Characterization of a sample of Chilean university students in terms of the bitter-tasting phenotype and genotype and their preferences for basic flavours and associated foods

Abstract

The majority of people have a bitter taster phenotype, they perceive substances such as phenylthiocarbamide (PTC). This could be associated with a lower preference for bitter foods. The ability to detect bitter taste is due to TAS2R28 receptor. The aim of this study was to determine the preferences for basic flavours, taste combinations and bitter taste-related foods in a sample of Chilean university students and to relate it to their PTC taster phenotype and genotype. A 5-point Likert-type online survey on taste and food preferences was applied to 149 Chilean university students (19.2 years; 69.8% women; 29.5% men and 0.7% prefer-not-to-say). It classified students as strong taster (ST), intermediate taster (IT) or non-taster (NT) through a PTC taste test. To assess the relationship between phenotype or genotype and students' preferences, we analysed frequency tables using Fisher's exact test. To genotype determination, it extracted DNA from buccal mucosal cells of 25 students (18.9 years; 72% female and 28% male). A fragment of TAS2R38 gene amplified (PCR) and digested (HaeIII). Our results show that 85.9% of students had a PTC taster phenotype (37.6% ST, 48.3% IT vs. 14.1% NT). Sweet taste was the most preferred, while bitter taste was the least. There was no association between taste and food preferences with student's phenotype or genotype. ST students presented homozygous taster genotype (55.6%); IT students, heterozygous taster genotype (75%); and NT students, homozygous non-taster genotype (50%). Both the PTC taster phenotype and genotype associated are not related to a lower preference for bitter taste and foods studied. Our results will allow us to generate promotion and education strategies for healthy eating, through the inclusion of bitter foods.