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The preference of protein powders among adult male and females- a protein powder taste study

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Title:
The preference of protein powders among adult male and females- a protein powder taste study
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English
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Manter, Joshua
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University of South Florida
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Amino Acids
Metabolism
Digestion
Whey
Protein Quality
Dissertations, Academic -- Physical Education -- Masters -- USF   ( lcsh )
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non-fiction   ( marcgt )

Notes

Abstract:
ABSTRACT: Protein is essential in one's diet because it is an important component in many organs and tissues throughout the body. Athletes ingest protein in order to stimulate protein synthesis and increase lean muscle mass. In order to assist with obtaining adequate amounts of protein, athletes and bodybuilders purchase supplemental protein in the form of protein powders. Protein metabolism and digestion play key roles in this because if the protein is not metabolized or digested effectively, then those who are wishing to gain fat free mass will not be successful. A high quality protein will be digested, metabolized, and directed towards lean tissue accretion more efficiently than a lower quality protein. In order to be a high quality protein, it must contain the essential amino acids. Fortunately, whey protein is a high quality protein because it contains an abundant supply of the essential amino acids. Whey protein is a high quality protein; hence, many athletes and physically active individuals purchase whey protein supplements. Some individuals do not care about taste and overcome awful protein powder taste, while others value a good tasting whey protein. After extensive research, it appears that scientific taste tests on protein supplements are lacking. The purpose of this study was to test some of the most popular protein supplements (Muscle Milk, BSN, Nesquik Vanilla Milk and Optimum Nutrition) and discover which one tasted the best. In this study, there were 94 males and 68 females. The results showed that there was a difference in initial taste and after taste in protein supplements among a male and female population. The difference among the drinks was statistically significant. The findings showed that both genders thought BSN and Muscle Milk were close to "neither good nor bad" while Nesquick Milk was rated as "good" and Optimum was "bad." The initial taste ratings were BSN (mean=4.05; SD=1.7), Muscle Milk (mean=4.6; SD=1.8), Nesquick Milk (mean=5.4; SD=1.2), and Optimum Nutrition (mean=3.1; SD=1.6). This research study showed that there was a statistically significant difference in taste among protein drinks, but the results do not answer as to why that is. Future research would need to be conducted in order to find the answer as to why there is a difference in initial and after taste.
Thesis:
Thesis (M.A.)--University of South Florida, 2010.
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Includes bibliographical references.
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by Joshua Manter.
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Title from PDF of title page.
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The Preference of Protein Powders Am ong Adult Male s and Females: A Protein Powder Taste Study by Joshua Manter A thesis submitted in partial fulfillment of the requirements for the degree of Master of Art s Department of Physical Education and Exercise Science College of Education University of South Florida Major Professor: Bill Campbell, Ph.D. Robert Dedrick, Ph.D. Marcus Kilpatrick, Ph.D. Date of Approval: April 13 2009 Keywords: Amino Acids Metabolism, Digestion, Whey, Protein Quality Copyright 2010, Joshua Manter

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i Table of Contents List of Tables ii i List of Figures iv Abstract v Chapter I INTRODUCTION 1 Purpose of the Study 2 Independent and Dependent Variables 2 Null Hypotheses 2 Chapter II REVIEW OF LITERATURE 3 Fundamentals of Protein 3 Functions of Protein 4 Protein Requirements 4 Amino Acids 5 Protein Digestion 6 Protein Quality 6 Protein Metabolism 8 The Tongue 10 Taste Studies 11 Purpose of the Present Study 12 Chapter III METHODS 14 Study Design 14 Participants 14 Screening 14 Materials 14 Tasting Protocol 15 Dat a Analysis 16 Chapter IV RESULTS 17 Initial Taste Data 1 7 Aftertaste Data 17 Correlation between First and Second Visit 18 Males vs. Females 19 Chapter V DISCUSSION 2 4 Comparison of the Present Study to Other Taste Test Studies 2 4 Explanation of Taste Difference 2 5 Males vs. Females Taste Scores 2 7

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ii References Cited 30 Appendices 34 Appendix A: Initial Screening Form 35 Appendix B: Protein Supplement Nutrition Information 36 Appendix C: Data Collection Form 40 Appendix D: Visit 1 Initial Taste Data 41 Appendix E: Visit 1 Aftertaste Data 42 Appendix F: Reliability Scores of First Visit to Second Visit 43 Appendix G: Reliability Scores of Initial to Aftertaste 44

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iii List of Tables Table 1 Fat, Sugar, and Protein Content of the Protein Supplements 24

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iv List of Figures Figure 1 Mean taste scores for each of the protein supplements Initial Taste Visit 1 1 8 Figure 2 Mean taste scores for each of the protein supplements After Taste Visit 1 1 9 Figure 3 Males vs. Females Initial Taste 20 Figure 4 Males vs. Females After t aste 20

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v The Preference of Protein Powders A mong Adult Male s and Females : A Protein Powder Taste Study Joshua Manter ABSTRACT Protein is essential i in many organs and tissues throughout the body. Athletes ingest protein in order to stimulate protein synthesis and increase lean muscle mass. In order to assist with obtaining adequate amounts of protein, athletes and bodybuilders purchase supplemental p rotein in the form of protein powders. Protein metabolism and digestion play key roles in this because if the protein is not metabolized or digested effectively, then those who are wishing to gain fat free mass will not be successful. A high quality protei n will be digested, metabolized, and directed towards lean tissue accretion more efficiently than a lower quality protein In order to be a high quality protein, it must contain the essential amino acids. Fortunately, whey protein is a high quality protein because it contains an abundant supply of the essential amino acids. W hey protein is a high quality protein; hence, many athletes and physically a c tive individuals purc hase whey protein supplements. Some individuals do not care about taste and overcome awful protein powder taste, while others value a good tasting whey protein. After extensive research, it appears that scientific taste tests on protein supplements are lacking. The purpose of this study was to test some of the most popular protein suppleme nts (Muscle Milk, BSN, Nesquik Vanilla Milk and Optimum Nutrition) and discover which one tasted the best.

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vi In this study, there were 94 males and 68 females. The results showed that there was a difference in initial taste and after taste in protein supplements among a male and female population. The difference among the drinks was statistically significant. The find ings showed that The initial taste ratings were BSN (mean=4.05; SD=1.7), Muscle Milk (mean=4.6; SD=1.8), Nesqu ick Milk (mean=5.4; SD=1.2), and Optimum Nutrition (mean=3.1; SD=1.6). This research study showed that there was a statistically significant difference in taste among protein drinks, but the results do not answer as to why that is. Future research wou ld need to be conducted in order to find the answer as to why there is a difference in initial and after taste.

