Plums-prune Drying Machine

The core of the Plums-prune drying production line lies in gentle dehydration and color and shape preservation, because the Plums-prune skin has a wax layer and high sugar content, which can easily cause problems such as skin crust and difficulty in transferring internal moisture during the drying process. The current mainstream solution is heat pump drying combined with segmented variable temperature technology, and the production line configuration may vary depending on the final product form (dried plums or candied plums).

Processing flow: Cleaning → Blanching → Segmented temperature controlled drying

Pre treatment of blanching: The optimal condition is blanching at 80 ℃ for 90 seconds. Under these conditions, the activities of polyphenol oxidase and peroxidase are significantly inhibited, which can effectively prevent enzymatic browning during the drying process while retaining anthocyanins and vitamin C.

Segmented variable temperature drying: The initial temperature of heat pump drying is low, and then the gradient increases. Each temperature stage is dried for 6 hours until the moisture content of plum drops to 0.21 (about 30% of the initial mass) and stops. The total drying time of this process is about 36 hours.

Key control points during the drying process: In the later stages of drying, the outer skin of Plums-prune quickly loses moisture, which can easily form "crust hardening" and hinder the continued outward migration of internal moisture. Therefore, it is necessary to adopt a stage cooling and drying strategy, and appropriately lower the temperature in the later stage of drying to reduce the adverse effects of skin crust.

Heat pump dryer is currently the mainstream choice for drying Plums-prune, which can save more than 40% energy compared to traditional hot air drying. Equipment typically has the following characteristics:

Intelligent control of temperature and humidity: It can automatically adjust the drying time and temperature according to the multi temperature range drying process, meeting the requirements of the gradient temperature changing assembly line process.

Low temperature slow drying: ensuring the taste of dried fruits, stable drying, suitable for low-temperature drying mode below 75 ℃.

Processing capacity reference: The processing capacity of small equipment is about 1000-1500 pounds per batch, with a power of about 7kW and a temperature range of 40-75 ℃.

For the large-scale production of candied plums, the drying section usually integrates supporting units such as sugar washing equipment, sorting and conveying equipment, oil immersion equipment, and air-cooled conveying equipment

The company's predecessor can be traced back to 1972. Its founder, Li Xueqi, started with the development of a hot air circulation cocoon drying machine. After more than 40 years of development, it has now become one of the large-scale intelligent agricultural machinery equipment manufacturers in China. At present, two manufacturing bases and one R&D innovation center have been built, with a total production base area of over 50000 square meters and more than 100 R&D, management, and technical workers.

The company has successively won the titles of National High tech Enterprise, Provincial Specialized and Innovative Enterprise, and Sichuan Province Industry "Little Giant" Enterprise. Up to now, it has accumulated more than 100 intellectual property rights and invention patents. In 2026, the company was selected as a key enterprise for customized production in Sichuan Province