F&N 453 Individual Project Written Report Effects of Ground Chickpea as Wheat Flour Replacer in Corn Muffins B.A. Hollingsworth ABSTRACT: Heart Disease and Stroke account for over 40% of deaths in America. Cardiovascular diseases are related to high blood cholesterol levels, which can be affected by consumption of pulses, or legumes. Infusing foods typically in the American diet with pulses, such as chickpeas, lentils, soybeans, or black beans could help to improve the American diet and reduce the incidence of high blood cholesterol. Pulses provide high levels of protein, fiber, a variety of micronutrients and phytochemicals with low levels of fat, and thus are ideal to help individuals maintain a low-fat, high-fiber diet and decrease disease risk. In this experiment, pulses were added as a flour replacer to corn muffins. Muffin volume, height, and texture were measured on 3 trials. Muffin volume and height decreased with an increase in percentage of chickpea, while force required to cut the muffin increased with an increase in percentage of chickpea in the recipe. Sensory panel analysis and preference ratings also indicated that 100% replacement of flour with chickpea results in a product with many undesirable texture and flavor changes. Introduction Close to 930,000 Americans die every year from cardiovascular diseases. Heart disease and stroke together account for over 40% of the deaths in America each year, and one main risk factor for both conditions is high blood cholesterol levels (Centers for Disease Control and Prevention 2005). According to data published by the CDC, over 106,000,000 individuals were diagnosed with high blood cholesterol levels in 2002. High cholesterol levels, along with many other diseases can be affected by consumption of legumes or pulses. Examples of pulses include black beans, lima beans, chickpeas, kidney beans, lentils, navy beans, soybeans, pinto beans, and great northern beans. Increased legume consumption is also linked to lower levels of LDL cholesterol in the body (Duane 1997). A high level of Low-Density Lipoprotein cholesterol is a risk factor for Metabolic Syndrome and Atherosclerosis (American Heart Association, 2007). Research has also shown that a Mediterranean diet, which includes legumes and is rich in alpha linolenic acid can have preventative effects on the development of coronary heart disease (de Lorgeril 1994). In a correlational study published in 2000, a protective effect of legumes against prostate cancer was found, as those who had the highest intake of legumes had the lowest incidence of prostate cancer (Kolonel). The benefits of pulses and legumes are not only limited to their connection to disease prevention, but they also assist in maintaining a low fat, high fiber diet. Pulses, or legumes, provide high levels of protein, dietary fiber, and a variety of micronutrients and phytochemicals, with relatively low levels of fat (Messina 1999). These pulses are used frequently in the cuisine of non-western countries such as India and China, but are currently are infrequently present in Western diets, and rarely, if ever, as replacements for typical flours made from wheat (Messina, 1999). The nutritional 1
content of pulses can help individuals maintain a low fat, high fiber diet, with good sources of protein. Because of the benefits of including legumes and pulses in the diet, infusing foods with additional pulses has become a subject of recent food product research, including a pulse breakfast bar that contains up to 30% yellow pea and lentil flour, according to an article in Food Product Design from September 2006 (Spurling). Research studying the effect on glycemia, insulinemia, satiety, and palatability of adding chickpea flour to white wheat flour bread was reported in the European Journal of Clinical Nutrition in 2005. This study reported no significant differences in the sensory acceptability ratings of control white bread and chickpea bread. (Johnson 2005). The type of muffin (corn) was prepared because the flavors fall more in line with the nutty, grainy flavors of the chickpea. Adding ground chickpeas to a fruit-flavored muffin could have adverse effects in consumer acceptability. These experimental procedures used canned chickpeas, ground directly before including in the recipe to measure the effects of adding ground whole chickpeas instead of pre-milled chickpea flour. This strategy is well-documented in lay websites promoting gluten-elimination diets, but rarely found in the scientific literature. Through the use of canned chickpeas, this allows for more experimental control and less variability between trials. The muffins were measured for volume, using the seed volume apparatus, height using a tape measure, and texture via the texture analyzer. Consumer acceptance was measured through sensory panel evaluation. The hypothesis of this experiment was that the replacement of flour with ground chickpea could be a simple way to incorporate more pulses into the average diet of Americans. Pulses are rarely present in the typical American diet, and although the benefits are well-documented, the effects on consumer acceptability may vary widely. Hence, the