Fermented foods from Fungi

Fermented foods from fungi or oriented food from

Traditional fermented protein rich foods are highly acceptable to millions of people . These preventive foods are easily made and are generally more attractive to consumers then the cooked original materials from which they are made. Some of the benefits of fermented food products are

• They have good flavor and smell

• fermentation increases the nutritional value of substrate

• it reduces cooking time and increases the keeping quality

Many different fermented foods are known in which mainly fungus species are employed . Some of them are

1 SOY SAUCE

The soy sauce is one of the most widely used fermented product and well known in cookery of Western countries . It is a dark brown liquid with a salty taste and distinct aroma.

Uses

It enhances the flavor and adds the colour to meat ,vegetables and other foods. This product is known by different names in different countries,Shoya in Japan and see iew in Thailand

• Soy sauce is made by fermentation of combination of soya beans ,wheat (cereals) and salt

• For fermentation, soya beans are soaked overnight and then excess water is drained off ,after this steamed off for several hours.

• Then cooked soya beans are mixed with wheat that has been already roasted or powdered

• The proportion of soya beans to wheat may vary from one manufacturer to another . The best soya sauce is made from a soybean wheat ratio 50 :50 by weight . The use of wheat decreases the total nitrogen content of soya sauce but adds the aroma and flavour.

Inoculation

The mixture is then inoculated with starter culture . A good starter culture is that which adds aroma and flavour to soya sauce. The commercial starter culture is obtained from strains of Aspergillus oryzae and Aspergillus soyae.The inoculated mixture is distributed in shallow wooden boxes and then incubated at 30 degrees celsius. After twenty four hours of incubation the mixture is covered with white growth of molds.

Brine fermentation

The molten mixture (Koji ) is transferred to deep vessel in which an equal volume of salt solution 17 to 19% is added to make mesh. Now pure culture of yeast and bacteria are added to mash to accelerate the fermentation and to improve the flavour of final product. The strains of Saccharomyces roxii, Pediococcus soyae and Torulopsis have been found to improve flavour and aroma . Soy sauce can be obtained after six months of fermentation.

Finishing

The mature meshes , pressed and liquid is then pasteurised at 70 to 80 degree celsius to stop the microbial reaction . This liquid is then filtered ,bottled and sold for marketing.

2 MISO

These are pastry like product which are obtained by fermentation of cereals such as soya bean . Miso is Japanese name given to all pastry like product .This is known as Chiang in China.

Preparation

• Soya beans are first washed, soaked in water and salted about 20 hours ,after this excess water is drained off and these are cooked in water at temperature 115 degrees Celsius for 20 minutes then cooled down

• Polished rice is then washed, soaked overnight and excess water is drained off ,now it is steamed for 40 minutes and cooled down . After this inoculated with Aspergillus oryzae ,then incubated to obtain molded rice after 40 to 48 hours at 32-35 degrees celsius then this rice is completely covered with white mycelium. At this stage ,this molded mixture gives pleasant smell and sweet taste to rice.Now these are removed from fermenter and mixed with salt to stop further growth of mold.

• The fermentation is carried out under an aerobic condition by yeast and bacteria . Now soaked soybeans are mixed with rice and is inoculated with starter culture containing pure culture of yeast and bacteria . The yeast mainly used Saccharomyces rouxii, Torulopsis species. Bacteria used are Pediococcus halophiles. Now this mixture is fermented in vats at 30 degrees Celsius then this mixture is riped, aged ,pasteurised and packed to obtain miso.

3 TEMPEH

It is the only food oriented fermented product that has been extensively investigated by scientist of West. This product is mainly originated in Indonesia and Malaysia . Tempeh is made by fermenting dehulled soya beans with a mold Rhizopus.

Process of production

• Soy beans grits are soaked in tap water overnight until hulls can be easily separated by hands at 25 degrees Celsius. Now dehulled soybeans are obtained

• These dehulled soy beans are boiled in the excess of tap water and drained off the excess water. Now it is cooled down and surface dried by spreading.

• Fermentation is carried out by inoculating these grids with Rhizopus oligospores . Then packed these in banana leaves. fermentation is carried out at room temperature or 31 degrees Celsius for 24 to 48 hours to obtain Tampeh cakes.

4 ONTJOM

This is the product closely related to tempeh. This is another traditional food in Indonesia ,popular in west Java . Like tempeh ONTJOM is a solid cake like product which is served after deep frying.

Peanut pressed cake is generally used as a substrate in ontjom fermentation . The fermentation is carried out by Neurospora or Rhizopus .the Neurospora fermentation results in pink or orange coloured cake formation while Rhizopus fermentation gives grey or black colour to cake.

Process of production

• Peanut pressed cake are broken into pieces by soaking in water for 24 hours , they are then washed and excess water is drained off

• the soaked pressed cakes are then mixed with cassava pressed cakes

• resulting mixture is then steamed for one to one and half hour and pressed it to form flat cake

• Cakes are cooked and then inoculated with starter culture of Neurospora or Rhizopus.

• Placed this cake into banana leaves or bamboo trays

• Now incubated at 20- 30 degrees Celsius for 1 to 2 days for the sporulation. So that fermented cakes is covered with orange Spores of Neurospora to form an orange cake while Covered with black spores of rhizopus to foam Gray coloured cake.

5 RICE WINE

This is also a fermented food product of western country and mainly used in Indonesia and Malaysia

Procedure for production

• Polished rice first soaked in tap water overnight then steamed. Cool down and incubated with Aspergillus oryzae and incubated at 30 degree Celsius to obtain molded rice ,after 24 to 48 hours these rice gives sweet taste and musty flavour.

• Starter inoculum of Saccharomyces cerevisae mixed with these molded rice in inoculation chamber with the addition of water.

• Brine fermentation of molded mixture is carried out by the addition of salt to obtain mash which is known as Moromi

• The fermentation of mash is carried out at 13 to 18 degrees Celsius for 2 to 3 weeks ,then settled ,filtered and blended. After this is pasteurised to obtain rice wine.