Starch syrups purification by MEGA electrodialysis

Success story – MEGA’s sustainable solution

MEGA offers highly efficient electrodialysis technology to demineralize starch-based syrups, which significantly affects their organoleptic properties. Using MEGA technology, you obtain a final product of excellent taste with significantly lower operating costs.

The demineralization of starch syrups using MEGA electrodialysis is an innovative technology compared to conventional ion exchange (IEX) columns methods of starch syrups treatment, both in terms of economics and quality.

At the same time, electrodialysis presents the great advantage of being a continuous process without the addition of reagents and thus meets the stringent conditions to produce organic (BIO) foods.

Why use electrodialysis instead of IEX for starch-based syrup purification

Ion‑exchange (IEX) columns have been used in the demineralization industry for decades and constitute a proven mature technology. But they have been displaced from most industries in the modern era, mainly due to their extensive use of chemicals.

MEGA has developed and introduced technology for the demineralization of maltodextrin and the replacement of ion‑exchange columns without causing extensive environmental impact.

Typical operating parameters for starch syrups purification by electrodialysis

• Temperature: approx. 60 °C.
• Feed conductivity: 0.5–2.5 mS/cm.
• Minimal achievable conductivity: 15 µS/cm.
• Average stable product conductivity: 25 µS/cm.
• Additional steam waste condensate required: approx. double the feed volume.
• Approx: 1–4.9 kWh per 1 ton of product (liquid).
• Negligible requirement for chemicals for CIP: (HNO₃ + NaOH).
• Product losses: approx. 4–5 % (liquid).

Advantages of MEGA solution

• No dilution and subsequent thermal concentration compared to IEX.
• 2–3× less waste produced compared to IEX columns.
• Return on investment 1–3 years (depending on product and level of demineralization).
• Solution suitable for organic production (IEX is no longer accepted in the EU).
• Technology can be made continuous, saving on accessories for the batch process; no recirculation means a reduced number of pumps, valves, instruments, etc.
• Mature and tested technology.
• Highly reduced requirement for chemicals, minor compared to IEX columns.
• Membranes with the highest lifespan on the market.
• Automatic membrane systems.

Process description

An electric field gradient‑driven process enables the separation of minerals from the feed solution. This is achieved by moving dissociated ions through ion-permeable selective membranes, thereby forming two different flows: a demineralized flow called diluate, and a concentrated flow called concentrate.

Substances without a permanent positive or negative electrical charge, such as sugars, do not pass through the membranes during the process. Therefore, purification of saccharide solutions can be achieved with minimal or no product losses.