Qianxi Chestnut Mushrooms

Qianxi Chestnut Mushrooms

Qianxi Chestnut Mushrooms are a product with geographical indication status.

　　Qianxi County is located at the southern foot of the Yanshan Mountains. It is not only famous for its world-renowned Purple Jade Chestnuts, but also produces the rare edible fungus delicacy – chestnut mushrooms.

　　Chestnut mushrooms, scientifically known as Grifola frondosa, are also called Maitake, Hen-of-the-Woods, or Cloud Mushroom, belonging to the Basidiomycota subphylum. Before the 1970s, they grew only in the wild. Between early May and October, fresh chestnut mushrooms could occasionally be found in the chestnut forests of Qianxi. These mushrooms have an elegant shape, stacking like lotus petals. They emit a fragrant aroma and have a crisp, tender, and refreshing taste, offering a unique flavor and mouthfeel. The locals of the "Chestnut Town" traditionally reserved these hard-to-find mushrooms either to send to their children living far away or to serve to honored guests as a gesture of warm hospitality.

　　Aside from being beautiful and delicious, chestnut mushrooms are especially valued for their nutritional content and medicinal value, which are unmatched by other fungi. According to tests conducted by the Quality Inspection Center of the Ministry of Agriculture and the Institute of Nutrition and Food Hygiene of the Chinese Academy of Preventive Medicine, every 100 grams of chestnut mushrooms contain 31.5 grams of protein (including 18 amino acids totaling 18.68 grams), 1.7 grams of fat, 10.7 grams of crude fiber, 49.69 grams of carbohydrates, and 6.41 grams of ash. They are rich in potassium, phosphorus, iron, zinc, calcium, selenium, as well as vitamins VE, VB1, VB2, VC, and carotene. Among them, the content of VB1 and VE is 10 to 20 times that of other mushrooms, and the protein content is comparable to that of chicken and beans. Another highlight is their high dietary fiber content, which is 3–5 times that of regular dehydrated vegetables. To date, research institutions both domestically and internationally have recognized that chestnut mushrooms can help prevent intestinal cancer. As such, chestnut mushrooms are considered a healthy, nutritious food rich in multiple beneficial nutrients.

　　After the 1970s, some began experimenting with artificially cultivating chestnut mushrooms. In 1992, the science and technology department of Qianxi County successfully cultivated chestnut mushrooms using a “biomimetic” method. Through vigorous development, the chestnut mushroom industry has gradually expanded and has now become one of the important economic sources for farmers to increase income. Large-scale mushroom growers are spread all over the county.

　　Qianxi Chestnut Mushrooms

　　 Geographical Scope

　　The protected geographical indication area for Qianxi Chestnut Mushrooms covers 17 townships and towns in Qianxi County: Han’erzhuang Township, Luanyang Township, Saheqiao Town, Santunying Town, Baimiaozi Township, Yuhuzhai Township, Shangying Township, Jinchangyu Town, Taipingzhai Township, Donghuangyu Township, Jiucheng Township, Luojiatun Town, Xingcheng Town, Yinzhao Township, Xinji Township, Xinzhuang Township, and Donglianhua Yuan Township, encompassing 400 administrative villages. The geographic coordinates range from 39°57′15″N to 40°27′48″N and from 118°06′49″E to 118°37′19″E, based on the boundaries of Qianxi County. The protected area is approximately 150,000 mu, with about 2,000 mu under cultivation each year, yielding around 10,000 tons annually.

　　Product Quality Characteristics

　　1. External Quality: The fruiting body of Qianxi chestnut mushrooms is fleshy, with a short stem and coral-like branching. The tips bear fan-shaped to spoon-shaped caps that overlap into clusters. The larger clusters can be 40–60 cm wide and weigh 3–5 kg. The caps measure 2–7 cm in diameter, are gray to light brown in color, and feature reflective stripes with thin, inrolled edges. The flesh is white, with white tubes and pores. The pore surface is white to pale yellow, and the pore openings are polygonal. The spores are colorless, smooth, and oval to elliptical in shape. The mycelium walls are thin, branched, with septa, and lack clamp connections.   2. Internal Quality: Qianxi chestnut mushrooms are highly nutritious, rich in protein, iron, selenium, vitamin B1, vitamin B2, vitamin E, and amino acids. They contain 1.06g of protein per 100g, 60μg of vitamin B1, 420μg of vitamin B2, 710μg of vitamin E, 0.38mg of iron, and 705.9mg of total amino acids per 100g. The dried product contains 1.28 mg of selenium per 100g.   3. Product Safety Requirements:    A. Ensure good factory sanitation: Select locations with convenient transportation and energy sources, clean water, fresh air, and good drainage. Avoid proximity to heavily polluted factories, soy sauce plants, livestock farms, or feed warehouses, and implement pest, fly, and rodent control.    B. Use high-vitality, age-appropriate spawn: The spawn selection criteria include thick, dense, white, healthy, and unpolluted mycelium, with small primordia forming on the surface and the scent of chestnut mushrooms.    C. Use qualified main and auxiliary materials, strictly prohibit unknown substances, and follow proper ingredient ratios. Main materials include chestnut wood sawdust and oak wood sawdust; auxiliary materials include wheat bran, cornmeal, and sucrose. All main and auxiliary materials must be fresh, clean, free of insects, pollution, and off-odors.    D. Strictly control sterilization, inoculation, and mycelium growth processes. Maintain a constant temperature of 100°C for more than 12 hours for normal-pressure sterilization, or 121°C at 1.5 kg/cm² pressure for 2–2.5 hours for high-pressure sterilization. The inoculation rate should be around 1%–3%, ensuring no contamination during the process. Keep the mycelium room dark, maintain temperatures between 25°C–28°C, and relative humidity at 55%–65%. Provide regular ventilation to keep the air fresh and disinfect the room periodically.    E. During cultivation, strictly control temperature, humidity, ventilation, and lighting. Ideal fruiting temperatures are 25°C–30°C, with relative humidity of 85%–95%. Enhance ventilation and appropriately increase light exposure. Remove waste such as mushroom roots and rotten mushrooms promptly to avoid contamination by other fungi.    F. Implement pest and disease control using physical methods. Use biological agents, blacklight traps, insect-proof nets, and fly-killing lamps for pest control. Strictly comply with national green food standards and prohibit the use of highly toxic or high-residue pesticides. Product quality must meet the national agricultural industry standard NY5095-2006 for pollution-free edible fungi.