ENGINEERING MATERIALS

ENGINEERING MATERIALS FOR STUDENTS 

HII THERE......

I am Ashish Kumar parida. 

Currently pursuing Batchelor of technology @IGIT,SARANG,DKL

NOW I AM IN 2ND SEMESTER..........

SO HERE I UPLOADED MY ALL SEMESTER NOTES AND SOME OF EBOOKS......

I SET IT IN GOOGLE DRIVES AS TO AVOID COPYRIGHT ISSUES........

All notes and pdf for igit,sarang .....

click here to get that folder

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All the Copyrights are reserved for @globalquora 

Germinating grape seeds 🍇 in odisha atmosphere

Germinating grape seeds 🍇 in odisha atmosphere!!! |part 1| |GlobalQuora|

Germinating grape seeds 🍇

You can learn how to grow grapes from seeds, but germinating grape seeds can be tricky. Start with a variety recommended for your growing region and that has been organically grown. Don’t use seeds from store-bought grapes or hybrid vines, as they may not sprout or produce plants like the original.

Vines grown from seeds may take two to seven years to produce grapes, so research the variety you want to grow. Soak the seeds in tepid water for 24 hours before planting. Then put them in a small container with some damp peat moss. Use about 50 seeds per tablespoon of peat moss. Put a lid on the container and keep it in your refrigerator at 35 to 40 degrees Fahrenheit for three months. (This is called stratification.)

After three months, plant the seeds three times as deep as their length in a tray of damp, sterile seed-starting mix. Make sure the tray has drainage holes. Sow the seeds every 1 1/2-inch and keep them under a grow light for 16 hours a day. Keep the seed-starting mix damp, but not soggy. Seeds should sprout in about two weeks, although some can take two months or more to germinate. When the seedlings have two sets of leaves, transplant them into 4-inch pots. If desired, feed them with a plant food made for seedlings at half-strength.

After six weeks, move each plant into a tall, one-gallon pot. Put the pots outside when the young plants have six more leaves in addition to the first two. Give them a partially shaded spot for a few days and gradually expose them to more sun. After your last spring frost, plant the young vines in a spot with well-drained, moderately rich soil and full sun. Space them 8 to 10 feet apart. After planting, prune each plant back to the two lowest leaf buds. Water them thoroughly and give them at least one inch of water weekly, if there's not enough rain. Feed the plants with a balanced fertilizer, such as a 10-10-10, in early spring through autumn, following the directions on the product label. If the vines look healthy, they may not need fertilizer. 

Full description 👇👇👇👇👇👇👇👇👇

Germinating grape seeds offers a challenge to any green thumb, thanks to inviable seeds and plenty of opportunity for contamination. Fortunately, careful preparation can increase the germination percentage for a healthy vineyard in the summer. During stratification, temperature and moisture need monitoring to ensure successful germination after planting grape seeds in the spring.

Choosing Viable Seeds

You can usually tell a viable seed by the way it looks and feels. Healthy seeds are firm, with a pale white or gray endosperm inside. Any seeds that are squishy when you gently squeeze them between your fingers are not viable.

To double-check this, you can drop the seeds in water and discard those that float to the top, as healthy seeds tend to sink. Planting grape seeds that are healthy and viable is an essential part of this process, so take the time to sort and test your grape seeds in order to improve your chances of successful germination.

Preparation of Grape Seeds

Before stratification, viable seeds need a thorough washing to remove the pulp. Soaking the grape seeds in distilled water for 24 hours before stratification increases the odds of germination. Because the seeds need to remain semi-moist during stratification, you'll need to prepare a proper bed for them, such as an air-tight bag or capsule filled with damp sand or wet paper towels. Damp peat moss is one of the best beds for grape seeds, as it has anti-fungal properties that can reduce the risk of mold that destroys the seeds during stratification.

Once you prepare the bed, you can tuck the seeds inside it and refrigerate them at 40 degrees Fahrenheit for about three months to stratify them, recommends Cornell University. You can safely store seeds in the fridge for a year or more, as they will not sprout in these conditions. The smartest time to do this is in December, as March is the time for planting in a greenhouse.

Planting Grape Seeds

After removing the seeds from stratification in early spring, you can plant them in small pots, or in larger pots with at least 1 1/2 inches of space between them. A greenhouse is the safest place for them until June, when you can transplant them to their permanent places outside.

