Mushroom Preservation Methods

1. According to Miles and Chang (2004), mushroom can be defined as a macro fungus with distinctive fruiting body which can either be epigeous (above ground) or hypogeous (below ground). Mushrooms is a vegetable that as long been known as food item, delicacy and for their medicinal values. They are consumed throughout the world irrespective of age and some households often consume them in place of meat, fish, egg, cheese and most vegetable (Hortson; 2018).

2. Getachew (2016) describes mushroom as “the future vegetable which is a guarantee for food insecurity, malnutrition problem and has malnutrition value. Mushroom contains unsaturated fatty acids, which constitute over 70% of the total content of fatty acids, contain essential fatty acids, and are low in calories, and high in vegetable proteins, minerals and vitamins. Also, mushrooms are rich source of secondary metabolites which may be essential for nutraceutical, pharmacological and medicinal applications. According to Kidukuli et al. (2010), ‘some mushrooms have therapeutic activity which is useful in preventing diseases such as hypertension, hypercholesterolemia, atherosclerosis and cancer’..

3. Demand for mushroom is rising as health conscious individuals are beginning to realize it’s nutritive therapeutic potential and has desirable alternative food, especially for vegetarians (United States International Trade Commission; 2010). Although there are varieties of mushrooms in Nigeria, they usually grow themselves. But with the realization of its nutritive therapeutic potential coupled with its potential to generate revenue, there has been noticeable deliberate cultivation and increasing interest and investment by individuals, private companies and government.

4. Mushrooms are perishable food that has to be consumed in three to four days after harvesting to prevent spoilage. Spoilage or produce waste can be avoided if local market or wholesalers can be found, and produce get sold off to customers the same day harvesting is done. Large scale farmers can also make use of cold rooms with temperature of 5 to 8 °C to store their produce before sending them to market. The high probability that mushroom produce will end up as waste is a discouraging factor for large scale farmers, especially in a country like Nigeria that its value chain is not regulated. Farmers can increase the shelf-life of mushrooms by transforming them into more durable forms..

5. There are different methods of preserving mushroom. These methods can increase mushrooms’ shelf-life (ranging from one to twelve months)

A. METHOD ONE: FREEZING STEAMED MUSHROOM

One: Hold the mushroom under cool running water and wash a few at a time, massaging away every bit of dirt with your fingers. You can also place the mushroom in a colander and rinse them all at once. Pat them dry with a paper towel. Extra care must be taken when working with oyster, enoki or lion’s mane. These varieties should be washed while they are still attached to the larger base and then pull them off and wash them again if necessary.

Step Two: If the mushrooms are larger than one inch (2.5cm) across, use a sharp knife to slice them into halves, quarters or small slivers. All pieces should have same size and thickness.

Step three: combine one teaspoon (4.9ml) of lemon juice with 4.9ml of water and stir together. Then pour the cut mushrooms into the solution and let them sit for five minutes. Pat them dry with a paper towel after taking them out. This step is to prevent mushrooms from darkening and to retain their colour as they cook.

Step four: Fill the bottom of the steamer pot with 5.1cm of water and bring it to a boil. Make sure the holes in the steamer basket are not so large that mushrooms pieces can fall through.

Step Five: Poke the mushrooms with a fork to test for doneness after 3-5minutes mark. The fork should go all the way through but a little resistance from the meaty inside should be felt.

Step Six: Choose a large plastic, plastic freezer bag or freezer-safe glass container with a fitted lid. Leave about half inch (1.3 cm) of headspace in the container.

Step Seven: let them cool off. They become ready for freezing when they are cool to the touch.

Step eight: Place the container towards the back of the freezer so that they do not experience temperature changes when the door is opened. With this method, mushrooms can last up to one year.

B. METHOD TWO: FRYING AND FREEZING

Step One: Run the mushroom under cool running water and use your fingers to rub away any dirt. Slice the mushrooms into halves or quarters. Note that whole mushrooms are unlikely to cook evenly in a pan. The stems can be cut off or left uncut and cooked just the same.

Step Two: Place 1-2 teaspoons of fat like butter or oil into an open frying pan and set stove to medium to high heat. Let it heat up until the butter has fully melted or the oil starts to move freely around the pan. Heavy pan should be used.

Step Three: Place the cleaned and sliced mushrooms into the pan and stir them around with a wooden spoon every 45 seconds so each one cooks evenly. Spices like basil, oregano, rosemary and thyme can be added to make it tastier. Oyster mushrooms and large strips of Portobello caps might take up to 4/5 minutes why varieties with smaller heads take up to 2 minutes.

Step Three: Once the mushrooms are fully cooked, spoon them into a bowl or onto a plate and allow them to cool. Mushrooms are fully cooked when they are tender and all or most of the moister from the pan has been absorbed.

Step Four: Choose a heavy-duty glass or plastic container to store the mushrooms. Fill with mushrooms while leaving half inch of headspace at the top. This is because mushrooms will expand as they freeze, so it is important to leave space.

Step Five: Store the container toward the back of the freezer so they are not exposed to temperature changes when opening and closing the door. This method can make mushroom last for nine months. If you see a gooey film or squishy, slimy texture, they have gone bad.

C. METHOD THREE: BLANCHING AND FREEZING

Step One: Choose a pot large enough to accommodate all the mushrooms you want to blanch. Putting a lid on the pot for this will help the water boil faster. Adding salt is optional but it will help preserve the mushrooms’ colour and bring out their flavor.

Step two: hold a few mushrooms in your hand or put them all in a colander to make it easier. Use your fingers, a mushroom brush or a towel to wipe away any dirt lodged in small crevices.

