in an attempt to determine overall acceptability of this fat-modified product. The independent variable that was altered among samples was fat content in the recipe. Viscosity was the primary dependent variable measured with the Brookfield Viscometer and Bostwick Consistometer. RECIPE INGREDIENTS (ENGLISH UNITS) RECIPE INGREDIENTS (METRIC UNITS) 1-1/2 eggs 52.5 g whole eggs 2 T Worcestershire sauce 36 g Worcestershire sauce 1-1/2 t white sugar 6.25 g white sugar 2 T white vinegar 25.5 g white vinegar ½ pinch ground cloves.08 g ground cloves 2 cups mayonnaise 416 g mayonnaise ¼ c + 2 T sweet pickle relish g sweet pickle relish ¼ c chopped black olives ¼ c diced red bell pepper 32 g chopped black olives 29.4 g diced red bell pepper Figure 1. Thousand Island salad dressing ingredients.

6 II. Methods A. Preparation This project was repeated three times. For each trial, three different recipes of Thousand Island salad dressings were prepared. The control recipe is listed in Figure 1 and was obtained from: Prior to beginning preparation of the salad dressings, Oatrim gel was prepared by mixing in a blender one gram of Oatrim powder with 3 grams of water. The gel was allowed to set by chilling it for thirty minutes. For each recipe, two eggs were placed in a saucepan and covered with cold water. The water was then brought to a boil and immediately removed from heat. The saucepan was then covered while the eggs sat in the hot water for eleven minutes. The hard-cooked eggs were then removed from the warm water and peeled grams of the hard-cooked eggs were mashed with a fork into very fine pieces and added to each of the three recipes. In a large bowl, the finely mashed eggs, Worcestershire sauce, sugar, white vinegar, ground cloves, fat (mayonnaise and/or Oatrim), sweet pickle relish, black olives, and red pepper were whisked together until completely blended. Black olives were bought finely chopped and canned. The red peppers were bought whole and were finely chopped for use in this recipe. The control recipe contained the fat as listed in the recipe in Figure 1, two cups (416 grams)of Real Hellmann s mayonnaise. The control recipe was then altered by substituting 50% of the fat in the recipe with Oatrim gel. Therefore the first variable contained 1 cup, or 208 grams of Real Hellmann s mayonnaise and 1 cup, or 174 grams, of Oatrim gel. The control recipe was again altered by replacing 100% of the fat in the recipe in a one to one ratio with Oatrim gel. The two cups of mayonnaise in this recipe were replaced with two cups of Oatrim gel.

7 B. Testing Each recipe in each trial yielded 2 cups of the desired variable. One cup of each variable was used to carry out objective tests using the Bostwick Consistometer and the Brookfield Viscometer. The Brookfield Viscometer measures viscosity as it measures the force in centipoise required to rotate a spindle in a fluid (Weaver, C. & Daniel, J, 2003). For the Brookfield viscometer, centipoise values for viscosity were recorded with spindle speeds of 6, 12, 30, and 60 rotations per minute (rpm). The spindle was placed in the center of each sample up to the level of the immersion groove cut into the spindle shaft and the value recorded was the most stable value displayed in the digital reading. Next, the salad dressings were objectively tested in the Bostwick Consistometer which measures viscosity by measuring the flow of a product under its own weight in a specified time (Weaver, C. & Daniel, J, 2003). The consistometer was first leveled on the countertop. The gate was then closed while the reservoir was filled with each individual salad dressing in turn. The trigger was released and the variables were allowed to flow for two minutes before being measured. A reading was taken at the edge and at the center of the trough. These two values were averaged to give a reading for each salad dressing in each trial. The remaining amount of each variable (1 cup) was poured into uniform custard dishes immediately after preparation and served at room temperature with raw baby carrots for sensory panelists to perform subjective testing. A sample of the sensory scorecard used is shown in Figure 2. The control recipe was assigned the random three digit number 921. The variable with 50% of its fat replaced was assigned to the number 126. The fully substituted salad dressing was displayed to sensory panelists as 852. The three samples were placed in random order in a row on the testing table.

