PREPARATION OF JAM AND JELLY

Kajal Sahu, Nupur Mandloi, Asha

Department of Fruit Science, College of Agriculture,

Indira Gandhi KrishiVishwavidyalaya, Raipur (C.G.)

Jam: Jam is a product obtained by the cooking fruit pulp with sugar and acid to a desired consistency. Jam contains 0.5-0.6% acidity and 68% TSS.

Jam can be prepared from: Apple, Mango, Pear, Loquat, Papaya, Strawberry, Pineapple.

According to FPO specification for Jam:

Minimum percent of fruit juice in final product should be 45.

Minimum percent of TSS in final product 68.

Principle of jam making: To make use of fruit pectin for binding the sugar and fruit extract and to bring it to a gel condition with a proper amount of acidity.

Recipes for preparation of jam from various fruits are:

Fruit	Ingredient for one kg pulp
Fruit	Sugar (kg)	Citric acid (g)	Water (ml)
Apple	0.75	2.5	150
Aonla	0.75	1.5	150
Mango	0.75	2.0	100
Pear	0.75	2.0	100
Papaya	0.75	3.0	100
Loquat	0.75	1.5	150
Strawberry	0.75	2.0	100
Pineapple	0.75	2.0	150
Guava	0.75	2.5	150

Problem in jam

i. Crystallization

ii. Sticty or gummy jam

iii. Premature setting

iv. Surface graining and shrinkage

v. Microbial spoilage Flow chart of Processing of Jam

PREPARATION OF JELLY

Jelly: Jelly is a semi solid product obtained by boiling a clear strained fruit juice with sugar and acid to a thick consistency. Jelly contains TSS not less than 65% and acidity 0.5-0.7%.

Jelly can be prepared from: Guava, Sour Apple, Papaya, Plum, Loquat, Wood Apple, Karonda.

According to FPO specification for Jam:

Minimum percent of fruit juice in final product should be 54.

Minimum percent of TSS in final product 65.

Fruit can be divided into four groups according to three pectin and acid content:

1. Rich in pectin and acid: Sour And Crab Apple, Grape, Sour Guavas, Sour Orange, Sour Lemon, Sour Plum, Jamun.

2. Rich in pectin but low in acid: Apple Banana Unripe Fig Unripe, Sour Cherry, Ripe Guava, Grape Fruit, Peel Of Orange, Pear .

3. Low in pectin and rich in acid: Sweet Cherry, Sour Peach, Sour Apricot, Strawberry, Pineapple.

4. Low in pectin and acid: Pomegranate, Strawberry Raspberry, Ripe Apricot Ripe Peach.

Fruit	Ingredient for one kg pulp
Fruit	Sugar (kg)	Citric acid (g)
Guava	0.75	3.0
Karonda	0.75	1.0
Apple	1.0	2.0
Wood apple	1.0
Plum	0.75	2.5
Jamun	0.75	2.0
Loquat	0.75	2.0

Flow chart of Processing of Jelly

Important considerations in jelly making:

Pectin, acid, sugar, and water are four essential ingredients. Pectin testanddeterminations of end point of jelly formation are very important for the quality of the jelly.

a) Pectin:

Pectin substances present in the form of calcium pectate are responsible for the firmness of fruits.

Stiffness of gel increase with increasing concentration of pectin up to a certain point beyond which the addition of more pectin has little effect.

The amount of pectin extracted varies with method of extraction, the ripeness of the fruit, the quality of water added for extracting the juice and the kind of fruit.

Usually about .5-1.0 percent of pectin of good quality in the extract is sufficient to produce good jelly.

If pectin content is higher a firm and tough jelly may fail to set.

b) Acid:

The jelly of extract depends on the amount of acid and pectin present in the fruit.

The three acids citric and tartaric found in fruits. Tartaric acid gives the best results.

The final jelly should contain at least 0.5% but not more than 1% total acids because a larger quality of acid may cause syneresis.

c) pH of extract:

Jelly strength increases with the increase in pH until optimum is reached.

Further addition of acid decreases the jelly strength.

d) Judging of end point:

Boiling of jelly should not be prolonged because excessive boiling results in a greater inversion of sugar and destruction of pectin.

If jelly is cooked for apro-longed period it may become gummy, sticky syrupy and deteriorate in colour and flavour.

The end point of boiling can be judged in the following way :

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 offin the form of a sheet or flakes instead of flowing in a continuous stream.

Temperature test: A solution containing 65% TSS boils at 105ºc.

Drop test: A drop of the concentrated mass is poured into a glass containing water. Settling down of drop without disintegration denotes the end point.