What Is Gelatinization?
Starch is found in various food sources including cassava, sorghum, maize, potatoes, wheat, barley, arrow roots etc. It is utilized for multiple food and industrial applications. It undergoes further processing through several mechanical and chemical methods to enhance its functionality aspects. Usually, natural starches and modified forms are applied as thickeners, bulking agents, stabilizers, and gel formers in addition to hydrolysis products, such as maltodextrins, and maltose.
Gelatinization occurs when starch granules are subjected to heat to form a gel- like substance. The functional properties of starch are impacted by moisture and heat. The subjection of starch granules to heat in water, breaks down the granules causing them to lose their semi-crystalline structure, creating a viscous solution. Heating causes molecular and structural changes in starch granules and polymers.
Factors That Affect Gelatinization
- Starch constituents-Not all starches form gels more so those with inadequate amylose content. That said, starches that contain high amounts of amylose i.e. corn starch form gels while those without amylose like waxy starches do not form gels.
- Changes in PH– With increasing pH, hydrogen bonding between polymers decreases thus impeding gelatinization. Lower pH values or increased acidity levels promote gelatinization due to hydrogen bonding.
- Temperature-High temperatures ranging between 60°C -70°C facilitate the gelatinization process. At these temperatures and in the presence of heat and moisture, most starches begin to form a gel-like substance.
- Ingredients-Such as sugars, fats, oils, salts etc compete for moisture, hindering the gelatinization process.
- Stirring –It promotes even distribution of heat, and the gelatinization of most of the starch granules. However, when doe excessively it results I reduced viscousity.