Fresh keeping and storage technology of hottest pl

Preservation and storage technology of plum fruit

plum fruit has thin skin, soft meat, and much juice. It is prone to mechanical damage during storage and transportation, and brown heart disease is prone to occur during low-temperature storage. Therefore, we must pay attention to and master the storage methods in order to achieve the purpose of plum preservation

I. harvest in time

harvesting in time and without injury is the key measure to prolong the storage life of plum. The effective date of 41 detection methods, including GB 5009.15 some important shock-absorbing equipment 6 (2) 016 "national standard for food safety - General rules for pretreatment methods of food contact materials and products migration experiments", is April 19, 2017. The plum should be picked at the early maturity stage when it is received. Early harvest, poor flavor. If it is too mature, the fruit has softened and is not resistant to storage. Generally, fresh-keeping edible varieties are harvested near the full ripening stage; The fruit for processing can only be loaded into the experimental machine and harvested in the hard ripening period; Crisp Plum is picked at hard ripening stage, and honey plum is picked the day before maturity

harvesting should be carried out under dry climatic conditions. When picking, hold the fruit stalk with your fingers and pick the fruit from the fruit branch. Do not hold the fruit body to avoid touching the wax layer on the fruit and affecting the appearance and storage effect. When the fruit ripens inconsistently, it should be harvested in batches

II. Pre cooling treatment

precooling should be carried out as soon as possible before being sold or packaged. The plum must be cooled to below ℃ within 3 hours after harvest, and no later than 24 hours, in order to effectively prevent the occurrence of brown rot and soft rot. Precooling method: use 0 ℃ cool down with cold water

III. packaging

after selection and classification, the precooled plums can be packed in wooden boxes lined with wrapping paper or with plastic plates, with one plum on each layer. It can also be packed in cartons. Each plum is packed with paper single fruit and put neatly and tightly into the box. A partition is added between each layer, and the packaging capacity is kg/box

IV. preservation methods

1. Cold storage. Cold storage conditions: the temperature is ℃, the relative humidity is%, and the warehouse is well ventilated. Before entering the storehouse, plum should be disinfected with formaldehyde or fumigated with SEC butylamine fumigant. In order to avoid pathogen infection caused by condensation of water vapor on the fruit surface after the fruit leaves the storehouse, the storage temperature should be gradually increased in the later stage of storage

2. Low temperature controlled atmosphere storage in plastic bags. Pack the fruit with 0.025mm thick polyethylene film, about 5kg per bag, fasten the bag mouth after loading, and store it at ℃. It can be stored for 10 weeks under the condition of oxygen concentration of 1%-3% and carbon dioxide concentration of 5%

3. Ice storage. Lay the bottom of the cellar with crushed ice, and then stack the precooled fruit baskets (boxes) on the ice. Fill the layers with crushed ice, and fill the stacks with crushed ice. After stacking, cover the fruit stacks with crushed ice, and then cover them with plastic film, and then stack cm thick sawn wood and other heat insulation materials on the film. In this way, the cellar door must be closed, and the cellar temperature should be controlled at ℃. When entering and leaving the cellar, the door should be closed immediately. The plum stored in the middle and late August can be transferred to the ordinary cellar until the beginning of winter, and can be stored until the Spring Festival

4. Controlled atmosphere storage. (1) controlled gas storage. With 0.025mm thick polymer, the manufacturer should provide ethylene film bags equipped with corresponding software control system for closed storage of plums. Under the conditions of temperature of ℃, carbon dioxide content of%, oxygen content of%, plums can be stored for 70 days; ⑵ controlled atmosphere refrigeration for small packages. Remove the stems of timely harvested plums, remove diseases and pests, and put them into polyethylene film bags, each bag 5kg, sealed and stored at -1 ℃ for months