The Effect of Fiber on the Physical Properties and Consumer Acceptability of Buttercream Frosting

Transcription

1 Megan Barnes, Christina Cook, Hailey Wilson The Effect of Fiber on the Physical Properties and Consumer Acceptability of Buttercream Frosting I. ABSTRACT Dietary fiber has been shown have beneficial health effects and may actually lower the risk for certain diseases and improve weight status. However most people do not consume adequate amounts of fiber from their diet; therefore the addition of fiber to commonly consumed foods may increase fiber intake. The purpose of this research was to examine the effect of adding PROMITOR Corn Fiber to butter cream frosting to determine if there was an effect on physical properties and consumer acceptability. Increasing amounts of fiber were added to the frosting and the fiber was then tested for texture, viscosity, and water activity as well with a blind consumer panel for preference and mouth feel. There was no significant difference in texture or water activity when fiber was added but viscosity was significantly greater in the frosting with fiber, and consumers preferred the normal frosting. The results of this research indicate that adding fiber to frosting may have minimal effects on the texture but may negatively affect consumer preference. More research is needed to identify the level at which fiber can be added to frosting without affecting consumer acceptability. II. INTRODUCTION Two major health issues in America are obesity and heart disease. Over a third of the U.S. is obese and heart disease is the number one cause of death (CDC, 2011). Intakes of adequate amounts of fiber have been shown to help cardiovascular disease, gastrointestinal health/disease, weight control, and diabetes. With cardiovascular disease, fiber has been shown to lower blood pressure and improve blood lipid levels (ADA, 2008). More specifically soluble fiber helps lower cholesterol by interfering with it absorption. Fiber can help with the weight control because it is relatively untouched as it passes through the system. This means the calories from fiber are not use by the body, and they also help with satiety. Unfortunately, Americans do not consume enough fiber in their diets, only consuming around 15 grams a day (Piscatella, 2006). The general rule of thumb is to consume 14g/1000kcal consumed; for example: 28 g for a 2000 kcal diet (ADA, 2008). In recent years, many products that do not traditionally contain fiber have had fiber added in an effort to increase fiber content in foods that people often use thereby increasing total fiber intake. Different types of fiber have been used to make a number of items (Mehta, 2009). Promitor Soluble Corn Fiber 70 powder has high soluble fiber content, low sugar concentration, and little effect on viscosity. The purpose of this research was to examine the effect that adding Promitor Soluble Corn Fiber 70 (independent variable) to frosting would have on the texture, viscosity, water activity, and consumer acceptability (dependent variables).

2 Fiber additives boasting various benefits have appeared on the market as more companies are looking for ways to increase fiber content in their products. Promitor Soluble Corn Fiber is a fiber additive that is 70% dietary fiber and less than 20% sugar (Tate & Lyle, PROMITOR 85, 2011). The Promitor fiber has a high concentration of soluble fiber which has the potential for cardiovascular benefits. It is also low in sugar and has minimal negative effects on the gastrointestinal system. Promitor Soluble Corn Fiber in the powder form has a low viscosity making it an ideal for adding fiber to foods without affecting the texture. Additionally, research shows that Promitor Soluble Corn Fiber has been used in many products like cereals, baked goods, soups, candy, beverages, frozen foods, salad dressings and confections (Tate & Lyle, PROMITOR 70, 2011). Generally, fiber is known to have high water-holding capacity which can affect water activity and therefore the texture of the frosting as well (Gelroth, 2001). Water activity and texture determine mouth feel, and the mouth feel of a product is directly related to the consumer acceptability. In addition to water-holding capabilities, fiber also has the ability to form gels, and gelling in foods changes the viscosity (Gelroth, 2001). Therefore, when adding fiber to foods it is imperative to test the texture, water activity, viscosity and palatability. A Water Activity System was used to measure and obtain a digital reading of water activity. Food texture is often tested with a texture analyzer using a cylinder probe, knife probe, cone probe, or puncture probe. For this project a cone probe was chosen to measure penetration and therefore spreadability of the frosting. Viscosity can be measure using Rapid Visco Analyzer or a Brookfield Viscometer; the Brookfield Viscometer was used to test the flow and determine the viscosity of the frosting. Lastly, consumer acceptability can be assessed through many methods including the paired comparison, duo-trio, triangle, ranking/rating, and hedonic tests. A triangle test was used for this experiment in order to determine whether there was a detectable difference between the no fiber and high fiber frosting. Also, a 9-point hedonic scale was used to evaluate whether the addition of fiber caused one sample to be preferred over the others. III. METHODS Frosting Preparation A typical buttercream frosting recipe was chosen for this experiment, and is as follows (Buttercream): 227 g (1 cup) butter 960 g (8 cups) powdered sugar 10 ml (2 tsp) vanilla 118 ml (½ cup) milk

