Psychophysical and hedonic responses to sweeteners in humans

Open Access
Author:
Antenucci, Rachel Grace
Graduate Program:
Food Science
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
March 28, 2014
Committee Members:
  • John E Hayes, Thesis Advisor
  • Joshua D Lambert, Thesis Advisor
  • Gregory Ray Ziegler, Thesis Advisor
Keywords:
  • sweeteners
  • intensity
  • hedonics
  • taste
  • psychophysical
  • sensory
Abstract:
Sweetness is an inherently positive sensation that is a highly liked. There are however, individual differences in sweet taste perception that are often overlooked in studies that investigate the intensity perception and hedonics of sweet taste. The objective of this thesis is to investigate human sweet taste perception through psychophysical and physiological responses to sweet stimuli. The present work includes a discussion of the issues concerning the measurement of human physiological and psychophysical responses to sweet taste including methodological inconsistencies, individual differences, and genetic variability. This thesis takes a modern approach to investigating sweet taste perception by using contemporary psychophysical scaling methods. Major experimental findings include: Study 1: Sucrose did not increase cold pain tolerance or threshold times in adult males even when controlling for hand temperature and hunger state. These results agree with reports that sucrose analgesia is an age dependent phenomenon. Study 2: Unlike previous reports, sucrose was found to have a sigmoidal dose- response function. Notably, most non-nutritive sweeteners (NNS) elicited a lower maximal sweetness than sucrose and other nutritive sweeteners. The decrease in NNS sweetness appears to be dependent on mixture suppression due to increasing bitterness. Study 3: Four hedonic groups for sucrose were identified: ‘Slope +’, ‘Slope –‘, ‘Horizontal Line’, and ‘Inverted-U’. Significant differences in hedonic liking of sweet foods and sweet alcoholic beverages were found between the four sucrose liking groups. Present results suggest that the hedonic liking of sucrose solutions can generalize to sweet food liking. Study 4: Contrary to what was expected, there were no significant differences in the opioid receptor mu-1 (OPRM1) genotype frequency between sucrose hedonic groups. Nor were there significant differences between genotypes in their hedonic ratings of sweet foods.