A Novel Approach for the Production of Natural Aroma Compounds Using Coffee Husk

Abstract

Flavouring compounds have been traditionally obtained from plant sources but there are strong dependences on factors such as the influence of the weather, plant diseases etc... that are difficult to fully control. As a result, alternative sources were exploited and chemical synthesis was found very effective. Most of the available flavour compounds (84%) are now produced via chemical synthesis, although extraction from natural material continues. However, recent trends have demonstrated that consumers globally prefer foodstuff that can be labelled as natural. A directly viable alternative route for their production can be based on microbial processes. Often, the market prices of such compounds produced from natural materials has been very high. For example, synthetic 4-decalactone (the impact flavour compound of peach) costs US$ 150/kg, while the same substance extracted from a natural source costs about US$ 6000/kg (Janssens et al., 1992). Several microbial species produce volatile fruity aromas. Fungi from the genus Ceratocystis produced a large diversity of fruit-like aromas (peach, pineapple, banana, citrus and rose), depending on the strain and culture conditions. Among this genus, C. fimbriata seems to be interesting because of its relatively rapid growth, its good ability for spore production and the variety of aromas synthesized (Senemaud, 1988; Christen et al., 1994).