Lichee fresh-keeping process

Abstract

The invention discloses a fresh-keeping method of litchi, which has the advantages that the operation is simple and convenient, the device investment is little, the refreshing cost is low, the environment can not be polluted, the materials of a device can not be corroded, the pulp flavor and the color of the litchi can not be influenced, the fruit structure can not be damaged, the bright red peelcan be recovered easily, the residual quantity of sulfur is low and the method is suitable for the industrialization production. A fresh-keeping package is used by the method of the invention for packing litchis, an antistaling agent is wrapped in the fresh-keeping package which is stored in a natural-convection type icebox or cold cupboard after the fresh-keeping package is sealed, the temperature of the icebox or the cold cupboard is controlled within 1 to 7 DEG C, The relative humidity is 83 to 95 percent, and the sulfur dioxide gas that is slowly released from the antistaling agent is evenly filled with the whole space of the fresh-keeping package for suffocating litchi peels for 36 to 120 hours; after that, the fresh-keeping package and the litchis are positioned in the icebox or thecold cupboard for refreshing and storage, the temperature in the icebox or the cold cupboard is controlled within 1 to 7 DEG C, the relative humidity is 83 to 95 percent and the oxygen content in airis 3 to 8 percent. The invention can be applied in the fruit fresh-keeping field.

Description

technical field [0001] The invention relates to a fresh-keeping method for litchi. Background technique [0002] Litchi is one of the most difficult fruits to keep fresh and store. Browning, qualitative change and rot will occur soon after picking. Among them, preventing the browning of the pericarp is the most difficult problem, and it is also the key to keeping fresh and storing lychees. At present, the sulfur treatment method is widely used to preserve fresh litchi on a large scale to prevent the browning of the litchi peel. The more commonly used sulfur treatment method is the sulfur dioxide fumigation method, which is to use a small sealed room or a large airtight jar as a fumigation room to fully burn sulfur powder, or Use the high-pressure liquid sulfur dioxide contained in the high-pressure steel cylinder to regularly release sulfur dioxide gas to the fumigation room to fumigate litchi. Due to the high concentration of sulfur dioxide gas during fumigation, although ...

AI Technical Summary

Problems solved by technology

Due to the high concentration of sulfur dioxide gas during fumigation, although the time of fumigation is short, the red peel of litchi can fade to yellow-green in 20-30 minutes, but the concentration of sulfur dioxide gas is not easy to control during fumigation.

This method plays a dual role of preservation and antisepsis for fresh lychees. After being treated with sulfur in this way, the lychee pericarp will not be browned. After the air treatment, the color of the pericarp will partially return to red but become dull or bleached, and the color of the flesh will change from the original. The crystal clear and transparent become matte white, the flavor becomes sour, some also have sulfur smell, the fruit structure is destroyed, easy to break, there are serious sulfur residues, damage the surrounding environment, and also corrode equipment materials

In addition, some sulfur dioxide release agents are used to slowly release sulfur dioxide gas to fumigate lychee fruits. Due to the poor permeability of the packaging bags used and the imperfect refrigeration equipment, the preservation effect is not ideal, and it will inevitably cause damage to the lychee fruits.