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1 Chapter One Introduction diet because it is found in many organs and tissues throughout the body. Athletes ingest protein in order to stimulate protein synthesis and increase lean muscle mass R esearch suggests that people should consume around 1 gram per kg of body weight (Pasqua le 2009 ). In order to assist with obtaining adequate amounts of protein, athletes and bodybuilders purchase supplemental protein in the form of protein powders. Protein metabolism and digestion play key roles in this because if the protein is not metaboli zed or digested effectively, then those who are wishing to gain fat free mass will not be successful. Protein digestion is essentially how the protein gets from the mouth to the blood stream, and metabolism is how the protein gets from the blood stream to its many endpoints. In order for protein to be digested metabolized, and directed towards lean tissue accretion, it must be a high quality protein. Therefore it must contain the essential amino acids. W hey protein is a high quality protein because it cont ains an abundant supply of the essential amino acids. Unfortunately, many whey proteins are known as having a poor taste yet individuals continue to drink whey protein. In regards to taste, the tongue has many taste buds which are made up of epithelial cells. Small hairs known as microvilli protrude from the taste buds, and these hairs essent ially provide the sense of taste According to Guyton (2000), taste preference is a result from a mechanism in the central nervous s ystem. Guyton fails to explain what the mechanism exactly is or how to find it. which solely

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2 determines taste preferences. One can infer the n that taste preference will in large part be subjective Taste could also be due to previous experiences that could have been related to emotional issues There have been taste test studies done on water, milk, iced tea, and donuts; h owever, it appears that there has yet to be a taste study on protein powders. Purpose of the S tudy W hey protein is a high quality protein; hence, many athletes and physically a c tive individuals purchase whey protein supplements. However, is it possible some whey proteins taste better than others ? After extensive research, it appears that scientific taste tests on protein supplements are lacking The purpose of this study is to test the some popular protein sup plements (Muscle Milk, BSN, and Optimum Nutrition) and Nesquik vanilla milk and discover which one taste s the best. Independent and Dependent Variables The independent variable for this study will be the protein drink with the four different types. Dependent variables will be the initial taste and the after taste measured on a 1 7 point scale Null Hypotheses Ho 1 : There will be no difference in the initial taste of the protein supplements Ho 2 : There will be no difference in the aftertaste of the protein supplements

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3 Chapter Two Review of Literature Fundamentals of Protein Protein is found in tissues, muscles, organs, bones, hormones, antibodies, and many other parts in the body. Because protein is a structural component of so many areas, it is impossible for the body to possess functional integrity without it In addition, there are eight amino acids (isoleucine, leucine, lysine, meth ionine, phenylalanine, threonine, tryptophan, and valine) sections will present a discussion of types of proteins are the most beneficial for health. Protein is an organic compound that is found in almost every cell of the human body. The building blocks of protein are amino acids. For amino acids to make protein, the ir peptide linkage must bond together to create a chain. These chains ar e what make proteins and what gives them different characteristics. There are several different types of protein with many different functions. Simple proteins are made up of only amino acids and some of them include albuminoids, glutelins, and prolamin es (Pasquale 2009). Conjugated proteins are bound together with several different non protein substances. Some of these include chromoproteins, lipoproteins, and nucleoproteins (Pasquale 2009). In addition, a protein structure can determine where they will be assigned in the body Some are round while many are simply long chains which are bound together Functions of Protein

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4 Even though there are several different types of proteins, all of them are limited to four specific functions. The first is growth because protein can help create many different types of tissues in the body. Maintenance is another function. Since the body is breaking down, it needs to try and restore itself so protein turnover helps that process. Proteins also help regulate functions throughout the body; it could be in tissues, the blood, or hormones. The last function is energy; the breakdown of amino acids help create energy within the body. The se four functions are vital to sustaining muscles and life. If protein be able to function properly, or even worse, life would not be possible. Protein Requirements It is very apparent that protein is necessary for life, yet it seems tha t there are several different opinions as to how much protein one should consume. Everyone has a different protein requirement because their bodies have a different turnover rate of amino acids and nitrogen requirements. Some nitrogen is not retained in th e body and is excreted in various ways (i.e., urine); therefore one must consume enough protein to maintain this balance. T herefore, protein requirements are more of estimations unless extensive tests are done on each individual person. In reference to t he recommended daily allowance of pr otein Pasquale states the normal amount of protein recommended for sedentary people is .8 g of protein per k ilogram of body weight per day. As for athletes, they need to ance athletes varies from 1.2 1.8 g/ k g /day (Pasquale 2009). In 1990, Gattas performed a nitrogen balance study on prepu bertal school age boys and discovered that 1.2 g/kg/day of protein should be enough

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5 to maintain protein balance. Rand conducted a meta an alysis in 2003 of nitrogen balance studies for protein requirements. His results stated that for healthy adults, they need between .63 and .85 g/kg/day of good quality protein. Lastly, Layman wrote a review article in 2004 which stated that people can take up to 1.5 g/kg/day or more and doing so it is very helpful with weight loss. Therefore, t he previous research shows that one can consume anywhere between .63 and 1.5 g/kg/day. These requirements vary quite a bit e most research states around 1 g/kg/day is enough that i s most likely a safe estimate for an adult who is moderately active to use. Amino Acids A mino acids are the building blocks of protein, which makes them vastly important. Of the 22 amino acids, the body can produce 14 which means the other eight must be ingested by food or supplements. These eight amino acids (isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine) are called essential amino acids. Three of the essential amino acids ( isoleucine, leucine, and valine) are known as branched chain amino acids (BCAAs) because they have a carbon chain which extends from the central carbon backbone. Also, the BCAAs are important with protein synthesis. In 2003, Rieu et al. conducted a leuci ne supplement ation study on rats to see its e ffects on protein metabolism. It was reported that leucine supplements after a meal aided protein metabolism in adult and old rats. Another study done on the essential amino acids (EAA) showed positive results a s well such as Borsheim et al. in 2000. They performed a study on humans and discovered that ingesting 6 g of EAAs post exercise increased net protein balance, thus displaying that supplemental EAAs have a positive effect on protein

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6 metabolism. Now that o ne has an understanding of protein and amino acids, they can build upon that foundation and move on to more difficult concepts such as protein digestibility and metabolism. Protein Digestion The digestion of protein could simply be described as the proc ess of how the protein goes from the mouth and eventually ends up in the blood. Pasquale (2009) defines protein digestion as : the mechanical, chemical and enzymatic breakdown of the protein in food into smaller units. Digestion involves several stages in cluding the mechanical extraction of the protein from the food, denaturation of the protein, and hydrolysis of the peptide bonds. Protein is mechanically extracted from the food in the process of mastication and by the action of the stomach. Summarizing P asquale, digestion breaks down the proteins into amino acids by breaking apart the peptide bonds, which allows them to either be absorbed in the body or broken down more and eventually excreted through the urine. The way protein is digested and how much th e body absorbs is mainly dependent upon the quality of the protein. Protein Quality and concentration of indispendable or essential amino acids, the protein digestibility, and different measures of protein quality. The five most often used methods of assessing protein quality are the Protein Digestibility Corrected Amin o Acid Score (PDCAAS), the

