The Effect of Hazelnut Flour on the Texture and Palatability of Banana Pancakes

The Effect of Hazelnut Flour on the Texture and Palatability of Banana Pancakes F&N 453 Group Research Project Heather Steele, Lisa Strueh, Sarah Kleine 11/3/11

Abstract: The world today is facing a huge obesity epidemic due to the numerous fast food choices and also the shift from complex carbohydrates to simple carbohydrates. White flour is used in a lot of products and so the use of hazelnut flour was explored as an alternative to all-purpose flour. This was done to create a healthier product and ultimately a healthier population. Four different variations of banana pancakes were prepared to test the qualities of the varying amounts of flours. A control pancake was prepared using the standard recipe which called for 1 cup of all-purpose flour. Three more variations of the banana pancakes were prepared, one containing 50% all-purpose flour/50% hazelnut flour, one containing ¼ cup all-purpose flour/ ¾ cup hazelnut flour, and also one containing no all-purpose flour/1 cup hazelnut flour. Linespread, viscosity, and texture were measured for each variation as well as subjective hedonic rankings were measured via a taste panel. The main finding was that the more hazelnut flour that was added, the less desirable the characteristics of the pancake became. The taste panel preferred the control pancake over all the others. It was concluded that up to 50% of the all-purpose flour could be replaced with hazelnut flour and still maintain desirable characteristics of a pancake. This would create a healthier product while still being desirable to consumers. Introduction: Gluten is a structure which traps carbon dioxide, a leavening gas, causing the food product to rise. Flour contributes gluten forming proteins like glutenin and gliadin. Gluten can only be formed when flour with glutenin and gliadin mixes with water to form a dough or batter. Hazelnut flour does not contain any gluten forming proteins. When adding sugar, it competes with water decreasing gluten formation. Fats also decrease the gluten formation by waterproofing the gluten-forming proteins. A lot of foods are made with white flour but can be substituted with healthier flour alternatives. These substitutions may have a negative effect on texture and palpability depending on the protein content of the flour. Hazelnut flour is commonly used for those with Celiac disease because it has no gluten forming proteins and a high fat content. Using hazelnut flour is a healthy alternative and a way to increase intake of fiber and vitamins that act as antioxidants daily. 1

Nuts are particularly important in the potential reduction of cardiovascular disease. There have been many studies done to show the numerous health benefits of nuts. Making nuts a part of one's diet has been shown to decrease the risk of cancer and coronary heart disease. Vitamin E, vitamin B-6, sterols, and dietary fiber have all been found in nuts. Hazelnuts are the second richest source of monounsaturated fatty acids (MUFAs) that have hypolipidemic effects, along with the highest ratio of unsaturated to saturated fatty acids. Low density lipoproteins (LDL) play an important role in coronary artery disease because of their effects in atherosclerosis when oxidized. Vitamin E and the high amount of MUFAs play an essential role in reducing the susceptibility of LDL to become oxidized (Richardson 1997). A study evaluating hazelnut consumption and the effects on coronary heart disease showed that adding 1gram of hazelnut to the diet increased the diets fiber content by 25.2%. Potassium, calcium, magnesium, tocopherols, and phytochemicals are found in nuts and serve as a way to protect the heart. An analysis of four studies showed that the group who consumed the most nuts had a 35% decrease in coronary heart disease because of a decrease in sudden cardiac death when compared to the groups who consumed a smaller amount (Yücesan and others 2010). Another study looked into the benefits of nuts for various diseases. The researchers looked into the effects of nuts on CHD, diabetes, cancer, and gallstone diseases. This study describes the fact that numerous past studies have shown the association between nut consumption and the reduced risk of coronary heart disease. This study also showed that frequent nut consumption reduced the risk of diabetes mellitus in women. The cancer results are inconclusive at this point due to the fact that not many studies have been done. Frequent nut consumption has also shown protective benefits for gallstone diseases in both genders. Also, a very important finding is that long-term consumption of nuts has been associated with lower 2

