Скачать или смотреть Starch Gelatinization Explained: From Rice to Mochi

Starch gelatinization and retrogradation explain how heating and cooling transform the texture of foods like rice and bread. Learn the chemistry, thermodynamics, and molecular mechanisms behind amylose, amylopectin, and hydrogen bonding in food science. Starch gelatinization, retrogradation, amylose, amylopectin, and food texture are explained in this video through the lens of modern food chemistry and thermodynamics. See how heating and cooling starch systems like rice and bread transforms granules into gels, then back into more rigid, stale-like structures that control softness, stickiness, and shelf life.

In this video you will learn:
How the semi-crystalline structure of starch granules (amylose and amylopectin) controls solubility and rigidity
What happens at the molecular level when starch is heated in water and granules swell and lose birefringence
Why gelatinization is an entropy-driven, endothermic transition and how it relates to ΔG = ΔH − TΔS
How rice cooking conditions and amylose content determine texture (sticky vs fluffy)
How retrogradation on cooling leads to hardening of rice and staling of bread, and why this is crystallization, not simple drying
How temperature, moisture, and time control retrogradation kinetics for amylose and amylopectin
How starch gels behave as viscoelastic materials and how G′ increases during retrogradation
Practical strategies used in food science (fats, emulsifiers, sugars, freezing, modified starches) to slow staling and extend shelf life

Timestamps:
00:00 — Introduction: starch and texture in foods
00:32 — Structure of starch granules (amylose vs amylopectin)
01:37 — Heating in water and disruption of hydrogen bonds
03:16 — Swelling, amylose leaching, and gel formation
05:16 — Thermodynamics of gelatinization (ΔH, ΔS, ΔG)
06:31 — Cooking rice: molecular basis of sticky vs fluffy grains
08:01 — Retrogradation: recrystallization during cooling
09:16 — Kinetics of retrogradation and role of temperature/moisture
10:51 — Bread staling: starch recrystallization and syneresis
12:01 — Viscoelastic behavior and glass transition of starch gels
13:11 — Preventing retrogradation: fats, sugars, freezing, modified starch

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