Flavour profile of idli batter prepared from defined microbial starter cultures

Idli is a traditional cereal/legume-based naturally fermented steamed produ ct with a soft and spongy texture which is highly popular and widely consum ed as a snack food item in India. The predominant fermentation microflora c omprises lactic acid bacteria and yeasts and causes an improvement in the n utritional, textural and flavour characteristics of the final product. The flavour profile of idli batter prepared with initial levels of 2 x 10(4) c. f.u. g(-1) of Candida versatilis CFR 505 and 2 x 10(1) c.f.u. g(-1) of Pedi ococcus pentosaceus CFR 2123 in 500 g idli batter, packed in polyester poly laminate pouches and stored at 30 +/- 2 degreesC was periodically analysed by GC-MS. The desirable flavour compounds such as ketones, diols and acids were found to be present upto 8 days of storage, whereas undesirable flavou rs like sulphurous and oxazolidone compounds, ethanone and thiazole appeare d in the batter subsequent to 6 days of storage. The sensory attributes of idlis (final product) prepared from the stored batter related well to the d etermined flavour profile. The present study appeared to indicate that the flavour profile of traditional fermented foods can be a reliable qualitativ e and quantitative parameter for objective assessment.