PURDUE UNIVERSITY, NUTR 453. A New Take on Mashed Potatoes Substitution of cauliflower in mashed potatoes for nutritional and caloric benefits

Transcription

1 PURDUE UNIVERSITY, NUTR 453 A New Take on Mashed Potaes Substitution of cauliflower in mashed potaes for nutritional and caloric benefits Alisha Chess, Katlynn Doyle, Brooke Slaughter 11/18/2013

2 Abstract: A study was done on the threshold on which the consumer would detect the hidden pureed cauliflower within mashed potaes. Many nutritional benefits lie in the incorporation of cauliflower in mashed potaes, including the reduced risk of renal cancer, reduced glycemic index, decreased caloric intake, and other general health benefits. Variables tested included an all pota control as well as ratios of 1:1, 1:2, and 2:1 pota cauliflower. Samples were tested on a consumer panel as well as on the Hunter Colorimeter, Water Activity Meter, and the Texture Analyzer for their differences in taste, color, water activity, and texture. Results from these tests showed that the substitution was not noticed objectively in all ratios in texture, water activity, and the lightness value in the samples. Within the red/green and yellow/blue coloring, however, samples compared the control variable were significantly different in the 2:1/1:2 and 1:1 and 1:2 ratios respectively. In palatability, consumers threshold for noticeable vegetable incorporation was shown be at the 1:2 pota cauliflower ratio level. This led the conclusion that incorporation of cauliflower up 2/3 the amount is unnoticeable in consumer taste, texture, water activity, and most of the color values. Assuming consumers are not sensitive the slight color change indicated in the samples, this could lead nearly full incorporation of nutritional benefits as well as significant caloric decrease of up 30%. This is in line with past studies depicting similar work. Future studies should examine more consumer studies, especially with color and specific taste profiles. Work in this area could also be expanded upon by further attempts conceal cauliflower detection, as well as testing consumers with hidden vegetables in different food groups. Introduction: The reason for adding cauliflower as a hidden ingredient mashed potaes is benefit the American population by adding nutritional benefits everyday foods. In a cup of mashed potaes, there is about 244 calories. However, in a cup of cauliflower there is about 27 calories. Therefore, in the process of adding cauliflower mashed potaes a consumer would be able eat a normal serving size, or an even larger portion, due the reduced calorie count. The American population would be able eat more, while actually gaining a nutritional benefit from the food. Some nutritional benefits of cauliflower found from research show that eating an increased intake of cruciferous vegetables, such as cauliflower, is associated with a decreased risk of renal cancer (Liu 2013). Vegetable studies have also shown that they are able fight against important human diseases with their contents of organosulfur compounds, specifically glucosinolates and thiosulfates (Kurshad et al. 2010). Other added benefits replacing a ratio of mashed potaes with cauliflower would be reduced fat intake and increased folic acid intake (University of California Cooperative Extension 2012). also is high in lipid antioxidants, polyphenols and vitamin C (Nunes 2009). Further research on potaes shows that they have a high glycemic index of 70 or more, which can quickly elevate someone s blood glucose levels (American Diabetes Association 2013). However, cauliflower is considered have a low glycemic index of 55 or less; therefore by replace mashed potaes with cauliflower one would be able possibly lower their blood glucose levels (American Diabetes Association 2013).There are several added benefits of cauliflower replacement in mashed potaes, which 1

3 have the potential increase general consumer health. The relationship between the independent and dependent variables is measure the point at which the ratio of hidden cauliflower in the mashed potaes is noticed in consumer palatability, texture, and color. If the product is successful, it can actually lower the calories in the product therefore lowering the consumer s caloric intake while they still consume the same volume. There were four different samples for consumers try which include: an all pota control variable, a 2:1 pota cauliflower variable, equal parts pota and cauliflower variable, and a 1:2 pota cauliflower variable. Estimated caloric values for each of these is 732 kcals for the control, 515 kcals for the 2:1 pota cauliflower variable, 406 kcals for the equal parts variable, and 298 kcals for the 1:2 pota cauliflower variable. It is expected that with the increasing cauliflower content in the variables, the hidden cauliflower will become more noticeable. The samples were tested with potential consumers see at which variable this would happen. The purpose of the experiment was see what amount would appropriately disguise the cauliflower additive in the mashed potaes without varying the taste significantly. This was done by transforming cauliflower in a pureed form, which was then incorporated in the potaes. In previous studies, pureeing has shown increase vegetable consumption without consumers noticing a difference in palatability. It also has been shown not affect hunger negatively even though there is a significant calorie decrease (Blatt, Roe and Rolls 2011). Methods: Variables There were four different samples for consumers try which include: an all pota control variable, a 2:1 pota cauliflower variable, equal parts pota and cauliflower variable, and a 1:2 pota cauliflower variable. Estimated caloric values for each of these is 732 kcals for the control, 515 kcals for the 2:1 pota cauliflower variable, 406 kcals for the equal parts variable, and 298 kcals for the 1:2 pota cauliflower variable. The tal grams of cauliflower that will be used is 481.5g. The all pota control variable will have 0g of cauliflower. The 2:1 mashed pota cauliflower variable will have 107g of cauliflower. The equal parts mashed pota and cauliflower variable will have 160.5g of cauliflower. The 1:2 mashed pota cauliflower variable will have 214g of cauliflower. Preparation Both the potaes and cauliflower were boiled separately until tender. Then the potaes were mixed with a hand mixer, while the cauliflower was put in a food processor. The food processor was used puree the cauliflower so that they could get as smooth as possible, which minimized the difference between the variables and the control. After both reached their desired consistency, the additional ingredients such as milk, butter, salt and pepper were added the mashed potaes. Then, the pureed cauliflower and the mashed potaes were measured out and 2