They need temperatures reaching at least 70 degrees Fahrenheit by day and approximately 60 degrees Fahrenheit at night during this germination period. Grape seed germination time varies from approximately two weeks to two months; sometimes receiving 15 hours of sunlight per day encourages them to germinate sooner rather than later. If some seeds don't germinate, you can always pop them back in the fridge for stratification until next season and try again then.

Although it is possible to start grapes from seed, it is not the recommended method for propagating grapes, notes Oklahoma State University. Growing grapes from cuttings or by grafting desired varieties to proven rootstock are much more common practices than planting grape seeds, especially among commercial producers. These methods of cultivating new grape vines tend to be more consistent and reliable for reproducing grapes that have the same characteristics as their parent plants.

Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 

International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, 

adaptation, distribution and reproduction in any medium or format, as long as you give appropriate 

credit to the original author(s) and the source, provide a link to the Creative Commons licence and 

indicate if changes were made.

The images or other third party material in this chapter are included in the chapter’s Creative 

Commons licence, unless indicated otherwise in a credit line to the material. If material is not 

included in the chapter’s Creative Commons licence and your intended use is not permitted by 

statutory regulation or exceeds the permitted use, you will need to obtain permission directly from 

the copyright holder.

RICE STRAW MASHROOM CULTIVATION

HELLO DEAR READERS !!

Hope you all safe in your home 🏡 . Here is my second blog.  

So me and my elder brother started a new cultivation  .....

  yes, rice straw mashroom cultivation... 

So it started from 15 rupees wala mashroom seed  about 200gm in a bottle  ...

I brought 2 then 30 rupees. 

And transparent polyethylene of 3 meter .. it costs Around 100 rupees. 

And a temperature,  humidity meter costs around 130 

click here to buy

From Amazon 

Then besan about 400gram 200 gram each bed .

So I set 2beds  

And it costs around  30+100+60+130 = 320 rupees. 

You can put the beds both in indoor or outdoor 

All you need is to control the temperature and humidity of that room .

Here is a pdf for preference of rice straw mashroom cultivation. 

Abstract The rice-straw mushroom (Volvariella volvacea) has a distinct flavor, 

pleasant taste, and rich protein content. It has low production costs and a cropping 

duration of approximately 45 days—making it an effective means for poverty alle-

viation for those farmers who grow it. Farmers in Vietnam, the Philippines, and 

Cambodia grow it. Rice straw is one of the most common substrates used for grow-

ing this mushroom. The mushroom can grow well in both outdoor and indoor condi-

tions; however, outdoor cultivation has risks of exposure to rain, wind, and/or high 

temperatures, all which reduce yield. The yield of indoor mushroom production is 

higher and more stable, as such, indoor growing is preferred. In addition to cultiva-

tion, this chapter also covers straw mushroom characteristics, cultivation principles 

and techniques, and rice straw substrate preparation.

Keywords Rice-straw mushroom · Indoor cultivation · Outdoor cultivation

Mushroom is considered an important food to address food and nutrition security 

and human health (Ishara et al. 2018; Cuesta and Castro-Rios 2017; Feeney et al. 

2014a) and climate change adaptation issues (Gellerman 2018; Langston 2014). 

Volvariella volvacea (Fig. 6.1), also known as the straw mushroom or rice-straw 

mushroom (RSM), is one species of edible mushroom cultivated throughout East 

and Southeast Asia (Sudha et al. 2008).

RSM production adds value to rice production and increases the income of the 

poor farmers in developing countries (Imtiaj and Rahman 2008; Shakil et al. 2014; 

Zhang et al. 2014).

Among more than 38,000 known mushroom species, such as Agaricus bispo-

rus, Lentinus edodes, Flammulna velutipis, Auricularia polytricha, etc., RSM is 

one of the most common mushrooms cultivated (Walde et  al. 2006) and ranks 

third among important mushrooms due to its delicious taste (Ramkumar et  al. 

2012; Thiribhuvanamala et al. 2012), as well as its short growing time compared 

to other species (Rajapakse 2011). In terms of production, RSM ranks sixth among 

edible mushrooms, accounting for about 5–6% of world production (Ahlawat 

et al. 2011).

RSM is known as a healthy food (Belewu and Belewu 2005; Feeney et al. 2014b; 

USITC 2010). It has high protein, potassium, and phosphorus contents (Ahlawat 

and Tewari 2007) while being salt-free and low in alkalinity, fat, and cholesterol. 

