The focus of flavor creation has gradually shifted from an almost exclusive interest in aroma to a more naturally balanced interest in both aroma and taste. δ-Hexadecalactone (FEMA# 4673, CAS# 7370-44-7) is a perfect example of this trend. The aroma of this chemical is relatively restrained, soft and creamy, but the taste effects are much more interesting.
Most dairy products contain a wide range of lactones but normally only four occur in significant quantities: δ-decalactone (FEMA# 2361, CAS# 705-86-2), δ-dodecalactone (FEMA# 2401, CAS# 713-95-1), δ-tetradecalactone (FEMA# 3590, CAS# 2721-22-4) and δ-hexadecalactone. All these ingredients have somewhat similar creamy odor characters, but δ-decalactone offers by far the most aroma strength and impact. The other chemicals offer progressively weaker aromas with increasing molecular weight. Adding δ-dodecalactone in a common, naturally occurring ratio of around two parts of δ-dodecalactone to one of δ-decalactone increases the odor impact marginally but makes the creamy taste noticeably more realistic. This is probably actually not the ideal ratio of these two chemicals if they are viewed in isolation. A ratio of as high as 10:1 offers a far better taste effect, but unfortunately at a prohibitively high raw material cost, depending on the end use.