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Description
The unpleasant bitter taste found in many nutritious vegetables may deter their consumption. While bitterness suppression by prototypical tastants is well-studied in the chemical and pharmacological fields, mechanisms to reduce the bitterness of foods such as vegetables remain to be elucidated. Here tastants representing the taste primaries of salty and sweet were investigated as potential bitterness suppressors of three types of Brassicaceae vegetables. The secondary aim of these studies was to determine whether the bitter masking agents were differentially effective for bitter-sensitive and bitter-insensitive individuals. In all experiments, participants rated vegetables plain and with the addition of tastants. In Experiments 1-3, sucrose and NNS suppressed the bitterness of broccoli, Brussels sprouts, and cauliflower, whereas NaCl did not. Varying concentrations of NaCl and sucrose were introduced in Experiment 4 to assess the dose-dependency of the effects. While sucrose was a robust bitterness suppressor, NaCl suppressed bitterness only for participants who perceived the plain Brussels sprouts as highly bitter. Experiment 5, through the implementation of a rigorous control condition, determined that some but not all of this effect can be accounted for by regression to the mean. Individual variability in taste perception as determined by sampling of aqueous bitter, salty, and sweet solutions did not influence the degree of suppression by NaCl or sucrose. Consumption of vegetables is deterred by their bitter taste. Utilizing tastants to mask bitterness, a technique that preserves endogenous nutrients, can circumvent this issue. Sucrose is a robust bitter suppressor whereas the efficacy of NaCl is dependent upon bitterness perception of the plain vegetables.
ContributorsWilkie, Lynn Melissa (Author) / Capaldi Phillips, Elizabeth D (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Sanabria, Federico (Committee member) / Arizona State University (Publisher)
Created2014
Description
The unpleasant bitter taste found in many nutritious vegetables may deter people from consuming a healthy diet. We investigated individual differences in taste perception and whether these differences influence the effectiveness of bitterness masking. To test whether phenylthiocarbamide (PTC) `supertasters' also taste salt and sugar with greater intensity, as suggested by Bartoshuk and colleagues (2004), we infused strips of paper with salt water or sugar water. The bitterness rating of the PTC strip had a significant positive linear relationship with ratings of both the intensity of sweet and salt, but the effect sizes were very low, suggesting that the PTC strip does not give a complete picture of tasting ability. Next we investigated whether various seasonings could mask the bitter taste of vegetables and whether this varied with tasting ability. We found that sugar decreased bitterness and lemon decreased liking for vegetables of varying degrees of bitterness. The results did not differ by ability to taste any of the flavors. Therefore, even though there are remarkable individual differences in taste perception, sugar can be used to improve the initial palatability of vegetables and increase their acceptance and consumption.
ContributorsWilkie, Lynn Melissa (Author) / Phillips, Elizabeth D. (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2012
Description
While the concept of healthcare is largely respected in Arab culture, the stigma underlying mental health is particularly startling. This study examined the differences in mental health treatment-seeking behaviors using data from Arabs living in Syria (12.9%) and Arabs (25.6%) and non-Arabs (61.5%) living in the United States of ages 18-60. A Web-based survey was developed to understand how factors like religiosity, acculturation, and positive attitudes towards psychological treatment increased help-seeking behaviors. This survey was also provided in Arabic to include non-English speaking participants. It was hypothesized that Arab-American individuals will be more open to pursuing professional psychological help when suffering from mental symptomology (i.e. anxiety) than individuals who identified as Syrian-Arabs. In contrast, both Syrian-Arabs and Arab-Americans would definitely pursue professional help when suffering from physical symptomology (i.e. ankle sprain). Striking differences were found based on Western acculturation. Findings suggested that Arab-Americans were less inclined towards treatment and more trusting of an in-group physician ("Dr. Ahmed") whereas Syrian-Arabs were more inclined to pursue psychological treatment and preferred to trust an out-group physician ("Dr. Smith"). The results of this study identify main concerns regarding Arab attitudes towards seeking mental health treatment, which can better inform future research and mental health services for this minority.
ContributorsRayes, Diana S (Author) / Brewer, Gene (Thesis director) / Cohen, Adam (Committee member) / Olive, Michael Foster (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2015-05