''Okara'', soy pulp, or tofu dregs is a pulp consisting of insoluble parts of the

soybean The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean. Soy is a staple crop, the world's most grown legume, and an important animal feed. Soy is a key source o ...

that remain after pureed soybeans are filtered in the production of

soy milk Soy milk (or soymilk), also known as soya milk, is a plant-based milk produced by soaking and grinding soybeans, boiling the mixture, and filtering out remaining particulates. It is a stable emulsion of oil, water, and protein. Its original ...

and

tofu or bean curd is a food prepared by Coagulation (milk), coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness: ''silken'', ''soft'', ''firm'', and ''extra (or super) firm''. It originated in Chin ...

. It is generally white or yellowish in color. It is part of the traditional cuisines of

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Korea Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...

, and

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. Since the 20th century, it has been used in the vegetarian cuisines of other cultures. It is called ''dòuzhā'' or ''dòufuzhā'' in Chinese, ''okara'' in Japanese, and ''biji'' or ''kongbiji'' in Korean. Okara is the oldest of three basic types of soy fiber. The other two are soy bran (finely ground soybean hulls) and soy cotyledon/isolate fiber (the fiber that remains after making isolated soy protein, also called "soy protein isolate").

Production

Okara is a food

by-product A by-product or byproduct is a secondary product derived from a production process, manufacturing process or chemical reaction; it is not the primary product or service being produced. A by-product can be useful and marketable or it can be cons ...

from

and soy drink production.David B. Haytowitz and Ruth H. Matthews for the USDA Human Nutrition Information Service, December 198
Agriculture Handbook No. 8-16. Composition of Foods: Legumes and Legume Products
. In 1983 it was estimated that the annual yield for okara in Japan was approximately 70,000 metric tons.Applewhite, Thomas H. (editor) (1989)
''Proceedings of the World Congress on Vegetable Protein Utilization in Human Food and Animal Foodstuffs''
The American Oil Chemists Society. Due to its high moisture and nutrient content, okara is highly prone to

putrefaction Putrefaction is the fifth stage of death, following pallor mortis, livor mortis, algor mortis, and rigor mortis. This process references the breaking down of a body of an animal Post-mortem interval, post-mortem. In broad terms, it can be view ...

, and this has limited its commercial use.Soy20/20. Spring 200
Okara: Overview of Current Utilization

Composition

Okara that is firmly packed consists of 3.5 to 4.0% protein, 76 to 80% moisture and 20 to 24% of solids. When moisture free, the gritty okara contains 8 to 15% fats, 12 to 14.5% crude fiber and 24% protein, and contains 17% of the protein from the source soybeans. It also contains potassium, calcium, niacin. Shurtleff, William; Aoyagi, Akiko (1979).
Tofu & Soymilk Production
'. Volume 2: The Book of Tofu. Most of the soybean

isoflavone Isoflavones are a type of naturally-occurring isoflavonoids, many of which act as phytoestrogens in mammals. Isoflavones occur in many plant species, but are especially high in soybeans. Although isoflavones and closely-related phytoestrogens ar ...

s are left in okara, as well as vitamin B and the fat-soluble nutritional factors, which include soy lecithin,

linoleic acid Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsat ...

, linolenic acid,

phytosterol Phytosterols are phytosteroids, similar to cholesterol, that serve as structural components of biological membranes of plants. They encompass plant sterols and stanol ester, stanols. More than 250 sterols and related compounds have been identified ...

tocopherol Tocopherols (; TCP) are a class of organic compounds comprising various methylated phenols, many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was named ''t ...

, and

vitamin D Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. In humans, the most important compo ...

. Okara contains some antinutritional factors: trypsin inhibitors (mostly destroyed by cooking),

saponin Saponins (Latin ''sapon'', 'soap' + ''-in'', 'one of') are bitter-tasting, usually toxic plant-derived secondary metabolites. They are organic chemicals that become foamy when agitated in water and have high molecular weight. They are present ...

s, and soybean agglutinins, which cannot be easily digested.

Fermentation Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduce ...

(by proper species of bacteria) of okara is conducive to digestion and absorption of okara nutrients, and it further improves the nutritional value. It can eliminate the bean's odor, increase the amount of edible fiber, free amino acids, sugars, fatty acids, vitamin B12, vitamin B2, and

flavoprotein Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin. These proteins are involved in a wide array of biological processes, including removal of radicals contributing to oxidative stress, photosynthesis, and DNA repair. ...

Uses

Most okara worldwide is used as feed for livestock especially hogs and dairy cows. Most of the rest is used as a natural fertilizer or compost, which is fairly rich in nitrogen. A small amount is used in cookery.

Culinary Use

In Japan, it is used in a side dish called ''unohana'' which consists of okara cooked with

soy sauce Soy sauce (sometimes called soya sauce in British English) is a liquid condiment of China, Chinese origin, traditionally made from a fermentation (food), fermented paste of soybeans, roasted cereal, grain, brine, and ''Aspergillus oryzae'' or ''A ...

mirin is a type of rice wine and a common ingredient in Japanese cuisine, Japanese cooking. It is similar to sake but with a lower alcohol (drug), alcohol content and higher sugar content. The sugar content is a complex carbohydrate that forms natur ...

, sliced

carrots The carrot (''Daucus carota'' subsp. ''sativus'') is a root vegetable, typically orange in colour, though heirloom variants including purple, black, red, white, and yellow cultivars exist, all of which are domesticated forms of the Daucus ...

