The current investigation reveals new findings concerning the substantial promotional activity of orange juice, orange peel and molasses on whey fermentation using single cell culture of kefir microflora. Specifically, the addition in whey of only 1 % v/v orange juice or 1% v/v molasses - 4% w/v orange peel reduced the fermentation time to 10 from 70 hours. But the lowest fermentation time (9 h) was observed when a composite biocatalyst consisted of cells entrapped with orange peel in corn starch gel was used, where also the highest 14 C-labeled lactose uptake rate by kefir was recorded. Bio-ethanol concentrations were increased using all the aforementioned promoters too and volatile byproducts such as esters were raised during the whey-orange juice mixtures fermentations, while terpenes by composite biocatalyst. The findings could be the base for new research projects for the rapid production of novel food stuffs and chemicals using whey as raw material.