4 mixed gether. Data Collection After the variables were made, objective data was then collected determine the difference in texture, color, palatability and water activity of each of the four different variables. Objective measures were recorded with a Texture Analyzer, Water Activity System meter, and a Hunter Colorimeter. Details of each of these objective tests are described in subsequent paragraphs. For the Water Activity System Meter, the pota mixture sample from each trial was loaded in small disposable plastic sample cups. Sample cups were filled around halfway. Then, the cups were loaded in the tray within the Water Activity System Meter machine until vapor equilibrium of the sample was reached. When it was done, the machine beeped and showed the water activity number on the machine display, which are reflected in the results. For the Texture Analyzer, a standard cone probe was used test the force in grams on the sample. The sample was put in medium sized plastic cups, placed underneath the probe, and a test was loaded on the Texture Analyzer machine. The test was then executed, and a graph was shown. Max force was then retrieved from the graph, and this is the value used in the results. For testing the pota mixture, the pre-set starch test was used. The settings for this test, as taken from the machine, are listed in Table 1 below. Table 1: Settings for the starch test for the Texture Analyzer used on the pota/cauliflower variables Pre Test Speed 1.0 mm/s Test Speed Post Test Speed Required Test Distance Distance Force Time 1.0 mm/s 1.0 mm/s 1.0 mm 4.0 mm 2000 g 5 sec Count 5 Sensitivity 50 g For the Hunter Colorimeter, the samples were spread in the botm of a wide, circular plastic sample dish. The dish was then placed on p of the circular scanner on the machine. When ready, the user hit analyze sample on the computer display, and after a scanning of the 3

5 sample, three numbers were made available on the display. These values, which were the L, a, and b values, are the Hunter values. The Hunter colorimeter is an objective method for measuring the color of different food samples. In the experiment, the Hunter Colorimeter was used obtain L, a, and b values regarding the different ratios and trials of mashed potaes cauliflower. The L values range from 0 being a black color 100 being a white color, while the number received for the a values range from negative being a green color positive being a red color. Lastly, the number received for the b values range from negative being a blue color and positive being a yellow color (Daniel, 2013). For the subjective measures, students in the 453 lab acted as a panel test the palatability. For the subjective measure they rated the palatability using a hedonic scale, which is shown below. The process was done separately three different times for each trial. For the score sheet with the hedonic scale, each variable was assigned a random three digit number and placed on a table in the front of the room. The variables were placed in a horizontal line and participants went through and put a scoop of each on their plate. They were given the sensory score card and were asked taste each sample and rate each on a scale of 1-9, 1 being dislike extremely and 9 being like extremely. The scorecard form used is shown below in Figure 1. Sensory Evaluation Taste each numbered sample in front of you, and rate each sample on a scale from 1-9. Figure 1: Scorecard form for sensory evaluation using the hedonic scale 4

6 Results: Table 2: Average water activity of the various pota cauliflower ratio variables Samples Trial #1 Trial #2 Trial #3 Averages Standard Deviations Control :1 Pota :2 Pota :1 Pota All variation in means within a column are non-significant with a p-value greater than (ANOVA test) Water Activity (A w ) Control 1:1 Pota Variables 1:2 Pota Fig 2: Potaes with Substitutes Using the Water Activity Meter 2:1 Pota 5