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7 Amino Acid Score (AAS), the Protein Efficiency Ratio (PER), the Biological Value (BV), and the Nitrogen Protein Utilization method. The PDCAAS is used the most of these five methods because it is simple, and it asses protein dige stibility in humans very well (Pasquale 200 9 ). The PER is not very reliable because it is a test which is used on rats. The BV measures the input and output of nitrogen, but it is difficult to account for every loss and gain of nitrogen in the body therefo re scientists do not have a lot of confidence in it. The PDCAAS has essentially been adopted has the primary means of measuring protein quality. (Schaafsma et al. 2000 ). The PDCAAS is based upon a score of 0.0 to 1.0. A protein with a score of 1.0 is cons idered to be a complete protein which contains the essential amino acids. The formula used for finding the PDCAAS score is limiting amino acid in 1 g of test protein divided by same amino acid in 1 g of reference protein times true fecal digestibility (Sc haafama et al. 2000 ). Proteins such as whey, whole egg, casein, and soy protein concentra te have a score of 1.0 (Pasin & Miller 2000). In 2003, a protein quality study was conducted on rats to see if the quality scores would be the same as for humans (Gili ani et al. 2003) The results showed that the PDCAAS scores were higher compared to human subjects. Therefore using rats for measuring protein quality cannot be compared to humans unfortunately. Even though the PDCAAS is the most common used method to m easure protein quality, there are several research studies stating that the method needs to be improved because it has its limitations (Darragh e t al. 2000; Schaafsma 2000; Gil ani et al. 2008; Sarwar 1997). One of the main complaints is that if any protein has a score greater than 1.0, it is rounded back down to 1.0 (Giliani et al. 2008). It appears that many are ignoring

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8 these limitations because the PDCAAS is still used often for measuring protein quality and will continue to be unless someone creates som ething better. The digestion of protein relies heavily on the quality of the protein. Once protein is digested, it will go to the blood and from there travel to many different end points, which is determined by metabolic needs Protein is broken down to amino acids by the time it reaches the various end points. The amino acids can either be absorbed by the body in skeletal muscle, the amino acid pool, different tissues, etc. or it will be excreted through the urine Protein Metabolism Nitrogen retention is often used to measure protein metabolism because if the protein is not absorbed in the body the amino acids are catabolized a nd the nitrogen is excreted through the urine. Nitrogen is a main component of amino acids thus protein as well. T her efore if nitrogen is in the urine, then the amino acids and proteins are not staying in the body. The liver is unique because of its capacity to degrade amino acids and to synthesize urea however is that there is a wide array of opinions as to what exactly determines protein absorption; it seems as if no one knows the exact answer. One study believes that the patte rn and kinetics of amino acids play a major role in absorption (Fouillet et al. 2002). There have been many studies done on protein absorption which used nitrogen retention to test it, but no one appears to have a definite answer as to why some protein is absorbed and some is not.

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9 Garlick et al. wrote a review article in 1999 on protein metabolism and nitrogen retention. Their findings were vague but provided some useful information They concluded that people can go from a low protein intake to a high protein intake, and their body will adapt by retaining more protein, which was shown through urine tests. However, they did state that they were not sure how long this retention period lasts, and if it will continue at this higher level. Therefore, they ad vocate a higher protein intake because it will result in greater retention but they are not sure if this retention is a permanent change or not. Previous studies also agree with Garlick et al. that nitrogen balance will remain positive when protein intak e is increased. (Pannemanns et al. 1993, Todd et al. 1984). According to Dangin et al. (2001), the digestion rate of protein is a factor in retention. In their s tudy, they compared whey and casein protein by administering these types of protein in liquid form to their subjects. They discovered that casein had a better retention rate, which was measured through leucine balance which in turn measured the nitrogen balance. They believed the casein absorbed better because it has a slower digestion rate. In the ir conclusion, they state that age can also have an effect on nitrogen retention, and other tests need to be done on different age groups and populations to see if the results will be the same. Two older studies provide interesting views on what causes n itrogen retention. Kies et al. (1964) makes a strong case that essential amino acids play a huge role in nitrogen retention. Their study showed that when individuals took a supplement of essential amino acids, their nitrogen retention was better than those who did not take the supplement. Leverton et al. (1949) did a preliminary study on how time of ingestion may

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10 affect nitrogen retention. Their results were astounding. One group of s ubjects was required to eat protein at every meal while another group was required to skip protein at breakfast. They discovered that there was greater nitrogen retention when subjects would eat animal protein at every meal compared to those who did not. In the end, one can see that nitrogen retention is a good method to me asure protein balance in the body, unfortunately there does not seem to be a consensus as to why some protein is absorbed and some is not. The processes of protein metabolism and digestibility are important to those who take protein supplements because c ustomers will want proteins that digest quickly and efficiently. This creates a question however as to why some people enjoy the taste of certain brands of protein while they dislike other brands. Is it possible to determine what causes one to like a certa in name brand of protein yet dislike another commercial brand? Everyone experiences taste, and everyone has taste preferences which is why some people enjoy certain protein brands compared to others. The Tongue The taste buds on the tongue determine whether one perceives something to taste sour, salty, sweet, or bitter. Taste buds are made up of about 50 epithelial cells, and these cells are essentially what cause taste. These cells have small taste hairs, also called microvilli that prot rude from the cells and provide the surface for taste. According to Guyton ( 2000 ), taste preference results from a mechanism located in the central nervous system and not from the taste receptors themselves. There does not seem to be any Therefore, taste preference is subjective and will be different for every person.

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11 Taste Studies There has been several research st udies conducted on taste and taste preference; s tudies have measured taste preference with milk, iced tea, water, and donuts. These studies provide excellent guidelines and a framework to follow for future taste studies. Bordi et al. (2008) performed a stu dy with a repeated measures design on donuts to compare the taste of trans fat and trans fat free donuts. Participants ate donuts that were cooked in trans fat shortening and trans fat free shortening. The participants were students and faculty from a northeastern university, and they agreed to participate after receiving an email in regards to the study. The participants sat in individual booths and were given three different donut samples to evaluate the taste. The donuts were created with three diffe rent types of shortenings to see if trans fat free shortenings had a different taste. Taste was rated on a 7 point hedonic scale (1= dislike very much; 7= like very much). The results showed that there was not a statistical difference between the different donuts Therefore, the study showed that donuts with trans fat free shortening can be used instead, which has significant health implications. Vickers et al. in 1998 c arried out a taste study on a beverage instead They wished to discover if a laboratory or foodservice setting would influ ence the taste ratings of milk. Students from a local university drank the milk in a foodservice setting, while a group of participants drank the milk in a laboratory setting, and the results were compared to one another. The students who were in the food service setting were not aware a taste study was occurring. The researchers measured the amount of milk in the machine before dinner and after dinner, and their results were based off of how much milk was cons umed. They placed 2% milk in the machine on certain evenings, and on the other

