ABSTRACT
INTRODUCTION: The US Food and Drug Administration banned most "sweet" flavorants for use in cigarettes due to the concern that sweet flavors appeal to young, beginning smokers. However, many of the same flavors, including fruity and confection-associated aromas (e.g. vanilla) are still used in e-cigarettes. Sweet flavors may have a number of effects, including enhancement of the taste of other ingredients. The current work focused on the impact of model flavorants on the taste of a mixture of propylene glycol and vegetable glycerine, solvents used in most e-cigarettes and related products. METHODS: A device delivered mixtures of propylene glycol and vegetable glycerine into the mouth in parallel with puffs of clean air (control) or odorized air. Aromas included two "fruity" esters ("pineapple" and "banana"), two confection-associated aromas ("vanilla" and "caramel/malty"), menthol (not a "sweet" aroma, but commonly used in e-cigarettes), and a "burnt" aroma not expected enhance flavor. Twenty young adults, aged 18-25, rated the sweetness, bitterness, and pleasantness of all stimuli (within-subjects design). RESULTS: Both fruity aromas significantly enhanced sweetness, both confection-associated aromas significantly enhanced pleasantness, and the caramel/malty aroma significantly reduced bitterness. Menthol and the "burnt" aroma had no measurable effects on the taste of solvent mixtures. CONCLUSION: Some flavorants modulated the taste of solvents commonly used in e-cigarettes in ways consistent with an enhanced sensory profile. IMPLICATIONS: If similar effects occur in actual products, improved flavor profiles could facilitate continued use, particularly in non-smokers experimenting with e-cigarettes and related products.
ABSTRACT
Six model compounds having a 2-(1 H-pyrrolyl)carboxylic acid moiety and a hydrophobic R group were synthesized to study their effects on garlic greening, the structures of which are similar to that of 2-(3,4-dimethyl-1 H-pyrrolyl)-3-methylbutanoic acid (PP-Val) (a possible pigment precursor for garlic greening). The puree of freshly harvested garlic bulbs turned green after being soaked in solutions of all these compounds, and with both increasing concentrations and incubation time the green color of the puree became deeper. In contrast, neither pyrrole alone nor pyrrole combined with free amino acids had the ability to discolor the puree. The compounds exhibited a good relationship between structure and activity of garlic greening, namely, the smaller the size of the R group, the larger the contribution. Also, it was found that the unidentified yellow species can be produced by reacting the model compounds with pyruvic acid at room temperature (23-25 degrees C). Moreover, blue species were formed by incubation of the model compounds with di(2-propenyl) thiosulfinate at room temperature. On the basis of these observations, a pathway for garlic greening was proposed.
