Our Little Thesis

Chapter 1

I. Introduction

Adhesive is a substance that holds two materials together by natural adhesion.

Glue is a form of adhesive and an impure form of gelatin. It is also the oldest adhesives known to man, it also makes very strong joint but it is not water proof. Glue was by far the most important adhesive until the latter part of 19th century. Thee glue is made from animal bones (Encarta 97 Encyclopedia, Adhesive). It also contains casein which is present in milk to produce glue (Wikipedia Encyclopedia, Glue).

Casein is the chief protein in milk and separates as curd milk sours, or when acid is added. It is commercially produced in skim milk and is widely used in medicines, cosmetics, and ass a sizing for paper. It is also used in glue, casein, paints, and certain plastic articles such as buttons. Casein can be found in the dairy products such as cheese, milk, cream, butter and yogurt.

Yogurt is a smooth semi-solid dairy product made from milk. It has a high acid content and thick curd that causes coagulation. Yogurt may be made from milk of buffaloes, cows, goats or other cud-chewing animals. Al though yogurt, like milk, is a rich source of protein, riboflavin, folic acid and calcium. Major components of yogurt includes globules of milk fats, protein, salts, milk sugar/lactose, vitamins, water and minerals Compositional changes occur as milk is converted into yogurt. These changes includes a decrease in lactose and vitamin B-6 and B-12 and an increase in peptide, free amino acid, free fatty acid, folic acid and choline contents. Yogurt contains calcium lactate whereas milk contains calcium caseinate. There are many types of yogurt such as regular yogurt, non-fat yogurt, lowfat yogurt, lite yogurt and swiss or custard yogurt. Yogurt made from whole milk has at least 3.25 percent of milk fat. Lowfat yogurt is made from lowfat milk or part-skim milk and has between 2 and 0.5 percent milk fat. Non-fat yogurt is made from skim milk and contains less than 0.5 percent milk fat.

Since yogurt contains casein, there is a possibility of making glue out of expired yogurt because it contains casein which is needed in making glue. Expired yogurt is more advisable to use than glue you can buy in the market because it is cheaper, more thickened, more slightly fermented liquid.

II. Statement of the Problem

1. What is the quality of glue out of expired yogurt and the glue made from expired in terms of:

a. Odor

b. Viscosity

c. Adhesiveness

2. Is there a difference between the quality of the glue made from expired yogurt and the glue made from expired milk in terms of:

a. Odor

b. Viscosity

III. Statement of the Hypothesis

There is no difference between the glue made from expired milk an the glue made from expired yogurt in terms of:

a. Odor

b. Viscosity

c. Adhesiveness

IV. Scope and Delimitations

This study is about glue made from expired yogurt. The main ingredient in

making glue is the expired yogurt. We will try to determine the differences between the glue made from expired yogurt and the glue made from expired milk.

V. Conceptual Framework

Milk is a highly nutrious and versatile food. It is used in making a wide range of food products including cream, butter, cheese, yogurt and ice cream. Milk contains nutrients that are needed by the body for good health including fats, carbohydrates, proteins, minerals, and vitamins. (Worthington- Roberts, 1997)

The most important milk is casein. It is curd that forms when milk is left to sour. It is most commonly used milk protein in the food industry. (Cohen, 1998)

Input