3 One recipe was made with a hand mixer. Butter was creamed, after which powdered sugar and vanilla were added. Milk was added last. The completed sample was weighed (1398.6g) and divided into 3 equal portions for control, variable 1 and variable 2 (466.2g each). To variable 1 and variable 2, we added 14g and 28g of Promitor Soluble Corn Fiber 70, respectively. The samples were analyzed objectively with the Brookfield texture analyzer, the Brookfield viscometer and the water activity system as well as subjectively with a 9-point Hedonic scale (see figure 1) and Paired Comparison test. Objective Testing Texture Analyzer: The texture analyzer gives a gram unit of the amount of force it takes to puncture the frosting. The cone probe was used and pre-programmed frosting setting. Three samples of equal size were taken from each variable of frosting and tested three times each with the texture analyzer, for a total of 9 measurements. The average for each sample was taken and standard deviation was calculated, for a total of 3 averages with corresponding standard deviations. Brookfield Viscometer: The viscometer gives a measurement of thickness or viscosity of the frosting. Three equally-sized samples were taken from each variable of frosting and tested with the viscometer three times for a total of 9 measurements. The average for each sample was taken and standard deviation was calculated, for a total of 3 averages with corresponding standard deviations. Water Activity System: The water activity system shows how closely the water content of each sample behaves as compared to pure water, giving an idea of the shelf stability of our frosting, which is undoubtedly important for producers of canned frosting. Three samples of equal size were taken from each variable of frosting and tested three times each with the water activity system, for a total of 9 measurements. The average for each sample was taken and standard deviation was calculated, for a total of 3 averages with corresponding standard deviations. Subjective Testing Subjective measurements were used as a gauge for consumer acceptability. The 9-point hedonic scale measures which frosting samples consumers prefer. 5g samples were used for testing. The consumers tried each of the three variables and ranked them on the scale shown in Figure 1. The paired comparison test, shown in Figure 2, measured which sample the consumers thought had the best mouth feel. Again, 5g samples were used, and consumers circled which sample had the best mouth feel. Variables that needed to be controlled were carefully considered. This included how the frosting was made before the fiber was added. As previously stated, a large batch of frosting was made and divided into equal samples for testing. In doing this, each sample started out with the same base before the fiber was added, and created the control. It also ensured the frosting was made with the same brands of ingredients and the same process of making the frosting was

4 completed for each variable. Subjective testing (Hedonic Ranking and Paired Comparison) were done by the same group of eight people three times. Each sample was labeled with three random digits to reduce bias. The subjects who tried the frosting were in the Thursday morning lab section of FN 453 at Purdue University, so the sample group was not entirely random and was the same for each of three trials. Figure 1: Hedonic Scale extremely very much moderately slightly Neither nor Slightly moderately very much extremely Figure 2: Paired Comparison Which sample has the best mouth feel/texture? 349 or 206 IV. DISCUSSION The purpose of this experiment was to determine if adding fiber to frosting would produce differences in the physical properties or customer acceptability of frosting. The results showed no significant difference between all three variables after measuring the texture and water activity (see figures 3 and 4). This is concurrent with the proposed null hypothesis. However, one study found that adding fiber to yogurt had a significant difference on texture as measured by a QTS 20 Texture Analyzer (Hashim, 2009). This study was comparable to the present study because the products were not baked goods where most fiber fortification/enrichment occurs. Also, similar instruments were used to measure the texture of the product. On the other hand, this study used date fiber left from date syrup production. The difference in fiber type was most likely the cause of the conflicting results. Averages of overall data are provided in Tables 3-5 and all raw data are available in the appendix Table 6-8. The present study showed there was a significant difference between all three variables in viscosity (see figure 5). The control was different than 14 g of added fiber with a p<0.01 while control was different from 28 g of added fiber with a p< The p value between 14 g and 28 g of added fiber was p< As seen in Figure 5, the more fiber added to the frosting the greater the viscosity or thickness. According to one review article, viscous fibers may have added benefits for the gastrointestinal health (Dikeman, 2006). In the date fiber study, the consumer acceptance and sensory evaluations were significantly affected by adding the fiber (Hashim, 2009). In the current study, it is believed that the change in thickness from increase fiber could have caused the difference in paired comparison test (see Table 2). More people seemed to identify a better mouth feel for the control (79.2%). On the other hand, consumers still seemed to

