Theory suggests that aroma and taste are two distinct characteristics. Although this is scientifically true, flavorists can, however, compile a substantial list of raw materials that are used primarily for aromatic characteristics but also have (or appear to have) a significant effect on taste perception.
3,5-Dimethyl cycolpentane-1,2- dione (FEMA# 3269) is a good example of this interesting category of raw materials. It has an aroma best described as a complex blend of maple, caramel, candy floss and phenolic notes, with a strong affinity to malt. At the same time it also confers a lingering sweet character, especially in “brown” flavor applications. This sweet character may be quite simply considered a sweet taste effect or, more probably, an enhancement of pre-existing sweetness, as the brain associates these odor types very strongly with sweet tastes. 3,5-Dimethyl cyclopentane-1,2- dione is a member of a small family of similar chemicals that can often be used interchangeably or, better still, in combination. The other chemicals belonging to this family are 3-methyl cyclopentane-1,2-dione (FEMA# 2700), often called maple lactone; 3-ethyl cyclopentane-1,2-dione (FEMA# 3152); 3,4-dimethyl cyclopentane- 1,2-dione (FEMA# 3268); and 3-methyl cyclohexane-1,2-dione (FEMA# 3305).
As all these chemicals exist in a balanced mixture of keto-enol tautomers, different chemical names are sometimes used to describe them. For example, 3,5-dimethyl cyclopentane- 1,2-dione is the tautomer of 3,5-dimethyl cyclopent-2-en-2- ol-1-one. Similarly, these chemicals possess the same mixture of odor characteristics, though in quite different ratios. For instance, sequential ranking of chemicals possessing the maple note, from strongest to weakest by FEMA number, is: 2700, 3269, 3268, 3305 and 3152. Similarly for caramel, it is: 3268, 3269, 2700, 3305 and 3152; for candy floss, it is: 3152, 3169, 3168, 2700 and 3305; and finally for phenolic it is: 3305, 2700, 3269, 3268 and 3152. However, in terms of overall strength, FEMA number ranking goes like this: 3305, 3268, 3269, 2700 and 3152.