What Are Truffles? The Latest Detailed Guide to Truffle Knowledge
Truffles are the general term for fungi in the genus Tuber of the family Tuberaceae in the phylum Ascomycota, with about 10 different varieties. They are usually annual fungi, mostly growing by attaching to the roots of broadleaf trees, generally growing under pine, oak and holm oak trees. They spread within a radius of 120 to 150 cm around the base of the tree, with the lump-shaped main body hidden 3 to 40 cm underground, and are found in countries such as Italy, France, Spain, China and New Zealand.
The truffle fruiting body is lump-shaped, and the ascocarp is spherical or oval, brown or dark brown. Some are as small as a bean, while others are as large as a Fuji apple. The surface has polygonal wart-like structures that reflect a red luster, with a depression at the top. The flesh (spore-producing tissue) is initially white, later turning brown or gray, and becoming black when mature. The cut surface is brown with marble-like veins, giving off a damp forest-like smell with a dried-fruit aroma, by which it lures small animals to come foraging and carry the spores elsewhere for reproduction.
Truffles grow in the soil and are a kind of tuberous fungus attached to the roots of pine trees, containing a large amount of water and trace mineral elements such as potassium, calcium, magnesium, iron and fluorine. Unlike ordinary mushrooms, which are soft and juicy, they are rather hard in texture. They prefer alkaline soil, and high-quality truffles are mainly produced in limestone terrain areas, such as Alba in Italy, Perigord in France and Yunnan in China, all of which are located in limestone terrain areas.
The nutrients of truffles come from the attached tree roots and the soil. If truffles have grown in a place, the nutrients of the soil and plants will be absorbed completely by the truffles, and nothing else can grow there for a period of time. Truffles also cannot tolerate any slight environmental change during their growth process, and their pickiness about the environment is truly astonishing. As long as the surrounding living environment undergoes a slight change, truffle spores will be unable to grow, but at present Western countries have achieved semi-artificial cultivation.
The maturity period of black truffles is usually from November each year to March of the following year, and the best season is usually between December and March of the following year. The people who collect truffles are called “truffle hunters”, and each truffle hunter carries a family-inherited treasure map recording the locations, times and sizes of truffles once found by their forefathers. The process of searching for truffles is very interesting, and the methods used by hunters in different countries are also not the same.
Truffles are rich in protein, 18 kinds of amino acids, unsaturated fatty acids, a variety of vitamins, and essential trace elements such as zinc, manganese, iron, calcium, phosphorus and selenium, as well as large amounts of metabolites such as sphingolipids, cerebrosides, ceramides, triterpenes, androsterone, adenosine, truffle acid, sterols, truffle polysaccharides and truffle polypeptides. They have extremely high nutritional and health-care value. Androsterone has remarkable effects in supporting yang and regulating the endocrine system. Sphingolipid compounds have obvious activity in preventing Alzheimer's disease and atherosclerosis as well as in anti-tumor cytotoxicity. Polysaccharides, polypeptides and triterpenes have effects such as enhancing immunity, anti-aging and anti-fatigue, and can be used for health preservation.