Because persimmons contain a large amount of soluble tannins, the tannins have strong astringent properties, which can stimulate the tactile nerve endings in the mouth to produce excitement and a "astringent" feeling. This astringency is not a taste sensation.

Therefore, how to remove "astringency" and still keep it fresh and crispy, there are the following methods:

1. Warm water deastringency method: Soak astringent persimmons in warm water at about 40℃ , so that under higher temperature and hypoxic conditions, the respiration will be strengthened and turn to anaerobic respiration, and the astringency can be removed after one day and night. The persimmon fruit removed by this method has crisp and hard flesh, beautiful color and good flavor. However, persimmon fruit has a high water content and is not durable for storage, so it is suitable for deastringent processing of a small amount of persimmons.

2. Alcohol deastringency method: Put astringent persimmons into a container, spray 5-7 ml of 40% alcohol per kilogram of fruit and seal. The astringency can be removed in 7-9 days. After alcohol treatment, Persimmons have a special aroma.

3. Lime water deastringency method: immerse astringent persimmons in 7% lime water, and the astringency can be removed in 3-5 days. The texture of the fruit treated with this method is crisp and tender, and it is not easy to rot, but There are signs of lime on the fruit surface and it is easy to clean, which hinders the aesthetics of the product.

4. Bitter water soaking and astringency removal method: Soak persimmons in bitter water containing 2 grams of MgCl per liter for 7-10 days to remove astringency. The persimmon peels that are removed by this method are not easy to swell and crack, and taste sweet and crisp. , if still stored in the original container, the storage time can be as long as 6 months under low temperature conditions.