Mushroom also contains selenium (Solovyev et al. 2018) and niacin (Ahlawat and 

Tewari 2007; Eguchi et al. 2015), which are two essential compounds in the immune 

system and the thyroid that have a role in cancer prevention (Hobbs 1995). Its fiber 

content is important for physiological functions in the gastrointestinal tract (Manzi 

et al. 2001). In addition, RSM has significant antimicrobial activity (Chandra and 

Chaubey 2017). It also provides good sources of polypeptide, terpene, and steroid 

(Shwetha and Sudha 2012) and phenolic compounds, such as flavonoids, phenolic

Fig. 6.1 Volvariella 

volvacea (Bull.; Fr.) Singer 

is an edible mushroom also 

known as the straw 

mushroom and, for our 

purposes, the rice-straw 

mushroom (RSM)

acid, and tannins that contribute to its high antioxidant properties (Hung and Nhi 

2012). Other sources of antioxidants in RSM are catalase, superoxide dismutase, 

glutathione peroxidase, peroxidase, glutathione-S-transferase, and glutathione 

reductase (Ramkumar et al. 2012). Table 6.1 summarizes the chemical composi-

tion of RSM.

Due to its many benefits and advantages, mushroom production and consump-

tion have significantly increased in many countries (Vizhanyo and Jozsef 2000; 

Bernaś et  al. 2006). The top mushroom producers are China, USA, and The 

Netherlands, contributing 47%, 11%, and 4%, respectively of the world’s total 

mushroom production

Physical Characteristics of RSM

RSM is best adapted in tropical and subtropical regions (Bao et al. 2013) and grows 

at relatively high temperatures (Obodai and Odamtten 2012). Its total crop cycle, 

under favorable growing conditions, is within 4–5 weeks (Biswas 2014). It belongs 

to the Fungi kingdom, Plutaceae family, Agaricales order, Agaricomycetes class, 

and Basidiomycota division (Chang 1969, 1974; Rajapakse 2011). RSM has an 

umbrella-shaped cap (pileus) ranging from dark grey to brown and a diameter of 

8–10 cm. When young, its cap has an egg-like shape and, as it matures, it becomes 

cone-like and nearly flat. The stalk (stipe) ranges in color from silky white to brown, 

which develops to a brownish gray sack-like cup (volva) (Chang and Miles 2004). 

The mycelia, the vegetative parts, comprise of threads and cord-like strands branch-

ing out through the substrate.

When the mycelia come together, the mushroom begins its first stage of develop-

ment called the pinhead stage. It is characterized by tiny clusters in white circular 

structures of interwoven thread-like hyphae. This is followed by the button stage in 

which buttons encircling the egg-shape structures are covered by a layer of tissue or 

a universal veil (volva). 

The stalk (stipe), cap (pileus), and gills (lamellae) are seen 

inside the button when it is cut lengthwise. Commercially, the button stage is preferred for harvesting because of the mushroom’s high-protein content at this point 

(about 25%), best palatability, and longer shelf life. The elongation stage occurs 

after the universal veil (volva) ruptures, exposing the stalk and the cap. The last 

stage, maturity, is characterized by the fully expanded cap exposing the brownish-

pink gills of its lower surface. At this stage, the spawns (basidiospores) begin to 

discharge. Figure 6.2 shows the mushroom lifecycle starting from generation of the 

spawns and ending with the formation of the ear .

Environmental and Nutritional Requirements

RSM is considered as one of the easiest mushrooms to cultivate because of its short 

production duration (Zikriyani et al. 2018) and advantages of having less fat. As 

mentioned, this species grows in warm weather, typically in the tropics and subtrop-

ics. The optimal temperature is from 30 to 35 °C for the RSM’s mycelial growth and 

from 28 to 30 °C for its fruiting body production (Le-Duy-Thang 2006). The suit-

able temperature for growing mushrooms is between 25 and 40 °C with the opti-

mum being 35 °C (Fasidi 1996). Relative humidity in the range of from 70% to 90% 

is best for RSM growth (Biswas and Layak 2014). The optimal pH is 6.5; anything 

higher hampers mycelia growth (Akinyele and Adetuyi 2005). This species grows 

well on a number of cellulosic substrates, such as rice straw, wheat straw, sugarcane 

bagasse, banana leaves, water hyacinth, etc. RSM production can be intensified with 

the development of cutting-edge technologies. It can be grown outdoors or indoors. 

Growing practices are described Sect. 6.4. Table 6.2 summarizes the main parame-

ters that enhance RSM growth.