objectives of this study were 1) to develop corn muffins with added pulses for enhanced nutritional content and 2) to measure effects on consumer acceptability of corn muffins with ground chickpea. Methods One control and two variables of corn muffins were baked and trials repeated in triplicate. The sensory panel evaluated muffins of each variable with no division respect to trial number. The objective measures of volume, height, and texture were completed on 3 muffins from each variable for each trial. Each variable was cooked in a muffin tin with 6-muffin cups, and samples were taken from the left row of muffin cups for each trial. Each muffin was expected to have some individual variability due to pouring of batter, which is why 3 muffins were measured for height and volume on each variable. 2
The recipe for the corn muffins follows. Control (Unaltered Recipe) 120 g flour 170 g cornmeal 50 g sugar 20 ml baking powder 3 ml salt 2 eggs 250 ml milk 50 ml vegetable oil Recipe adapted from: http://www.jsward.com/cooking/cornbread.shtml 50% Flour replaced with Ground Chickpeas 60 g flour 60 g chickpeas, ground 170 g cornmeal 50 g sugar 20 ml baking powder 3 ml salt 2 eggs 250 ml milk 50 ml vegetable oil 100% Flour replaced with Ground Chickpeas 120 g chickpeas, ground 170 g cornmeal 50 g sugar 20 ml baking powder 3 ml salt 2 eggs 250 ml milk 50 ml vegetable oil 3
The single variable modified in the corn muffin recipe was the amount of flour vs. amount of ground chickpea. Flour (g) Ground Chickpea (g) Control 120 0 Variable 1 60 60 Variable 2 0 120 The chickpeas were ground in a food processor to a very fine texture, with no particles larger than 1mm cubes. The 2 eggs were cracked into a separate bowl and mixed prior to addition to the other ingredients. The dry ingredients were mixed in a small bowl first, then milk, vegetable oil, and mixed eggs were added. Ground chickpea was added last and the mixture was stirred by hand until just mixed, where all dry ingredients were moist. The increasing amount of ground chickpea increased water content, making a much less viscous batter prior to cooking. The batter was poured into each cup of a 6-cup muffin tin, lined with paper baking cups, as even as possible. After baking, muffins were measured for volume, height, and texture. Volume measurements were completed in a seed volume apparatus. All 3 muffins were placed into the compartment and the total volume of the 3 muffins was recorded. This measurement was repeated in triplicate. Height measurements were completed using a centimeter measure, and the height of each of the 3 muffins was measured and recorded. Texture measurements were completed via the Texture Analyzer using a knife probe and muffin settings. Texture measurements were recorded for each of the 3 muffins. Sensory panelists scored muffins from each trial, and each sample was numbered with a three-digit number. The muffin samples were moved in position on the table between sensory panelists to avoid the middle-sample bias. The sensory scorecard used by the sensory panel is included. 4
Sensory Evaluation Scorecard Please taste each sample in front of you. On the scale below, please place an X where you would rate each muffin. 815 SOFTNESS Neither nor Very Slightly Slightly Very 134 Neither nor Very Slightly Slightly Very 647 Neither nor Very Slightly Slightly Very Please rank the samples in order of FLAVOR preference, 1= muffin you like most, 3= muffin you like least. 814 134 647 Please rank the samples in order of TEXTURE preference, 1= muffin you like most, 3= muffin you like least. 814 134 647 5
815 GRAININESS Neither nor 134 Very Slightly Slightly Very Neither nor 647 Very Slightly Slightly Very Neither nor Very Slightly Slightly Very Comments: 6
Discussion & Results Volume in Muffin Variations Increasing chickpea content of the muffin recipe significantly decreased muffin volume as measured by the seed volume apparatus (Table 1, Figure 1). This effect may be due mainly to the loss of gluten formation resulting from replacing flour in the muffin recipe with ground chickpea. Table 1: Volume in cubic centimeters of each 3-muffin sample, Trials 1-3. St St St Variable cm 3 Avg Control 1475 1500 1475 Dev cm 3 Avg 1483.33 14.43 1460 1445 1450 Dev cm 3 Avg Dev 1415 8.66 1451.67 7.63 1425 1410 1410 50% Flour + 50% Chickpea 1360 1385 1400 1381.67 20.20 1415 1430 1420 1421.67 7.63 1375 1360 1365 1366.67 7.63 100% Chickpea 1345 1350 1375 1356.67 16.07 1390 1385 1410 1395 13.23 1295 1310 1305 1303.33 7.63 1550 1500 (cm3) Seed Volume Apparatus 1450 1400 1350 1300 1250 1200 1150 Control 50% Flour + 50% Chickpea 100% Chickpea Figure 1: Total Volume Decreases with Chickpea Replacing Flour 7
