Blanching (cooking)
A limitation to hot water blanching is the leaching of water-soluble nutrients and the degradation of thermal sensitive compounds. Vitamins, minerals, and other water-soluble compounds, such as proteins, sugars, and flavor compounds, diffuse out of the food and into the water, lowering the overall quality of the food. The degree to which compounds diffuse out of food depends on the food's composition and characteristics, the water to food ratio, the blanching temperature, and other variables. Ascorbic acid, thiamin, and many aromatic compounds are heat-sensitive.