Traditionally, RSM is mostly cultivated outdoors because of the low investment 

cost. However, outdoor cultivation has low and unstable productivity due to expo-

sure to changing weather conditions (Reyes 2000). Although controlled indoor 

mushroom cultivation requires more investment, it usually results in higher and 

more stable yields (Chang 1996). In addition, through environmental control, RSM 

can be intensively cultivated, growing from six to eight crops annually. Palitha 

(2011) reported that the yield of indoor RSM cultivation can be 2.7 times higher 

than that of outdoor practice with the same application of feedstock.

Biological efficiency (BE) is an important parameter used in the mushroom 

industry to evaluate the effectiveness of a mushroom strain on different substrates 

(Chang et al. 1981; Biswas and Layak 2014; Girmay et al. 2016). It is calculated as 

follows:

            BE = (FWm/ DWs ) .100%

                        

where:

BE is the biological efficiency

FWm is the total fresh weight (g) of mushroom yield across all flushes, and

DWs is the substrate dry weight (g)

As already mentioned, RSM can be cultivated on several lignocellulose materi-

als; however, RSM productivity is attributed to substrates of the best quality 

(Ahlawat et al. 2011). 

Table 6.3 shows the biological efficiency of RSM production 

on different substrates.

Current Practices for Growing Mushroom

6.4.1 Outdoor RSM Cultivation

The steps for outdoor RSM production (Fig. 6.3), as it is done in Vietnam, are shown 

in Fig. 6.4.

6.4.1.1 Rice Straw for Mushroom Growing and Preparation 

of the Growing Location

Rice straw intended for growing RSM should be dry, clean, without mold contami-

nation, and should not have been exposed to rain or should not have started rotting 

in the field. Rice straw contaminated with molds may have mycelia or spawns with 

a white color. To minimize contamination and for best quality, the straw should be 

collected right after harvest. The location for growing RSM should be cleaned and 

treated with 300–500  kg  ha−1

 (3–5  kg 100  m−2

) of lime (CaCO3) 3  days before 

incubation.

6.4.1.2 Growing Preparation and Maintenance of Planting Spawn

The most commonly used spawn substrate is a mixture of tobacco midrib and saw-

dust. The tobacco midribs are first soaked in clean water overnight. After soaking, 

they are washed at least three times, drained, and then chopped into lengths of from 

2 to 4 cm. The chopped midribs are boiled for 30 minutes and then drained until the 

moisture content reaches around 65%. Next, the midribs are mixed with the saw-

dust. About 350 g of mixed spawn substrate is placed inside a 6- × 12-in. polypro-

pylene (PP) bag. For easier handling, a plastic ring may be placed as a “bottle neck” 

on the PP bag. This can be done by pulling out the PP bag end through the poly-

vinylchloride (PVC) ring then folding the pulled-out part outward to make an open .

Fig. 6.3 Growing RSM outdoors

ing. Next, the folded part is secured by tying with a rubber band. The PVC neck 

opening is plugged with a rolled cotton waste then covered with paper secured with 

rubber band.

The PP bags containing the spawn substrates are sterilized using an autoclave at 

15 psi pressure and 121 °C for 30 min. The sterilized PP bags with the spawn sub-

strates are then transferred to the inoculation room and allowed to cool down.

The sterilized bags are kept inside the laminar flow under a UV tube or inocula-

tion chamber for 20–30 min. Inoculation is done by removing the cotton plug of 

each bag, then placing a 1-sq mm pure culture mycelial block on top of the spawn 

substrate using a sterilized inoculation needle, then replacing the cotton plug. The 

process is repeated until all the bags with substrates have been inoculated.

The inoculated bags are kept in the incubation room at 32 °C temperature for 

2 weeks, or until mycelial growth reaches the bottom of each bag. The bags should 

always be checked for contamination during the incubation period. The shelf life of 

the spawn is about 4 weeks at room temperature. It can also be refrigerated at 4 °C 

to prolong storage. The refrigerated spawn should be primed at room temperature 

before using in order to activate spawn growth.

6.4.1.3 Preparation of Growing Beds and Spawning

Rice straw or stubble can be used as bedding materials or substrates. These 

materials collected from the field must be sun-dried. If bundled substrates are 

used as bedding, the straw should be cut into 30-cm long strips to make bundles 

10  cm in diameter. The beds can be created manually (Fig.  6.5a) or using a

Fig. 6.5a Manual bedding

Fig. 6.5b Bedding using a 

wooden frame

wooden frame (Fig.  6.5b). The wooden frame size is 0.3–0.4  m in width, 

0.35–0.4 m in height, and 1.5 m in length. Straw should be placed into the frame 

and compacted so that the first layer is 10 cm thick; then the spawn is added to 

the straw surface. A second layer using similar steps should be done. The two 

layers of straw are compressed, and then the frame is removed to have the beds 

on the ground for growing RSM.

