The Spanish region of Murcia has started cultivating organic king oyster mushrooms. It is a local and fresh product that is normally only found in the wild. The king oyster mushroom, or Pleurotus eryngii, is the largest variety of the oyster mushroom family and grows originally in the Mediterranean.
The Councillor of Agriculture in Murcia, Miguel Ángel del Ámor, recently visited the only company dedicated to the cultivation of this mushroom variety, based in Cabezo de Torres.
The crop's cultivation "is carried out with residues from beer production, namely the barley or bagasse that remains after the cooking process. These residues serve as a breeding ground for the cultivation of organic oyster mushrooms," said del Amor.
Moreover, the crop leaves a residue in the soil (non-productive mycelium), which is very valuable for the environment. It can be used for soil cleaning and it has also been shown to serve as an effective nematicide (a plant protection product used to kill plant parasites).
The regional harvest of king oyster mushrooms amounts to around 90 kilos a week. The cultivation process is divided into three stages. The first stage is the preparation of a substrate which is made from a mixture based on bagasse. Special bags are filled with this substrate for the cultivation of mushrooms.
Subsequently, the mycelium of the mushrooms is grown under a controlled temperature. This process lasts for between 35 and 45 days. During the growing stage, the temperature must stay between twelve and twenty degrees Celsius, with an air humidity of approximately 85%.
The king oyster mushroom is one of the most appreciated species in the culinary sector due to its taste and aroma. The product has a number of health properties. It "regulates cardiac activity, strengthens the immune system and converts proteins and fats into energy," said the regional councillor.
Both this and other similar varieties "offer enormous environmental benefits, since they contribute to the degradation of organic material and also serve as food. The product is therefore also treated as a potential tool for sustainable development," said del Amor.
The company also grows chestnut mushrooms, or Agrocybe aegerita. "The sodium content of this product is very low, but the high potassium content contributes to the degradation of liquids. Also, this mushroom is rich in fibers, minerals and vitamins," said the politician.