Soybean Soymilk

Table II. Protein to Oil Ratio of Tofu and Soymilk as Affected by Protein and Oil Content of Soybeans (14)...

Irreversible Insolubilization of Soybean Protein During Drying. Soymilk is an economical high-protein food of high nutritive value produced by grinding soaked whole soybeans with water, heat-... 

A 100 g sample of soybeans was soaked for 12 h in 1+50 ml of tap water at ambient temperature. This increased the moisture level of the beans to 62.1. If the beans received no heat treatment they were processed immediately. Drained beans were ground in 1 i of tap water (20°C) in a 1 gal stainless steel Waring Blendor at high speed for 3 min. The resultant slurry was passed through a small household centrifugal separator Cjuice extractor) which trapped the solid particles in a triple layer of cheesecloth. The soymilk was stored at 0-4°C until needed. 

Matsuura, M., Obata, A., and Fukushima, D. 1989. Objectionable flavor of soymilk developed during the soaking of soybeans and its control. J. Food Sci. 54 602-605... 

Soymilk. In the traditional process, soybeans are soaked in water, ground into a slurry, cooked, and filtered to remove the insoluble cell wall and hull fractions. A number of modifications have been made in the process since the 1960s, including heat treatment before or during grinding to inactivate the enzyme lipoxygenase and thus prevent formation of grassy and beany flavors. The soymilks are available in plain and flavored, eg, vanilla and chocolate, forms (90,91). 

Identity-preserved soybeans for food use are one of the primary markets where soybean size is important. Generally, tofu and soymilk processors prefer large soybeans (4,400—5,500 seeds/kg) natto producers prefer small soybeans (10,000—11,000 seeds/kg) and processors of miso prefer medium-sized soybeans that are uniform in size (Brumm, 2004). In soy products where minimal fiber is wanted, large soybeans have less seed coat (fiber) relative to total seed weight. 

Hilum color is also an important consideration for many buyers of soybeans to be used for food uses. Many buyers prefer a light-colored (yellow or clear) hilum as opposed to a buff, brown, or dark hilum. Clear hilums are usually desired for soymilk and tofu production. Soybeans that are small with clear hilums and thin seed coats are preferred for natto beans. Hilum color is determined by the genetics of the soy-... 

The protein solubility test (KOH) or nitrogen solubility index (NSI) is an indicator of solubility of protein in an alkaline solution of potassium hydroxide (KOH). It indicates the percentage of total nitrogen (protein) that is soluble. Protein solubility is important for tofii and soymilk production and for estimating the level of toasting or damage in soybean meal. Soybean meal should have a protein solubility index when... 

Torres-Penaranda, A.V. C.A. Reitmeier L.A. Wilson WR. Fehr J.M. Narvel. Sensory characteristics of soymilk and tofu made from lipoxygenase-free and normal soybeans./. Food Sci. 1998, 63, 1084-1087. 

Liu, Z.S. S.C.K. Chang L.T. Li E. Tatsumi. Effect of selective thermal denaturation of soybean proteins on soymilk viscosity and tofu s physical properties. Food Res. Int. 2004,37, 815-822. 

Tezuka, M. H. Taira Y. Igarashi K. Yagasaki T. Ono. Properties of tofus and soymilks prepared from soybeans having different subunits of glycinin. J. Agric. Food Chem. 2000, 48, 111 1—1117. 

In general, traditional soyfoods, also known as Oriental soyfoods, are classified as non-fermented and fermented. Non-fermented soyfoods include soymilk, tofu, soy sprouts, yuba (soymilk film), okara (soy pulp), vegetable soybeans, soynuts and toasted soy flour, whereas fermented soyfoods include soy sauce, miso (fermented soy... 

Soymilks in North American markets nowadays are mostly chilled products, made by modern food-processing techniques. The starting material can be whole soybeans, soy flour, soy protein isolates, or combinations of the former. 

Kim, Y. L. Wicker. Soybean cultivars impact quality and function of soymilk and tofii./ Sci. Food. Agric. 2005, 85, 2514-2518. 

Lakshmanan, R. M. de Lamballerie S. Jung. Effect of soybean-to-water ratio and pH on pressurized soymilk properties./. Food Sci. 2006, 71, E384-E391. 

Other soy protein products include dried soy milk and tofu (see the Chapter Food Use of Whole Soybeans), as well as mixtures of SF, SPC, or SPI with milk or egg protein, gelatin, or other components for specific functional applications. Extruder-texturized fburs and concentrates and spun fiber isolates, which resemble meat in appearance, may be made at the point of use but usually are supplied in bulk from strategically located production facilities. Edible co-products of soy protein ingredient manufacture include the hulls and the cotyledon fiber (cell walls) from SPI or soymilk production. The extract by-product from SPC may be used as the feedstock for isolating isoflavones. 

In 1991, a processing plant was constructed in Jefferson, Iowa (MicroSoy Corp.), to make easily-extractable full-fat flakes from white hilum soybeans for export to make soy milk and tofu. Using these flakes eliminates the need for soaking the beans prior to wet grinding reducing soymilk preparation time. 

Thomas, R. J.M. deMan L. deMan. Soymilk and tofu properties as influenced by soybean storage conditions./. Am. Oil Chem. Soc. 1989, 66, 777—782. 

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