Gelatin is dissolved in water, but to use it in industries (like food, pharma, or photography), it often needs to be concentrated. Instead of boiling off water (which uses a lot of energy and can damage gelatin’s properties), membranes are used. Membrane type: Ultrafiltration or nanofiltration membranes are chosen because they allow small molecules (like water and salts) to pass through, while holding back the larger gelatin molecules. Process: The gelatin solution is pumped across the membrane surface. Water and impurities move through the membrane (called the permeate), while the gelatin-rich solution stays behind (called the retentate). Advantages: Energy-efficient compared to evaporation. Maintains gelatin’s functional properties (like gelling strength). Produces a consistent, high-quality concentrated solution. Think of it like a very fine sieve that lets water slip through but keeps the gelatin molecules in place, gradually thickening the solution.