Principles of fruit canning process
Food Canning Methods / Process
Various types of fruits, fruit juices, jams, jellies, fish, and meat are preserved and marketed by canning. For this purpose, a few general steps are followed:
1. Sterilization:
The cans or containers in which the food will be preserved, along with their lids, must be sterilized by boiling them in hot water for 0.5 hours and then dried. All spoons, knives, vessels, and trays used in the preservation process must also be sterilized in this manner.
2. Collection of Raw Materials:
Fresh, flawless, and visually appealing (in size and color) fruits are collected.
3. Washing:
The food items must be washed thoroughly with clean, germ-free (sterilized) water.
4. Peeling, Waste Removal, and Slicing:
Unnecessary parts, peels, and seeds of the fruits are removed, and then they are cut into pieces according to specific sizes.
5. Blanching:
The sliced food pieces are heated in boiling water or freshly prepared steam for 5–10 minutes. This process is known as Blanching. Note that blanching is avoided for overripe fruits.
6. Can Filling and Liquid Addition (Syruping/Brining):
The food pieces are placed into sterilized cans, and suitable preservatives or solutions (liquid) are added.
Composition of Liquid / Preservatives for Different Foods:
- Pineapple: 40% Sugar solution.
- Mango: 40% Sugar solution and 0.25% Citric acid.
- Jackfruit: 40% Sugar solution and 0.25% Citric acid.
- Guava: Mixture of 40% Sugar solution, 0.06% Citric acid, and 0.125% Ascorbic acid.
- Tomato: 10% NaCl (Salt) solution.
7. Exhausting:
Before sealing the container, the food is heated again to drive out air. This step is called Exhausting.
8. Sealing:
Immediately after exhausting, the can lid is placed and rapidly sealed. This must be done technically and cautiously to ensure the sealing is completely airtight.
9. Cooling:
The hot cans are cooled down rapidly to bring them to room temperature.
10. Labeling:
Finally, labels are attached to the outside of the cans. The label displays the name of the food, the list of ingredients with their quantities, manufacturing date, expiry date, and other necessary information.
11. Marketing and Distribution:
These cans are stored in warehouses, from where they are supplied and marketed to consumers.