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12 nights, they used an off flavored milk. After 16 days, they compared how much milk was consumed on the different nights. They stated approximately 300 students owned meal contra cts and roughly 35 to 75 students consumed milk at dinner. In the laboratory, 39 participants drank the 2% milk and the off flavored milk. The taste of the milk was rated on a 9 point hedonic scale (1= dislike extremely; 9= like extremely). The research ers used ANOVAs to determine if the amount of milk consumed or the likings ratings were related to the type of milk. It was not stated how much milk they were told or allowed to consume. The results showed that roughly the same amount of milk (20 Kg) was c onsumed in the lab and food service setting. In 2004, Koseki et al. conducted a taste study on water which had various concentrations of hardness. The participants were 108 female junior college students who ages ranged from 19 20. They were not given an y instructions in regards to breakfast, lunch, dinner, or tooth brushing before the test. Ten samples of bottled water were given to the participants and the water was evaluated in terms of 5 grades very good tasting, good tasting, neither, bad tasting, v ery bad tasting (+2, +1, 0, 1, 2). The participants were told to drink the different waters in any order they choose; the room and sample temperatures were both 75.2 degrees Fahrenheit In addition, participants judged the water on aftertaste, bitterness, sweetness, and overall impression of the water using the same scale. The results were how each water concentration was rated for taste, and with that rating, it was compared to the other concentrations. This study would be good for future studi es to follow because of the 5 point rating scale they used for taste and because they tested aftertaste as well. Purpose of the Present Study

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13 After searching the literature on this topic it appears evident there is no published research conducted on ta ste testing and protein supplements Therefore, there is a need to perform a taste test study on popular protein supplements. The previous taste test studies will be used as a guide for this study in order to ensure this study i s designed adequately and carried out in an effective manner. The goal of the proposed study is to see which brands (BSN, Muscle Milk, Nesquick Vanilla Milk, and Optimum Nutrition) have the best taste

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14 Chapter Three Method s Study Design The study design was a quantitative, non experimental design Participants In this study, there were 162 participants (94 males, 68 females). The average age of the males was 21.9 ( SD =3.3) and the average age of the females was 21.4 ( SD =2.8). The average weight and height o f the males was 177 pounds ( SD =33.2) and 70 inches ( SD =3.0) respectively The average weight height and height of the females was 136 pounds ( SD =25.5) and 64 inches ( SD =2.7). In order to participate in this study, pa rticipants had to be physically active individuals not allergic to milk or wheat and between the ages of 18 25. Physically active was defined by either being active at least 3 hours per week or active 2 days per week. Participants were students from the University of South Florida and out of convenience, most were recruited in the campus recreation center. T hey were personally asked in the recreation center to participate or they responded to the posted flyers in the recreation center about the study Participants initially sign ed a consent form to be a part of the study. Participants were blinded to the protein supplements that were used during the study. Screening Participants were screened before they participated They w ere asked the initial screening questions (appen dix #1) in person to make sure they qualified for the study. The only questions on the initial screening form that made one eligible for the study was

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15 if they were physically active, not allergic to milk or wheat, and between the ages of 18 25. They were a lso asked on the screening form if they had purchased protein powders in the past. The researcher was interested in determining if familiarization might play a role Materials The necessary mate rials were 3 oz cups, t hree blenders, and the f our different types of protein drinks ( Nesquik, Muscle Milk, Optimum Nutrition, and BSN see appendix #3 for nutritional info ). Dish soap was used along with a scrub brush to clean out the blen ders after they had been used. Testing Protocol Participants were required to come to the lab o n the lower floor of the re creation center 2 times within approximately one week and they were asked to not to ingest any food an hour before testing Out of 162 participants, 115 students returned for a second visit (70% return rate). Testing Session #1 : After signing the informed consent form, participants were given the four protein supplements in a randomized order. The website psychicscience.org was used to generate the randomized order for the drinks. The drinks were made w ith bottled water, which was kept refrig erated, and the blenders were used to create the drinks. The participant was blinded to the preparation of the protein supplements The blenders were turned on at the lowest setting for 30 seconds. The drinks were put in a small 3 oz cup. The participants drank each supplement and answer ed a questionnaire (see appendix C) on the initial taste and the aftertaste after each individual drink bad slightly bad neither

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16 good nor bad slightly good good , which was recorded as 1 7 for data analysis (See appendix C for example of rating form). The participants were given 15 seconds after their taste of each drink to rate t he initial taste A fter another 15 seconds the participants were asked to rate the aftertaste. Therefore, within 30 45 seconds, the participant rated the initial and aftertaste of each drink. The particip ants either t ook several sips or drank all 3 oz before providing their opinion of the taste. During the pilot study, the participants found the 7 point scale and the instructions easy to understand. Participants were provided water if they wished to rinse their mouth in between drinks Once the p articipants had tasted each protein dri nk and filled out the questionnaire for each drink, they were free to go until the next time they return ed to the lab Testing Session #2 : This session was identical to testing session #1, except the randomization of the drink s was different Data Analysis Data w ere analyzed via a 2x4 repeated measures design with gender as a between subjects factor and protein as a within subjects factor utili zing SPSS 15.0. Criterion for si gnificance for all tests was set at p < .05

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17 Chapter Four Results Familiarization Out of the 94 male participants, 54 purchase d protein on a regular basis (57%). Only 8 of the 68 females purchase d protein on a regular basis (12%). Initial Taste Data Mean scores for the initial tastes of the protein beverages are as follows: the mean score for drink #1 (BSN Syntha 6) was 4.05 ( SD =1.7) the mean score for drink #2 (Muscle Milk) was 4.6 ( SD =1.8) the mean score for drink #3 (Nesquik Vanilla milk) was 5.36 ( SD =1.2) and the mean score of drink #4 (Optimum Nitro Core) was 3.13 ( SD =1.5) The amount of variability in the ratings, as measured by the standard deviation, was similar across the four drinks, a nd t he range for each drink was 6 The mean rating for and drink 4 was close There was an overall significant difference ( p < .05) between the four protein supplement beverages (the p level for each was 0.00) P ost hoc paired t tests corrected for alpha inflation (Bonferroni correction) we re utilized for identifying the specific differences Figure one highlights these significant differences. Nesquik Vanilla m ilk was rated the most positive in taste followed by MM, BSN and Optimum H o1 stated that there would be no difference in the initi al tast es of the protein supplements. Due to the observed statistical differences

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18 between the protein supplements, we reject H 01 (see appendix D for more data on visit one initial taste) Aftertaste Data The results of the After Taste Visit 1 had similar results. Mean scores for the protein are as follows: the mean score for drink #1 (BSN Syntha 6) was 4.06 ( SD =1.4) the mean score for drink #2 (Muscle Milk) was 4.28 ( SD =1.7) the mean score for drink #3 (Nesquik Vanilla Milk) was 5.08 ( SD = 1.3) an d the mean score for drink #4 (Optimum Nitro Core) was 3.07 ( SD = 1.6) There was an overall significant difference ( p < .05) between the four protein supplement beverages and the score for each was 0.00 P ost hoc paired t tests corrected for alpha inflati on (Bonferroni correction) were utilized for identifying the specific differences Figure two highlights these significant differences. Again, Nesquik Vanilla milk was rated the most positive in taste followed by MM, BSN and Optimum. H o 2 stated that there would be no difference in the aftertastes of the protein supplements. Due to the observed statistical differences between the protein supplements, we reject H 0 2 (see appendix E for more data on visit one aftertaste)

