Study on the membrane filtration of starch hydrolysates

The aim of the study was to compare potato and potato–tapioca hydrolysate quality obtained by membrane filtration with the application of tubular ceramic membranes. The substrate for membrane filtration was maltodextrins obtained by enzymatic hydrolysis of potato and a mixture of potato and tapioca starches. Colour, turbidity, iodine value, qualitative and quantitative distribution of carbohydrate (HPLC), amount of reducing groups and viscosity were determined. The influence of starch source on permeate flow rate and hydrolysate quality was investigated. Results of hydrolysate membrane filtration were compared with the results obtained during conventional filtration. According to the literature, results of research confirmed better quality parameters of membrane hydrolysates than hydrolysates obtained by conventional filtration. Hydrolysates obtained from a mixture of potato and tapioca starches indicate better filtration ability than only potato hydrolysates.

Membrane filtration decidedly improves the quality of hydrolysates. The influence of membrane filtration on colour and transmittance value is higher for potato starch hydrolysates than for potato–tapioca starch hydrolysates. However, permeate flux of a 0.14 µm cut-off membrane for potato–tapioca starch hydrolysates was higher by 50% in comparison to potato starch hydrolysate flux. Membrane filtration decreases the percentage amount of higher sugars of starch hydrolysates by 5.9–8.2%. Potato starch can be partly replaced by tapioca starch in the production of starch hydrolysates.