Reasons Longan Is Difficult to Keep Fresh and Storage Methods
We are all familiar with longan. Its fruit is nutritious, sweet and juicy, and deeply loved by consumers. However, because its ripening season falls in hot and humid weather, its market period is short, it is difficult to store, and it rots very easily and loses its edible value, which seriously affects the commercial value and selling price of longan. So why is longan difficult to keep fresh? And how should it be stored properly? Let's take a look together.
I. Reasons Longan Is Difficult to Keep Fresh
Longan is mainly produced in our subtropical regions. The fruit ripens in the hot season, and after harvest its physiological metabolism is vigorous, so fresh fruit easily loses water, browns and rots. The main cause of rotting during storage is latent fungal infection, so preventing fungal infection before harvest is the key point in keeping longan fresh.
II. Longan Storage and Fresh-keeping Methods
1. Storage at room temperature
Preservative and fresh-keeping agents can be dissolved in water, and the longan soaked in it, so that a transparent film quickly forms on the longan, effectively sealing the stomata, reducing respiration intensity and delaying fruit senescence. Commonly used preservative and fresh-keeping agents include sec-butylamine, thiabendazole, imazalil, carbendazim and so on.
2. Low-temperature storage
Low-temperature storage mostly uses freezer warehouses. Suitable low temperatures can reduce the respiration intensity of the fruit and effectively inhibit polyphenol oxidase activity and microbial activity, but the cost is relatively high and it is not suitable for small and medium-sized fruit growers.
3. Sulfur fumigation fresh-keeping
After fumigation with sulfur dioxide, the longan peel changes, and soaking it in an acidic solution can restore its original color, but it is not the original fresh color. This method is generally used for imported fruit. Its disadvantage is that sulfur dioxide remains in the peel and flesh and is toxic, so at present the state has banned longan treated by sulfur fumigation.
4. Hot-water blanching fresh-keeping
This is a traditional folk fresh-keeping method. The whole fruit cluster is put into boiling water for 30 to 40 seconds, as long as the flesh is not scalded, then immediately lifted out and hung in a windy place to dry. After this treatment the fruit basically remains fresh and tastes sweeter, but its color is not attractive and it does not sell well.
5. Quick-freezing fresh-keeping
After the fresh fruit is treated to prevent cracking, the fruit temperature is lowered to minus 30 degrees within hours, and then stored long-term in a cold store at minus 18 degrees, where it can be kept for one year or longer.
The above is an introduction to the reasons longan is difficult to keep fresh and storage methods. We hope it helps you. To learn more related knowledge, please stay tuned to us.