Four key points of anti-spoilage techniques for chestnut storage, chestnut growers need to know
Chestnuts are afraid of heat and dryness, and also afraid of freezing and moisture. Although there are many storage methods, slight impropriety can lead to weight loss, sprouting, and mildew spoilage. Corresponding measures must be taken to reduce losses and extend the fresh-keeping period.
1. Prevent mildew and spoilage. Chestnut mildew is mostly caused by infection with Rhizopus nigricans or Mucor, and it is related to variety disease resistance, harvest maturity, and environmental conditions. Preventive measures include: 1. Timely harvest. Harvesting can only be done after the chestnuts are fully mature, which can enhance their disease resistance. 2. Strengthen ventilation management. Appropriately lowering the temperature and creating suitable low-temperature conditions can weaken chestnut respiration and slow metabolism, avoiding mildew and spoilage. 3. Adding a certain amount of pine needles to sand storage, basket storage, and refrigerated bags can inhibit mold growth. 4. Rapidly cooling freshly harvested chestnuts to below 5°C can not only avoid mold occurrence and reduce mildew, but also extend the storage period.
2. Prevent weight loss and air-drying. Chestnut weight loss and air-drying are mainly caused by too-low humidity and too-high temperature in the storage environment. The preventive method is to increase the humidity of the storage environment and lower the storage temperature. For example, regularly increase moisture during sand storage; before cold storage, wash the nuts with clean water and pack them without drying; use plastic film bag packaging, etc. Increasing the relative humidity of the warehouse and reducing ventilation is also an effective method.
3. Prevent sprouting. The conditions for chestnut sprouting are relatively high humidity and suitable temperature. Measures to prevent germination include: 1. Chemical treatment. Soaking the nuts in 0.1% daminozide, or maleic hydrazide, or naphthaleneacetic acid can inhibit chestnut sprouting. It can also be prevented by wax coating. 2. Salt water treatment. When chestnuts are about to sprout 30-50 days after harvest, soak and wash them for 1 minute in a mixed aqueous solution of 2% table salt and 2% soda ash, then put them into baskets or gunny bags before they are air-dried, and add some pine needles, which can inhibit sprouting. 3. Carbon dioxide treatment. Before sprouting after harvest, filling plastic film bags with 5% carbon dioxide and 3%-5% nitrogen can effectively inhibit chestnut sprouting.
4. Pest control. During chestnut storage, rot is often caused by damage from chestnut weevils and other borers. Fumigation with 40-60 g/cubic meter of methyl bromide can be used, with a treatment time of 3.5-10 hours. Or sealed treatment with 50 mg/L carbon disulfide for 18-24 hours.