Product Overview
Soybeans are one of China's major crops, valued for their edible oil and protein resources, offering high nutritional value. Soybean protein is the most abundant protein in nature, with an amino acid profile similar to that of human essential amino acids, and is also rich in calcium, phosphorus, iron, oligosaccharides, and various vitamins, earning it the title "golden growth." Industrial soybean protein products include soybean protein powder (SF), soybean protein concentrate (SPC), soybean protein isolate (SPI), and textured soybean protein (TSP).
Soybean protein, also known as soybean protein isolate, contains about 38% protein, which is 4-5 times that of cereal grains. It is a plant-based protein, with an amino acid composition similar to that of milk protein. Except for slightly lower methionine levels, it is rich in all essential amino acids and is considered a complete plant protein. It matches animal proteins in nutritional value and is closest to human amino acid needs in its genetic structure, making it a highly nutritious plant protein. Despite its high protein content and lack of cholesterol, soybean protein has some drawbacks, such as sensitivity to high temperatures and a peculiar smell.
Soybean Protein Production Process
Powdered soybean protein is produced from defatted soybeans through processes that remove or partially remove carbohydrates, resulting in a high soybean protein content. Based on protein content, it is classified into three types:
(1) Soybean Flour, with a protein content of 50-65% (dry basis).
(2) Soybean Protein Concentrate, with a protein content of 65-90% (dry basis). Products like Solcon, Kangton, and Healthy E-Life High Calcium Soybean Protein Powder fall into this category. Functional Soy Protein Concentrate, such as Solcon S, is modified physically to include emulsifying and gelling functions.
(3) Soybean Protein Isolate, with a protein content of over 90% (dry basis), includes products like Solpro.
Textured Soybean Protein is made from powdered soybean protein through extrusion cooking, resulting in products with a meat-like texture. It is classified into two types:
(1) Textured Soy Protein Flour, with a protein content of 50-65% (dry basis), such as Soytex.
(2) Textured Soy Protein Concentrate, with a protein content of around 70% (dry basis), such as Contex.
Most commercial soybean protein products are defatted soybean protein, with the main raw material being low-temperature defatted soybean meal. This meal is processed either by butane subcritical extraction or hexane solvent extraction (A or B tube or flash evaporation). Defatted soybean meal after low-temperature extraction can achieve a protein content of over 50%.
Soybean Protein Effects and Functions
Soybeans are rich in protein, containing more than twice the amount found in wheat and rice, typically between 40% and 50%. Storage proteins make up over 70% of soybean protein, including 7S globulin (soybean legumin) and 11S globulin (soybean globulin), with smaller amounts of other storage proteins like 2S, 9S, and 15S. Soybean protein also contains biologically active proteins such as β-amylase, cytochrome c, plant lectins, fat oxidase, urease, Kunitz trypsin inhibitors, and Bowman-Birk trypsin inhibitors. To improve digestibility, these inhibitors are usually removed or inactivated during processing. Commercial soybean protein products often contain isoflavones, saponins, and lecithins.
In terms of amino acid content, soybean protein is the only plant protein reported to provide all nine essential amino acids in sufficient quantities for human needs, making it a complete protein. Its protein quality rating, PDCAAS (Protein Digestibility Corrected Amino Acid Score), matches the maximum value of 1 found in casein and egg white. Soybean protein can meet the daily essential amino acid needs of both young children and adults. For infants, adding threonine, methionine, lysine, and tryptophan can enhance the protein efficiency ratio (PER) and net protein ratio (NPR) of soybean protein.
Modern diets should stimulate appetite without adverse effects and provide rich nutrition. Soybeans, meeting these criteria with abundant raw material sources, are highly valued. Soybean protein beverages are praised as "green milk" by nutritionists. Soybean protein significantly lowers cholesterol levels. It contains more arginine than milk, with a balanced arginine to lysine ratio and is rich in lipids and linoleic acid without cholesterol. Its lecithin content is also high.
Soybean protein beverages are easier to digest than milk. Milk forms large, hard clumps in the stomach, whereas soybean milk forms smaller, softer flakes, making it more digestible. While soybean protein is essential for everyone, daily dietary intake is often insufficient, especially for specific groups such as children, pregnant women, lactating mothers, and the elderly, who may need to supplement with protein powders.
Soybean Protein Applications
Food industry.
Consumption Drawbacks:
Soybean protein has some drawbacks, including sensitivity to high temperatures and an odd taste. It is best not to use boiling water (100°C), as it can damage the protein structure and reduce nutritional value. Soybean protein can also have a beany flavor due to substances like soy isoflavones.
Recommendation: Use water at 50-60°C and add sugar as needed for diabetics.
Soybean Protein Packaging and Storage
【Storage Conditions】Keep sealed, shielded from light, and stored in a cool, dry, well-ventilated place.
【Packaging】Bulk in 25kg cardboard drums; small samples in 1kg aluminum foil bags, with custom packaging available.
【Shipping】Courier or logistics; domestic courier within three days, logistics within five days. Pricing generally includes domestic shipping costs.
【Shelf Life】Two years.
Plant Source
Soybean (Glycine max (L.) Merr.) is an annual herbaceous plant in the legume family, growing 30-90 cm tall. Soybeans contain 35%-40% protein. Transgenic soybeans are round in shape. The soybean stem is robust, upright, and covered with brown, long, stiff hairs. Leaves typically have three leaflets; stipules are veined and covered with yellowish soft hairs; leaf petioles are 2-20 cm long; leaflets are broadly ovate and papery. The inflorescence is a short, few-flowered raceme or a long, many-flowered one; the peduncle usually bears 5-8 closely spaced, unstemmed flowers; stipules are lanceolate with rough appressed hairs; flowers are purple, light purple, or white, with a petal base and wing petals arranged in a comb-like pattern. The pods are large, slightly curved, and drooping, yellow-green, densely covered with brownish-yellow hairs; seeds are 2-5 per pod, oval to nearly spherical, with smooth seed coats in green, yellow, brown, and black. Flowering occurs from June to July, and fruiting from July to September.
Originally from China, soybeans are cultivated throughout the country and widely grown worldwide. Soybeans are an important food crop in China, with a cultivation history of over 5,000 years. Historically known as "shu," northeastern China is a major production area. Soybeans are rich in plant protein, with a protein content of 35%-40%. Soybeans are most commonly used to produce various soy products, extract soybean oil, brew soy sauce, and extract protein.