7 Table 3: Average texture results, in grams force, of the various pota cauliflower ratio variables Sample Trial #1 Trial #2 Trial #3 Averages Standard Deviations Control :1 Pota :2 Pota :1 Pota All variation in means within a column are non-significant with a p-value greater than (ANOVA test) Force (g) Control 1:1 Pota 1:2 Pota 2:1 Pota Variables Fig 3: Potaes with Substitutes Using the Texture Analyzer 6

8 Table 4: Average hedonic rankings, on a scale of 1-9, of the various pota cauliflower ratio variables Samples Trial #1 Trial #2 Trial #3 Averages Standard Deviation Control :1 Pota :2 Pota :1 Pota Table 5: Statistical comparison of average hedonic rankings of the control variable the 1:1 pota cauliflower variable Control 1:1 Pota Average Standard Deviation The two tailed P value was , considered not significant. (Two tailed T test) Table 6: Statistical comparison of average hedonic rankings of the control variable the 1:2 pota cauliflower variable Control 1:2 Pota Average 7.18a 5.14b Standard Deviation Averages bearing different subscripts between columns indicate significant difference between the means. The two tailed P value was , considered relatively significant. (Two tailed T test) Table 7: Statistical comparison of average hedonic rankings of the control variable the 2:1 pota cauliflower variable Control 2:1 Pota Average Standard Deviation The two tailed P value was , considered not very significant. (Two tailed T test) 7

9 Palate Rating (1 9) Control 1:1 Pota 1:2 Pota 2:1 Pota Variables Fig 4: Potaes with Substitutes Using the Hedonic Scale Table 8: Average hunter colorimetric values of the various pota cauliflower ratio variables Color Value Control 1:1 Pota 1:2 Pota 2:1 Pota L a b Table 9: Standard deviation of the hunter colorimetric values of the various pota cauliflower ratio variables Color Values Control 1:1 Pota 1:2 Pota L a b :1 Pota 8

10 Table 10: Statistical comparison of average L hunter colorimeter values Control 1:1 Pota 1:2 Pota 2:1 Pota All variation in means within a column are non-significant with a p-value greater than (ANOVA test) L value Control 1:1 Pota 1:2 Pota 2:1 Pota Variables Fig 5: Potaes with Substitutes Using the Hunter Colorimeter L Values Table 11: Statistical comparison of the average a values for the hunter colorimeter of the control variable the 1:1 pota cauliflower variable Control 1:1 Pota Average Standard Deviation The two tailed P value was , considered relatively not significant. (Two tailed T test) 9

11 Table 12: Statistical comparison of the average a values for the hunter colorimeter of the control variable the 1:2 pota cauliflower variable Control 1:2 Pota Average 0.943a b Standard Deviation Averages bearing different subscripts between columns indicate significant difference between the means. The two tailed P value was , considered extremely significant. (Two tailed T test) Table 13: Statistical comparison of the average a values for the hunter colorimeter of the control variable the 2:1 pota cauliflower variable Control 2:1 Pota Average 0.943a b Standard Deviation Averages bearing different subscripts between columns indicate significant difference between the means. The two tailed P value was , considered very significant. (Two tailed T test) a Value Control 1:1 Pota 1:2 Pota 2:1 Pota Variables Fig 6: Potaes with Substitutes Using the Hunter Colorimeter a Values 10

12 Table 14: Statistical comparison of average b hunter colorimeter values of the control variable the 1:1 pota cauliflower variable Control 1:1 Pota Average 19.72a b Standard Deviation Averages bearing different subscripts between columns indicate significant difference between the means. The two tailed P value was , considered relatively significant. (Two tailed T test) Table 15: Statistical comparison of average b hunter colorimeter values of the control variable the 1:2 pota cauliflower variable Control 1:2 Pota Average 19.72a b Standard Deviation Averages bearing different subscripts between columns indicate significant difference between the means. The two tailed P value was , considered very significant. (Two tailed T test) Table 16: Statistical comparison of average b hunter colorimeter values of the control variable the 2:1 pota cauliflower variable Control 2:1 Pota Average Standard Deviation The two tailed P value was , considered not very significant. (Two tailed T test) 11

