Natural fermentation of lentils

Abstract

Lentils (Lens culinaris, var. vulgaris cultivar Magda-20) were naturally fermented for 96 h at different lentil flour concentrations (79, 150 and 221 g/l) and temperatures (28, 35 and 42°C). During fermentation, samples were taken at 24-h intervals and the changes in thiamin (vitamin B1), riboflavin (vitamin B2) and total and available niacin (vitamin B3) were investigated. Preparation of the lentil flour suspension to be fermented (i.e. the process of mixing the flour and sterilized tap water) caused an increase of the available niacin content in all batches, while changes in thiamin and riboflavin content were related to the conditions in which the preparation of the suspensions was carried out. The whole natural fermentation process (from the raw state to after 96 h of fermentation), either did not affect or produced a slight decrease in the thiamin content of lentils. In contrast, riboflavin, available niacin and total niacin contents increased throughout the 96 h period, which ended with a 35 – 82% increase of riboflavin, a 24 – 91% increase of available niacin and a 20 – 58% increase of total niacin. The temperature during the fermentation procedure had significant effect on the levels of thiamin and riboflavin in fermented lentils. To obtain lentil flours with an improved amount of riboflavin and available niacin with a minimum loss of thiamin, the natural fermentation of lentils should be carried out for 96 h at 42°C and with a lentil flour concentration of 221 g/l.