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19 Figure 1 Mean taste scores for each of the protein supplements Differences between values with uncommon letters (e.g., A,B, C ) are statistically significant at p < .05. SD for BSN =1.7, SD for M.M.= 1.8, SD for Milk= 1.2, and SD for Optimum= 1.5. Correlation and Reliability between F irst and S econd V isits Unfortunately during the data collection, not all of the participants c a me back for a second visit. Out of the 162 participants, 115 came back a second time (representing a 71% return rate). 60 of the 94 males returned for a second visit (64% return rate), and 55 of the 68 females returned (81% return rate). The reason for the second visit was to be sure the rating scores correlated from the first to second visit. There was a highly significant correlation ( p < .05) for the four protein supplement beverages when comparing the first and second visits This was true for the initial tastes and after tastes. The correlations (i.e., reliability ) w ere not very strong however. For initial taste visit one to visit two, the correlation between the ratings for the first and second visits for BSN was .37, for Muscle mil k 50 for Nesquik Milk .34, and for Optimum .40. For aftertaste 4.05 4.6 5.36 3.13 1 2 3 4 5 6 7 BSN M.M. Milk Optimum Initial Taste Visit 1 C D B A

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20 visit one to visit two the correlation between the ratings for the first and second visits for BSN was .36, Muscle Milk .5 1 Nesquik Milk .35, and Optimum .4 9 (see appendix F for graph of d ata) The correlations between initial taste and aftertaste were much stronger compared correlation was .7 5 Muscle Milk .82, Nesquik Milk .7 8 and Optimum .8 3 For initial to afterta ste at visit two the correlation between the two ratings for BSN was .7 4 Muscle Milk .7 5 Nesquik Milk .77, and Optimum .8 1 (see appendix G for table of correlations ) Figure 2 Mean taste scores for each of the protein. Differences between values with uncommon letters (e.g., A,B,C ) are statistically significant at p < .05. Males vs. Females In regards to initial taste ratings at visit one the males rated BSN at 4.14 ( SD =1.6) while the females rated it 3.93 ( SD = 1.8) The males rated Muscle Milk at 4.9 ( SD =1.8) and the females at 4.19 ( SD =1.8) The males rated Nesquik milk at 5.33 4.06 4.28 5.08 3.07 1 2 3 4 5 6 7 BSN M.M. Milk Optimum After Taste Visit 1 C B A A

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21 ( SD =1.3) and the females gave it 5.41 ( SD =1.2) The males gave Optimum a 3.37 ( SD =1.5) rating and the females gave it at 2.79 ( SD =1.7) rating. For males and females the order of taste preference was the same. Nesquik Vanilla milk was rated the most positive in taste followed by M M BSN and Optimum. Figure 3 highlights th e s e data. As for the aftertaste, the males gave BSN a rating of 4.11 ( SD =1.4) and the females a rating of 4.0 ( SD =1.6) For Muscle Milk, the males gave it a rating of 4.54 ( SD =1.6) and the females a rating of 3.93 ( SD =1.7) For Nesquik milk, the males gave it a r ating of 5.07 ( SD =1.4) and the females a rating of 5.09 ( SD =1.1) For Optimum, the males gave it a 3.21 ( SD =1.6) and the females a 2.88 ( SD =1.6) The order of pr eferences was nearly the same. Nesquik was rated the most positively in taste for males and females and Optimum was rated the least positively, BSN was rated slightly higher than Muscle Milk for the females. Figure 4 highlights th ese data. Figure 3. Males vs. Females Initial Tastes. denotes a significant statistical difference from Independent sample t test. 1 2 3 4 5 6 7 BSN Muscle Milk Nesquik Optimum 4.14 4.9 5.33 3.37 3.93 4.19 5.41 2.79 Males Females *

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22 Figure 4. Males vs F emales A fter t aste. denotes a significant statistical difference from Independent sample t test. As for the ratings of the second visit, the ma les rated the initial taste of BSN at 4.44 ( SD =1.7) while the females rated it 4.27 ( SD = 1.6). The males rated Muscle Milk at 4.42 ( SD =1.5) and the females at 4.15 ( SD =1.6). The males rated Nesquik milk at 5.06 ( SD =1.3) and the females rated it 5.46 ( SD =1. 4) The males gave Optimum a 2.84 ( SD =1. 6 ) rating and the females gave it a 2.52 ( SD =1. 3 ) rating. For males and females the order of taste preference was the same. Nesquik Vanilla milk was rated the most positive in taste followed by M.M., BSN and Optimum. As for the aftertast e of the second visit the males gave BSN a rating of 4.52 ( SD =1.4), and the females a rating of 4.2 ( SD =1. 4 ). For Muscle Milk, th e males gave it a rating of 4.15 ( SD =1. 4 ) and the females a rating of 3.8 3 ( SD =1. 6 ). For Nesquik milk, th e males gave it a rating of 4.84 ( SD =1. 2 ) and the females a rating of 5.00 ( SD =1. 3 ). For O ptimum, the males gave it a 2.95 ( SD =1. 5 ) and the females a 2.58 ( SD =1. 2 ). The order of preferences was nearly the same again Nesquik was rated the most positively in taste 1 2 3 4 5 6 7 BSN Muscle Milk Nesquik Optimum 4.11 4.54 5.07 3.21 4.0 3.93 5.09 2.88 Males Females

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23 for males and females and Optimum was rated the least positively, BSN wa s rated slightly higher than Muscle Milk for the females.

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24 Chapter 5 Discussion The results of the study showed that Nesquik Vanilla milk was the most favored among the four drinks. Muscle Milk was a close second, followed by BSN, and Optimum was at a distant fourth. These results were consistent with the initial taste and aftertaste of visit one and visit two. As for the comparison of males vs. females, both genders preferred Nesquik the most then Muscle Milk and BSN, while Optimum was the least favored. Comparison of the Present Study to Other Taste Test Studies Due to this study being the first of its kind, the goal of the researchers was to determine if there were differences in the tastes of protein supplements. As stated in the review of literature, taste is based upon the working of the Central Nervous System; therefore each The methodology from this study was very similar compared to other taste studies previously done (Koseki et al 2000 ; Bordi et al. 2008). The main difference was that Koseki et al. (2000) used a five point scale for rating the test compared to this study and Bordi et al. (2008) used a 7 point scale. The 7 point scale allowed for the scores to be spread apart more which in turn showed which drinks were rated more highly (refer to Appendix C). The present study utilized some of the strong points of the previous taste studies and added a second trial to confirm the reliability of the taste test scores.