, burdock root and

shiitake The shiitake (; ''Chinese/black mushroom'' or ''Lentinula edodes'') is a macrofungus native to East Asia, which is cultivated and consumed around the globe. Taxonomy The fungus was first described scientifically as '' Agaricus edodes'' by ...

mushrooms. Okara can be used to make

tempeh Tempe or tempeh (; , ) is a traditional Indonesian food made from fermented soybeans. It is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form. A fungus, '' Rhizopus oligosporus'' or '' Rhizopu ...

, by fermenting with the fungus '' Rhizopus oligosporus,'' using a tempeh starter. It can make

press cake A press cake or oil cake is the solid matter remaining after Expeller pressing, pressing something to extract the liquids. Their most common use is in fodder, animal feed. Some foods whose processing creates press cakes are olives for olive o ...

tempeh using ingredients such as brown rice, bulgur wheat, soybeans and other legume and grain combinations. Okara is also eaten as red

oncom Oncom ( IPA: ) is a fermented food which is one of the traditional staples of the Sundanese cuisine of Indonesia. There are two kinds of oncom: red oncom and black oncom. The food is closely related to tempeh; both are fermented using mold. U ...

by the

Sundanese people The Sundanese (; ) are an Austronesian people, Austronesian ethnic group native to Java in Indonesia, primarily West Java. They number approximately 42 million and form Ethnic groups in Indonesia, Indonesia's second most populous ethnic group. T ...

on Java in

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

after fermentation by

Neurospora ''Neurospora'' is a genus of Ascomycete fungi. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble axons. The best known species in this genus is '' Neurospora crassa'', a common model organ ...

. Okara is eaten in the Shandong cuisine of eastern China by steaming a wet mixture of okara that has been formed into blocks of ''zha doufu'' (also known as ''xiao doufu'' or ''cai doufu''). The product is sometimes used as an ingredient in vegetarian burger patties. Additional uses include processing into a granola product, as an ingredient in ''soysage'', as an egg replacement in vegan quiche, and as an ingredient in

pâté Pâté ( , , ) is a forcemeat. Originally, the dish was cooked in a pastry case; in more recent times it is more usually cooked without pastry in a terrine. Various ingredients are used, which may include meat from pork, poultry, fish or bee ...

s. In Japan, there have been experiments with incorporating okara into

ice cream Ice cream is a frozen dessert typically made from milk or cream that has been flavoured with a sweetener, either sugar or an alternative, and a spice, such as Chocolate, cocoa or vanilla, or with fruit, such as strawberries or peaches. Food ...

. Gyoda Zeri Fry.JPG, Japanese ''zerii furai'', fried soy pulp and potatoes U-no-hana, at The Meshiya (2014-10-18).JPG, Japanese ''unohana'', stirred fried with vegetables Biji (soy pulp).jpg, Korean ''biji jjigae'', soy pulp soup Bijitteok (soy pulp rice cake).jpg, Korean ''bijitteok'', soy pulp rice cakes Korean cuisine kongbiji jeon(okara) Hwasun Jeollanamdo South Korea 2015.jpg, Korean ''kongbiji jeon'', soy pulp pancakes Soy Okara Curls (8723794772).jpg, Baked soy pulp curls Vegan okara burgers.jpg,

Vegan Veganism is the practice of abstaining from the use of animal products and the consumption of animal source foods, and an associated philosophy that rejects the commodity status of animals. A person who practices veganism is known as a ve ...

okara burgers

Livestock Feed

Most okara is used as

animal feed Animal feed is food given to domestic animals, especially livestock, in the course of animal husbandry. There are two basic types: fodder and forage. Used alone, the word ''feed'' more often refers to fodder. Animal feed is an important input ...

, especially for farms in vicinity of soy milk or tofu factories.

Pet Food

The product is used as an ingredient in pet foods.

Gardening and Agricultural Use

Okara is sometimes spread on fields as a natural nitrogen fertilizer. It adds

tilth Tilth is a physical condition of soil, especially in relation to its suitability for planting or growing a crop. Factors that determine tilth include the formation and stability of aggregated soil particles, moisture content, degree of aeration, ...

to the soil. Likewise, it can be added to

compost Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical, and biological properties. It is commonly prepared by Decomposition, decomposing plant and food waste, recycling organic materials, and man ...

to add organic nutrients and nitrogen.

Waste/environment

When not considered foodstuff, it may be deemed 'soybean curd residue' (SCR). Some 800,000 tons of soybean curd residue is disposed annually as tofu production byproducts in Japan. As mass waste, it is a potential environmental problem because it is highly susceptible to

. The protein in SCR is of better quality than from other soy products; for example, the

protein efficiency ratio Protein efficiency ratio (PER) is based on the weight gain of a test subject divided by its intake of a particular food protein during the test period. From 1919 until very recently, the PER had been a widely used method for evaluating the quality ...

of SCR is 2.71 compared with 2.11 for soymilk. The ratio of essential amino acids to total amino acids is similar to tofu and soymilk. Nevertheless, it remains a challenge to current processes to commercially extract the proteins and nutrients from SCR waste.

References

External links

Ellen's Kitchen: okara tempeh

Okara Mountain: recipe blog

Okara Project: recipe blog
{{DEFAULTSORT:Okara (Food) Soy-based foods Shandong cuisine Japanese cuisine terms Vegan cuisine Vegetarian cuisine Tofu Vegetarian dishes of China Vegetarian dishes of Japan