Quinoa as a Substitute for White Rice in a Mediterranean Pilaf Dish NUTR 453 Final Research Project Chelsea Slayter, Amanda Deckard, and Melanie Sturm 11/19/2013 1
Abstract: Quinoa is a supergrain that has been around for hundreds of years. It can be substituted in countless recipes as a nutrient dense alternative for grains such as white rice. The purpose of this experiment was to test, by objective and subjective tests, the final products of a Mediterranean pilaf dish when white rice is replaced by quinoa. The objective tests included a measure of viscosity by a Linespread apparatus, and a measure of color by the Hunter Calorimeter. The subjective tests included a triangle difference test and a preference test on a 7 point Hedonic scale. Three variations of the recipe were produced: 100%Rice, 50%Rice/50%Quinoa, and 100%Quinoa. The subjective tests showed that consumers can differentiate between white rice and quinoa, but prefer the quinoa to the white rice. The objective tests and statistical analysis show that white rice and quinoa are different in appearance, but the same in viscosity. After performing the objective tests and subjective tests, it can be concluded that while quinoa cannot pass as white rice, quinoa is an acceptable substitute for white rice by taste. Introduction: Quinoa has been recognized for centuries as a key food crop in the high Andes Mountains of South America. Quinoa offers valuable adaptation for numerous demanding environments. Quinoa can tolerate different relative humidity conditions (from 40% to 88%), a large range of altitudes (from sea level up to 4000 m), and a wide range of temperatures (from 8 C to 38 C) (Bazil, 2013). In addition to the plant s strength in diverse environments, quinoa has amazing nutritional value, being rich in protein, fiber, polyunsaturated fat, monounsaturated fat, vitamins, and minerals (James, 2009). Quinoa is a grain that when cooked in water will puff up and give a fluffy, creamy texture much like rice (Baker, 2013). The idea of replacing quinoa for rice is very simple and approachable for the everyday American to understand and apply. Quinoa far surpasses rice in its nutritional value and could fill in some of the nutritional gaps of Americans. Despite the Dietary Guideline s suggestion and instruction, Americans do not consume enough dietary fiber (Anderson, 2009). Quinoa offers 12g of fiber per cup uncooked, contributing greatly to the daily needs of adults and children. According to the International Life Sciences Institute, generous intake of dietary fiber reduces the risk of developing coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal disorders. The protein in quinoa is of the highest quality, providing many amino acids essential and non essential such as histidine, isoleucine, lysine, methionine, cysteine, phenylalanine, tyrosine, tryptophan, threonine, and valine(bhargava, A. and Srivastava, S. 2013). The mean protein content reported for quinoa grain is 12 23%, which is greater than that of barley, rice or maize. Similar to 2
its high quality protein, quinoa s oil is also nutrient dense, being rich in essential fatty acids such as linoleate and linolenate. Quinoa contains high concentrations of natural antioxidants such as α tocopherol and γ tocopherol (Bhargava, A. and Srivastava, S. 2013). Finally, quinoa also offers large amounts of vitamins and minerals. The magnesium, manganese, copper, and iron present in 100g of quinoa seed covers the daily needs of infants and adults, while the phosphorus and zinc content in 100g is sufficient for children, but covers 40 60% of the daily needs of adults (James, 2009). Quinoa is a nutritional powerhouse. The nutritional information of this grain is almost too good to be true. Just one simple grain contains the answer to so many nutritional demands and deficits. There is no question that quinoa is more nutritionally valuable than white rice. Therefore, by replacing white rice for quinoa in simple dishes, such as a Mediterranean pilaf, the dietary needs for protein, fiber, and many vitamins and minerals can be met in and easy, approachable way. The purpose of this experiment is to test, by objective and subjective tests, the final products of a Mediterranean pilaf dish when white rice is replaced by quinoa. The independent variables are the 100% Rice, 100% Quinoa, and 50%Rice50%Quinoa variable. The dependent variables are the Hunter Calorimeter values, Linespread values, and the participants ratings. Methods: This recipe was developed from an online recipe by the company Stonyfield Organic. The recipe is titled Mediterranean Pilaf. This recipe would normally be served as an entrée during a meal. Recipe: Trial 1 Greek plain nonfat (Oikos) yogurt 264 grams Uncooked white rice/uncooked quinoa 900 grams each Olive oil 54 grams Unsalted butter 28 grams Small onions (2) 140 grams Small zucchinis (4) 472 grams Red peppers (2) 238 g Fresh mozzarella 454 grams Dried ground basil 36 grams Salt 9 grams Black pepper 3.2 grams Low sodium vegetable broth 588 grams Procedure: Trial 1 First, 900 grams each of white rice and quinoa was cooked. One half c. of each was set aside for objective tests. All of the vegetables were chopped, and the pepper and zucchini were set aside. 3