13 b Value Control 1:1 Pota 1:2 Pota 2:1 Pota Variables Fig 6: Potaes with Substitutes Using the Hunter Colorimeter b Values Discussion: The main goal of this experiment was incorporate various ratios of mashed cauliflower in a standard recipe of mashed potaes, and determine the ratio at which the consumer noticed a significant difference between the control and the ratio variables. This served two nutritional purposes: reduce the caloric intake of the product and incorporate additional functional food properties of cauliflower, including a reduced risk of renal cancer, a lower glycemic level, increased folic acid, and reduced fat intake. The results show how water activity, color, texture (measured in grams force on the Texture Analyzer), and overall consumer taste varied with increasing ratios of cauliflower mashed potaes. These results are further analyzed in the subsequent paragraphs. Water Activity Based on observation of the results in Figure 2 and analyzing the data using statistics, it was shown that the water activity averages of all variables used in experimentation were not significant with each other at a p value greater than This is a desired result because it means even with the higher ratios of cauliflower, water activity is not significantly affected. Although deemed not significantly different, Figure 1 shows that the 1:2 pota cauliflower ratio had the highest water activity average, the 1:1 pota cauliflower the second highest, the 2:1 pota cauliflower the next highest, and the control variable the lowest water activity. This showed that the samples with cauliflower in them caused a higher water activity compared the control; however, the averages themselves did not differ by much. This is in line with current literature that evaluates the water activity of mashed potaes. Based on a past study that calculated the water activity of fresh potaes, the value was plus or minus (Leuchapattanaporn et. al. 2004). The results corresponded with this value, with all of the values being around the water activity of

14 Color Evaluation of the color of variables was made by using the Hunter Colorimeter, which uses three values determine where on the spectrum the sample color lies. These values are called the L, a, and b values. After testing of the Hunter Colorimeter, results were analyzed, and variables were compared against each other. For the L values, the averages were very similar, with the 1:2 pota cauliflower ratio having the highest L value, followed by the 1:1 pota cauliflower ratio, then the 2:1 ratio, and finally the control variable averaging the lowest. These averages, as shown in Figure 4, are not far from each other. Upon statistical analysis, these means were considered non-significant with each other, supporting the fact that there is not much difference in the L value between variables. The lightness hue between variables did not change compared the control. The a values from the variables, however, did not show the same results. Figure 5 shows the variation between the different ratios of pota cauliflower, which shows the control be the only positive a value. The 1:1, 1:2, and 2:1 ratios all had negative a values, which leads the conclusion that the incorporation of cauliflower changed the hue of the mashed pota mixture. The second highest a value was the 2:1 ratio, then the 1:1 ratio, then lastly the 1:2 ratio of pota cauliflower with the lowest a value. This supports the theory that the cauliflower resulted in a lower a value due the trend of decreasing a value with increasing amounts of cauliflower. Further, statistical analysis showed the control being significant with the ratios heavy in cauliflower and pota (2:1 and 1:2 pota cauliflower ratios). All other results showed no significance, meaning the 1:1 pota cauliflower ratio did not differ that significantly from the control, and was the only variable do so. This shows that the red/green color in the samples was similar the control in the 1:1 ratio case, but differed significantly from the control in the 2:1 and 1:2 pota cauliflower ratios. The b values from the samples showed strikingly similar results the a values. Shown in Figure 6, the control had the highest b value, followed by the 2:1 pota cauliflower ratio, then the 1:1 ratio, and finally the 1:2 pota cauliflower ratio had the lowest b value. In statistical analysis, the control differed significantly from the 1:1 and 1:2 pota cauliflower ratio while showing no significance between the 2:1 and the control. In this case, the 2:1 ratio showed no difference compared the control, while the 1:1 and 1:2 ratios showed a difference in the yellow/blue coloring of the samples. Texture In characterizing the texture of the pota and cauliflower variables, it was decided use the texture analyzer measure the max force, in grams, required penetrate the sample. In general, the higher the force, the ugher the sample is. With mashed potaes, it is desirable have a lower grams force, meaning a softer product. According Figure 2, there is slight variation between the control and the three variables. The control had the highest force, with the 1:2 pota cauliflower ratio having the next highest force, the 2:1 pota cauliflower ratio having the third highest, and the 1:1 ratio having the smallest force. Upon completion of statistical analysis, it was determined that all the variables had a p value higher than This means the null hypothesis, which is that the variables do not differ significantly from the control, 13