body weight and lower risk of obesity and weight gain. This study expressed the fact that study after study has shown beneficial health outcomes related to nut consumption (Sabate and Ang 2009). Adding hazelnut flour to commonly consumed food products like pancakes is an easy way to increase the nutrition content of an otherwise nutritionally dense food in an attempt to decrease the risk for certain diseases. The problem is finding a balance between flour with gluten forming proteins and hazelnut flour in order to produce a product with desirable texture and palatability with the proposed health benefits. To determine the correct ratio, independent and dependent variables were used and measured with several tests. A taste panel used hedonic ranking test in order to show the pancake with the best perceived palatability. A paired comparison test was used to determine the pancake consumers preferred. The Brookfield texture analyzer, the Brookfield computerized viscometer, and the linespread apparatus were used to evaluate the dependent variables. The texture analyzer was used to determine the force required to compress the pancake. The Brookfield texture analyzer and the linespread apparatus were used to show how the hazelnut flour affected the viscosity of the pancake batter. The more hazelnut flour that is added (independent variable); the texture, viscosity, and linespread values will most likely change (dependent variables). The purpose of the experiment is to determine the ratio of flour with gluten forming proteins to hazelnut flour to produce a pancake with the most desirable texture and palatability. Methods: The design of the experiment was to substitute hazelnut flour into the standard banana pancake recipe using a control and three variables. The basic recipe for banana pancakes for all 3

control and experimental samples is a banana pancake recipe from the website: Allrecipes.com. The control was a basic banana pancake recipe listed below. The variables had differing amounts flour substituted with hazelnut flour. The first variable had ½ cup (64 grams) all-purpose flour and ½ cup (64 grams) hazelnut flour. The second had ¼ cup (32 grams) all-purpose flour and ¾ cup (96 grams) hazelnut flour and the last variable was completely substituted with hazelnut flour. The variables and the control were made three times in order to obtain the most accurate and consistent results. The basic recipe for the banana pancake is as follows: 1 cup (128 grams) all-purpose flour 1 tablespoon (12.5 grams) white sugar 2 teaspoons (9.2 grams) baking powder 1/4 teaspoon (0.948 grams) salt 1 egg, beaten 1 cup (235.577 ml) skim milk 2 tablespoons (29.609 ml) vegetable (canola) oil 2 ripe medium sized bananas, mashed The control and three variables were assembled in the same way. First the flour, white sugar, baking powder, and salt were combined in one bowl and stirred for 30 seconds. In a separate bowl the egg, milk, vegetable oil, and bananas were combined. This was also stirred for 30 seconds. Then the flour mixture was stirred into the banana mixture. The combination was stirred for one minute. The pancakes were then cooked in a lightly oiled frying pan on medium high heat until golden brown. Approximately ¼ cup of batter was used for each pancake. 4

After the variables were prepared, they were tested for texture using the Brookfield texture analyzer. The pancake batter was tested for a change in viscosity using the Brookfield viscometer using spindle number 5 at 30 rpm and the linespread apparatus. The measurement for the linespread was taken three times for each variable, for each trial. The average was then taken use the three measurements. A taste panel performed two sensory evaluations done on the same day to ensure freshness. A hedonic ranking test comparing the variables was done as was a paired comparison. This procedure was repeated three different times to complete the three trials. Examples of the structured ranking system Hedonic Ranking Appearance Taste Overall Liking 1 2 3 4 5 6 7 8 9 Dislike Dislike Dislike Like Like Like very moderately slightly slightly moderately very much much Dislike extremely Neither like nor dislike Like Extremely Paired Comparison: Circle Preferred Sample Pair Sample No. Sample No. A 312 183 B 924 576 C 183 924 D 576 312 Discussion: Tables 1-3 display all of the data for all of the trials including linespread, viscosity, and texture analyzer values. They also show the average for each of the three tests for each trial along with the standard deviation. Figure 1 shows the linespread (mm) data for all of the trials. 5

According to this graph, the control pancake had the highest linespread value. Figure 2 shows the viscosity data (g) for all of the trials. The control group also had the highest values for viscosity. Figure 3 shows the texture analyzer data (g) for all of the trials. The control group also had the highest values for texture analyzer. Table 4 shows the subjective ratings of different pancake characteristics using the 9 point hedonic scale. Figure 4 shows these average values in graph form. The control group had the highest ratings for all categories and the pancake with no allpurpose flour and 1 cup of hazelnut flour had the lowest ratings for all categories. Based on this graph, the hedonic ratings go down as more hazelnut flour replaces the all-purpose flour. This shows that the control pancake was preferred over all of the other variables. Table 5 shows the sample ID numbers for the varied amounts of the Hazelnut flour variables used for the paired comparisons test. Table 6 shows the results of the paired comparison test and which sample was preferred for each test. The sample with the less hazelnut flour was preferred over the sample with more hazelnut flour in every test. Figure 5 shows the average Linespread measurement data for all of the trials along with the standard deviation error bars. Figure 6 shows the averages for all of the texture analyzer results for the different variations of pancakes with the standard deviation error bars. Figure 7 shows the average viscosity for all the trials of pancake variations. Scientific evidence exists to explain why our control pancake was preferred over our other trials. Hazelnut flour is hazelnut meal and so essentially it is ground up hazelnuts, so it does not have the same effect as all-purpose flour. All-purpose flour works to hold the pancake together, but hazelnut flour caused the pancake to fall apart and have a grainier texture. The hazelnut flour did not produce the desired qualities of a pancake and so it was less preferred by our taste panel. The journal article Influence of hazelnut flour and skin addition on the physical, chemical and sensory properties of vanilla ice cream discusses how the addition of 6

