Food Chemistry Checkpoint Review

What is the main function of starch in most foods, especially liquids or gels?

• Thickening

• Gelling

• Binding

• Coating

The property of starch which means the resistance to flow.

• Dextrinization

• Gelatinization

• Viscosity

• Syneresis

The oozing of liquid from a rigid gel.

• Gelatinization

• Viscosity

• Retrogradation

• Syneresis

What are the 2 primary polymers found in starches? Choose 2 correct answers.

• Amylose

• Hydrogen

• Amylopectin

• Viscous

Hydrogen bonds break and are replaced by water molecules; starch molecules swell with water. This is describing:

• Leaking of liquid out of a gel

• Adding room temperature liquid to room temperature starch

• COOLING of a gel during gelatinization

• HEATING of a gel during gelatinization

Answer explanation

If you need to review this concept, read through your Sticky Starches notes and the Sticky Starches PowerPoint (including the video we watched in class), found on Google Classroom.

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Firming of a gel while it is cooling or standing

• Syneresis

• Retrogradation

• Opacity measurement

• Gelatinization

Water molecules are forced out of starch molecules when hydrogen bonds reform during retrogradation, causing water to leak. This describes:

• Why syneresis occurs when a gel cools

• Why viscosity of a gel changes

• Why a gel becomes gritty in texture

• None of these are correct

Answer explanation

If you need to review this concept, read through your Sticky Starches notes and the Sticky Starches PowerPoint (including the video we watched in class), found on Google Classroom.

If a liquid has a HIGHER concentration of starch, would you expect it to be more or less viscous?

• More viscous

• Less viscous

Which likely has the HIGHEST viscosity at room temperature?

• Apple juice

• Ranch dressing

• Honey

• Heavy cream

Answer explanation

More viscous = thicker liquid. Less viscous = thinner, runnier liquid.

How constant a thickened mixture can remain over time and temperature changes is a food's _____.

• Stability

• Viscosity

• Gel formation

• Translucency