The onion was sautéed in a saucepan with butter. The yogurt, olive oil, basil, pepper, and salt were all blended together into a sauce. The rice and quinoa were separated into three different variations. The first, being the control, was 100% Rice, the second was 50%Rice and 50% Quinoa, and the third was 100% Rice. The sauce, zucchini, broth, mozzarella cheese, and peppers were evenly distributed between the three samples. Each variation was mixed and served. Recipe: Trial 2 Greek plain nonfat (Oikos) yogurt 264 grams Uncooked white rice/uncooked quinoa 450 grams each Olive oil 54 grams Unsalted butter 28 grams Small onions (2) 140 grams Small zucchinis (4) 472 grams Red peppers (2) 238 g Dried ground basil 36 grams Salt 9 grams Black pepper 3.2 grams Low sodium vegetable broth 588 grams Procedure Trial 2: First 900 grams each of white rice and quinoa was cooked. One half c. of each was set aside for objective tests. All of the vegetables were chopped, and the pepper and zucchini were set aside. The onion was sautéed in a saucepan with butter. The yogurt, olive oil, basil, pepper, and salt were all blended together into a sauce. The rice and quinoa were separated into three different variations. The first being the control was 100% Rice, the second was 50%Rice and 50% Quinoa, and the third was 100% Rice. The sauce, zucchini, broth, and peppers were evenly distributed between the three samples. This trial is without mozzarella cheese. Each variation was mixed and served. Recipe: Trial 3 Greek plain nonfat (Chobani) yogurt 264 grams Uncooked white rice/uncooked quinoa 450 grams each Olive oil 54 grams Unsalted butter 28 grams Small onions (2) 140 grams Small zucchinis (4) 472 grams Red peppers (2) 238 g Dried ground basil 36 grams Salt 9 grams Black pepper 3.2 grams Low sodium vegetable broth 588 grams 4
Procedure Trial 3: First 900 grams each of white rice and quinoa was cooked. One half c. of each was set aside for objective tests. All of the vegetables were chopped, and the pepper and zucchini were set aside. The onion was sautéed in a saucepan with butter. The yogurt, olive oil, basil, pepper, and salt were all blended together into a sauce. The rice and quinoa were separated into three different variations. The first being the control was 100% Rice, the second was 50%Rice and 50% Quinoa, and the third was 100% Rice. The sauce, zucchini, broth, and peppers were evenly distributed between the three samples. This trial is without mozzarella cheese. Each variation was mixed and served. Objective Methods: The objective tests were performed directly after cooking to ensure that time and temperature did not significantly affect the results. The Hunter Colorimeter and Linespread apparatus were used to test the rice and quinoa. The Hunter Colorimeter was performed on the rice and quinoa separately three times. The rice or quinoa was spread in a petri dish, placed on top of the Hunter Colorimeter, and then measured. The L stands for the lightness, the a stands for what color the sample is on the spectrum of red to green, and the b stands for what color the sample is on the spectrum of yellow to blue. The Linespread apparatus is used to measure the distance of flow of a substance under the influence of gravity. The Linespread apparatus is a measurement of viscosity. Four different flow measurements are taken around the sample, and the measurements are averaged to determine the average flow of the sample. To perform the Linespread test the rice or quinoa was placed inside the metal ring on the glass dish with the scale underneath. The ring is removed, and the spread of the substance is measured at 4 spots. The average of these 4 measurements is then the overall measurement of the Linespread apparatus. Subjective Methods: A 7 point hedonic scale and triangle test were used as the subjective testing measures. The hedonic tests were performed three separate times on three different groups of people. There was a total of 30 participants used for the hedonic test. However, due to communication errors among team members, there were only a total of 20 participants for the triangle tests. The triangle test was done on the second and third trials. 5
The first trial was tested on nutrition students from class, the second was a church group, and the third was a group of friends. Each of the variables was labeled with numbers so that the participants did not know the identity of the variables. The participants tested the 100%rice, 100%quinoa, and 50%rice/50%quinoa recipes for the hedonic test and evaluated them by marking 1 7 on the scale on the sensory sheet (1 being like very much and 7 being disliked very much). Next, the participants did the triangle test. Two of the samples were 100% quinoa, and one was 100% rice. They had to select the sample that was different. The sample cups were labeled with completely new number, so that the participants would not be influences by the previous test s numbers. Sensory Evaluation 157 638 492 Now mark the sample that is different from the other two. 734 389 922 6
Results: Subjective Tests: Table 1: Average Hedonic Rating for All Variables Variable Average Hedonic Rating Rice (control) 3.7 50%Rice50%Quinoa 3.3 Quinoa 3.1 Figure 1: Average Hedonic Rating 7
Table 2: Triangle Test Variable Rice (734) 7.5 Quinoa(389) 2 Quinoa(922) 0.5 Figure 2: Triangle Test Avg. Number of Participants 8
