Lianzhou Choy Sum

Lianzhou Choy Sum

Lianzhou Choy Sum is a protected geographical indication agricultural product.

　　Lianzhou Choy Sum is a specialty of Lianzhou City in Qingyuan, Guangdong Province. Known for its sweet, tender, juicy, and refreshing taste with a unique flavor, it is highly favored by diners in Guangdong, Hong Kong, and Macau. Lianzhou Choy Sum has been designated as a nationally protected geographical indication agricultural product.

　　Located in northwestern Guangdong, Lianzhou has exceptional conditions for winter crop production, with significant diurnal temperature variations, making it very suitable for growing winter choy sum.

　　The unique climate of Lianzhou during autumn and winter, characterized by large diurnal temperature differences, results in choy sum that is sweet, tender, juicy, and refreshing. Especially when touched by frost, the choy sum becomes even sweeter, making it a widely renowned high-quality vegetable. Whether stir-fried with cured meats, boiled whole in salted water, sautéed with garlic, cooked in clay pot soup, or served with shredded chicken and shark’s fin, each dish offers a unique flavor—consistently sweet, refreshing, tender, and free of grit. They are also highly nutritious, serving as an excellent food for cleansing intestinal toxins and improving bodily functions. When dried, the choy sum makes a premium soup ingredient, yielding a sweet and rich broth with an intense choy sum aroma. It is believed to have the effects of clearing the heart, moistening the lungs, reducing heat, and detoxifying.

　　Currently, the planting area of Lianzhou Choy Sum has reached 30,000 mu, with an annual output of over 45,000 tons and an annual output value of nearly 300 million yuan. Xian’an Town, the largest growing area for Lianzhou Choy Sum, had a planting area of 9,200 mu in 2010, yielding a total production of 10,120 tons and an annual output value of 10.8 million yuan. The “Lianzheng Vegetable Development Co., Ltd.” established in 1999 in Chongkou Village of the town is a key agricultural leading enterprise in Qingyuan City, with a vegetable planting area of 2,500 mu. Among these, the high-quality choy sum obtained green and pollution-free agricultural product certification from the National Ministry of Agriculture in 2010.

　　In 2013, “Lianzhou Choy Sum,” applied for by the Crop Technology Extension Station of Lianzhou City, passed the review of the Agricultural Product Quality and Safety Center of the Ministry of Agriculture and expert evaluation, and was granted national geographical indication agricultural product registration protection.

　　Geographic Scope

　　Lianzhou City in Guangdong Province is located in the northwest of the province, at the southern foot of the Mengzhu Mountain Range within the Five Ranges, primarily consisting of hilly basins along the upper reaches of the Lianjiang River, a tributary of the Beijiang River. To the northeast, it borders Yizhang County in Hunan Province; to the southeast, it borders Yangshan County; to the southwest, it neighbors Liannan County; to the northwest, it adjoins Lanling County and Jianghua County in Hunan; and to the north, it connects with Linwu County in Hunan. The protected area lies between 112°7′ to 112°48′ east longitude and 24°37′ to 25°12′ north latitude. The protected region includes 12 towns in Lianzhou City: Dalu Road, Xingzi, Longping, Xijiang, Jiubei, Lianzhou, Xian’an, Dongbei, Fengyang, Bao’an, Yao’an, and Sanshui. The production area spans 120,000 mu, with an output potential of 170,000 tons.

　　Product Quality Characteristics

　　(1) External Sensory Characteristics: Lianzhou Choy Sum has numerous fibrous roots and a shallow root system. The plant stands upright or semi-upright with a short stem. Generally, the plant is 50–70 cm tall and 2–3 cm in diameter, with an edible portion of 25–30 cm weighing about 200 g. The basal leaves are spread out or obliquely upright, smaller than common leafy vegetables, oval or elliptical in shape, green or yellow-green in color, with wavy leaf margins, sometimes lobed at the base or not, and may have extended leaf wings. Leaf veins are distinct, with narrow and long petioles. The flower stalk is green, with flower leaves ranging from oval to lanceolate, short-petioled or sessile. The flower stalk is the main edible part, known for its tenderness and distinctive flavor. Usually, only the main stalk is harvested, with few side shoots sprouting. (2) Internal Quality Indicators: Lianzhou Choy Sum is highly nutritious, with zinc content ≥3.1 mg/kg, iron ≥0.42 mg/100g, manganese ≥0.15 mg/100g, calcium ≥47.40 mg/100g, phosphorus ≥25 mg/100g, protein ≥1.7%, crude fiber ≥0.9%, moisture ≥93.1%, and ash ≥0.87 g/100g. It helps tonify qi and nourish kidneys, as well as strengthen the spleen and stomach. It serves as an excellent ingredient for culinary dishes and dim sum, as well as a nutritious health food. (3) Safety Requirements: The production process of Lianzhou Choy Sum complies with laws and regulations such as the Food Safety Law and the Agricultural Product Quality and Safety Law. Pre-harvest quality monitoring is conducted, and inputs such as pesticides and fertilizers must strictly follow the requirements for pollution-free and green food production. Product quality must meet green food standards.