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25 One of the methods that was foll owed was testing for aftertaste, and Koseki et al. (2005) tested aftertaste in their study on hard water. They used a 5 point scale for rating (2005) 7 point scale. In a ddition, Koseki et al. (2005) and Bordi et al. (2009) used different foods and beverages in their study. Koseki et al. (2005) tested different types of water and Bordi et al. (2005) tested different types of donuts. None of the studies had their subjects r eturn to repeat the trials to discover if there was any correlation between the results of the first and second visit Following these methods and adding a second visit to the testing gives strength to the methods of the present study. Explanation of Ta ste Differences It is not exactly known as to why there are differences in taste; there could be a variety of reasons for the differences. O ne explanation that may have been responsible is the differing amounts of sugar and fat that were unique to each pr otein supplement. Sugar could have been the main factor in making Nesquik milk the best tasting because it has 29 grams of sugar per 8 ounces Twenty nine grams per 8 ounces is a large amount when compared to the other protein supplements for such a small serving; it is easy to conclude that all the sugar will help the taste. Also, it only contains 8 grams of protein per serving. The other proteins had much more reasonable amounts of sugar in the servings. Future research may wish to control the amount of s ugar in each supplement and perhaps that will have an effect on the results. Muscle Milk is well known for having a high fat content, which most likely causes it to be one of the best tasting. It only contains 3 grams of sugar per 8 ounces, but it has 9 g rams of fat and 4.5 grams of saturated fat. However, Muscle Milk writes in large

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26 print on their product that 80% of the saturated fat is Medium Chain Triglycerides (Bach and Babayan, 1982) T Muscle Milk even though it has a high fat content, and it has 24 grams of protein per serving. BSN Syntha 6 and Optimum Nutrition Nitro Core both have very similar contents. BSN h as 2 grams of sugar, 6 grams of fat, 2 grams of saturated fat, and 22 grams of protein. Optimum has 2 grams of sugar, 5 grams of fat, 1.5 grams of saturated fat, and 24 grams of protein. It was interesting to note that even though they have similar content s, Optimum scored significantly lower in taste as compared to BSN. The nutrition labels identify what sugars are used in each supplement, but they do not distinguish how much of each type of sugar is used. The Nesquik Vanilla Milk just contains sugar, whi Nitro Core only contains fructose, and BSN only contains sucralose. Perhaps the different types of sugar were responsible for the taste scores of the various protein supplements. A future study could manipulate the types or amount of sugar in each protein supplement. Optimum might taste just as good as Muscle Milk if it contained maltodextrin, fructose, and sucralose as well. k did not list any but it can be assumed that they would be milk proteins. Muscle Milk contained milk protein isolate, whey protein isolate, whey protein concentrate, whey peptides, calcium caseinate, also had whe y protein isolate, whey protein concentrate, and whey peptides. BSN contained whey protein concentrate (milk and soy),

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27 whey protein isolate (whey and soy), calcium caseinate casein, micellar casein (milk and soy), milk protein isolate (milk and soy), egg a lbumen, and sodium caseinate (milk). Table 1 below summarizes the macronutrient content of each protein supplement utilized in the present study. The order of the drinks was likely not a factor on the taste scores due to the randomization. The drinks could have been placed in the same order each time, but the researchers felt the randomization would help strengthen the study. Table 1. Fat, Sugar, and Protein Content of the Protein Supplements Name Brand Fat (g) Saturated Fat (g) Sugar (g) Protein (g) BSN Syntha 6 6 2 2 22 Muscle Milk 9 4.5 3 24 Nesquik Milk 4 8 29 8 Optimum Nitro 5 1.5 2 24 Male vs. Female Taste Scores According to the data collected in the present study, it was revealed that the male participants purchase d protein more often than the female participants. Out of 94 men, 54 of them purchase d protein on a regular basis. As for women, out of 68 females, 8 of them purchase d protein powders on a consistent basis. Roughly 50% of men and 10% of women purchase d prot because the men may be more accustomed to protein powder and its unique taste, while the women may likely not be as familiar with the protein supplements. The familiarization could be the differ ence in the taste between genders. Perception and previous experience could be another answer. When men were asked to participate in the study, they were eager to participate. Conversely, when females were asked to volunteer, their first response was so mething of disgust. Most

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28 likely their experience with protein supplements was minimal and negative. These experiences may have biased their perceptions about the tastes of the protein supplements utilized in the present study. The marketing of protein supplements may also partly explain how they are Muscle Milk also state s on their labels that the ir protein is the perception of Muscle Milk, thus causing men to have a positive perception of the protein before they even try it. Subconsciously men believe that Muscle Milk is the best protein and best tas ting therefore they will enjoy it when they try it. The researchers believe this marketing works because whenever men were asked to be participants, the men brought popularity and help position it, at least perceptually, as a great tasting protein supplement. provided for each participant to sip in between the protein drinks. Some chose to drink it while s ome did not. The researchers did not record how many did and did not use the water. The researchers did notice that the vast majority did not drink the water in between the protein drinks. While it is difficult to definitely state why one protein supple ment was rated differently than others in terms of taste, any of the aforementioned reasons may be contributing factors. It clear from the present study that some of the more popular protein supplements are sig nificantly different in taste. Future studies may wish to control the amount and types of sugar in the protein supplements, and the fat content as well. Future

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29 research on this topic could also investigate potential mechanisms of taste preferences in relation to protein supplements.

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30 References Cited 1 Bach A. and Babayan, V. (1982). Medium Chain Triglycerides: an update. The American Journal of Clinical Nutrition 36 (5): 950 962 2 Bordi, P. Hack, D. & Cocci, S. (2009). Comparing Trans fat and trans fat free doughnut shortenings based on sensory evaluation and oil degradation. Journal of Sensory Studies University Park, PA. 24: 41 57. 3 Borsheim, E. Tipton, K. Wolf, S. & Wolfe, R. (2002). Essential a mino acids and muscle protein recovery from resistance exercise. American Journal of Physiology Endocrinology and Metabolism Galveston, TX. 283: 648 657. 4 Bos, C. Mahe, S. & Gaudichon, C. (1999). Assessment of net postprandial protein utilization of N labeled milk nitrogen in human subjects. British Journal of Nutrition Bobigny, France. 81: 221 226. 5 Dangin, M. Boirie, Y. & Garcia Rodenas, C. (2001). The digestion rate of protein is an independent regulating factor of postprandial protein retentio n. American Journal of Physiology Endocrinology and Metabolism. Lausanne, Switzerland. 280: 340 348. 6 Dangin, M. Boirie, U. Guillet, C. & Beaufrere, B. (2002). Influence of the protein digestion rate on protein turnover in young and elderly subjects. T he Journal of Nutrition Lausanne, Switzerland. 132: 3228 3233. 7 Darragh, A. & Hodgkinson, S. (2000). Quantifying the digestibility of dietary protein. The Journal of Nutrition. Palmerston North, New Zealand. 130: 1850 1856.

