How To Dry Jujube?
How to dry jujube — traditional methods:
How to dry jujube? There are two traditional methods: air-drying and heat drying.
Air drying:The air-drying method is to place the fresh jujube under natural conditions, and dry by sunlight and natural ventilation. The drying time is 3-4 weeks. Dried jujube contains 20 % of moisture. Its disadvantages are poor sanitation and high loss of nutrients. Once encountering rainy days, the jujubes are easy to mold and deteriorate, resulting in reduced production and income.
Another traditional drying method is to put the fresh jujube in a drying room or an oven for roasting at a temperature of about 70°C for 20-24 hours. Though the moisture content is the same as in the first method, jujube dried using this way has better hygiene. But due to long-term high-temperature treatment, the loss rate of nutrient components is also high.
How to dry jujube? Is there any way that saves as many nutrients as possible?
Using a freeze dried food machine can ultimately reach your expectation. Such a lyophilization machine can not only keep the jujube’s original structure but also maximizes the preservation of its nutritional ingredients, with over 85% retention rate.
How to dry jujube — non-traditional method (freeze-drying)
1. Pre-freeze the cored fresh jujube at -15℃～-40℃ for 1～5 hours.
2. Put the pre-frozen jujube into the cold trap of a vacuum freeze dryer, and continue to freeze at -25℃～-55℃ for 0.5～2 hours.
3. Put the frozen jujube into the drying chamber, adjust the temperature of the heating plate to 50℃～70℃, apply a vacuum, maintain the vacuum degree of the drying chamber(30～80pa), and control the temperature of the cold trap(-40℃～-55℃). After drying for 9-14 hours, freeze-dried jujubes are obtained.
People who search for the answer to the question “how to dry jujube?” may want to know the best way to get the dried fruit. Hawach has come up with three methods, and the last freeze-drying method is the best one (In the case you have a food freeze dryer). But here are also things you need to remember when freeze dry jujubes.
How to dry jujube — notes
1. The fresh jujube is first pre-frozen to quickly reach the freezing temperature and then put into the cold trap of the freeze dryer to continue freezing to make it completely frozen. The faster the fresh jujube freezes, the smaller the ice crystals formed by the water inside, and the less damage the fresh jujube tissue structure.
2. The frozen fresh jujubes must be quickly dried by vacuum sublimation. When performing sublimation drying in the drying chamber, the drying chamber is required to quickly reach the required vacuum. The ice crystals in the fresh jujube have to absorb a certain amount of heat during the sublimation process, so the temperature of the heating plate should be adjusted to supplement the heat required for the sublimation of the ice crystals in time.
Now you should have a basic idea on how to dry jujube. If you want to know more about food freeze-drying, come to hawach!