The bedding materials are soaked in clean water for 12 h to make them soft and 

pliable. The soaked substrates are rinsed with clean water to remove the slime, fer-

menting odor, and to reduce acidity. Soaking is a prelude to composting.

In composting, the soaked substrates are piled up then covered with plastic 

sheets. The composting period is 14 days and the pile should be turned on the 7th 

day to ensure even composting. In some cases, 1% molasses and 5% complete fertil-

izer (14–14-14 NPK) are mixed into the substrate during composting. Agricultural 

lime (1%) is also added when the compost pile is turned. Through composting, the 

substrates are converted into a rich medium suitable for mushroom growth.

The moisture content of the substrate during bed preparation must be close to 

65%. Growing beds are established by piling the bundled substrates into layers. The 

spawns are sprinkled thinly over the bundles in each layer. It can also be placed in 

thumb-size bands 7 cm from the edge of the bed at a distance of 10 cm between 

bands. Sometimes the spawn is covered with newspaper to protect the spawn from 

drying and to enhance better mycelial growth. If the substrate were not applied with 

molasses and fertilizer during composting, a nutrient solution, containing 10 g of 

urea and 30 g of sugar mixed in 4 L of water, is sprinkled over each substrate layer. 

The process should be repeated until all layers have been treated. Ideally, the bed 

should have three layers and should be from 2.5 to 3 m long.

The growing bed is covered with a polyethylene plastic sheet to maintain the 

desired temperature and relative humidity appropriate for mycelial growth. The 

optimum temperature for incubation ranges from 30 to 35 °C with a relative humid-

ity ranging from 75 to 85%. The incubation period takes from 10 to 14  days. 

Mushroom primordia or pinheads usually appear on the side and surface of the 

growing beds 5 days after spawning. Once pinheads are observed, the plastic sheet 

cover should be lifted for a while to introduce fresh air. The temperature should be 

maintained at 30 to 32 °C to synchronize fruiting body formation during the fruiting 

stage. The surroundings of the beds should be watered to help maintain the desired 

temperature.

6.4.1.4 Mushroom Growing Care

In the first 3 days after adding spawn to the straw beds, the beds need to be exposed 

to the sun to increase the temperature inside, which stimulates mycelial growth. 

Then, the beds are covered with a net and dry straw. Some nutritional supplements 

or stimulants such as Bioted, HQ, or HVP 301 can be sprayed onto the beds to 

enhance better mushroom growth. The beds can be watered and covered with rice 

straw to maintain the temperature and humidity as well as to maximize the yield and 

quality of RSM production, as indicated in Table 6.2.

6.4.1.5 Harvesting and Processing

The first fruiting flush occurs about 14 days after incubation and continues for about 

5 days. After the fruiting flush, water is sprinkled over the bed and covered again 

with the plastic sheet to build up the temperature. Within 7–14 days, the next fruit-

ing flush will appear. The succeeding fruiting flushes often consist of larger, but 

fewer fruiting bodies than the first flush. Hand picking is the common method of 

harvesting and sorting the mushrooms. This guarantees less damage and better qual-

ity. The mushrooms are picked from the growing beds with a rotating motion. The 

harvest is sorted based on quality and size. To enhance higher protein content, better 

palatability, and longer shelf life, the preferred times for harvesting are during the 

button to egg-shaped stages.

6.4.2 Indoor RSM Growing

Indoor mushroom growing requires the same preparation and treatment steps as in 

the outdoors. However, the environmental criteria, such as heap temperature 

(>70 °C) to sterilize straw, moisture content (60–65%), etc., have to be strictly con-

trolled. Indoor RSM growing uses shelves with two types of bedding, spread 

(Fig. 6.6a) and compacted (Fig. 6.6b). The ratio of spawn used is about 200 g m−2.

Fig. 6.6a Spread bedding

Fig. 6.6b Compacted 

bedding

It is necessary to cover the substrate beds to secure the moisture content for 2–3 days. 

Water may be sprinkled upon seeing the fungus grow on most of the beds. Organic 

fertilizer, such as chicken manure or cow dung, is added to the substrate at a rate of 

about 0.5–1.5 kg m−2

 to increase the nutrient uptake by the mushrooms. All materi-

als have to be sterilized before adding them to the substrate.

