Butterscotch flavour

At low levels (5 mg/L), diacetyl is considered to add complexity to wine aroma since it can impart positive nutty or caramel characteristics, although at levels above 5 mg/L it can resuit in spoilage, creating an intense buttery or butterscotch flavour, and is perceived as a flaw. Microbial formation of diacetyl is a dynamic process and its concentration in wine depends on several factors bacterial strain, pH, wine contact with lees, SO2 content (Martineau and Henick-Kling 1995 Nielsen and Richelieu 1999). The sensory threshold for the compound can vary depending on the levels of certain wine components, such as sulfur dioxide. It can also be produced as a metabolite of citric acid when all the malic acid has been used up. However, diacetyl rarely taints wine to levels where it becomes undrinkable. 

Typical flavours are chocolate, noisette, caramel, butterscotch, coffee etc. 

The most widely used flavour types for neutral dairy products are vanilla and chocolate. Caramel, butterscotch, coffee etc. are also being used. 

The most important off-flavour and aroma associated with the lactic acid bacteria is the sweet, butterscotch or honey note provided by diacetyl and related vicinal diketones. It can be discerned readily in lager beers at concentrations as low as 0 5 (xg/ml. The defect was formerly called Sarcina sickness after Sarcina, the outdated generic name for brewery gram-positive bacteria. 

Produced by alkaline hydrol. of Streptomycin, S-83. Found in larch trees (Larix decidua), pine needles, chicory. Also from ferns Aracltniodes maximowiezii and Macrotltelypteris torresiana. Used as metal indicator (e.g. for Fe(///)). Flavour enhancer and flavouring agent, used in foods and pharmaceutical formulations. Needles or prisms (toluene or CHCI3) with odour of caramel/butterscotch. Mod. sol. H2O sol. EtOH. 

Maple and burnt sugar flavours, vanilla, butterscotch, licorice and rum compositions. 

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