Pineapples are harvested when they have reached full maturity in order to obtain maximum flavour and quality. Usually the fruit is harvested when 20 to 25 per cent of bracts have turned orange in colour, and then transferred to the cannery in the shortest possible time. Fruit weighing 1.5-2.0 Kg are the best suited for canning as rings.
Fruit is size graded and the crown removed. It is then washed thoroughly and prepared, which includes peeling, coring, slicing and punching. Slices are then graded for size, colour and maturity. Slices should be free from peels and eyes. Each can is filled with slices of the same size and colour. The filled cans are syruped hot, exhausted, sealed, processed, cooled, labelled and packaged.
Firm ripe pineapple
Citric acid – as acidulant
Calcium Chloride – as firming agent
1.Select firm ripe pineapple free from rots and dents.
2. Wash to remove surface dirt, slice into rings or cubes, and place in sterilized jars.
3. Prepare medium syrup 35 degree Brix (approximate 1 cup sugar for every 2 cups of water). If desired, use 50-degree Brix syrup (1-cup sugar for a cup of water).
4. Boil and add calcium chloride (1/4 teaspoon per 4 cups syrup) and citric acid (1/8 teaspoon per 4 cups syrup).
5. Pour hot syrup into jars leaving a ¼-inch headspace. Exhaust by heating the filled jar over a steamer until the internal pressure seals cap jars tightly.
6. Process in boiling water for 25 minutes. Cool, label, and store.
Measure the following physico-chemical properties and and adjust accordingly to your set standard. These properties should be uniform every batch. Adjustments can be computed using Pearson’s Square formula.
a. sugar content. Sugar concentration can be increased by adding sugar or can be lowered by adding water or pulp.
b. pH. This can be lowered by adding citric acid or can be increased by adding water or pulp.
c. titrable acidity. Same as in (a), just replace sugar with citric acid. Be cautious because citric acid affects both pH and titrable acidity.