Covalent crosslinking in heated protein systems

Changes in the solubility (in water or in 1% sodium dodecyl sulfate plus 1% beta-mercaptoethanol), isoelectric point, and degree of browning were foll owed for a range of food proteins when they were heated to 105 to 145 degre es C at 3 relative humidities (RH). In general, there is a decrease in solu bility with increasing RH and temperature of heating, but most proteins als o showed an increase in solubility on extensive heating. The order for the proteins, based on the temperatures at which an increase in solubility occu rred was: gelatin < gluten < soya isolate, sodium caseinate < egg albumin, bovine serum albumin < whey isolate, milk powder, beta-lactoglobulin. The b onds that could be formed and broken during this thermal treatment are cons idered.