Supplied at 1% in IPM
 
 
Similar to Acetoin and Diacetyl, this substance primarily contributes to a buttery aroma. However, unlike these two compounds, which are overused to the point of immediate recognition in most products (including cheap Margarine), this elongated form smells more interesting.

You might have also come across discussions regarding potential new regulations aimed at restricting or even banning Diacetyl, especially in eg. vapes. This is largely due to concerns over a condition known as "popcorn lung," which affected factory workers exposed to high concentrations of this compound over years. However, the debate continues on whether small amounts of Diacetyl in flavorings are safe (given its widespread natural occurrence in butter and certain fruits). Nonetheless, alternatives like acetyl propionyl, Yoghurt Dione (acetyl valeryl), and Bipropionyl (this one) appear to be considerably safer options.