BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The role of PEG as a plasticizer is to form strong hydrogen bonds with the ─OH groups in starch, which weakens hydrogen bonds in both intramolecular and intermolecular interactions of starch chains and enlarges the free volume, leading to higher mobility and flexibility.

Detailed explanation-2: -Glycerol is the most common plasticiser due to its high plasticising capacity and thermal stability at processing temperatures.

Detailed explanation-3: -The most common examples of starch gelatinization are found in sauce and pasta preparations and baked goods. In sauces, starches are added to liquids, usually while heating. The starch will absorb liquid and swell, resulting in the liquid becoming thicker.

Detailed explanation-4: -When starch is heated with limited water (e.g., during pelleting), swelling and distortion of starch granules are limited. The amount of available water affects the degree of completion of the gelatinization process at a given temperature, but it does not affect the temperature at which starch starts to gelatinize.

Detailed explanation-5: -By plasticization, raw starch can be transformed into a homogeneous polymeric state, which is known as “thermoplastic starch (TPS).” The phase transition of starch plays a critical role in the plasticization of starch. The degree of phase transition also determines the processability and final product properties.