Objective Tests Table 3: Average Hunter Calorimeter Data L a b Rice Average 70.99 1.61 8.21 Rice SD 1.05 0.23 0.5 Quinoa Average 53.01 1.58 17.05 Rice SD 1.87 0.49 2.02 Figure 3: Average Hunter Calorimeter Data The Hunter Parameter with the same letter above are not significantly statistically different. Table 4: Statistical Analysis: Comparison Difference P value Rice L vs Quinoa L 17.983 P<0.001 Rice a vs Quinoa a 3.187 P>0.05 Rice b vs Quinoa b 8.837 P<0.001 Table 5: Linespread Apparatus Variable Trial 1 Trial 2 Trial 3 Average Rice 0mm 0mm 0mm 0mm Quinoa 0mm 0mm 0mm 0mm 9
Discussion The results and conclusions of this project could have been altered due to several sources of error. For example, between the trials different kitchens were used with different utensils, scales, and stovetops. There could have been some measurement error because different people were doing each step. Trial 3 used a different brand of Greek yogurt. The subjective tests have error because in the last two trials there was no more mozzarella, and the triangle test only had 20 people. Finally, for the 50%rice50%quinoa variable each mixture could have been slightly more rice or slightly more quinoa. The results of the objective data show that the color of rice and quinoa is different, but the viscosity is the same. The average data from the Hunter colorimeter (table 3) shows that the rice L value was higher than the quinoa L value, the rice a value was lower than the quinoa a value, and the rice b value was lower than the quinoa b value. This means that the rice was lighter, slightly green, and less yellow. The quinoa was darker, slightly red, and more yellow. These results match the expected results for these samples. The statistical analysis of the data in table 4 shows the significance of each comparison. The table shows that the L and b values were statistically significantly different from each other for rice vs. quinoa. This means that white rice is much lighter than quinoa and will have a statistically significant difference in the L measurement. The b value as well was significantly statistically different meaning that along the yellow green spectrum quinoa and rice are different. However, the a parameter was not statistically significantly different meaning that on the red to green spectrum rice and quinoa are similar. The Linespread apparatus was not an accurate comparison of viscosity for these samples because neither rice nor quinoa flowed (table 5). Both the rice and quinoa stuck together because each was slightly sticky. This prevented them from flowing or breaking apart. Since every value from the Linespread apparatus was 0 it was not necessary to do a statistical analysis or display the data in a graph. Using the texture would have been a better instruments to use, and should be used in future studies of quinoa. The subjective tests showed that the participants preferred the sample that was 100% quinoa (figure 1). The participants did not dislike any sample, and only marginally preferred quinoa. However, this data shows that quinoa has the potential to replace rice in many settings. The triangle tests show that the participants can tell the difference between quinoa and rice (table 2). This analysis makes complete sense and lines up with the objective tests. Quinoa and rice are different in appearance and have different colors. Given the statistical analysis and triangle test it can be definitively stated that consumers can tell the difference between rice and quinoa. However, 10
on the same token, it can also be said, given the Hedonic tests, that quinoa can not only replace white rice in a pilaf dish, quinoa can surpass the flavor make up of white rice. There is still a lot of research that could be done in regards to quinoa. Quinoa could be evaluated as a replacement for other commonly used grains such as oats. Quinoa flour could also be developed. In conclusion, the subjective tests showed that consumers can differentiate between white rice and quinoa, but prefer the quinoa to the white rice. The objective tests and statistical analysis show that white rice and quinoa are different in appearance, but the same in viscosity. After performing the objective tests and subjective tests, it can be concluded that while quinoa cannot pass as white rice, quinoa is an acceptable substitute for white rice by taste. References Anderson, W James. 2009. Health benefits of dietary fiber. Nutritional Reviews, Vol. 67, No. 4: pg 188 191. Baker M.G. 2013. Physical, Textural, and Sensory Properties of Gluten Free Muffins Prepared Using Quinoa Flour as a Replacement for Rice Flour. Journal of the Academy of Nutrition and Dietetics Vol.113, No. 9: pg 60. Bazil, Fuentes D., Mujica F. Á. (2013). Chapter 2: Historical perspectives and domestication. Quinoa: Botany, Production, and Uses. Retrieved from http://www.cabi.org.ezproxy.lib.purdue.edu/cabebooks/fulltextpdf/2013/2013332448 8.pdf Bhargava, A. and Srivastava, S. (2013). Chapter 1: Introduction. Quinoa: Botany, Production, and Uses. Retrieved from http://www.cabi.org.ezproxy.lib.purdue.edu/cabebooks/fulltextpdf/2013/2013332448 7.pdf James, E Abugoch James. 2009. Quinoa (Chenopodium quinoa Willd.): Composition, Chemistry, Nutritional, and Functional Properties. Advancements in Food and Nutrition Research, Volume 58, No. 1: pg 19 20. 11