Apple slices
A number of different techniques are used to maintain flesh color, flavor, and crisp texture of apple slices. Apples are size graded peeled, cored, sliced and immersed in a 3% salt solution.
Just before filling into cans, the slices are rinsed to remove salt. They are then filled into can with 40% sugar solution, the cans are then heat-exhausted, sealed and heat processed.
The canned apples are either at 82,2° C and immediately to 32-40 °C.
Frozen apple slices
For the production of frozen apple slices, the slices are immersed in brine subjected to vacuum (in order to remove air), re-immersed in brine, washed and packed with sugar in a ratio of 4 fruit to 1 sugar, the product is then frozen.
One method differs in that a bisulfite dip is included to prevent non enzymatic browning. It done after inspection. The alternatives to sulfite are based on ascorbic acid, citric acid and calcium salts.
Nitrogen and carbon dioxide (CO2) are the most popular freezing media. From vacuum tank, the apple slices pass though and IQF unit, whether the slices are individually frozen.
Dried apple
Drying as a method of food preservation has been practiced since the earliest recorded history. The best quality are obtained from ‘Red Delicious’ and ‘Golden Delicious’ apples.
Some apples are dried, although the volume of this type of product has decreased in recent years. For drying, the peeled, cored and sliced apples are first treated in a weak solution of citric and a bisulfite dip.
Up to 300 ppm of bisulfite are used to prevent enzymatic browning. The sulfured slices should be held in refrigerated storage for at least 24 hrs to allow the sulfur dioxide to penetrate the apple slices, the apple slices are eventually spread in the slatted floors of natural draft, loft-type kilns.
In the kilns, heated air rises through the apples slice and removes moisture. After the moisture content has reached about 10%, the apples are packaged in moisture proof containers to be used in the bakery trade.
Consumers like the dried apples to be as possible in eating quality to a fresh apple, thus the texture, color, and taste of dried apple are important.
Processing of Apples
