Fruit Jelly Production Process

Jam, jelly & marmalade attract consumer due to its high fruit and content and good nutrition value. Fruits such as orange, mango, berries, apple, banana, papaya are mostly utilized for jelly and marmalade making. Fruit Jelly means the product prepared by boiling fruit juice or fruit (s) of sound quality, with or without water, expressing and straining the juice, adding nutritive sweeteners, and concentrating to such a consistency that gelatinization takes place on cooling. The product shall not be syrupy, sticky or gummy and shall be clear, sparkling and transparent.

Jelly Should Have Following Requirements
Total soluble solids not less than 65%
Fruit content should not less than 45%
An important consideration in the jelly making is pectin, acid content, sugar content, and end point detection. Pectin is present in the form of Calcium Pectate which is responsible for firmness in fruits. Under suitable conditions, pectin forms a gel with sugar and acid. Both immature and over ripe are not suitable for jelly. The pH and sugar are important parameters for settling of jelly. The amount of pectin can be determined by alcohol test or jelmeter test which helps to indicates how many parts of sugar are to be added to one part of juice. The final jelly should contain at least 0.5 % acid but not more than 1%because more amount of acid leads to syneresis in jelly. Sugar imparts sweetness as well as body. If the level of sugar is high jelly retains less water which results in stiff jelly because of dehydration. Prolonged boiling of jelly leads to inversion of sugar and destruction of pectin. The end point of boiling can be judged by sheet or flake test, drop test, or temperature test.

Jelly Production Flow Chart

Industrial Jelly Production Video 

The process of jelly making is of 2 types batch process and continuous process
1. Batch process of Jelly Making
The ingredients water, fruit juice or fruit pulp are poured into the vessel and then the mixture is stirred. A separation should be prevented when using a pectin-sugar mixture. The boiling point of the solution is maintained till pectin is added.  The mixture is boiled till total soluble solids are reached. Then it is cooled to 80 ℃. And flavor color, is added at the end of the process.

2. Continuous Process 
In continuous production instead of pectin powder pectin solution is used which is s mixed with sugar, sugar syrup, water and fruit juice or fruit pulp and are heated to dissolve the ingredients and mixed in vacuum station.

Note:

Problems in Jelly Making

• Failure to set- more amount of sugar, lack of acid /pectin, coking below or above end point leads to settling problem in jelly.
• Cloudy or foggy jellies are due to non clarified extract, immature fruit for jelly making, scum is not removed.
• An excessive amount of sugar leads to the formation of crystals in jelly.
• Syneresis of jelly is caused due to excess of acid, low concentration of sugar, fermentation of sugars etc.

Jam vs Jelly Vs Marmalade
The major difference between jam, jelly, and marmalade is that
1). Jam is prepared from fruit pulp
2). Jelly is prepared from clarified fruit juice
3). Marmalade is prepared by addition of peeled portion into fruit juice or fruit pulp

References:

• Fruits and Vegetable Preservation By R.P Shrivastava