Effects of the Glucose Addition during Lactic Fermentation of Rice, Oat and Wheat Flours

Background and objective: Consumer interests in probiotic foods have increased in recent decades. Food industries respond to these growing interests by developing innovative products and guaranteeing high production efficiency. Cereals, due to their prebiotic nature, are good fermentable substrates; from which, potentially functional foods could be achieved. The aim of this study was to verify effects of D-glucose addition on fermentation of rice, oat and wheat flours. Material and methods: Suspensions of 15% of cereals flours (rice, oat and wheat) in distilled water added with increasing glucose concentrations (2, 5, 7 and 10% w v-1) were fermented by Lactobacillus paracasei CBA L74 for 24 h. Then, pH, microbial growth and lactic acid production were assessed. Results and conclusion: Rice fermentation was not affected by glucose addition. For oat and wheat, addition of D-glucose increased bacterial concentration, as well as lactic acid production. In particular, the best growth was achieved by the addition of 2 and 5% of glucose. Furthermore, lactic acid concentration increased with increased glucose concentration. In conclusion, D-glucose addition seems to be unnecessary for the improvement of rice fermentation. On the contrary, oat and wheat fermentations need further available carbon sources for a better Lactobacillus growth and a higher lactic acid production.