Membrane-Based Decolourisation and Purification of Starch Hydrolysates: A Systematic UF-NF Screening Study

Area of Science:

• Food Science and Technology
• Chemical Engineering
• Materials Science

Background:

• Membrane processes are sustainable solutions for starch hydrolysate purification.
• Selecting appropriate membranes and operating conditions is crucial for effective treatment.

Purpose of the Study:

• To systematically evaluate ultrafiltration (UF) and nanofiltration (NF) membranes for starch hydrolysate decolourisation and purification.
• To determine optimal operating conditions for membrane performance.

Main Methods:

• Lab-scale cross-flow filtration system.
• Testing five UF and three NF polymeric membranes.
• Varying temperature, transmembrane pressure, and feed concentration.

Main Results:

• UF membranes achieved 18-32% color removal with high permeate flux and low sugar loss at 60 °C and 8 bar.
• NF membranes showed 32-100% color rejection but with substantial sugar losses (up to 96%).
• UF demonstrated suitability for partial decolourisation, while NF excelled in sugar retention for concentration.

Conclusions:

• UF is effective for partial color removal in starch hydrolysates.
• NF is applicable for product concentration, impurity removal, and water recovery.
• Findings provide a basis for industrial membrane selection and process optimization.