Optimizing Plant Protein Production: Process Overview and Centrifuge Applications

Protein is the foundation of life, with varying requirements across different age groups, typically constituting 16% to 20% of body weight. Protein deficiency can negatively impact bodily functions and growth, particularly in children.

Plant-based proteins have regained attention in regions with higher per capita GDP due to their absence of saturated fatty acids and cholesterol, aligning with health and safety requirements.

Compared to animal proteins, plant-based proteins are more affordable and offer comparable taste. The trend towards premium consumption has shifted protein demand towards health and safety, favoring the gradual adoption of plant-based proteins.

Common sources of plant-based proteins include soy, pea, and wheat proteins, with demand mainly divided into industrial and consumer segments. In addition to conventional sources, protein can also be extracted from ordinary plants.

Enhancing Protein Production: Innovations in Separation Technology

In protein production, separation technology is employed to isolate protein from other components in raw plant materials, enhancing protein purity and functionality. For instance, separation processes applied to plants like soybeans and wheat yield high-purity soy or wheat proteins, widely used in industrial and consumer markets.

Separation technology also aids in adjusting protein properties, such as controlling amino acid composition, improving taste, and solubility, to meet various requirements and applications.

Classic Plant Protein Production Process

The entire process involves protein extraction and separation, acid precipitation protein separation, washing and moisture adjustment, neutralization, flash sterilization, spray drying, and packaging. The detailed process descriptions are as follows:

Protein Extract Separation Process

During production, predetermined proportions of process water and raw materials (such as low-temperature defatted soybean meal, pea flour, or chickpea flour) are added to the extraction tank, along with specified amounts of sodium metabisulfite and liquid caustic soda.

The extraction pH value and temperature are maintained for a certain period. The resulting mixture is then pumped into a horizontal spiral centrifuge for solid-liquid separation. Secondary extraction may be performed to enhance product yield.

The solid phase (such as soybean residue or pea/chickpea starch + fiber) is transported to processing workshops for further processing, while the liquid phase (plant protein extract) from primary and secondary extraction is conveyed to protein extract storage tanks.

Sometimes, a disc separator may be added after the storage tank to further enhance product purity by removing residual solid particles, obtaining a purer plant protein extract.

Acid Precipitation Separation, Washing, and Moisture Adjustment

Hydrochloric acid is added to the plant protein extract to control the pH within the protein’s isoelectric point range. This allows separation using a horizontal spiral centrifuge to obtain curd and whey.

The curd is washed, separated, and then its moisture content is adjusted using the centrifuge to optimize solid moisture content for drying processes, reducing equipment costs and energy consumption. Grinding and mixing the curd with water into a uniform slurry are necessary before neutralization.

Neutralization

A predetermined amount of alkali solution is added to the protein slurry in the neutralization tank, adjusting the pH to the specified range.

After removing impurities through a filter, the slurry is transported to a sterilizer for high-temperature instant sterilization using steam. The sterilized protein slurry enters the flash evaporation tank for cooling and concentration, achieving deodorization simultaneously.

Drying

The concentrated and deodorized protein slurry from flash evaporation is uniformly fed into a spray drying tower via a filter and high-pressure pump. Inside the drying tower, hot air is used for dehydration drying, with the bottom product collected in a cyclone separator and the exhaust gas discharged into the atmosphere.

The plant protein powder collected by the cyclone separator undergoes sieving using a vibrating screen and is then transported to a bag filter via air. The product obtained through settling is uniformly mixed in a finished product tank, sieved again using a vibrating screen, and then sent to the packaging room.

Packaging

The plant protein powder product sent to the packaging room is packaged and passed through a terminal metal detector. If metal contamination is detected, the product is immediately reviewed and processed, while those safely passing through the metal detector are stored in the finished product warehouse.

Applications of Horizontal Spiral Centrifuge and Disc Separator in Protein Separation and Purification

It’s evident that centrifugal separation-related processes are essential for the separation and purification of plant proteins. We can categorize the applications of Decanter centrifuges and disc separators in the above processes as follows:

Horizontal Spiral Centrifuge

Primary and secondary extraction of plant protein.
Separation of acid-precipitated protein.
Washing, separation, and moisture adjustment of acid-precipitated protein.
Dehydration treatment of plant fibers.
Washing and concentration of starch in plant proteins from peas, chickpeas, and other starch-containing plants.

Disc Separator

Clarification and purification of plant protein extracts.
Recovery of small particle proteins from whey.
Washing and concentration of starch in plant proteins from peas, chickpeas, and other starch-containing plants.

Huading’s Decanter centrifuges and disc separators are nearly applicable to all industrial plant protein production processes. Leveraging decades of technical expertise, we collaborate with customers to develop and match separation, clarification, concentration, washing, dehydration, and other core processes for each raw material.