6.4.3 Case Study of Cost-Benefits for Growing Indoor 

and Outdoor Mushroom

We conducted assessments for indoor and outdoor mushroom growing in the 

Mekong River Delta (MRD) of Vietnam in 2018 that resulted in the cost-benefit 

comparison shown in Table 6.4. For the outdoor practice, total input cost was about 

1.28 $US kg−1

 of mushroom produced and 1.23 $US m−2

 of land used. It comprises 

the main component costs of rice straw (40%), labor (23%), chemical inputs (11%), 

and the rest for land use, depreciation of net and pump, and watering. On the other 

hand, for the indoor practice, the total input cost was 1.37 $US kg−1

 of mushroom 

produced and 10.79 $US m−2

 of.

land used. The indoor practice cost breakdown was depreciation of growing 

house and facilities, 44%; rice straw, 31%; labor, 7%; and the rest for use, deprecia-

tion of net, pump, and growing house (for indoor scenario), and watering. Net profit 

accounted for 1 kg of mushroom produced was the same for both indoor and out-

door practices at 0.5–0.6 $US kg−1

. Whereas, accounting for a square meter of land 

Table 6.4 Comparing cost-benefits between outdoor and indoor RSM growing practices in MRD

used, net profit of the indoor practice was 4.6 $US m−2

 about 9 times higher than 

that of the outdoor practice. However, RSM is commonly cultivated in rural areas, 

near the rice fields to reduce the cost of transporting the rice straw. So, outdoor 

mushroom growing is still widely done in Vietnam.

6.5 Pest and Disease Problems

RSM is very sensitive to the environment including temperature, sunlight, water, 

oxygen (O2), and carbon dioxide (CO2). Sudden changes in temperature may ham-

per or even stop mushroom growth. Sunlight is needed from the sphere to the egg 

stages. With a lack of sunlight, vitamin E will be significantly reduced, vitamin D 

will not be available, and melanin pigment (black pigment) will not form in RSM.

Green mold (Verticillium fungicola), orange mold (Neurospora spp.), plaster 

mold (Scopulariopsis fimicola), acne mushroom (Selerotium rolfsii), etc. are the 

typical diseases that affect RSM.  These diseases can be prevented or treated by 

using lime water with a 0.5–1% concentration and applied by watering on the 

affected area. Gypsum disease can be treated with potassium permanganate 

(KMnO4) or acetic acid (40%). If the disease is severe, it can be treated by fungi-

cides, such as Benomyl 0.1%, 7% Zineb, or Validacin (for acne).

6.6 Preservation and Consumption of RSM

RSM can be used and processed into many different products but it is easily dam-

aged during harvesting and primary processing. The selection of appropriate tech-

nology for product storage and processing on a scale that is compatible with 

production conditions will promote the cultivation of mushrooms and help stabilize 

consumption.

RSM spoils very quickly and can be stored at most for 3 days at temperatures 

between 10 and 15 °C or in controlled atmosphere packaging (Jamjumroon et al. 

2012) it loses moisture in 4 days, resulting in a 40–50% loss of mushroom weight 

when stored under normal ambient temperature. Thus, other methods are used for 

longer storage, one of which is dried RSM. However, sun drying often changes the 

color and taste of the product. Furthermore, RSM exposed to the sun outdoors is 

susceptible to microbial contamination. The drying process takes 24 h at 30 °C. The 

drying temperature can start at 40  °C and then gradually increase over 8  h to 

45 °C. Raw materials of dried mushrooms can be left or cut in half. If cut in half, 

they must be pretreated before drying. Blanching for 3–4  min in hot water or 

4–5 min in hot steam helps mushrooms keep their color better during storage. When 

RSM is dried at 60 °C for 7 h, the moisture content may reach 5%. Dried mush-

rooms can be stored or pulverized for use in spices. Other methods recommended 

for RSM preservation include air-conditioning packaging with storage media .

(Lopez-Briones et al. 1992), drying (Izli and Isik 2014), freezing (Murr and Morris 

1975), soaking in saline or acid solution (Cliffe-Byrnes and O’Beirne 2008), and 

canning (Vivar-Quintana et al. 1999).

Storage time can be extended for 3–6  months by soaking the mushrooms in 

acidic or saline solutions, which help extend shelf life and maintain their color. The 

mushrooms are washed in plain water before dipping into the saline solution. The 

mushrooms are then put in the containers and covered with the saline solution.

