Preparing Useful Colloid Activity Sheet

Name: ____________________                                 Yr. & Section: ___________

Group No: __________                                              Date: __________

Preparing Useful Colloid

Mayonnaise

By: Annallee Q. Aron

I.                   Objective: At the end of the class the students will be able to prepare useful colloid.

II.                Introduction:

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.             Procedure:

A.   Ingredients:

• 1 egg yolks
• 3/4 teaspoon salt
• 1/2 teaspoon powdered mustard
• 1/8 teaspoon sugar
• 4 to 5 teaspoons lemon juice or white vinegar
• 1/2 cups olive or other salad oil
• 4 teaspoons hot water

B.    Preparation:

Beat yolks,  sugar, and 1 teaspoon lemon juice in a small bowl until very thick and pale yellow. (Note: If using electric mixer, beat at medium speed.) Add about 1/4 cup oil, drop by drop, beating vigorously all the while.  Add another 1/4 cup oil, a few drops at a time, beating vigorously all the while. Beat in another teaspoon each lemon juice and water. Add 1/2 cup oil in a very fine steady stream, beating constantly, then mix in remaining lemon juice and water; slowly beat in remaining oil. If you like, thin mayonnaise with a little additional hot water. Cover and refrigerate until needed. Do not keep longer than 1 week.

V.                  Evaluation: Rate the other groups’ mayonnaise by putting a check mark.

Taste of the Mayonnaise	Like it	Don’t like it
Group I
Group II
Group III
Group IV
Group V
Group VI
Group VII
Group VIII
Group IX
Group X
Texture of the Mayonnaise
Group I
Group II
Group III
Group IV
Group V
Group VI
Group VII
Group VIII
Group IX
Group X
Scent of the Mayonnaise
Group I
Group II
Group III
Group IV
Group V
Group VI
Group VII
Group VIII
Group IX
Group X

VI.                Discussions:

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? ________________________________________________________________________________________________________________________________________________________________________________________________________________________

VII.              Application: Peanut butter is also a colloid. What method is used in preparing Peanut butter? ____________________

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