5 like the frosting despite the added fiber (see Table 1). It is really interesting that 87.4% of people liked (marked greater than neither like for dislike) the control, while 95.8% of people also liked the 14 g fiber, and 87.5% people liked the 28 g fiber. With these results, the fiber did not seem to cause a difference in consumer acceptability. Overall, adding fiber to foods will help consumers increase their fiber intake possibly helping with many chronic diseases. The current experiment showed that there is no difference in texture and water activity and possibly consumer acceptability. Further research is needed to determine if greater amounts of fiber would cause a difference. Because there were differing results between the current study and Hashim s study, more research should be done to determine the difference between fiber types. Additionally, it would be beneficial if research looked into the shelf-life stability of the final product so it could be used in commercial pastries. V. RESULTS No significant difference between variables (p>0.05)

6 No significant difference between variables (p>0.10) Different subscript letters indicate differences between variables. Control vs. 14 g P<0.01, Control vs. 28 g P<0.001, 14 g vs. 28 g P<0.001.

7 Table 1: Subjective Hedonic Scale Percentage Data from all three trials. Hedonic Scale Percentages (All trials) Variation ext. very much mod slightly Neither slightly mod very much ext Control 0.0% 0.0% 4.2% 4.2% 4.2% 8.3% 25.0% 45.8% 8.3% 14 g Fiber 0.0% 0.0% 0.0% 4.2% 0.0% 33.3% 37.5% 25.0% 0.0% 28 g Fiber 0.0% 0.0% 4.2% 4.2% 4.2% 29.2% 33.3% 16.7% 8.3% Table 2: Subjective Paired Comparison Percentage Data from all three trials. Paired Comparison Percentages (all trials) Control 79.2% 28 g Fiber 20.8% Table 3: Texture Analyzer Averages Over 3 Trials Texture Analyzer (g) Variation Average Control g Fiber g Fiber 12.9 Table 4: Water Activity Averages Over 3 Trials Water Activity Variation Average Control g Fiber g Fiber Table 5: Viscosity Averages Over 3 Trials Viscosity (cp) Variation Average Control g Fiber g Fiber 44467

8 VI. REFERENCES American Dietetic Association Position of the American Dietetic Association: Health Implications of Dietary Fiber. J Am Diet Assoc. 108: Buttercream Frosting. AllRecipes.com. Accessed September 21, Center for Disease Control and Prevention Data & Statistics. From: Dikeman CL, Fahey GC. (2006). Viscosity as Related to Dietary Fiber: A Review. Critical Reviews in Food Science and Nutrition 46: Gelroth J, Ranhotra GS Food Uses of Fiber. In: Cho S, Dreher M, editors. Handbook of dietary fiber. New York: Marcel Dekker, Inc. p Hashim B, Khalil AH, Afifi HS. (2009). Quality characteristics and consumer acceptance of yogurt fortified with date fiber. J Dairy Sci 92: Piscatella, JC, Piscatella, B Road to a Healthy Heart runs through the kitchen. New York: Workman Pub. 554 p. Rajen M Dietary Fiber II. AIB International. 31(2):1-19. Tate & Lyle PROMITOR Soluble Corn Fiber 70. From: ber70.aspx Tate & Lyle PROMITOR Soluble Corn Fiber 85: More fiber. Less sugar. Great value.

9 VII. APPENDIX Texture Analyzer (g) Variation Trial 1 Average SD Trail 2 Average SD Trail 3 Average SD Control g Fiber g Fiber Table 6: Texture Analyzer raw data for each trial with averages and standard Water Activity Variation Trial 1 Average SD Trail 2 Average SD Trail 3 Average SD Control g Fiber g Fiber Table 7: Water Activity raw data for each trial with averages and standard deviation. Viscosity (cp) Variation Trial 1 Average SD Trail 2 Average SD Trail 3 Average SD Control g Fiber g Fiber Table 8: Viscosity raw data for each trial with averages and standard deviation.