hazelnut flour to a food product changes the sensory qualities of the food. This explains why our pancakes did not turn out like a normal pancake and had differing sensory qualities than the control pancake (Dervisoglu 2006). When interpreting the results there are a number of difference sources of error. One source of error is human error. This could occur due to misuse of the equipment used to measure objective data. Another source of error could be that the recipes were not consistently made each time when preparing the pancakes. An additional source of error could be misuse of the subjective testing sheets by the taste panel. They could potentially mark the wrong sample or make a mistake when tasting our pancakes. Our project resulted in the finding that up to 50% of the all-purpose flour could be replaced with hazelnut flour with only minor hedonic differences. Most of the characteristics remained the same and our taste panel indicated that they only liked it slightly less than the control pancake. This is good because using hazelnut flour creates a healthier product, as it eliminates some of the white flour that is used. Creating healthier foods is very important in today s world due to the fact that so many people are overweight and have increasing health problems due to their diets. Further work could be done in this area to investigate the use of hazelnut flour in other food products besides pancakes to create a healthier product for our population. Also, other additives/substitutions could be explored to enhance the qualities of the hazelnut flour and make it more acceptable to consumers. 7

Results: Table 1: The Effect of the Addition of Hazelnut Flour on the Viscosity of the Pancakes as Measured by the Linespread Apparatus: Control Variable 1 (½ c allpurpose flour + ½ c Variable 2 (¼ c all-purpose flour + ¾ c hazelnut flour) Variable 3 (0 c all-purpose flour + 1 c Trial 1 32 32 28 25 Trial 2 34 30 30 26 Trial 3 30 32 32 25 Average 32 31.1 30 25.3 SD 2 1.155 2 0.5774 Table 2: The Effect of the Addition of Hazelnut Flour on the Texture (g) of the Pancakes as Measured by the Texture Analyzer Control Variable 1(½ c allpurpose flour + ½ c Variable 2 (¼ c all-purpose flour + ¾ c Variable 3 (0 c allpurpose flour + 1 c Trial 1 16.2 9.4 14.4 14.2 Trial 2 18.2 12.4 11.3 14.9 Trial 3 16.2 13.8 14.9 10.6 Average 16.9 11.9 13.5 13.2 SD 1.155 2.248 1.95 2.307 8

Table 3: The Effect of the Addition of Hazelnut Flour on the Viscosity for All Three Trials as Measured by the Brookfield Viscometer Control Variable 1 (½ c all-purpose flour + ½ c Variable 2 (¼ c all-purpose flour + ¾ c hazelnut flour) Variable 3 (0 c allpurpose flour + 1 c Trial 1 5190 2360 1630 4280 Trial 2 5230 2320 1650 3420 Trial 3 5090 2330 1610 3680 Average 5170 2336.7 1630 3793.3 SD 72.111 20.817 20 441.06 Subjective Tests Table 4: Average subjective ratings on a 9-point hedonic scale of different pancake characteristics Appearance Taste Overall Liking Control 8.3 8.5 7.8 Variable 1: ½ cup all-purpose flour 7.7 6.5 7.1 + ½ cup hazelnut flour Variable 2: ¼ cup all-purpose flour 6.4 4.7 4.9 + ¾ cup hazelnut flour Variable 3: No all-purpose flour + 1 cup hazelnut flour 1.7 2.1 1.9 (* 9=Like Extremely, 8=Like Very Much, 7=Like Moderately, 6= Like Slightly, 5=Neither Like nor Dislike, 4= Dislike Slightly, 3= Dislike Moderately, 2= Dislike Very Much, 1=Dislike Extremely) 9

