PROCESSING OF JAM

Jam is prepared by boiling the fruit pulp with sufficient quantity of sugar to a reasonably thick consistency, firm enough to hold fruit tissues in position. It should contain not less than 68 per cent soluble solids.

Jam may be made from a single fruit (apple, strawberry, banana, pineapple etc.) or from combination of two or more fruits.

Jam contains 0.5-0.6% acid and invert sugar should not be more than 40%. Components of Jam Fruit Pulp:- 45%, TSS:- 68% , Acidity:- 0.5-0.6%, Water:- 33-38%

Processing of Jam

1. Selection of fruit: - Fully ripe fruit should be harvested for Jam making. Jam is best fruit for Jam making. Pineapple, carrot, strawberry, banana, peach, pear also used for jam making.

2. Washing/Cleaning of fruit: - Fruit should be cleaned by clean water.

3. Preparation of Fruit: - Fruit should be peeled and remove of core material for Jam making.

4. Blanching: - Blanching is the heating of fruit or vegetables for a short time with either steam or water, and is an essential step before canning, drying or freezing of food. This heating process is not meant to cook the food but to inactivate substances that would otherwise adversely affect the nutrient content, color, flavour or texture during subsequent processing and storage.

5. Cooking with Sugar: - Fruit pulp start cooking with 1/3 quantity with sugar. After some time add remaining sugar.

6. Adding of Citric Acid: - For enhancement of test citric acid should be added at 103oC temperature.

7. Judging of End-Point:-

a. Sheet or Flake test:-A small portion of jam is taken out during boiling, in a spoon or wooden ladle and cooled slightly; it is then allowed to drop. If the product falls off in the form of a sheet or flakes instead of flowing and a continuous stream or syrup, it means that the end-point has been reached and product is ready, boiling is continued till the sheet is positive.

b. Temperature: - 1050C.

c. TSS: - 68-70%

d. Weight Test: - If total weight of jam is 1.5 times is more than sugar weight, jam is prepared.

8. Packing: - Jam should be filling in glass jar. 9. Storage: - Jam should be stored at dry and cool place.