Basic principles of food fermentation

food technology

1. Basic principles of food fermentation Anchal F.T, 18/ A

2. Fermentation It refers to a metabolic process in which organic compounds ( particularly carbohydrates ) are broken down to release energy without the involvement of a terminal electron acceptor such as oxygen . or It is the term used by the microbiologists to describe any process for the production of a product by means of the mass culture of a microorganisms.

3. Products can either be : The cell itself : refered to as biomass production e.g spirullina Microorganism own metabolite : refered to as product from a natural or genetically improved strains e.g. Amino acids, lipids, carbohydrates, vitamins, co-enzymes, antibacterial agents, antifungaletc Microorganism foreign product : refered to as product from recombinant DNA technology on genetically engineered strain that is recombinat strain e.g. Human therapeutics, Enzymes, Amino acids . (Brian Pumphrey New Brunswick Scientific (UK) Ltd and Christian Julien New Brunswick Scientific Benelux BV,The Netherlands)

4. APPLICATIONS OF FERMENTATION In the production of organic solvents such as citric and lactic acids Production of foods and food products such as ogi, fufu, gari e.t.c Production of condiments such as iru Production of dairy products such as yoghurt, butter milk, sour cream In processing of meat and fish to refined products like sausages, cured harms, fish sauce In production of beverages and related products such as beer, ale, vinegar, palmwine e.t.c In pharmaceutical industries for producing compound such as antibiotics and vaccines in food supplement production such as production of single cell protein, amino acids,vitamins In production of organic solvents e.g acetone, butanol ethanol e.t.c

5. The main advantages of fermentation as a method of food processing are: The use of mild conditions of pH and temperature which maintain (and often improve) the nutritional properties and sensory characteristics of the food . The production of foods which have flavours or textures that cannot be achieved by other methods Low energy consumption due to the mild operating conditions Relatively low capital and operating costs Relatively simple technologies .

6. The component parts of a fermentation process Microorganism Bioreactors Type of fermentation process Consideration of factors that control the growth of m.o . in food fermentation. Sterilization of medium, fermenters/bioreactors and ancillary equipments . Growth of organism in the production fermenter . Extraction and purification of the product . Disposals of effluents produced by the process. ( principals of fermentation technology, P.F. Stanbury et.al.,)

7. Knowledge of nutritional requirements Knowledge of environmental requirements (incubation temp, O2 requirement) M/Os must be removed from natural environments and cultured in lab. Separation techniques required Isolation of pure culture of one type of M/O M/O of interest must be separated from all other bacteria in the environmental sample. All media, lab supplies must be sterile. Once a pure culture is achieved, no contaminating M/O can be introduced. Aseptic techniques Techniques for storage of pure cultures Techniques are needed that facilitate working with pure cultures. Microorganisms

8. Isolation Techniques Isolation of Discrete Colonies from a Mixed Culture Spread Plate Method Streak Plate Method Pour Plate Technique Isolation of Pure Cultures from a Spread Plate/Streak Plate Preparation Aseptic Transfer Techniques

9. Bioreactors/Fermenters

10. Submerged culture fermenters Stirred tank fermenter Bubble column Airlift fermenter Fluidized bed fermenter Trickle-bed fermenter Tray fermenter Static bed fermenter Tunnel fermenter Rotary disc fermenter Rotary drum fermenter Agitated tank fermenter Continuous screw fermenter Solid state fermenters

11. Types of culture systems

12. Factors that control the growth of m.o. in food fermentation Intrinsic factors Nutrient content Substrate pH Antimicrobials Redox potential Water activity Extrinsic factors Storage temperature RH of environment Presence of other m.o .

13. References http://lecturenotesfree.blogspot.in/2013/03/fermentation.html principals of fermentation technology, P.F. Stanbury et.al., FOOD PROCESSING TECHNOLOGY Principles and Practice Second Edition, P. Fellows https://www.researchgate.net/publication/225946883