Extraction Techniques

Depending upon need and quantities of material to be handled, different extraction techniques are used in food industries. Some popular extraction techniques are
1. Single stage batch extraction
2. Multi stage cross flow extraction
3. Multi stage counter current extraction

1. Single stage batch extraction:
It is a batch extractor in which the solids are brought in contact with adequate quantity of solvent so as to leach out the solute from solid into the solvent. The process can be accompanied with heating or stirring as the process demands. When the extraction process reaches equilibrium, the solution is decanted and excess solvent from the solution is removed to obtain pure solute. Example; brewing tea or coffee, extraction of oleoresins. Read more

Preservation and Maintenance of Industrially Important Cultures

Microorganism for the production of industrially important products are useful only if they can be maintained indefinitely in healthy, pure and genetically stable form. Industrial culture collection consists of stock culture. Stock culture may be simply defined as a culture which serves as source of inoculum. Stock cultures are of two types.
1. Working stock culture: Working stock culture: This culture is maintained at vigorous and uncontaminated condition. Since this culture is used frequently, it must be routinely checked for characteristic feature and contamination.
2. Primary stock culture: This culture is kept for long term storage and are maintained at low physiological activity condition. The cultures are used to produce new working stock culture as per need. Read more