Why Longan Is Hard to Keep Fresh and a Detailed Guide to Storage Methods

We are all familiar with longan. Its fruit is rich in nutrients, sweet and juicy, and deeply loved by consumers. However, because its ripening season falls in a period of high temperature and high humidity, its market window is short, it is hard to store, and it very easily rots and loses its edible value, seriously affecting the commercial value and selling price of longan. So why is longan hard to keep fresh? How should it be stored properly? Let's take a look together.

I. Reasons Why Longan Is Hard to Keep Fresh

Longan is mainly produced in our subtropical regions. The fruit ripens in the high-temperature season, and after harvest its physiological metabolism is vigorous, so the fresh fruit easily loses water, browns, and rots. The reason for rotting during storage is mainly 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. Room-temperature storage

An anti-rot and fresh-keeping agent can be dissolved in water, and the longan soaked in it. In this way a transparent film quickly forms on the longan, effectively sealing the stomata, reducing respiration intensity, and delaying fruit senescence. Commonly used anti-rot and fresh-keeping agents include sec-butylamine, thiabendazole, imazalil, carbendazim, and others.

2. Low-temperature storage

Low-temperature storage mostly uses freezer warehouses. Appropriately low temperatures can reduce the respiration intensity of the fruit and effectively inhibit the activity of polyphenol oxidase and the activity of microorganisms, 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 it to 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. Blanching fresh-keeping

This is a traditional folk fresh-keeping method. Whole clusters of fruit are 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 drafty place to dry. After this treatment the fruit basically stays fresh and tastes sweeter, but the 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 warehouse at minus 18 degrees, where it can be stored for one year or longer.

  The above is an introduction to why longan is hard to keep fresh and to storage methods. We hope it can help you. To learn more related knowledge, please stay tuned to us.