Industrial Cross-Flow Ultrafiltration System for Soy Protein Concentration and Desalination

With the global popularity of plant-based diets and clean-label food trends, soybean protein has become one of the most important alternative protein raw materials in the food industry. Traditional soybean protein extraction produces crude soybean protein liquid containing large amounts of soluble salt, oligosaccharides, suspended impurities and pigment substances. If treated by conventional heating and evaporation, high temperature will destroy the solubility, emulsification and water retention properties of soybean protein, resulting in low product quality and narrow application range. Meanwhile, thermal evaporation requires massive steam and electric energy, leading to high comprehensive production costs and serious wastewater discharge pressure. To solve these industrial pain points, cross-flow ultrafiltration membrane separation technology has gradually become the mainstream purification and concentration process for soybean protein processing.

Ultrafiltration membrane separation is a low-temperature, pressure-driven physical separation technology without chemical additives and thermal heating. The membrane elements with fixed molecular weight cut-off can accurately intercept macromolecular soybean protein molecules, while allowing inorganic salts, small-molecule sugars and free water to pass through smoothly. Adopting continuous cross-flow circulation mode, the material liquid continuously scours the membrane surface, effectively suppressing protein deposition and membrane fouling, and maintaining stable long-term operating flux. The whole purification and concentration process is completed at room temperature, completely retaining the natural functional characteristics of soybean protein and avoiding quality degradation caused by traditional thermal processing.

Our factory independently develops and manufactures industrial ultrafiltration skid systems specially designed for soybean protein purification and concentration, suitable for soybean isolate protein, concentrated protein and pea protein liquid low-temperature refining. The integrated equipment is equipped with anti-fouling food-grade UF membrane modules, full 304 stainless steel sanitary pipelines, variable-frequency high-efficiency circulation pumps, real-time online pressure and concentration monitoring systems, and fully automatic CIP acid-base cleaning units. All material contact parts meet food production hygiene standards, supporting 24-hour continuous automatic industrial operation. The optimized circulating flow channel structure reduces local protein accumulation, extends membrane service life and reduces long-term maintenance costs for plant protein factories.

Compared with traditional thermal concentration and washing processes, soybean protein ultrafiltration membrane systems have obvious comprehensive advantages. Firstly, low-temperature physical separation fully retains protein solubility and functional activity, greatly improving the quality and added value of finished plant protein products. Secondly, the membrane process removes salt and heterosugars synchronously during concentration, significantly improving protein purity and product taste. Thirdly, no phase-change evaporation reduces energy consumption by more than 40%, effectively lowering factory operating costs. In addition, the integrated skid-mounted design saves workshop space, and fully automatic operation minimizes manual management, realizing energy-saving and efficient production.

In standardized plant protein production lines, the ultrafiltration system is installed after soybean liquid extraction and rough filtration. Impurity-free soybean crude liquid enters the membrane cross-flow circulation system for continuous purification and concentration. After reaching the target protein solid content, the high-purity concentrated protein liquid is delivered to spray drying equipment to produce high-quality soybean protein powder. Permeate water containing salt and small molecular sugar can be recycled for raw material cleaning and workshop reuse, realizing resource recycling. Enterprises can adjust operating pressure and flow rate flexibly to meet different production requirements of concentrated protein and isolated protein.

The standard operation flow of the soybean protein ultrafiltration system includes raw liquid security filtration, constant-pressure cross-flow concentration, high-purity protein liquid collection, permeate water recycling and automatic CIP cleaning. The pretreated soybean liquid is pressurized and circulated through the membrane module. Macromolecular protein is intercepted and continuously enriched, while salt and small-molecule impurities are separated and discharged. After daily production, the PLC intelligent system automatically performs acid and alkali circulating cleaning to remove surface protein dirt, restore membrane flux and ensure stable and consistent product quality for each batch.

With the continuous expansion of the global plant protein market and stricter food quality standards, low-temperature ultrafiltration purification technology has become essential core equipment for modern soybean protein processing factories. It effectively solves the defects of high salt content, easy denaturation and high energy consumption in traditional processes, and has broad application prospects in plant protein deep processing and functional food raw material production.

Our company provides customized membrane separation solutions for plant protein manufacturers. According to daily processing capacity, raw liquid impurity content and target protein purity, we configure professional membrane systems and provide full lifecycle services including equipment manufacturing, installation and commissioning, process debugging and after-sales technical support, helping global plant protein enterprises achieve high-purity, low-energy and green intelligent production.