There are over 2,000 types of mushrooms, but less than 100 have been approved or used as food. Some of the edible ones include the button top, shiitake, oyster and beech mushrooms.
Some mushrooms are known to be deadly or poisonous, but increased farming of the fungi has made the good crop available in most supermarkets and other outlets.
Farmers sell a punnet at between Sh150 and Sh200, but they can make more if one chooses to add value to the produce.
Mushrooms have great health benefits that include boosting immunity and helping in weight loss besides reducing the risk of some types of diabetes, hypertension, tumour growth and hepatitis.
They are also rich in proteins, which is almost as much as that in chickens, have vitamins B2, B3, C, D, E and minerals (selenium and potassium). They are low in calories as they have little carbohydrates and fat.
They have low sodium thus are good for those that have been advised to avoid salt. Mushrooms are a good substitute for meat. Unlike most proteins, they grow faster, have less input requirements and are perfect for vegetarians.
Avoiding poisonous mushrooms
Poisonous mushrooms, whose consumption could be lethal, has white gills. A mushroom with good gills should be light brown or brown. Avoid mushrooms whose lower stem is too large (bulbous).
A red colour on the cap and stem may be an indication that the mushroom is poisonous. The cap and stem should be white, light brown or brown.
There might be exemptions to the rules, but unless you are sure, avoid mushrooms with the named characteristics.
Preparation for cooking
Mushrooms are best cooked soon after picking. They can, however, be kept well in the fridge for about a week. Avoid storing them in polythene paper, put them in an open container or in a paper that will facilitate breathing and moisture absorption from the mushroom.
If dried or dehydrated, they can be kept for months so long as they are in a cool dry place. During cooking, it may be necessary to soak them in warm water to rehydrate.
For fresh mushrooms, quickly trim away the soiled parts and rinse in a perforated container such as that one used to wash vegetables.
This is usually done to reduce uptake of water since mushrooms are very porous. Place in a kitchen towel to dry off the moisture (this can take about an hour).
Alternatively, you can wipe off dirt with a damp or dry kitchen paper or use a soft mushroom brush. Cleaning may, however, not be required for mushrooms grown indoors.
Then one may remove the skin on the mushroom but this is optional. This may be done using a knife or potato peeler to grasp the tip of the stem or cap and pull the skin, which comes out neatly.
Some people may choose to remove the gills that you can easily scrape by the use of a spoon. Then depending on taste or necessity, you may or may not remove the stem.
Mushrooms can be cooked whole, halved, quartered, sliced or sectioned as desired. For use in soups, it is normally usual to dice into small pieces. Below are ways you can cook mushrooms.
Sautéed or stir fried
Prepare the mushrooms for cooking as explained above but preferably use sliced or quartered pieces. Use a large fried pan so that you have only one layer of the pieces.
Use medium high heat to heat the oil, butter or fat (three tablespoons for every 200g fresh mushrooms) and add the pieces to the hot oil.
You may also add salt, pepper and a grated garlic clove. At first, water will be released before the browning occurs.
Let them fry for about four minutes before turning them over for another four minutes. They will have turned light golden brown and will be crispy at the edges.
Turn them and let them simmer for another five minutes as you turn them for an even colour. Remove when golden brown or tender.
One may use the bigger types of mushrooms to avoid them falling through the grill. Pre-heat the grill to medium high.
Mix oil, garlic, salt, black pepper and then use a basting kitchen brush to apply the mixture on the mushrooms and grill over medium high heat for five minutes turning them over for another five minutes.
Alternatively, you marinate in seasoning and herbs of your choice.
For marinade, the 250g clean mushrooms maybe mixed with oil, 4 tablespoons, onion (medium-sized), clove of garlic grated or crushed, vinegar (a tablespoon), lemon juice (about two tablespoons), pepper (1/8 of a teaspoon) and a little brown sugar (half a teaspoon).
Leave it to stand for about an hour-and-half. Then grill directly without having to brush any mixture on them.
Adding to omelette/sandwiches
Dice the mushrooms and stir fry with seasoning of your choice then leave them to cool and add to the eggs and mix and fry as you do an omelette.
Alternatively, you can load the stir fried mushrooms onto a slice of buttered bread, add other ingredients of your choice such as bacon, cheese slices, tomatoes, lettuce and cover with another buttered slice.
Then you may toast it in a sandwich toaster and serve hot.
Use whole or big pieces and brush them with oil. Pre-heat the oven to 3750C and place on the roast pan that is covered with parchment paper or a baking mat.
You may add seasoning or herbs or use marinated mushrooms and roast for about 20 minutes depending on the size.
It may be cooked and used as a substitute for minced meat or together with minced meat in dishes as you would mincemeat.
It can be used in meatballs, samosas, in sandwiches, as an accompaniment to rice, and with pasta such as noodles, spaghetti and vermicelli.
It may be added to eggs and stews to thicken the soups and for the nutritional benefits. You can also blend the flour with porridge flour for a highly-nutritious product.
Use the diced or minced type to extract the umami (savoury flavour) as much as possible. One may stir fry the mushroom with onions, garlic, thyme or sea salt. One portion of the mushroom is blended and added to the unblended part with or without cream.
The soup can be garnished with freshly minced herbs. It is possible to have almost every type of food, lasagne, bread and salads blended with mushroom.
Dr Ngoda is a lecturer at the Department of Food Science and Technology, Egerton University.