Mushroom preservation through industrial canning technology is used in many 

countries around the world. The process of producing canned RSM includes pre-

liminary processing, blanching, stacking, sterilization, cooling, labeling, and pack-

aging. In order to produce canned mushrooms of good quality, it is necessary to 

process harvested mushrooms as soon as possible. In case of unavoidable delay, 

mushrooms should be stored at 4–5 °C until processed.

However, all the other preservation methods result in inferior mushroom eating 

quality compared to that of fresh mushroom, in terms of the original flavor, color, 

hardness, and so on. Extending the shelf life of fresh mushroom beyond 3 days is 

most important, as illustrated in the case of the Mekong Delta in Vietnam. In the 

local market, mushrooms are consumed as a fresh vegetable with the price normally 

fluctuating from 2 to 4 US$ kg−1

 at the first and 15th day of the lunar month. A small 

portion of salted or dried RSM is also exported at 2 US$ kg−1

, but is not as much 

appreciated as fresh mushrooms. For estimating consumer trends, we can look at the 

American market. In 2012, the share of fresh mushrooms was 87% in quantity and 

93% in value; the remaining minor portion is processed mushroom, with a farm gate 

price of only one half compared to that of fresh mushroom (Phan-Hieu-Hien 2017).

The price of fresh RSM at US supermarkets in 2013 was about 10 $US kg−1

, 

while that of salted mushroom was only 5 $US kg−1

 (personal communication with 

Mr. Le Duy Thang, mushroom expert). From farms in Vietnam to US supermarkets, 

fresh RSM needs a minimum of 8  days to “travel”, including 2–3  days through 

customs and 2–3 days at supermarkets before reaching consumers. The 8-day shelf 

life of fresh mushroom is the greatest constraint to boost mushroom production, or 

indirectly to increase the use of rice straw. Luckily after decades of deadlock, some 

research results are promising (Dhalsamant et al. 2018). Factors to help ensure a 

successful 8-day storage cycle include: (1) a suitable temperature, say 12 °C; (2) a 

controlled-atmosphere packaging, which is balanced between oxygen and carbon 

dioxide content; and (3) a chemical pretreatment, such as CaCl2. More in-depth 

research is needed in parallel with pilot testing for economic performance.

6.7 Summary and Recommendations

Producing RSM is a sustainable option for adding value to rice production and 

reducing environmental harm through avoiding the burning of rice straw in the field. 

Growing outdoor RSM is a traditional practice with low investment costs but gener-

ates low yield and incurs high risk because it is strongly affected by changes in the weather. On the other hand, growing indoor RSM has higher investment costs but 

greater productivity and lower risks due to its well controlled environment.

One of the major bottlenecks for developing RSM is its market. Even though 

fresh RSM has high value, it cannot be stored for more than 3 days because it is 

highly perishable. Using technology to improve preservation to lengthen the storage 

time is a key to increasing the market and price and improving RSM’s value chain.

Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 

International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, 

adaptation, distribution and reproduction in any medium or format, as long as you give appropriate 

credit to the original author(s) and the source, provide a link to the Creative Commons licence and 

indicate if changes were made.

The images or other third party material in this chapter are included in the chapter’s Creative 

Commons licence, unless indicated otherwise in a credit line to the material. If material is not 

included in the chapter’s Creative Commons licence and your intended use is not permitted by 

statutory regulation or exceeds the permitted use, you will need to obtain permission directly from 

the copyright holder.

MCB (MINIATURE CIRCUIT BREAKER)

DESCRIPTION 

• MCB stands for Miniature Circuit Breaker .

• is an automatically operated electrical switch used to protect low voltage electrical circuits 

from damage caused by excess current from an overload or short circuit.

• Back in the day we protected against over-current by using fuse wire (indeed, we used to sell 

it!). The principle was fairly simple - an over-current would quite literally, 'blow' the fuse 

wire by rapidly heating and melting it, thus breaking the electrical connection and in doing so, 

protected the rest of the electrical circuit.

• MCBs improve on this functionality as they are usually not destroyed during over-current so 

are reusable. They are also much easier to use, offering the convenience of 'on/off switching' 

for circuit isolation and since the conductor is housed within a plastic casing, they are much 

safer to use and operate.

CONSTRUCTION 

Every MCB consists of the following part:-

1. External Casing:

External Casing holds all the internal components firm and protects them from dust. It is made of insulating materials such as plastic or ceramics.

