Whey protein is a mixture of globular proteins found in milk and establishes primary,
secondary, tertiary and quaternary structures maintained by non-covalent interactions.
Soybean proteins approximately 90% are classified as globulins, based on their solubility in
salts. More specifically, the proteins are conglycinin (a glycoprotein) and glycinin. Tofu is
manufactured by coagulating proteins in soymilk with magnesium sulfate. As bonding occurs
between the positively charged magnesium ions and negatively charged anionic groups of
the protein molecules, the proteins coagulate.