Fungal Metabolism.pptx

Fungal Metabolism

1. Fungal Metabolism (Reference to Food and Beverages ) Amjad Khan Afridi Lecturer, Department of Health & Biological Sciences Chapter # 07

2. Introduction Fungi metabolism consists on a series of reactions ( biochemical reactions) constantly occurring inside the cells to keep it alive and active and in the results biosynthesis of a huge number of compounds . These compounds area usually divided into primary and secondary metabolites . Primary metabolism is common to several species and usually produces compounds with the function of assuring fungi growth and development. Primary metabolites are involved in the growth, development, and reproduction of organisms.  The primary metabolites consist of vitamins, amino acids, nucleosides and organic acids

3. Cont … Secondary metabolism refers to the production of compounds that are not indispensable during fungi development . Secondary metabolites are commonly referred as "natural products“ and have been extensively utilized in the pharmaceutical, cosmetics and food industry. Alkaloids, steroids, antibiotics, gibberellins, and toxins are the secondary metabolites.

4. Cont … The metabolism of filamentous fungi is capable of producing numerous secondary metabolites that can used for the development of functional foods, nutraceuticals, and bioactive substances that can be used as medicines. Fungal metabolism is usually fast and the scale up is usually easier than in some other processes. 

5. Cont … The use of the term  food-making process   is used here to mean those food products that require the aide of fungi in their production. For example, the one with which you are most familiar is baked bread . The yeast is utilized in making the dough rise so that bread will come out light and fluffy. Without yeast, bread would be much denser and harder.

6. Moldy Cheeses Although the sight of mold in food is a sign that it is contaminated and should be discarded, there are some foods in which the presence of visible fungal mycelium is very much a part of the product. Among these are some of our cheeses. Two of the most familiar examples are Camembert and Roquefort, also known as blue cheese.

7. Cont … These cheeses are among the favorites among gourmets. These cheeses are made from two species of  Penicillium  ( P. camemberti & P. roqueforti )   Camembert cheese prepared with P. camemberti while Roquefort cheese prepared by  P. roqueforti .  

8. Roquefort cheese In making Roquefort cheese, in Roquefort,  P. roqueforti  is added to the cheese made from sheep's milk. The cheese is salted and holes made throughout the cheese for aeration, and left for several days. The cheese is then allowed to age for two to five months. Americans like the cheese to be new and mild, while the French prefer it to be very old and strongly flavored.

9. Camembert cheese Camembert cheese is quite different in appearance. The fungus involved in the manufacture of this cheese is  Penicillium camemberti . The mycelial growth of this species occurs only on surface of the cheese and does not work its way inside to form veins as in  P. roqueforti . Fable has it that the process for making this cheese was a relatively recent. It's creation has been credited to Marie Harel , in 1791, a native of the tiny village of Camembert, in Normandy. 21 st April, 2022

10. Shoyu (soy sauce) Shoyu (soy sauce) is probably the most familiar Asian food product in this country, but probably few people know how it is made. All of you probably are aware that it is made from soybeans. The soybeans are cooked mixed with wheat flour, pressed into cakes, and placed in a special room where it is inoculated with  Aspergillus oryzae   (the same species used in making saki ). The mixture is then incubated for three days. If all goes well the cakes will become covered with yellow mycelial growth. 25 th May, 2022

11. Koji The molded cake is referred to as Koji, which is a fermentation product of grains. The koji is now mixed with salt and water and is now referred to as the  Moromi . The moromi is then inoculated with a bacterium,  Peiococcus soyae , which will ferment the mixture for approximately 6 months. The aged liquid which is pressed out is the soy sauce. Because it is a fermentation product, soy sauce does not spoil when left out.

12. Miso Miso is a Japanese word for fermented soybean paste. Miso is not usually consumed by itself, but is dissolved in water as a base for soup or used as a flavoring agent. Miso fermentation consists of washed, polished rice, which is steamed and inoculated with  Aspergillus oryzae . The inoculated rice is incubated for 48 to 50 hours at 40 C or below, resulting in rice koji.

13. Cont … The carbohydrates and proteins of the inoculated rice are digested by the fungus and converts it to sugars and amino acids. The rice koji is then inoculated by yeasts and bacteria and allowed to ferment for about a week at 28 C and then raised to 35 C for about seven months.

14. THANK YOU 16 25 th May, 2022