Step Three: Pour 2-3 cups of water into a large mixing bowl with 1-2 cups of ice. The amount of water and ice needed depends on how many mushrooms to be cooked. For every cup (220 grams) of mushrooms, 470ml of water and 220 grams of ice should be used. There is need to prepare the ice bath ahead because mushrooms will be placed into cold water immediately after boiling.

Step Four: Use a sharp chef’s knife to slice the mushrooms into your desired shape. Mushroom slices or pieces should be about the same size so they cook evenly. After the water has come to a bubbling, rolling boil, place the mushrooms into the pot. Allow them to cook for about 2 minutes.

Step Five: Place a colander or standing sieve into the sink and pour the water and mushroom over it. Plop mushroom into the ice bath. Let them sit in the ice water for 3-5minutes or until they have cooled completely. Make sure there is enough water to cover all of the mushrooms. If necessary, add some more water and a few ice cubes.

Step Six: When the mushrooms are cool to the touch before transferring them into a freezer-safe container or plastic freezer with a lid. Leave half inch (1.3cm) of headspace because they will expand a little as they freeze. They should be stored at the back of the freezer. They will keep for up to year.

D. METHOD FOUR: PICKLING MUSHROOMS

Step One: Hold the mushrooms under cool running water and gently massage away any dirt and debris. Leave them whole or slice larger mushrooms into quarters or halves.

Step Two: Thick mason jars are best for pickling because the glass can withstand extreme temperature changes. Make sure the jar has lid that is airtight. Herbs such as thyme, bay leaves, rosemary, oregano and dill work well for pickled mushrooms. Put these herbs into already cleaned jars.

Step Three: Pour 180ml of water, 79ml of white vinegar into a saucepan. These liquid ingredients will be the base of the pickling brine. Non-reactive saucepan made from stainless steel, ceramic, glass and metal cookware. Avoid aluminum, cast iron and copper pans because these will release a metallic taste after coming in contact with vinegar.

Step Four: Add 1 tablespoon of salt, 1 tablespoon of peppercorns and any other spices to the brine. To complement the flavor of the mushrooms, thinly sliced garlic, shallots, or spring onions are great options.

Step Five: Put your whole or sliced mushrooms into the saucepan along with the other with the other ingredients and set the stove to high heat. Bring it just to a boil, which should take about 3 to 4 minutes. Overcooking should be avoided because it will cause the pickles to be limp and mushy.

Step Six: Once the brine comes to a full boil, reduce the heat to medium or medium-low and let the mixture simmer for about 15minutes. Make sure it is a simmer and not a boil.

Step Seven: Use both hands to lift the saucepan and slowly pour the brine and mushroom into the jar. Let the mixture cool to the touch, then cap the jar with an airtight lid and place it in the refrigerator. They will be ready to enjoy in 3 days. Quick-pickled mushrooms will stay good in the refrigerator for up to a month.

E. METHOD FIVE: DRYING METHOD

Step One: Dehydrating mushrooms using low heat is the best way to preserve their earthy, umami flavor. Preheat dehydrator to 43 degree Celsius or 56 degree Celsius if you want to them to dry a little faster. Caution should be taken not to use too much heat as it can cause the mushrooms to lose their flavor.

Step Two: Wash the mushrooms under cool running water. Pat the mushrooms dry with a paper towel and slice them into even pieces about quarter inch or half inch thick. They should be cut thin as much as possible because the thinner they are, the quicker they dry.

Step Three: Check for dryness after 3 hours and each hour after that. Open the door of the dehydrator to check the pieces for dryness. They should feel crispy and snap apart when you try to bend them with finger. If they are not dry yet, wait another hour before checking again. Smaller strings of enoki and lion’s mane mushrooms takes 2 to 3 hours, so there is need to check them sooner and more often. If some of the mushrooms are dry at the 3 hour mark, take out the dry ones and let the others dry.

Step Four: Once all of the mushrooms are crispy, slide the tray out of the dehydrator and let them cool on the counter top until they are completely cool to the touch.

Step five: the dried mushrooms can be stored in glass jars with airtight lid or zipper bags. Place the vessel in a cool, dark place and they will stay good for 6 months or 1 year. To re-hydrate them pour boiling water over the mushrooms and let them soak for 20 to 30 minutes. Dried mushrooms can be used to add flavor soups and sauces. They are no longer effective then they lose their scent (typically after one year).

6. CONCLUSION

With the realization of the potentials of mushroom, farmers, especially large scale farmers are able to produce large quantity of mushrooms with the aid of sophisticated farming implements. However, mushroom waste will increase as production increases if efforts are not made to increase their shelf-life. To ensure reduction of post production waste, profitability of mushroom farming, and durability to meet consumers’ need, there is need for farmers and consumers to preserve their mushrooms into more durable forms.

REFERENCES

Chang, S.T and Miles, P.G (2004): Mushrooms: Cultivation, nutritional value, medicinal effect and environmental impact. CRC Press. Boca Raton, 451pDevelopment, 8(8), 130–140. Getachew, D., Zemedu, L., & Eshete, A. (2016). Activity, Protease Inhibition and Brine Shrimp Lethality of Selected Tanzanian Wild Edible Mushrooms. wikiHow’s team of trained editors and researchers (2020); How to preserve fresh mushrooms Journal of Agricultural Extension and Rural Development Journal of Applied Biosciences, 31(1), 1887–1894. Kidukuli, A. W., Mbwambo, Z. H., Malebo, H. M., Mgina, C. A., & Mihale, M. J. (2010). In Vivo Antiviral Mushroom value chain analysis in Addis Ababa, Ethiopia. Journal of Agricultural Extension and Rural. Proceedings of the 36th Annual Conference of the Horticultural Society of Nigeria (Hortson) Lafia; 2018. Faculty of Agriculture Shabu-Lafia Campus, Nasarawa State University, Keffi, Nasarawa State, Nigeria ,

August 20,2020