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31 8 Fouillet, H. Mariotti, F. & Gaudichon, C. (2002). Peripheral and Splanchnic Metabolism of Dietary Nitrogen Are Differently Affected by the Protein Source in Humans as Assessed by Compartmental Modeling. The Journal of Nutrition Paris, France. 132:125 132. 9 Garlick, P. McNurlan, M. & Patlak, C. (1999). Adaptation of protein metabolism in relation to limits to high dietary protein intake. European Journal of Clinical Nutrition Stony Brook, NY. 53: 34 43. 10 Gattas, V. Barrera, G. & Riumaio, J. (1990). Pro tein energy requirements of prepubertal school age boys determined by using the nitrogen balance response to a mixed protein diet. American Journal of Clinical Nutrition Dallas, TX. 52: 1037 1042. 11 Gilani, G. & Sephr, E. (2003). Protein Digestibility and Quality in Products Containing Anti nutritional Factors Are Adversely Affected by Old Age in Rats. The Journal of Nutrition Ontario, Canada. 133: 220 225. 12 Gilani, G. Xiao, C. & Lee, N. (2008). Need for accurate and standardized determination of a mino acids and bioactive peptides for evaluating protein quality and potential health effects of foots and dietary supplements. Journal of AOAC International Ottawa, Canada. 91(4): 894 900. 13 Guyton A. & Hall J. (2000) Textbook of Medical Physiology (1 0 th ed.). Philadelphia, PA: Saudners. 14 Kies, C. & Linkswiler, H. (1964). Effect of nitrogen retention of men of altering the intake of essential amino acids with total nitrogen held constant. The Journal of Nutrition Lincoln, NE. 139 144.

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32 15 Koseki, M. Fujiki, S. Tanaka, Y. Noguchi, R. & Nishikawa, T. (2005). Effect of water hardness on the taste of alkaline electrolyzed water. Journal of Food Science Tokyo, Japan. 70(4) 249 253. 16 Layman, Donald. (2004). Protein Quantity and Quality at Levels ab ove the RDA Improves Adult Weight Loss. Journal of the American College of Nutrition Urbana, IL. 23(6): 631S 636S. 17 Leverton, K. & Gram, M. (1949). Nitrogen excretion of women related to the distribution of animal protein in daily meals. The Journal of Nutrition Lincoln, NE. 57 65. 18 Pannemans, D. Halliday, D. Westerterp, K. & Kester, A. (1995). Effect of variable protein intake of whole body protein turnover in young men and women. The American Journal of Clinical Nutrition Maastricht, Netherlands. 61: 69 74. 19 Pasquale M. ( 2009 ). Amino acids and proteins for the athlete 2nd edition. CRC Press, Boca Raton, FL. 20 Pasin, G. & Miller, S. (2000). U. S. Whey Products and Sports Nutrition. Sports Nutrition Arlington, VA. 1 6. 21 Rand, W. Pellet, P. & Young, V. (2003). Meta analysis of nitrogen balance studies for estimating protein requirements in healthy adults. American Journal of Clinical Nutrition Boston, MA. 77: 109 127. 22 Sarwar, Ghulam. (1997). The Protein Digestibilit y Corrected Amino Acid Score Method Overestimates Quality of Proteins Containing Antinutritional Factors and of Poorly Digestible Proteins Supplemented with Limiting Amino Acids in Rats. The Journal of Nutrition Ontario, Canada. 127: 758 764.

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33 23 Schaaf sma, G. (2000). The Protein Digestibility Corrected Amino Acid Score. The Journal of Nutrition. Wageningen, the Netherlands. 130: 1865 1867. 24 Tang, J. & Philips, S. (2009). Maximizing muscle protein anabolism: the role of protein quality. Current Opinion in Clinical Nutrition and Metabolic Care. Ontario, Canada. 12:66 71. 25 Todd, K. Butterfield, G. & Galloway, H. (1984). Nitrogen balance in men with adequate and deficient energy intake at three levels of work. The Journal of Nutrition B erkley, CA. 2107 2118. 26 Vickers, Z. Mullan, L. & Holton, E. (1999). Impact of differences in taste test ratings on the consumption of milk in both a laboratory and foodservice setting. Journal of Sensory Studies. St. Paul, MN. 14: 249 262.

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34 Appendices

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35 Appendix A Initial Screening Form Personal Information Name: Address: City: _____________ State: _____ Zip Code_________ Cellular (___) ________________ Email address: ______________________ Birth date:___ /___ /____ Age: ____ Height: _____ Weight: ______ Exercise History/Activity Questionnaire 1. Do you have any food allergies? Protein powders, milk, eggs, nuts? 2 Describe your typical recreational activities 3 Describe any exercis e training that you routinely participate. 4 How many days per week do you exercise/participate in these activities? 5 How many hours per week do you train? 6. Do you ingest protein supplements? 7. How often? 8. Name the brands you have had in the last 3 months? 9. Name the brands you have had in the last month?

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36 Appendix B Protein Supplements Nutrition Information Nesquik Vanilla Milk

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37 Muscle Milk Optimum Nutrition

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38 BSN

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39

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40 Appendix C Data Collection Form Please drink the protein supplement s you can take a few sips or drink all 3 oz, and rate its initial taste within 15 seconds and after taste within another 15 seconds, a total of 30 seconds Protein Drink #1 initial taste (Code______) Very Bad Bad Slightly Bad Neither good nor bad Slightly Good Good Very Good Protein Drink # 1 after taste (Code _____ ) Very Bad Bad Slightly Bad Neither good nor bad Slightly Good Good Very Good Protein Drink # 2 initial taste (Code _____ ) Very Bad Bad Slightly Bad Neither good nor bad Slightly Good Good Very Good Protein Drink # 2 after taste (Code _____ ) Very Bad Bad Slight ly Bad Neither good nor bad Slightly Good Good Very Good

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41 Appendix D Visit 1 Initial Taste Data Statistics V1.D1.Init V1.D2.Init V1.D3.Init V1.D4.Init N Valid 162 162 162 162 Missing 27 27 27 27 Mean 4.05 4.60 5.36 3.13 Std. Error of Mean .134 .144 .098 .125 Median 4.00 5.00 6.00 3.00 Mode 3 6 6 2 Std. Deviation 1.701 1.833 1.245 1.585 Variance 2.892 3.358 1.550 2.511 Skewness .086 .541 .546 .420 Std. Error of Skewness .191 .191 .191 .191 Kurtosis 1.018 .773 .121 .774 Std. Error of Kurtosis .379 .379 .379 .379 Range 6 6 6 6 Minimum 1 1 1 1 Maximum 7 7 7 7 Sum 656 746 869 507 V1.D1.Init. = Visit 1, Drink 1 (BSN) Initial Taste; V1.D2.Init= Visit 1, Drink 2 (Muscle Milk) Initial Taste; V1.D3.Init= Visit 1, Drink 3 (Nesquik Milk) Initial Taste; V1.D4.Init= Visit 1, Drink 4 (Optimum) Initial Taste.