15 is accepted. This is a good result, meaning texture is not changed with the addition of cauliflower. Palatability In determining the overall consumer taste we used the hedonic scale average the overall rating of our panelists. The hedonic scale is a subjective method of responses from panelists used understand the relationship of the chemical senses of food preference and selection (Green, Lim and Wood 2009). For several years now, various formats of the traditional 9-point hedonic scale have been used determine the average liking and disliking of consumer food and products uching numerous varieties of foods and products (Green, Lim and Wood 2009). This subjective method was very useful in determining the preferred taste and texture between the different variables of pota cauliflower ratios. Panelists were randomly picked within the lab try the different samples and rate them using the hedonic scale. For the results shown in figure 4, on average the control of all mashed potaes was liked the most, the equal parts mashed potaes and cauliflower came in second for most liked, the 1:2 mashed potaes cauliflower came in third for the most liked, and the 2:1 mashed potaes cauliflower ratio was disliked the most. This was supported by statistical analysis, which showed that compared the control, the only significant average was the 1:2 pota cauliflower ratio. This determined that this was the threshold at which the consumer noticed the cauliflower in palatability. Overall Results In this study, results were in the positive direction. Analyzing both water activity and texture using the Water Activity System Meter and the Texture Analyzer respectively showed that there was no significant difference in the variables. While two of the variables were significantly different with the control in the a and b values from the Colorimeter data, L values remained not significant across the board. In addition, the facr of consumer palatability and recognition of the cauliflower within the mashed potaes proved significantly different from the control in only the case of the 1:2 pota cauliflower ratio. Even if the consumer noticed the difference from the control, the consumer still subjectively rated the 1:2 variable relatively high. This proved that, even with the addition of pureed cauliflower up until a point, the difference was subjectively and objectively not noticed. This agrees with previous, similar studies done on hiding vegetables in food, both in adults and children, increase nutritional benefit and decrease caloric intake. In both studies, subjects consumed a greater percentage of vegetables than the control and the energy density decreased by a significant amount while taste remained constant throughout the variables. In the study focused on adults, entrees were rated similar in palatability across all variables. The study also showed an increase in vegetables up 487±25 g (Blatt, Roe and Rolls 2011). In parallel, the other study done with subjects in the 3-5 year old age range showed that daily vegetable intake increased by up 73 grams (73%) compared the control condition. Children also rated the variables the same in terms of palatability and how much they had liked the dishes. (Spill, Birch, Roe and Rolls 2011). Possible sources of error could have resulted from inaccurate measurements. While each ingredient possible was measured the nearest gram, the mashed pota recipe called for a certain amount of medium potaes. This was a subjective form of measurement, so 14

16 inconsistencies in size were inevitable. There also could have been spills of the product that resulted in differences within batch sizes. Another source of error could have been associated with the load size in the objective measurements. There might have been an overload that caused incorrect results, or not enough sample cover the botm of the sample cup. For future work in this study, more sensory tests and subjective data should be looked in tie more specific objective results in with subjective results. For example, does the consumer notice a significant difference in the texture of the variables? This could further support results gained from the objective measures. It would also increase merit due the target result being consumer health and palatability of the product. In addition, more tests on the subject could be performed using additional ingredients or spices aim further conceal the flavor and texture of the cauliflower increase the ratio at which consumers detect the cauliflower. To reduce the caloric intake even further, the mashed pota recipe itself could be examined and made become a healthier option pair with the pureed cauliflower. Finally, similar tests could be ran by replacing other nutritionally beneficial foods within potaes or other high risk foods. 15

17 References: American Diabetes Association The glycemic index of foods. Virginia. Blatt AD, Roe LS, Rolls BJ Hidden vegetables: an effective strategy reduce energy intake and increase vegetable intake in adults. Am J Clin Nutr. 93(4), pg Daniel JR NUTR food chemistry: Lecture notes. Purdue Memorial Union Room 157: BoilerCopyMaker. 47 and 61 p. Green BG, Lim J, Wood A Derivation and evaluation of a labeled hedonic scale. Chemical Senses. 34 (9): Kushad MM, Masiunas J, Eastman K, Kalt W, Smith MAL Health Promoting Phychemicals in Vegetables. Horticultural Reviews 28. John Wiley & Sons, Inc., Oxford, UK. p 130. Leuchapattanaporn K, Wang Y, Wang J, All-Holy M, Kang DH, Tang J, Hallberg LM Microbial Safety in Radio-frequency Processing of Packaged Foods. Journal of Food Science 69 (7): M201-M206 Liu B, Mao Q, Wang X, Zhou F, Luo J, Wang C, Lin C, Zheng X, Xie L Cruciferous vegetables consumption and risk of renal cell carcinoma: a meta-analysis. Nutrition and Cancer. 65: Nunes MCN Legumes and Brassicas. In: Color Atlas of Postharvest Quality of Fruits and Vegetables. John Wiley and Sons, Inc. p Spill MK, Birch LL, Roe LS, Rolls BJ Hiding vegetables reduce energy density: An effective strategy increase children s vegetable intake and reduce energy intake. The American Journal of Clinical Nutrition 94(3): University of California Cooperative Extension Reasons for the seasons: Produce tips for placer & Nevada county consumers. Division of Agriculture and Natural Resources. 16