Texture of Muffin Variables With increasing percentage of chickpea in the muffin recipe, the force required to cut the muffin increased (Figure 2). Across all trials, the force required to cut the 100% Chickpea muffin was more than 200% the force required to cut the Control muffin (Table 2). In conjunction with the lower volume with increasing chickpea content, lower amount of gluten formation would cause an increase in force necessary to cut into the muffin. Table 2: Force Required to Cut Muffins via Texture Analyzer increases with Increases in Percentage Chickpea, Trials 1-3. Force St Force St Force Variable (g) Control 228.1 204.3 171.5 Avg Dev (g) 201.3 28.41 165.1 109.3 129.5 Avg Dev 134.63 28.25 148.3 130.3 158.9 (g) Avg St Dev 145.83 14.45 50% Flour + 50% Chickpea 217.2 185.6 288.7 230.5 52.81 126.2 124.5 146.2 132.3 12.06 194.9 180.9 191.9 189.23 7.37 100% Chickpea 398.8 526.2 492.5 472.5 66.01 183.4 241.1 243.9 222.8 34.15 205.6 422.2 226.1 284.63 119.57 600 500 400 Force (g) 300 200 100 0 Control 50% Flour + 50% Chickpea 100% Chickpea Figure 2: Force Required to Cut One Muffin via Texture Analyzer 8
Height Increasing percentage of chickpea in the muffin recipe showed a decrease in muffin height (Figure 3). This change in height could be explained by less gluten forming proteins available when more of the flour in the recipe is replaced with the ground chickpeas. The average across trials for the Control muffin was almost 0.5cm taller than for the 100% Chickpea muffin (Table 3). Table 3: Height of Muffins per Variable, Trials 1-3. Variable Height (cm) Avg St Dev Height (cm) Avg St Dev Height (cm) Avg St Dev Control 5.0 3.7 3.7 4.13 0.75 4.8 4.5 3.2 4.17 0.85 5.2 4.4 4.6 4.73 0.42 50% Flour + 50% Chickpea 4.7 4.0 3.5 4.07 0.60 5.1 4.2 3.7 4.33 0.71 3.9 4.5 4.1 4.17 0.31 100% Chickpea 4.8 3.6 3.3 3.9 0.79 4.9 4.3 3.3 4.17 0.81 3.6 3.3 3.3 3.4 0.17 6 5 4 Height (cm) 3 2 1 0 Control 50% Flour + 50% Chickpea 100% Chickpea Figure 3: Height of One Muffin per Variable 9
Consumer Sensory Evaluation A small sensory panel evaluated the product on two qualities, softness and graininess. The control muffin was rated as the softest muffin and the least grainy (or most smooth) muffin (Table 4). The 100% Chickpea muffin was rated as the hardest muffin and the most grainy. No consumers on the sensory panel preferred the 100% Chickpea muffin on texture or flavor, only one consumer preferred the 50% Chickpea + 50% Flour on texture, while the clear majority of consumers preferred the Control muffin on both texture and flavor (Table 5). These results are consistent with the obvious changes measured in volume, height, and texture. Table 4: Sensory Panel Ratings Sensory attributes Control 50% Flour + 50% Chickpea 100% Chickpea ness 1 4.33 (1.75) 5.33 (1.63) 6.67 (1.51) Graininess 2 5.00 (1.26) 3.50 (1.64) 2.17 (1.60) Numbers in parentheses refer to standard deviation 1 Nine point scale, 1=, 9= 2 Nine point scale, 1=, 9= Table 5: Sensory Panel Preferences Control 50% Flour + 50% Chickpea 100% Chickpea Texture 5* 1 0 Flavor 6 0 0 *n=number of panelists selecting muffin variable as favorite (asked to rank samples in order of preference 1-3) Conclusions As identified, there is substantial difference in product quality and consumer acceptability when replacing flour with ground chickpea in a corn muffin recipe. Replacing only 50% of the flour caused smaller, but still noticeable changes in the corn muffin qualities. More research and testing is necessary before ground chickpeas can be considered an acceptable replacement for flour in muffin recipes. Because of the substantial effect on volume, height, and texture with the increasing percentage of chickpea, the optimal percentage of chickpea to flour would be presumably less than 50%, unless gluten formation or leavening is made possible by other means. As the benefits of human consumption of pulses have been outlined, discovering a method for incorporation of pulses into typical foods in the American diet is a significant problem for a future focus of food development. Perhaps the use of ground dried or roasted chickpeas would make a difference in limiting liquid content in the muffin recipe. Also, chickpeas could be tested in products which depend less on volume, texture, and height for acceptance, such as granola or breakfast bars. 10
References American Heart Association. 2007. LDL and HDL Cholesterol: What s Bad and What s Good? http://www.americanheart.org/presenter.jhtml?identifier=180. Accessed on September 11, 2007. Centers for Disease Control and Prevention. 2005. http://www.cdc.gov/nccdphp/ publications/factsheets/prevention/pdf/cvh.pdf. Accessed on November 18, 2007. de Lorgeril M, Renaud S, Mamelle N, et al. 1994. Mediterranean alpha-linolenic acidrich diet in secondary prevention of coronary heart disease. Lancet. 343(8911):1454-1459. Duane WC. 1997. Effects of legume consumption on serum cholesterol, biliary lipids, and sterol metabolism in humans. Journal of Lipid Research. 38:1120-1128. Johnson SK, Thomas SJ, Hall RS. 2005. Palatability and glucose, insulin and satiety responses of chickpea flour and extruded chickpea flour bread eaten as part of a breakfast. European Journal of Clinical Nutrition. 59:169-176. Kolonel LN, Hankin JH, Whittemore AS, et al. 2000. Vegetables, fruits, legumes and prostate cancer: a multiethnic case-control study. Cancer Epidemiology, Biomarkers & Prevention. 9(8):795-804. Messina MJ. 1999. Legumes and soybeans: overview of their nutritional profiles and health effects. The American Journal of Clinical Nutrition. 70(supplement):439S- 450S. Spurling CP. 2006. A Healthy Pulse. Food Product Design. p90. 11