The fruit used to make sultanas must be ripe; the water content within the sultanas is only 15-25 per cent, and their fructose content is up to 60 per cent. It is therefore very sweet. Sultanas can therefore be preserved for a long time. The fructose in the sultanas may crystallise over time, but this does not affect their consumption.
Sultanas can be eaten directly as a snack or in pastries, and in some parts of the world they are used as a flavouring for cooking. The traditional drying method is sun-drying in the sun, but the sultanas are easy to sour, bad colour, uneven drying, sugar is easy to emit, so what to do? At present, more heat pump dryer to dry grapes to drying operations, instead of the traditional sun-drying method.
Grape dryer process introduction
1. The initial temperature is between 40-50 degrees Celsius, time is 2 hours, the skin water evaporation. 2.
2. the middle period of a large number of moisture discharge temperature rise to 55 degrees Celsius, time for 10 hours, at this time the rate of dehydration of grapes for about 70 per cent.
3. deep drying, temperature rise to 60 degrees Celsius, intensified dehumidification, humidity of 55 per cent, time of 10 hours.
4. grapes uniform dehumidification, temperature cooling control at 55 degrees Celsius, baking time of 5 hours, at this time the moisture content of the grapes is less than 12 per cent.
Post time: Jul-26-2024
