MCS 3040 Lecture Notes - Peptide, Retrogradation, Amylopectin
16 Sep 2014
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Document Summary
Gelatinization is the irreversible swelling of starch granules when heated with h2o. As starch granules are heated, the kinetic energy of the water molecules surrounding the starch granules increases. Hydrogen bonds holding the starch molecules (amylose & amylopectin) together within the starch granules are broken. Water moves into the starch granules, expanding them in size. Resulting in a thicker and clearer pourable mixture. Retrogradation = setting of a cooled gelatinized starch sol. Sol or gel dependent upon stirring while heating) A sol will form when the recipe is stirred while the egg proteins are coagulating. Therefore, stirring will break some of the new hydrogen bonds forming along the polypeptide chain. A gel will form when the recipe is not stirred while the egg proteins are coagulating. This allows many new hydrogen bonds to form at new locations along the polypeptide chain. Syneresis occurs as a starch gel continues to cool (>24 hours) additional hydrogen bonds form between the amylose molecules.
