Plant Freeze Dryer

Equipment Introduction

Plant freeze dryers (vacuum freeze dryers) are available in three structural types: chamber freeze dryer (tray type), tunnel freeze dryer, and continuous contact freeze dryer, meeting the deep processing needs of different scales of plant materials.

This series of plant freeze dryers uses advanced vacuum freeze-drying technology. Various plant materials (vegetables, fruits, flowers, herbs, edible fungi, Chinese medicinal herbs, etc.) are rapidly frozen at low temperatures, and then under a vacuum environment, the ice is directly sublimated into water vapor. It preserves the natural color, aromatic compounds, vitamins, polyphenols, flavonoids, and other active components (retention rate >95%) of plant materials. After rehydration, the shape is full and the texture is close to fresh. The equipment is suitable for deep processing of vegetables, fruits, edible flowers, spices, edible fungi, and valuable medicinal herbs. It is an ideal device for manufacturing high-end freeze-dried plant snacks, herbal teas, instant soup ingredients, prepared herbal slices, plant extract raw materials, health food ingredients, and aerospace food, significantly extending product shelf life and enabling room temperature transportation and storage.

Equipment Composition

Equipment Features

1. The freeze-drying chamber and shelves are made of high-quality SUS304 food-grade stainless steel, with finely polished interiors and no死角, complying with GMP/FDA food hygiene standards, resistant to plant juice and weak acid corrosion, easy to clean and disinfect without residue.

2. The core refrigeration and vacuum systems use internationally renowned brands (such as Bitzer compressors, Leybold vacuum pumps), ensuring stable capture of water vapor at extremely low temperatures. Optimized water capture efficiency for the high moisture content and易氧化特性 of plant materials. The equipment can operate continuously and stably 24 hours a day.

3. The chamber and cold trap are filled with high-quality polyurethane high-pressure foam, with thick insulation and very low thermal conductivity, effectively preventing cold loss, significantly reducing operating energy consumption, with energy consumption per ton reduced by 25%.

4. The fully automatic PLC control system features a high-definition touch screen. Freeze-drying curves dedicated to plants (pre-freezing, primary drying, secondary drying) can be programmed and preset. Parameters are automatically adjusted according to different plant types (leafy, root, flower, fungus, medicinal) based on tissue structure and moisture content, with real-time monitoring of material temperature, vacuum level, and cold trap temperature, truly achieving unattended intelligent operation.

5. For the characteristic of plants being prone to oxidation and discoloration and the degradation of active components, a vacuum nitrogen backfill system is available. Immediately after freeze-drying, nitrogen protection is applied to prevent oxidation of chlorophyll, anthocyanins, and polyphenols, maintaining the original bright color and functional components, and extending shelf life to over 5 years.

Technical Parameters

Working Principle

Principle of vacuum freeze-drying: Fresh plant materials are pre-treated (washing, cutting, color protection if applicable) and then frozen to below their eutectic point (usually -30°C to -45°C), completely solidifying the water in the plant tissues. Then, under a high vacuum environment (10-30Pa), the heating shelves provide latent heat of sublimation, causing the solid ice in the plant materials to directly sublimate into gaseous water vapor. The water vapor condenses into frost on the surface of the low-temperature cold trap (-50°C to -60°C), thereby completing dehydration and drying. The entire process takes place under low temperature and anaerobic conditions, so the heat-sensitive components, natural pigments, and volatile aromatic compounds of the plant materials are almost completely preserved, with excellent rehydration. The product is crisp or tender after rehydration.

Production Results

Freeze-Drying Effect