2. Contacts:

A pair of contacts can be found inside an MCB. One of them is fixed and the other is movable.

3. Knob:

MCBs can be turned ON and OFF using this knob.

4. Mechanical Latch:

A latch arrangement is made inside MCBs to hold the contacts under spring tension at ON position.

5. Bimetallic strip:

The bimetallic strip offers delayed overload protection by sensing the prolonged flow of current greater than its rated current.

6. Solenoid:

Solenoid offers instantaneous protection against short circuit by releasing the mechanical latch. Solenoid gets activated when the current through 

the coil exceeds a particular value, normally more than 3 times of its rated current. This solenoid is not activated by overloads.

7. Arc Chutes:

Arc chutes are used for splitting and quenching of arcs.

I uploaded a ppt (PowerPoint presentation) You can download it from here.

ADVANTAGES 

• MCB is more sensitive to current than fuse. It detects any abnormality in the current flow and 

automatically switches off the electrical circuit.

• In case of MCB, the faulty zone of electrical circuit can be easily identified. Faulty circuit trips to 

the off position. On the other hand in case of fuse, the complete fuse wire needs to be checked by opening fuse 

grip for confirming the faulty zone.

• With MCB it is very simple to resume to the supply. You just need to push the knob of MCB back 

to on position. But in case of fuse, the entire fuse wire needs to be replaced.

• MCB provides a better interface with the help of knob than a fuse. In case of fuse the complete handle 

needs to be taken care out.

• Handling MCB is electrically safer than handling a fuse.

• MCB is reusable and hence has less maintenance and replacement cost. Whereas a fuse needs to be 

replaced whenever it goes faulty.

The working principle of MCB

Whenever continuous overcurrent flows through MCB, the bimetallic strip is heated and deflects by bending. This deflection of bi-metallic strip releases a mechanical latch. As this mechanical latch is attached with the operating mechanism, it causes to open the miniature circuit breaker contacts, and the MCB turns off thereby stopping the current to flow in the circuit. To restart the flow of current the MCB must be manually turned ON. This mechanism protects from the faults arising due to overcurrent or overload.

But during short circuit condition, the current rises suddenly, causing electromechanical displacement of plunger associated with a tripping coil or solenoid. The plunger strikes the trip lever causing immediate release of latch mechanism consequently open the circuit breaker contacts. This was a simple explanation of a miniature circuit breaker working principle.

An MCB is very simple, easy to use and is not generally repaired. It is just easier to replace. The trip unit is the main part, responsible for its proper working. There are two main types of trip mechanism. A bi-metal provides protection against overload current and an electromagnet provides protection against short-circuit current.

MCB operation

If the circuit is overloaded for a long time, the bi-metallic strip becomes overheated and deformed. This deformation of Bi-metallic strip causes, displacement of latch point. The moving contact of the MCB is arranged by means of spring pressure, with this latch point, that a little displacement of latch causes, release of spring and makes the moving contact to move for opening the MCB.

The current coil or trip coil is placed so that during short circuit fault the magneto-motive force (mmf) of the coil causes its plunger to hit the same latch point and make the latch to be displaced. Again, when operating lever of the miniature circuit breaker is operated by hand, that means when MCB goes off position manually, the same latch point is displaced as a result moving contact separated from fixed contact in the same manner.

It may be due to deformation of a bi-metallic strip, or increased mmf of a trip coil or maybe a manual operation, the same latch point is displaced and same deformed spring is released, which ultimately responsible for movement of the moving contact. When the moving contact separated from fixed contact, there may be a high chance of arc. This arc then goes up through the arc runner and enters arc splitters and is finally quenched. When we switch it on, we reset the displaced operating latch to its previous on position and the MCB is ready for another switch off or trip operation.

COMPARISON BETWEEN MCB , RCCB, ELCB AND MCCB

I uploaded a ppt (PowerPoint presentation) You can download it from here.

SUMMARY 

• Miniature Circuit Breaker is an automatically operated electrical switch used to protect low

voltage electrical circuits from damage caused by excess current from an overload or short 

circuit.

• Whenever continuous overcurrent flows through MCB, the bimetallic strip is heated and 

deflects by bending. This deflection of bi-metallic strip releases a mechanical latch.

• Types of MCB based on Number of Poles

1.Single Pole (SP)

2.Double Pole (DP)

3.Triple Pole (TP)

I uploaded a ppt (PowerPoint presentation) You can download it from here.