Table 5: Sample ID Numbers Used for Varied Amounts of Hazelnut Flour Variables Variable Type Sample ID Amount of All Purpose Flour Amount of Hazelnut Flour Added Control 312 1 Cup 0 Cups Variable 1: ½ cup allpurpose flour + ½ cup hazelnut flour 924 ½ Cup ½ Cup Variable 2:¼ cup allpurpose flour + ¾ cup hazelnut flour 183 ¼ Cup ¾ Cup Variable 3: No allpurpose flour + 1 cup hazelnut flour 576 0 Cups 1 Cup Table 6: Paired Comparisons Pair Preferred Sample 312 Preferred Sample 183 A 18 2 Preferred Sample 924 Preferred Sample 576 B 20 0 Preferred Sample 183 Preferred Sample 924 C 1 19 Preferred Sample 576 Preferred Sample 312 D 0 20 (Control sample 312 not pictured) 50% all-purpose flour/50% hazelnut flour ¼ cup all-purpose flour/ ¾ cup hazelnut flour No all-purpose flour/1 cup hazelnut flour 10

Linespread Measurement (mm) 40 35 30 25 20 15 10 5 0 Trial 1 Trial 2 Trial 3 Average Trials Figure 1: The Effect of Varied Amounts of Hazelnut Flour on the Viscosity the Pancake Batter as Measured by the Linespread Apparatus (mm) Control Variable 1:(½ c allpurpose flour + ½ c Variable 2: (¼ c allpurpose flour + ¾ c Variable 3: (0 c allpurpose flour + 1 c 6000 Control 5000 Viscosity (cps) 4000 3000 2000 1000 0 Variable 1:(½ c allpurpose flour + ½ c Variable 2: (¼ c allpurpose flour + ¾ c Variable 3: (0 c allpurpose flour + 1 c Trial 1 Trial 2 Trial 3 Average Trials Figure 2: The Effect of the Addition of Hazelnut Flour on the Viscosity for All Three Trials as Measured by the Brookfield Viscometer 11

25 20 Control Force (grams) 15 10 5 Variable 1:(½ c all purpose flour + ½ c Variable 2: (¼ c all purpose flour + ¾ c 0 Trial 1 Trial 2 Trial 3 Average Trials Variable 3: (0 c all purpose flour + 1 c Figure 3: The Effect of the Addition of Hazelnut Flour on the Texture (g) of the Pancakes as Measured by the Texture Analyzer Hedonic Ranking of Pancake Characteristics Average Score on a 9 point Hedonic Scale 9 8 7 6 5 4 3 2 1 0 Appearance Taste Overall Liking Control 50% all purpose flour/ 50% hazelnut flour 1/4 cup all purpose flour/ 3/4 cup hazelnut flour No all purpose flour/ 1 cup hazelnut flour Pancake Characteristics Figure 4: The average of the effect of adding hazelnut flour on the appearance, taste and overall liking as Measured by Subjective Tests from all Three Trials 12

40 Linespread Measurement (mm) 35 30 25 20 15 10 5 a a b c 0 Control Variable 1 Variable 2 Variable 3 Samples Figure 5: The Average Linespread of all Variables as Measured by the Linespread Apparatus P-Value=.0031 (Very significant) Mean Penetration Force (g) 20 18 16 14 12 10 8 6 4 2 P-Value=.0702 a b 0 Control Variable 1 Variable 2 Variable 3 Samples Figure 6: Mean Penetration Force (g) on all Variables as Measured by the Texture Analyzer c c 13

6000 5000 a Viscosity (cps) 4000 3000 2000 b c d 1000 0 Control Variable 1 Variable 2 Variable 3 Figure 7: The Mean Viscosity (cps) of all Variables as Measured by the Brookfield Viscometer P-Value= <.0001 14

References: Allrecipes. 2002. Banana pancakes I. http://allrecipes.com/recipe/banana-pancakes- i/detail.aspx Sabate J and Ang Y. 2009. Nuts and health outcomes: new epidemiologic evidence. Am J Clin Nutr 89(suppl):1643S 8S. Richardson, D.G. 1997. The health benefits of eating hazelnuts: implications for blood lipid profiles, coronary heart disease, and cancer risks. Acta Hort. (ISHS) 445:295-300 Dervisoglu M. 2006. Influence of hazelnut flour and skin addition on the physical, chemical and sensory properties of vanilla ice cream. International Journal of Food Science & Technology 42(6):657-661. 15