What is soy protein?

Soy protein is a plant protein whose amino acid composition closely resembles that of milk protein. Although it contains slightly less methionine, it is rich in other essential amino acids, making it a complete plant protein. Nutritionally, soy protein can be equivalent to animal protein. Its genetic structure is also the closest to human amino acids, making it the most nutritious plant protein. Unlike animal protein, soy protein has several incomparable advantages. For instance, it does not contain cholesterol and includes unique physiologically active substances called isoflavones, which help lower cholesterol levels.

Basic Information

Soybeans are one of China’s main crops, valued for their dual role as both an edible oil and protein resource with high nutritional value. Soy protein is the most abundant protein found in nature. Its amino acid composition closely matches that of essential amino acids, and it is rich in calcium, phosphorus, iron, oligosaccharides, and various vitamins. Due to these benefits, soy protein is often referred to as “growth gold.” Industrialized soy protein products include soy protein powder (SF), soy protein concentrate (SPC), soy protein isolate (SPI), and textured soy protein (TSP).

The FAO/WHO (1985) human test results show that the essential amino acid composition of soy protein suits human needs well. For individuals over two years old, the physiological potency of soy protein is rated at 100. Soybeans are rich in protein, nearly twice the content found in meat, eggs, and fish. Furthermore, the protein in soybeans contains all the “essential amino acids” required by humans, classifying it as “high-quality protein.” The demand for protein varies by age, gender, weight, and type of work. To guide dietary habits, countries have developed “recommended daily dietary nutrient supply” (RDA) based on their specific conditions. In 1999, the U.S. Food and Drug Administration (FDA) stated that a daily intake of 25 grams of soy protein can reduce the risk of cardiovascular and cerebrovascular diseases.

Protein Overview

Proteins are the most important components in nature and the basic elements constituting organic organisms. All life activities of animals and plants are closely related to proteins. Proteins are the primary nutrients required by the human body, making up 45% of the total dry matter and 70% of total muscle. The main components of human cells, tissues, and organs are proteins. Metabolism, disease resistance, immunity, body fluid balance, and genetic information transmission are all closely linked to proteins. Without proteins, life cannot exist, which is why proteins are often called the “first nutrient” or “vital element” of humans.

Product Categories

Soy protein products fall into two categories: powdered soy protein products and structured soy protein products.

1. Powdered Soy Protein Products: These are rich in soy protein obtained by defatting and removing or partially removing carbohydrates. Based on protein content, they include:

  • Soy Protein Powder: Contains 50-65% protein (dry basis).
  • Soy Protein Concentrate: Contains 65-90% protein (dry basis). Functional soy protein concentrate, obtained by physical modification, offers emulsification and gelation properties.
  • Soy Protein Isolate: Contains more than 90% protein (dry basis).

2. Textured Soy Protein: This product is made from powdered soy protein products and has a meat-like texture achieved through extrusion and cooking technology. Based on protein content, it includes:

  • Textured Soy Protein Powder: Contains 50-65% protein (dry basis).
  • Organized Soy Protein Concentrate: Contains about 70% protein (dry basis).

By understanding the unique qualities and benefits of soy protein, we can better appreciate its role as a vital and versatile component in our diet.