Freeze-dried crispy jujubes are produced using the "BOTH" Freeze Dryer and a specially developed freeze-drying process. The full name of freeze-drying technology is vacuum freeze-drying, a process that involves rapidly freezing the material at temperatures below -30°C (this step can be done by pre-freezing in a cold storage or using the pre-freezing plate of the Xin Yu freeze-dryer), and then under vacuum conditions, sublimating the solid water directly into vapor to achieve drying. The highest sublimation drying temperature is typically set to be below 40°C.
The relatively low pressure and drying temperature effectively preserve the nutritional components in the jujubes. For example, in an experiment using the "BOTH" freeze-dryer to produce crispy jujubes, the freezing temperature was set to -35°C with a pre-freezing time of 5.5 hours. The vacuum chamber had an absolute pressure of 27Pa, and the heating plate for drying was gradually heated to 35°C, with a drying time of 22 hours. The final product had a moisture content of 4%–5%.
It was measured that the Vitamin C (Vc) content in the freeze-dried product during the semi-red stage reached 1065.93mg/100g. Simply put, the major advantage of freeze-dried products is the minimal loss of nutrients, and the taste is also good.
Currently, there are various drying methods for jujubes, such as fried crispy jujubes. Most of them use vacuum frying technology, where high temperatures from palm oil in the frying process evaporate the moisture from the jujubes and make them crispy. Although fried crispy jujubes taste good, the high temperature results in significant nutrient loss, and the product has a high oil content, which is a drawback.
If you are interested in our Freeze Dryer or have any questions, please feel free to contact us. As a professional manufacturer of freeze dryers, we offer a wide range of specifications including home, laboratory, pilot and production models. Whether you need household equipment or large industrial equipment, we can provide you with the best quality products and services.
Post time: Nov-25-2024
