Preparing Useful Colloid
By: Annallee Q. Aron
March 9, 2011
I. Objective: At the end of the class the students will be able to prepare useful colloid.
Colloidal sizes expose much of the surface area of the substances present in the mixture. To prepare a colloid is to reduce the molecular sizes or to enlarge the minute particles into colloidal sizes at about 1-100 nanometer (1nm=0.0000001 cm). There are method use in preparing mixture one is homogenization (use of emulsifying agent such as milk) which converts the minute particle to colloidal sizes and the other is peptization (use of peptizing agent such as HCl) which converts large sizes into colloidal sizes. Food quality is enhanced when achieving colloidal sizes in preparing mixture.
III. Reference: http://homecooking.about.com/od/saladrecipes/r/blcon64.htm
Some rubrics were adopted from rubistar.com
IV. Lesson Proper:
A. Motivation/Review: types of colloid
B. Strategy: Do a Laboratory Activity (see attached lab. Procedure)
1. What type of colloid is mayonnaise? _____________
2. What method of preparing colloid is used in preparing mayonnaise? ____________
3. Which of the mayonnaise ingredient is used as emulsifying agent? _____________
4. Why a lot of food preparation is converted to colloidal sizes? ________________________________________________________________________________________________________________________________________________________________________________________________________________________
V. Assignment: What is the emulsifying agent used in preparing peanut butter?