Purification of beet molasses using bentonite and gelatin: process evaluation and optimization

In this research, response surface methodology based on 3-factor 5-level central composite design was used to determine the effect of refining pretreatment variables on quality indexes of beet molasses. Hence, the effect of bentonite concentration (2-10 g/L), gelatin concentration (0.01-0.1 g/L) and pH (3-7) on turbidity, color, concentration of colloids (CCs) and ash of beet molasses were studied and well fitted by a quadratic polynomial model (R2 > 0. 85). The results showed that the pH was the main factor affecting the purification indexes as it had a significant effect on all responses. Bentonite and gelatin as two common clarifying agents improved the quality of molasses, although the ability of bentonite was much higher. The optimum condition for purification pretreatment was found as 8.3 g/L for bentonite, 0.08 g/L for gelatin and 4.03 for pH which were determined on minimization of the turbidity, color, concentration of colloids (CCs) and ash. At this condition, the turbidity, color, ash and concentration of colloids were calculated as 12.1 NTU, 2573 IU, 2.7, 0.9 g/L respectively.