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Importance of yeast

  1. Importance of Yeast
  2.  Bread Making: For the manufacture of bread, yeast is mixed with white flour, . The process of fermentation starts .The bread swells up and becomes spongy due to the pressure exerted by accumulated carbon dioxide Beneficial uses: 1) Food Industry
  3. Flavor and quality of bread is attained by selecting different strains of yeast
  4. Production of alcohol  Ethyl alcohol is manufactured by the fermentation of potatoes, cereals, molasses etc.  C6H1206 + Yeast zymase > 2C2H5OH + 2C02  (Glucose) Fermentation >(ethyl alcohol) + (carbon dioxide)
  5. Fermentation Breakdown of starch and sugar by yeast into carbon dioxide and ethyl alcohol in the absence of oxygen is called alcoholic fermentation. The alcohol is the major ingredient in brewing industry.
  6. Yeast as a source of Food  Yeast contains nutritive substances and proteins in sufficient quantities.  Dried yeast cells contain 40 - 50% of protein.  Some strains of yeast have considerable amount of fat.
  7. As Food Supplements Yeast as a source of Vitamins  with ultra-violet rays, they produce Vitamin - D  Yeast is used in the preparation of Vitamin - B complex tablets. When yeast cells are irradiated. endogenous ergosterol - to - ergocalciferol (Vitamin D2)
  8. 2) Use in Brewing Industry  Beer: Yeast is added to malted grains and allowed to ferment.  The type of yeast used will affect the type and flavor of produced.  Commonly used Yeast is S. cerevisiae, also known as a “top fermenting” or “top cropping” yeast.
  9. Use in Brewing Industry  Wine: Yeast is naturally present on the skins of grapes and can be used to naturally ferment grape juice into wine.  There are many different strains of S. cerevisiae and each produce a unique flavor characteristic in a finished wine.
  10. 3) Nutrition:  Yeast is a good source of protein, B vitamins, and minerals.  Yeast intended as a nutritional supplement is often sold as “nutritional yeast” or “yeast extract.”
  11. 4) Use in Medicine  Lowering high cholesterol. Research showed that taking a specific red yeast product for two to three months could significantly lower total and “bad cholesterol”  They are also utilized in medicine as a source of enzymes Monascus purpureus Red yeast rice
  12. Medical Use  Yeast causes Lowering of high cholesterol and triglyceride levels caused by human immunodeficiency virus (HIV) disease (AIDS).
  13. 5) Yeast and biotechnology:  Yeast belongs to traditional biotechnology  In the industry of fermentation, yeast is used not only in food industries to make bread, wine and beer, but also in non-food industries, such as the Biofuel industry, to produce ethanol.
  14. 6) Use in Molecular Genetics  Yeasts are Model organisms in genetics.  Used as Synthetic pathways for antibiotics or other molecules of interest .
  15. 7) Cleaning of Environment Yeast protects and cleans the environment by following ways: 1) Pollution cleanup 2) Waste recycling 3) Crop protection 4) Many Yeasts live symbiotically in organisms. 5) Bioremediation
  16. Disadvantages: 1) YEAST & WEIGHT LOSS Yeast infections can range in severity from minor discomfort to a life-threatening ailment, depending on your immune system, the type of yeast, the location of the yeast and the way you combat it
  17. 2 ) HAIR LOSS DUE TO RED YEAST RICE Red yeast rice is a culture of the yeast, grown on rice and consumed as food, may cause hair loss
  18. 3) Food spoilage  During their growth, yeasts metabolize some food components (sucrose, ethanol, acetic acid) and produce metabolic end products.  This causes the physical, chemical, and sensible properties of a food to change, and the food is spoiled.
  19. 4) Intoxication  Yeasts cause Intoxication of food and imbibed drinks
  20. 5) Resistant  Yeasts can tolerate very high temperature, hence difficult to check their reproduction
  21. 6) Plant Pathogens  Certain species of Yeast are plant pathogens and decrease crop production Magnaporthe grisea
  22. 7) Animal Diseases  Some species cause skin, hair and nail infections in humans e.g. Candida albicans  Yeasts cause respiratory diseases in humans e.g. Aspergilus

Notas del editor

  1. The yeasts have a lot of economic value to the mankind. They have certain beneficial as well as harmful activities.
  2. Zymase is a mixture of enzymes obtained from yeast which catalyse the breakdown of sugars in alcoholic fermentation.
  3. The active yeast is subjected to ultraviolet (UV) light under controlled conditions to catalyze the conversion of the natural occurring endogenous ergosterol in yeast to ergocalciferol (Vitamin D2). The yeast cream is then inactivated through pasteurization and roller dried. This process naturally enhances the content of vitamin D in the yeast and preserves the level of vitamins, minerals and other micronutrients from yeast. Vitamin D only occurs naturally in a small range of food comprising fatty fish, fish liver oils, meat liver and eggs. The principal function of vitamin D is to maintain intracellular and extracellular calcium concentrations within a normal range by regulating calcium and phosphorus metabolism in the intestine and bones and vitamin D is therefore widely recognized for its important role in the prevention of osteoporosis. Also growing evidence suggests that vitamin D also helps boost our immune system, reduce inflammation, and maintain muscle strength.
  4. (low-density lipoprotein (LDL)
  5. Used in Gene Therapy
  6. Mycoriza- fungi and plant roots Lichens – fungi and algae
  7. Magnaporthe grisea