8 Sample Sensory Scorecard: **Please rate the flavor, texture and mouthfeel of variables A, B, and C using a 5-Point Hedonic Scale. (1=worst flavor, texture, mouthfeel; 5=best flavor, texture, mouthfeel). VARIABLE FLAVOR TEXTURE MOUTHFEEL Figure 2. Sensory Scorecard. III. Discussion Each Thousand Island salad dressing variable in each trial was analyzed objectively by the Brookfield Viscometer. Averages from the three trials can be seen in Table 1 and are also depicted in a line graph in Figure 3. Variable 921, the control recipe, had the lowest viscosity and was the most fluid product. Variable 126, the 50% substituted recipe, is represented as the most viscous product with values as high as 378 cp. The Brookfield Viscometer measured Variable 852, the fully substituted recipe, to have a slightly lower viscosity than Variable 126, but significantly higher viscosity than Variable 921. Similar results were found in a study that measured the influence of oat beta-glucan preparations on rheological properties in beverages. Viscosities of the beverages increased significantly with increasing concentrations of beta-glucan in the beverages (Lyly, 2003). The viscosity in the beverages showed shear-thinning behavior with the highest viscosity at the lowest shear rate. Another look at Figure 3 shows all three salad dressing recipes used in this study also displayed shear-thinning fluid properties.

9 The Bostwick Consistometer was also used to analyze the variables objectively. Averages of the three trials can be seen in Table 2 and Figure 4. Table 2 also included the raw data from each trial. The control recipe traveled significantly farther under its own weight to an average of 4.58 cm and as far as 4.75 cm. The 50% substituted product and the 100% substituted product traveled on average 1.92 cm and 1.75 cm, respectively. Results from the Tukey-Kramer Multiple Comparisons test are shown in Table 3. The comparison between variables 921and 126 and also variables 921 and 852 showed P values of less than 0.001, or a 99% confidence interval. In other words, these variables were significantly different from each other. However, when variables 126 and 852 were compared, the difference between them was not significant with a P value of greater than In a study using a soluble fiber gel from rice bran and barley flour in place of coconut cream, the gel was found to display shear-thinning functionality just as the coconut cream did (Inglett, 2004). Real mayonnaise also exhibits shear-thinning properties and therefore the results from this experiment were expected. Sensory panelists were used to analyze the salad dressings subjectively. The raw data collected from the trials for flavor, texture, and mouthfeel can be seen in Table 7. The averages of all 21 sensory panelists are summarized in Figure 5. As expected in relation to viscosity measurements, Variable 921 (control) was rated highest in flavor, texture, and mouthfeel in all three trials. Variables 126 and 852 were rated in that order in respect to their flavor, texture and mouthfeel. Tables 4,5, and 6 show results from the Tukey-Kramer Multiple Comparisons test for flavor, texture, and mouthfeel respectively. For each sensory component, flavor, texture and mouthfeel, the variables were found to all be significantly different from each other. Results from a study using Oatrim-5 as a fat substitute for low calorie salad cream, demonstrated that the highest intensity of aroma, sourness, viscosity, and flavor belonged to the control sample.

10 Intensity became lower and lower as more and more Oatrim-5 was substituted in for salad cream (Kasetsart,2000). Sources of error in this study include preparing the salad dressings on different days and at different times. Machines used may have been calibrated differently. Recipes were prepared as exact as possible each time, but potential for human error should be noted. For example, the degree to which the hard boiled eggs were mashed could have had an effect on the reading from the Brookfield viscometer. Additional sources of error deal with subjective testing. Different numbers of panelists were obtained for each trial and different panelists comprised the sensory panel in each test. Samples were tasted at different times during the day. In future replications of this project, a food processor to chop both the hard boiled egg and fresh red pepper would make the samples more uniform. For better acceptability among sensory panelists, the samples should be chilled before serving. In conclusion, obesity rates have increased in the last decade to include nearly 59 million American adults. Food sources of fats have changed as people consume more hidden fats and fewer visible fats (ADA,2005). High consumption of fat can cause an accumulation of fat in blood vessels, ultimately leading to atherosclerosis, hypertension, and heart disease (Kasetsart, 2000). The use of fat replacers can reduce the amount of calories eaten in foods typically containing fat. A fat replacer is an ingredient that can be used to provide some or all of the functions of fat, yielding fewer calories than fat (ADA, 2005). However, in certain foods such as the Thousand Island Salad Dressing used in this study, palatability, flavor, texture, mouthfeel, and viscosity simply cannot be duplicated with a fat replacer.

