Although often categorized as vegetables, mushrooms are part of the fungi family. In Portugal, they are grown mainly in the Trás-os-Montes, Beira Litoral, Ribatejo and Oeste regions. The most common types of mushrooms in this country are white, brown, Shiitake, and wild mushrooms.
Mushrooms are a great food. Nutritionally, they have a low energy content (approx. 20-30kcal/100g) and low fat content (0.1-0.5g/100g). They also have an interesting amount of protein for a non-animal source (3g protein/100g white mushrooms), and several essential amino acids, making mushrooms an excellent food for vegetarians. Mushrooms also contain some fiber (namely hemicelluloses and pectin), especially the Shiitake variety (2.5g fiber/100g) and a good amount of vitamins, minerals and antioxidants.
Mushrooms are a good source of micronutrients, such as B vitamins, namely riboflavin (vitamin B2), niacin (vitamin B3) and pantothenic acid (vitamin B5). Interestingly, mushrooms are virtually the only non-animal food source of vitamin D. Mushroom also contain a good amount of potassium, a very important mineral that helps optimizing blood pressure, reducing the risk of renal and coronary diseases, and that can help improve the health status of diabetic patients.
Furthermore, mushrooms are a good source of phosphorus, selenium and copper. Selenium (almost 50% DRI per 100g) has structural and enzymatic roles, particularly as an antioxidant and catalyst for hormone production as well as being essential for a functioning immune system.
Mushrooms are very rich in bioactive substances such as polyphenols, terpenoids, sesquiterpenes, lactones, chelants, polysaccharides and glycoproteins. Some of these substances have high antioxidant activity and are able to stimulate the body’s immune reactions and cellular anti-inflammatory response.