How and why does gelatinisation occur? (chemical and physical changes)

Question

How and why does gelatinisation occur? (chemical and physical changes)

Answer 1

Gelatin is a translucent, colourless, brittle, nearly tasteless solid substance, extracted from the collagen inside animals' connective tissue. It has been commonly used as a gelling agent in food, pharmaceutical, photography, and cosmetic manufacturing.

Gelatin is a protein produced by partial hydrolysis of collagen extracted from the bones, connective tissues, organs, and some intestines of animals such as the domesticated cattle, and horses. The natural molecular bonds between individual collagen strands are broken down into a form that rearranges more easily.

Gelatin melts when heated and solidifies when cooled again. Together with water, it forms a semi-solid colloid gel.  Gelatin forms a solution of high viscosity in water, which sets to a gel on cooling, and its chemical composition is, in many respects, closely similar to that of its parent collagen.  If gelatin is put into contact with cold water, some of the material dissolves.

Gelatin gels exist over only a small temperature range, the upper limit being the melting point of the gel, which depends on gelatin grade and concentration and the lower limit, the ice point at which ice crystallizes.