11 IV. Results Variable Spindle Speed RPM 6 RPM 12 RPM 30 RPM Table 1. Brookfield Viscometer Results Measuring the Effect of Fat on Viscosity. This table represents the three trial average for each variable at each spindle speed. Values listed here are in centipoises (cp). Viscosity (cp Brookfield Viscometer RPM 6 RPM 12 RPM 30 RPM 60 Spindle Speed (rpm) Variable 921 Variable 126 Variable 852 Figure 3. The Effect of Fat Content on Viscosity. This figure displays the averages of all three trials as measured by the Brookfield Viscometer. Variable 921, 126, and 852 represent the control recipe, 50% substituted recipe, and 100% substituted recipe respectively.

12 CONSISTOMETER (in cm) Variable Trial 1 Trial 2 Trial 3 Average Table 2. Bostwick Consistometer Results Measuring the Effect of Fat on Viscosity. Consistometer Distance (cm Bostwick Consistometer Salad Dressing Variables Variable 921 Variable 126 Variable 852 Figure 4. The Effect of Fat on Viscosity. Comparison Mean Difference q P value 921 vs P < vs P < vs P > 0.05 (ns) Table 3. Consistometer Tukey Kramer Multiple Comparisons Test.

13 Comparison Mean Difference q P value 921 vs P < vs P < vs P < Table 4. Sensory Flavor Analysis Tukey-Kramer Multiple Comparisons Test. Comparison Mean Difference q P value 921 vs P < vs P < vs P < Table 5. Sensory Texture Analysis Tukey-Kramer Multiple Comparisons Test. Comparison Mean Difference q P value 921 vs P < vs P < vs P < Table 6. Sensory Mouthfeel Analysis Tukey-Kramer Multiple Comparisons Test. FLAVOR Variable Trial Trail Trial TEXTURE Variable Trial Trail Trial MOUTHFEEL Variable Trial Trail Trial Table 7. Subjective Analysis by Sensory Panelists using 5-Point Hedonic Scale. Trial 1 consisted of 8 sensory panelists while Trials 2 and 3 contained 7 and 6 respectively. A score of one was associated with the least desirable flavor, texture and mouthfeel while a score of five indicated the best flavor, texture, and mouthfeel.

14 Subjective Analysis by Sensory Panelists Hedonic Scale Rating Flavor Texture Mouthfeel Variable 921 Variable 852 Variable 126 Sensory Evaluation Figure 5. Subjective Analysis by Sensory Panelists using 5-point Hedonic Scale. This figure represents the averages of all 21 sensory panelists who subjectively analyzed the three variables. Variable 921, 126, and 852 represent the control recipe, 50% substituted recipe, and 100% substituted recipe respectively.

15 References American Dietetics Association Position of the American Dietetics Association: Fat Replacers. Journal of the American Dietetics Association. Vol 105. No. 2. Bob s Red Mill Natural Foods Oatrim: A Fat Replacer For Many Foods (made from whole oats). Charley, H. & Weaver, C Foods: A Scientific Approach, 3 rd Ed. Prentice-Hall, Inc. Upper Saddle Ridge, New Jersey. Chapter 15, pp Hallfrisch, J., Scholfield, D.J. & Behall, K.M Glucose and Insulin Responses to a New Zero-Energy Fiber Source. Journal of the American College of Nutrition. Vol. 21, No.5, Inglett, G.E. et al A soluble fibre gel produced from rice bran and barley flour as a fat replacer in Asian foods. International Journal of Food Science and Technology. Vol 39, Inglett, G.E Development of a Dietary Fiber Gel for Calorie-Reduced Foods. American Association of Cereal Chemists. Vol. 42. No.5. Kasetsart J., Oatrim-5 as Fat Substitute in Low Calorie Salad Cream: Nutritional and Microbiological Qualities. Journal of Natural Science. Vol. 34: Kurtzweil, P Taking the Fat Out of Food. FDA Consumer Magazine. Obtained from fda.gov/fdac/features/696_fat.html. Lyly, M. et al Influence of Oat Beta-Glucan Preparations on the Perception of Mouthfeel and on Rheological Properties in Beverage Prototypes. Cereal Chemistry. 80(5): McBride, J Two Thumbs Up for Oatrim. Agricultural Research. December Meadows, M Healthier Eating. U.S. Food and Drug Administration Consumer Magazine. May/June Retrieved from Nestle, M. Increaseing portion sizes in American diets: More calories, more obesity. Journal of the American Dietetics Association. Vol No. 1. Warner, K. & Inglett, G.E Flavor and Texture Characteristics of Foods Containing Z-Trim Corn and Oat Fibers as Fat and Flour Replacers. Cereal Foods World. Vol. 42, No. 10.

16