Decoding Amino Acids: Plant-Based vs. Animal-Based, Hydrolysis vs. Enzymatic Hydrolysis

As the most fundamental building blocks of living organisms, amino acids play an irreplaceable role in crop growth, physiological metabolism, and stress resistance. They are widely applied as functional nutrients in modern agriculture. Based on raw material sources, amino acids can be categorized into plant-based and animal-based types; based on production technology, they can be divided into hydrolyzed amino acids and enzymatically hydrolyzed amino acids. This article provides a systematic explanation of their origin characteristics, production processes, and application scenarios to support scientific decision-making in agricultural practice.

I. Raw Material Sources of Amino Acids: Differences Between Plant-Based and Animal-Based Types

The core source of amino acids is the breakdown and conversion of proteins. Depending on the protein raw material, amino acids can be classified into plant-based and animal-based types. Their differing amino acid composition leads to varying effects in crop application.

(1) Raw Material Origins and Composition Characteristics

1. Plant-Based Amino Acids

Raw materials mainly come from soybeans, wheat, oats, corn, and their processing by-products. These amino acids typically contain high levels of water-soluble amino acids such as aspartic acid and glutamic acid. They feature natural composition, broad raw material availability, and good compatibility with plant nutritional needs. Different plant materials offer different amino acid profiles—for example, corn and wheat are rich in glutamic acid, while soybeans contain higher proportions of essential amino acids such as lysine and leucine.

2. Animal-Based Amino Acids

Raw materials include animal hair (feathers, pig bristles), silkworm pupae, animal blood, internal organs, skin, bones, and low-value fish. Their amino acid composition varies significantly with raw material type:• Hydrolyzed hair contains high cystine and serine.• Hydrolyzed skin and bone are rich in glycine and proline.• Animal blood-derived amino acids contain high levels of leucine and phenylalanine. Animal-based amino acids also generally have higher nitrogen content and stronger stimulation of soil microbial activity.

(2) Comparison Table: Plant-Based vs. Animal-Based Amino Acids

Comparison Dimension	Plant-Based Amino Acids	Animal-Based Amino Acids
Core Raw Materials	Soybeans, wheat, corn, oats, agricultural by-products	Animal hair, pupae, blood, skin, bones, low-value fish
Dominant Amino Acids	Aspartic acid, glutamic acid, lysine	Glycine, proline, phenylalanine, cystine
Primary Mechanism	Direct involvement in plant metabolism; promotes nutrient absorption & growth	Stimulates soil/foliar microbial activity; improves soil environment + targeted physiological regulation
Typical Applications	Seedling growth, leafy vegetable development, chlorophyll enhancement	Stress resistance (drought/cold), shoot control + flowering, fruit coloring & sweetness
Water Solubility	Generally excellent	Varies; some require solubility improvement
Application Restrictions	No major limitations	Restricted in the EU—prohibited on edible plant parts
Crop/Timing Suitability	Seedling stage, vegetative growth	Fruit trees, fruit enlargement, coloring stages; stress periods

(3) Application Effects and Scenario Matching

Plant-based and animal-based amino acids have no absolute superiority—selection depends on crop needs:

• For promoting leaf growth and accelerating nutrient absorption (seedling stage, leafy vegetable yield improvement):Plant-based amino acids rich in glutamic acid offer fast absorption and direct physiological effects.

• For improving stress resistance (drought, cold, pests):Animal-derived glycine/proline amino acids enhance cell wall stability and osmotic pressure.

• For promoting lignification, shoot control, flowering, and fruit coloration: Amino acids from animal blood containing phenylalanine are more effective—the key precursor for lignin and anthocyanin synthesis.

⚠ Regulatory note: Animal-based amino acids are strictly regulated in certain regions (e.g., the EU prohibits foliar application on edible crop parts), which is essential for export-oriented production.

II. Production Processes of Amino Acids: Hydrolysis vs. Enzymatic Hydrolysis

The two core technologies for converting proteins into amino acids are hydrolysis and enzymatic hydrolysis. They differ significantly in reaction principles, operating conditions, product quality, and environmental impact.

(1) Comparison Table: Hydrolysis vs. Enzymatic Hydrolysis

Comparison Dimension	Hydrolysis (Acid/Alkali)	Enzymatic Hydrolysis
Principle	Strong acids (HCl/H₂SO₄) or bases (NaOH) break peptide bonds	Biological enzymes (trypsin/pepsin) selectively catalyze peptide bond cleavage
Reaction Conditions	High temperature, high pressure (acid hydrolysis 100–110 °C)	Mild conditions, ambient temperature, near-neutral pH
Product Characteristics	Heat-sensitive amino acids destroyed; incomplete profile; high salt content (animal-based)	Complete amino acids retained; high biological activity; low salt and impurities
Environmental Impact	Acid/alkali waste liquid, high pollution	Environmentally friendly; nearly zero emissions
Equipment Requirements	Requires high-temp/pressure-resistant equipment & defoaming	Ordinary reactors; no special equipment
Industrial Use	Declining; used for low-cost, low-spec products	Mainstream method for high-end fertilizers & PGRs
Cost	High energy and environmental costs	Higher enzyme cost but overall cost optimizable

(2) Hydrolysis: Characteristics and Limitations of the Traditional Method

Hydrolysis relies on strong acids or bases to break peptide bonds.

• Conditions: Requires high temperature and pressure; generates significant foaming requiring defoaming systems.• Product limitations:– Heat-sensitive amino acids (cysteine, tryptophan, methionine) are easily destroyed.– Animal-based acid hydrolysis results in high sodium chloride content, increasing soil salinity risk.– Low-cost inferior products produced by natural fermentation (“self-hydrolysis”) may contain low amino acid content, high impurities, and fail hygiene standards.• Industrial status: Declining due to high energy consumption, environmental pollution, and inferior product purity.

(3) Enzymatic Hydrolysis: Advantages of Modern Biotechnology

Enzymatic hydrolysis uses specific biological enzymes to catalyze peptide bond cleavage under mild conditions.

• Conditions: No need for high temperature or pressure; environmentally friendly with almost no pollutant discharge.• Product characteristics:– High specificity avoids destruction of sensitive amino acids.– Preserves full amino acid activity; high purity and bioavailability.– No strong acids or bases → low salt content, safer for soil.• Industrial status: Now the mainstream technology for producing high-end amino acid fertilizers and plant growth regulators. Although enzyme costs are higher, process optimization continues to lower overall production costs.

III. Summary: Scientific Selection and Development Trends of Amino Acids

1. Source Selection Principles

• Plant-based amino acids → direct nutrient supplementation, rapid vegetative growth, minimal restrictions.• Animal-based amino acids → stress resistance, soil improvement, fruit quality enhancement; must comply with regional regulations.

2. Preferred Processing Technology

Enzymatically hydrolyzed amino acids outperform hydrolyzed types in purity, activity, environmental compatibility, and agricultural benefits—ideal for green agriculture development.

3. Industry Trends

• Toward high efficiency, precision, and environmental friendliness.• More specialized amino acid formulations (stress-resistance formulas, quality-enhancement formulas).• Increased use of agricultural waste and food-processing by-products for sustainable production.

In conclusion, the value of amino acids in agriculture depends not only on their source but also significantly on the production process. Scientific product selection—aligned with crop needs, application scenarios, and regulatory requirements—is essential for optimal performance. For manufacturers, advanced enzymatic hydrolysis and optimized raw material formulation are key to competitive, high-quality amino acid products.