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Industrialization of Indegenous Fermented Food Process: Biotechnological Aspects. Prof. Dr. Ir. Sri Kumalaningsih, M.App.Sc Agroindustrial Technology – Brawijaya University. Introduction. 1.
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Industrialization of Indegenous Fermented Food Process: Biotechnological Aspects Prof. Dr. Ir. Sri Kumalaningsih, M.App.Sc Agroindustrial Technology – Brawijaya University
Introduction 1 • Some of these fermentation processes have been developed very successfully to commercial scale (e.g., cheese and yogurt amking, soy sauce and wine making) while others, such as tempeh and indigenous fermented beverages, offer scale process. • The advantages of this lie in more economic and standardized fermentation and in making the indegenous foods more commercially attractive and freely available to urban dwellers in developing countries and to a growing in the west • It is not envisaged, however, that such process developments will supplant the village and household level fermentations which will clearly continoue among low-income families
2 Comparison of Indigenous Fermentation Submerged Culture Solid Substrate Fermentation Slower fermentation due to slow growth of fungi on solid substrate Mixed fungal cultures predominated: relatively high biomass and enzyme concentrations. Relatively low levels of separation and agitation, the latter due to the shear sensitivity of filamentous and process control Scale-up problems due to limitations of heat and mass transfer and process control Process control more difficult due to three-phase (gas-liquid-solid), heterogeneous fermentation Final product obtained from SSF Process Possible problems due to contamination and mycotoxin production • Relatively rapid growth and product formation can be achieved by yeast and bacteria • Mixed or pure cultures of filamentous fungi, yeast, and/or bacteria at relatively low cell concentration • Aeration and agitation requirements can be high for aerobic cultures • Process scaled up readily to large fermenter volumes • Process control (Ph,temp., DO) relatively easy to achieve. Processes suited to computer control • Product recovery (e.g, cell separation, distillation) can be an imortant part of overall process
Comparison of Indigenous Fermentation • The practice of submerged culture is clearly much more developed technically with large-scale industrial process now existing for a wide range of product (e.g, ingle cell protein, yeast, amino acids, enzymes, antibiotic, recombinant DNA) from culture fermentations • Microbial growth and product fermentation occur in two a two-phase (gas-liquid) system. • By comparison, SSF process are more complex and involve three-phase interactions (gas-liquid-solid) as well as mixed microbial culture in many intances
SSF The kinetics of SSF are difficult also to describe due to the limitation in measuring: • Cell mass, consumption of substrates, product yield • Process variables In a heterogeneous system where substrate in a present as a solid.
Criteria for Bioreactor Design • In the industrialization of an SSF process it is fruitful to consider those factors which have been found critical in the choice of bioreactor design for commercial submerged culture.
Criteria for Bioreactor Design SSF are likely to differ from submerged processes on the following points: • Substrate choice and characteristics impinge on reactor design perhaps more than does the choice of microorganism • Due to current difficulties in measuring cell mass and product formation already discussed and in applying Monod Kinetic to Multisubtrate System • In the short term, genetic stability of strains used in indigeneous SSF will not modify the choice of bioreactor due to the use of predominantly wild-type strain • Hydrodynamics is a consideration in SSF bioreactor design in the sense that the moisture content • Aseptic equipment is less imperactive in SSF than submerged due to the selective conditions e.g, low pH, low water activity
Criteria for Bioreactor Design 6. SSF bioreactors need to allow for the control of temperature and moisture content of the substrate and for the provision of O2 7. Downstreaming processing is not a najor consideration in SSF bioreactor design indigeneous solid state food fermentation since product 8. For SSF bioreactor, the overriding issues of how to provide adequate heat and mass transfer dominate their design and operation. The availability of moisture and O2 and the removal of heat and CO2 are critical to the success of the fermentation 9. Most of the difficulties associated with large-scale solid substrate fermentation center on the problem of heat buildup, process control and scale up
Effect of water activity on the growth rate of selected fungi
Instrumentation Available for Fermentation Processes in Submerged Culture • Physical Sensor • Temperature • Pressure • Power Input • Foam Level • Gas and Liquid flow rates • Turbidity • Load Cells 2. Chemical Sensor • pH • Dissolved Oxygen Concentration • Dissolved CO2 Concentration • Exit gas analysis O2 CO2 Redox Potential
Instrumentation Available for Fermentation Processes in Submerged Culture
SSF The Variables which may be controlled in an SSF process are summarized as follows: • Temperature • pH • Moisture content • Composition of input gas (e.g, %O2 dan &CO2)