Viscosity of evaporated soymilk prepared in the laboratory using normal and 11S‐lacking soybean seeds

Abstract

BACKGROUND Soymilk is utilized not only as a beverage but also as an alternative to bovine milk, including products such as yoghurt and cream. Evaporated soymilk is expected to be utilized as condensed milk. Raw and heated soymilk samples prepared in our laboratory were evaporated and then subjected to viscosity measurement. The soymilk samples were made from two different varieties: Fukuyutaka, which contains 7S and 11S globulin proteins; and an 11S‐lacking soybean (Nanahomare). RESULTS Raw Fukuyutaka soymilk had a lower viscosity and could be concentrated to a solids content of over 300 g kg−1 compared to heated soymilk (around 250 g kg−1), but the viscosity changes of Nanahomare soymilk showed an opposite trend. Only 7S globulin was denatured during evaporation at 75 °C and likely affected the interaction between proteins and oil bodies. This tendency was remarkable in the Nanahomare soymilk. The strange viscosity change behavior of evaporated Nanahomare soymilk, number of protein particles, intrinsic fluorescence and flow behavior suggest that thermally denatured 7S globulin accelerates the interactions between oil bodies, whereas 11S globulin, which is probably in its native state, suppresses the acceleration by denatured 7S globulin. CONCLUSION Raw soymilk containing native globulins shows a slower increase in viscosity during evaporation. However, denatured 7S globulin accelerates the increase in viscosity during evaporation through interactions between oil bodies. The effect of the denatured state of individual proteins on interactions is expected to be useful in understanding the interaction between proteins and in controlling their properties and functions. © 2022 Society of Chemical Industry.

Effects of pH and salt concentration on freeze–thaw fractionation of soymilk protein

“…The intense bands observed around the molecular weights of 50 000 and 70 000 are considered to be the β subunit and the α and α′ subunits of 7S globulin, respectively 27 . The bands observed around 23 and 36 kDa are considered to be the basic and acidic polypeptides derived from 11S globulin, respectively 2 . In the samples with a pH of 4.3 and 4.9 (Nos.…”

“…Soybean is generally composed of about 40% protein, and thus soymilk has a high protein content. 1,2 In addition, soymilk is low in fat and has no cholesterol, making it a nutritional and healthy drink. Furthermore, a systematic review and meta-analysis revealed that consumption of soymilk might have beneficial effects on cardiovascular health.…”

“…Soymilk is a milk‐like beverage made from soybeans and it has been attracting increasing attention as more and more people worldwide consume it as an alternative to bovine milk. Soybean is generally composed of about 40% protein, and thus soymilk has a high protein content 1,2 . In addition, soymilk is low in fat and has no cholesterol, making it a nutritional and healthy drink.…”

Investigating thermal denaturation kinetics of 7S and 11S proteins and lipoxygenase in soymilk through ohmic heating

“…Soymilk was prepared following a previously described method with minor modification (Shimoyamada et al, 2015, 2022). A 30 g of soybeans were washed twice with distilled water and soaked in distilled water for 13 h in a refrigerator at 4°C.…”

“…Soymilk was prepared following a previously described method with minor modification (Shimoyamada et al, 2015(Shimoyamada et al, , 2022. A 30 g of soybeans were washed twice with distilled water and soaked in distilled water for 13 h in a refrigerator at 4 C. The hydrated soybeans were then mixed with 210 g of distilled water, including absorbed water, and this mixture was homogenized using a homogenizer (SX10; Mitsui Electric Co., Ltd., Noda, Japan) for 8 min at 10,000 rpm.…”