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42 Appendix E Visit 1 Aftertaste Data Statistics V1.D1.After V1.D2.After V1.D3.After V1.D4.After N Valid 162 162 162 162 Missing 27 27 27 27 Mean 4.06 4.28 5.08 3.07 Std. Error of Mean .116 .130 .099 .125 Median 4.00 4.00 5.00 3.00 Mode 4 6 6 3 Std. Deviation 1.473 1.659 1.256 1.594 Variance 2.170 2.751 1.577 2.541 Skewness .155 .247 .477 .436 Std. Error of Skewness .191 .191 .191 .191 Kurtosis .098 .818 .213 .539 Std. Error of Kurtosis .379 .379 .379 .379 Range 6 6 5 6 Minimum 1 1 2 1 Maximum 7 7 7 7 Sum 658 694 823 498 V1.D1.After. = Visit 1, Drink 1 (BSN) aftertaste; V1.D2.After= Visit 1, Drink 2 (Muscle Milk) aftertaste; V1.D3.After= Visit 1, Drink 3 (Nesquik Milk) aftertaste; V1.D4.After= Visit 1, Drink 4 (Optimum) aftertaste.

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43 Appendix F Reliability Scores of First Visit to Second Visit V2.D1.Init V2.D2.Init V2.D3.Init V2.D4.Init V1.D1.Init Pearson Correlation .372 .089 .054 .158 Sig. (2 tailed) .000 .344 .566 .093 N 116 115 115 114 V1.D2.Init Pearson Correlation .228 .498 .090 .163 Sig. (2 tailed) .014 .000 .336 .083 N 116 115 115 114 V1.D3.Init Pearson Correlation .037 .059 .340 .066 Sig. (2 tailed) .694 .533 .000 .485 N 116 115 115 114 V1.D4.Init Pearson Correlation .205 .039 .088 .403 Sig. (2 tailed) .027 .679 .348 .000 N 116 115 115 114 V1.D1.Init. = Visit 1, Drink 1 (BSN) Initial Taste; V1.D2.Init= Visit 1, Drink 2 (Muscle Milk) Initial Taste; V1.D3.Init= Visit 1, Drink 3 (Nesquik Milk) Initial Taste; V1.D4.Init= Visit 1, Drink 4 (Optimum) Initial Taste. V2.D1.After V2.D2.After V2.D3.After V2.D4.After V1.D1.After Pearson Correlation .361 .153 .258 .152 Sig. (2 tailed) .000 .102 .005 .106 N 116 115 115 114 V1.D2.After Pearson Correlation .117 .505 .054 .210 Sig. (2 tailed) .210 .000 .570 .025 N 116 115 115 114 V1.D3.After Pearson Correlation .145 .029 .352 .061 Sig. (2 tailed) .122 .757 .000 .516 N 116 115 115 114 V1.D4.After Pearson Correlation .149 .119 .131 .486 Sig. (2 tailed) .110 .205 .162 .000 N 116 115 115 114 V1.D1.After. = Visit 1, Drink 1 (BSN) aftertaste; V1.D2.After= Visit 1, Drink 2 (Muscle Milk) aftertaste; V1.D3.After= Visit 1, Drink 3 (Nesquik Milk) aftertaste; V1.D4.After= Visit 1, Drink 4 (Optimum) aftertaste.

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44 Appendix G Reliability Scores of Initial to Aftertaste Paired Samples Correlations N Correlation Sig. Pair 1 V1.D1.Init & V1.D1.After 162 .745 .000 Pair 2 V1.D2.Init & V1.D2.After 162 .824 .000 Pair 3 V1.D3.Init & V1.D3.After 162 .776 .000 Pair 4 V1.D4.Init & V1.D4.After 162 .825 .000 V1.D1.Init. = Visit 1, Drink 1 (BSN) Initial Taste; V1.D2.Init= Visit 1, Drink 2 (Muscle Milk) Initial Taste; V1.D3.Init= Visit 1, Drink 3 (Nesquik Milk) Initial Taste; V1.D4.Init= Visit 1, Drink 4 (Optimum) Initial Taste. Paired Samples Correlations N Correlation Sig. Pair 1 V2.D1.Init & V2.D1.After 116 .737 .000 Pair 2 V2.D2.Init & V2.D2.After 115 .747 .000 Pair 3 V2.D3.Init & V2.D3.After 115 .773 .000 Pair 4 V2.D4.Init & V2.D4.After 114 .806 .000 V1.D1.After. = Visit 1, Drink 1 (BSN) aftertaste; V1.D2.After= Visit 1, Drink 2 (Muscle Milk) aftertaste; V1.D3.After= Visit 1, Drink 3 (Nesquik Milk) aftertaste; V1.D4.After= Visit 1, Drink 4 (Optimum) aftertaste.


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The preference of protein powders among adult male and females- a protein powder taste study
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ABSTRACT: Protein is essential in one's diet because it is an important component in many organs and tissues throughout the body. Athletes ingest protein in order to stimulate protein synthesis and increase lean muscle mass. In order to assist with obtaining adequate amounts of protein, athletes and bodybuilders purchase supplemental protein in the form of protein powders. Protein metabolism and digestion play key roles in this because if the protein is not metabolized or digested effectively, then those who are wishing to gain fat free mass will not be successful. A high quality protein will be digested, metabolized, and directed towards lean tissue accretion more efficiently than a lower quality protein. In order to be a high quality protein, it must contain the essential amino acids. Fortunately, whey protein is a high quality protein because it contains an abundant supply of the essential amino acids. Whey protein is a high quality protein; hence, many athletes and physically active individuals purchase whey protein supplements. Some individuals do not care about taste and overcome awful protein powder taste, while others value a good tasting whey protein. After extensive research, it appears that scientific taste tests on protein supplements are lacking. The purpose of this study was to test some of the most popular protein supplements (Muscle Milk, BSN, Nesquik Vanilla Milk and Optimum Nutrition) and discover which one tasted the best. In this study, there were 94 males and 68 females. The results showed that there was a difference in initial taste and after taste in protein supplements among a male and female population. The difference among the drinks was statistically significant. The findings showed that both genders thought BSN and Muscle Milk were close to "neither good nor bad" while Nesquick Milk was rated as "good" and Optimum was "bad." The initial taste ratings were BSN (mean=4.05; SD=1.7), Muscle Milk (mean=4.6; SD=1.8), Nesquick Milk (mean=5.4; SD=1.2), and Optimum Nutrition (mean=3.1; SD=1.6). This research study showed that there was a statistically significant difference in taste among protein drinks, but the results do not answer as to why that is. Future research would need to be conducted in order to find the answer as to why there is a difference in initial and after taste.
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