Longan meat, also known as dried longan, yizhi, or mipi, is the false seed coat of the longan plant, a member of the Sapindaceae family. It has a warm nature and a sweet taste, and enters the heart and spleen meridians. It has the functions of nourishing the heart and spleen, replenishing qi and blood, and calming the mind and improving intelligence. It is used to treat symptoms such as weakness, thinness, insomnia, and forgetfulness. There are unscrupulous vendors in the market who use sulfur to fumigate longan meat, making it look more attractive, and then add white sugar to increase its weight and sweetness. When using it, attention should be paid to identification.
To identify adulterated longan meat, the first thing to look at is the appearance. Longan meat adulterated with white sugar will not be too dry, otherwise the added white sugar will be noticeable. Longan meat fumigated with sulfur has a very beautiful surface, with a whitish color and a very attractive appearance.
The next step is to smell it. Longan meat has a strong fragrance, while longan meat fumigated with sulfur loses this fragrance and smells of sulfur.
The third step is to touch it. Longan meat, after processing and drying, is generally not too dry and feels slightly sticky when touched. However, longan meat adulterated with white sugar feels sticky when squeezed in the hand.
The fourth step is to taste it. Longan meat has a rich and sweet taste with a special flavor, while longan meat adulterated with white sugar tastes less fragrant and overly sweet.
Longan meat is a commonly used tonic medicine. The "Shennong Bencao Jing" states: "Longan has a sweet taste and is neutral in nature. It can regulate the five viscera, calm the mind, and alleviate loss of appetite. Long-term consumption can strengthen the soul, improve intelligence, lighten the body, delay aging, and connect with divine spirits." Longan meat treats the evil qi of the five viscera and stabilizes the mind. It can treat loss of appetite. Long-term consumption can boost the soul, enhance hearing, improve vision, and keep the body light and agile without easy aging. However, longan meat fumigated with sulfur may contain residual sulfur dioxide, which, when ingested, can damage the digestive and respiratory systems, causing mutations. It also harms organs such as the liver and kidneys. Longan meat adulterated with white sugar greatly reduces its efficacy, affecting its tonic and therapeutic effects. Therefore, it is important to carefully identify longan meat before use.
