Releasing intact protein bodies from the plant matrix is the core technical prerequisite for dry pulse and bean protein enrichment. In peas, mung beans, lentils and other legumes, protein bodies — the natural, membrane-bound organelles that store functional protein — are tightly embedded within a rigid matrix of cellulose cell walls, starch granules and fibrous tissue. Simply crushing beans into coarse flour cannot free these particles; targeted, controlled processing is required to break down the surrounding matrix while preserving the structural and functional integrity of the protein bodies themselves. For chemical-free, sustainable plant protein production, a systematic, multi-stage workflow combining pre-treatment, precision pulverization and closed-loop classification delivers maximum protein release with minimal quality degradation.
1. Pre-Treatment: Remove Non-Target Matrix Components Upstream
Effective protein release starts by stripping away unnecessary matrix layers before the core size-reduction stage. Raw legumes contain high-fiber hulls and foreign impurities that add grinding resistance, interfere with cell disruption, and introduce contaminating fiber particles into the final product.
- Precision dehulling and cleaning: The material cleaning and precision dehulling process removes seed coats, stones, dust and other foreign matter from raw legumes. This eliminates the tough, fibrous outer matrix that would otherwise absorb grinding energy and produce indigestible fine fiber fragments. Processing clean, fiber-reduced cotyledon feedstock allows all pulverization energy to be directed at breaking open cotyledon cells, rather than grinding down inert hull material. This step not only boosts final protein purity, but also increases the efficiency of subsequent protein body release.
- Feedstock homogenization: Uniform cotyledon particle size and consistent moisture content create stable, predictable grinding conditions. Homogeneous feed ensures even energy input across the entire material stream, preventing partial under-disruption in harder particles and over-processing in softer ones.
2. Ultra-Fine Pulverization: Mechanically Disrupt Cell Walls to Liberate Protein Bodies
Micron-level pulverization is the core step that physically breaks through the plant cell wall matrix and releases individual protein bodies. When executed with precise control, this process ruptures the surrounding cellulose-pectin cell structure while leaving the protein bodies and starch granules themselves largely intact.
- Calibrated impact-shear breakage mechanism: Advanced ultra-fine grinding systems apply a balanced combination of impact force and shear force to legume cotyledon particles. This mechanical energy breaks down rigid cell walls in a short residence time, releasing protein bodies and starch granules from the intracellular matrix as separate, discrete particles. The mechanism is tuned to target the cell wall structure specifically, rather than shattering all particles indiscriminately.
- Precision fineness control (D90 10–65μm): Protein release performance is directly governed by output particle size. A controlled D90 range of 10–65μm is calibrated to match the cellular scale of pulse cotyledons: at this fineness, the vast majority of cell walls are ruptured and protein bodies are fully liberated. For high-purity applications, tightening fineness to D90 < 20μm further increases release efficiency by freeing protein from denser, more resistant cell clusters. Coarser milling fails to break cell walls completely, leaving protein trapped in intact cell fragments; excessive over-grinding shatters protein bodies and reduces fiber particles to protein-sized dust, destroying the size and density differences required for downstream separation.
- Low-temperature gentle processing: Integrated airflow cooling and short material residence time keep processing temperatures below the protein denaturation threshold throughout pulverization. This preserves the native membrane structure and molecular conformation of released protein bodies, maintaining their solubility, emulsification capacity and other critical functional properties.
3. Closed-Loop Air Classification: Ensure Complete Release Without Over-Processing
Even with optimized grinding, a portion of particles will remain incompletely disrupted after a single pass through the mill. A closed-loop grinding-classification circuit ensures near-complete protein body release while avoiding the quality and efficiency penalties of over-grinding.
- Selective discharge of fully released fines: High-precision aerodynamic fractionation separates pulverized powder by particle size and density. Fine particles that have reached the target fineness — corresponding to fully released protein bodies and free starch granules — are immediately discharged as qualified product and exit the processing circuit. This removes successfully released material instantly, preventing unnecessary further grinding that would damage protein body structure.
- Automatic recirculation of under-disrupted coarse fractions: Larger particles containing unbroken cells and trapped protein bodies are rejected by the classifier and automatically fed back into the grinding mill for additional pulverization. This selective recirculation ensures that virtually all feed material eventually undergoes sufficient cell wall disruption, achieving a high overall protein release rate without subjecting the entire material stream to extended grinding.
- Sharp cut-point calibration: Refined aerodynamic control delivers a precise separation cut-point, creating a clear divide between fully released fine particles and incompletely disrupted coarse material. This sharp boundary maximizes both release efficiency and product consistency.
4. Multi-Parameter Intelligent Optimization: Stable Release Across Variable Raw Materials
Plant matrix properties — including cell wall thickness, hardness and moisture content — vary significantly between legume varieties and growing regions. A static grinding setup will produce inconsistent release rates as feedstock changes. Intelligent, real-time process control maintains reliable protein release under dynamic conditions.
- Real-time parameter adjustment: The integrated control system continuously monitors outlet particle size and product characteristics, and automatically adjusts core operating parameters including grinding rotor frequency, feed rate and air velocity. When processing harder raw material with thicker cell walls, for example, the system can increase rotor speed or reduce feed load to maintain consistent cell disruption and protein release performance.
- Adaptive tuning for different legume types: Peas, mung beans, lentils and other pulses differ in matrix structure and protein body morphology. The intelligent optimization platform can be configured with material-specific parameter sets to deliver optimized release efficiency for each feedstock type, eliminating the need for time-consuming manual re-calibration between product runs.
- Data-driven continuous improvement: Ongoing logging of particle size, energy consumption and protein recovery data supports fine-tuning of the release process, helping operators balance maximum protein yield, minimum energy use and preserved protein functionality.
5. Preserving Protein Body Integrity During Release
Maximizing release quantity is only valuable if the released protein bodies retain their commercial quality. Poorly controlled processing can break open protein bodies themselves, denature protein molecules, or contaminate the protein stream with fine matrix fiber particles, reducing both purity and functionality.
Key protective measures include:
- Avoiding over-grinding to prevent protein body rupture and fiber matrix micronization
- Maintaining low processing temperatures to prevent thermal denaturation of protein
- Using sharp classification cut-points to remove residual fiber matrix fragments from the protein fraction
When properly executed, dry matrix disruption releases protein bodies in their native, intact state, producing protein fractions with clean-label appeal and full functional performance suitable for premium food, beverage and nutraceutical applications.
Releasing protein bodies from the plant matrix is a multi-stage, precision-controlled process that relies on coordinated pre-treatment, targeted ultra-fine pulverization, closed-loop classification and intelligent process regulation. It is not simply a matter of grinding material as fine as possible; it requires balancing thorough cell wall disruption with careful preservation of protein body structure and separability.
With 19 years of specialized expertise in ultra-fine grinding and air classification technology, 150+ dedicated R&D engineers and hundreds of technical patents, JACAN delivers industrial-grade protein release solutions optimized for pulse and bean processing. Our dry fractionation systems achieve industry-leading protein body release rates while preserving native protein functionality, supporting high-yield, high-purity production without chemicals or water extraction. Trusted by over 1,200 clients across 50+ countries and serving more than 40% of top-tier plant-based protein processors, JACAN combines German and Japanese-grade engineering quality at roughly one-third the cost, with delivery in 30–60 days, on-site installation and training, and 24/7 global technical support for reliable, long-term production performance.
