(D)  Methodology:

This being the kind of exploratory research, flexible wide ranging and versatile research approach was adopted. This covered reference to all possible secondary sources ad primary sources. It has been summarized as follows:

• All possible books, Journals & seminar proceedings on this subjects like Cryogenic Technology, storage & presentation of food/fish/drug & milk, rural technologies and published data, of the products were referred.
• A list of equipments, accessories manufacturers Worldwide was prepared from the trade directories as well from mentions in Journals.
• Correspondence as made with 100 Concerns & 40 of then were contacted to get their further information & views on the technology application.
• Initial rapport was established with agencies like Indian Cryogenic Council, All India Gas Manufacturers Association, Food Preservers Association, Marine Products & Export Development Agency etc. to understand and shortlist key respondents for personal interviews.
• About 46 persons were interviewed in depth who are associated with the subject. These respondents were from Bombay, Calcutta, Vishakapattanam, Bangalore, Pune, New Delhi, Karnal & Anand etc.
• Simultaneously we received responses form 6 persons to our mailed questionnaires.
• Focus group discussion was conducted in Bombay amongst 10 experts representing specific dimensions.
• A second round of personal interviews was made with select experts at Bombay & Calcutta to discuss preliminary research findings and have more in depth discussions.
• In order to ascertain views on the recommended action plan, all short listed Institutions were mailed approach for suggested research.
• Observations & experimental data was obtained from the select installations currently in operation in India.
• All the information obtained was compiled, analyzed and the report was presented to TIFAC.
• After the receipt of comments from TIFAC on the draft all further information was collected, complied, collated and final report was submitted in January 1991.

(E)  Findings:

The critical finding of this study are as follows:

i) Amongst the various ramifications of Cryogenic Technology the use of cryogenic fluids like Liquid Nitrogen and Carbon-Dioxide appears as the possible route for the technology application for the subject of this report in the near future.

ii) It can be construted as a distant possibility of using effects on materials at low temperature or magnetic cooling for cooling down temperature of large volumes in economical way by avoiding the use of CFC’s. However, on international level at this stage Cryogenic Technology is not considered as a substitute for CFC’s.

iii) For none of the products the preservation and storage is desired at cryogenic temperatures but the use of liquid nitrogen is found as a superior method of lowering the temperature to near 0C and maintaining for products such as Shrimps, Prawans, Lobsters, Cherries, Lichees, Ice-creams and prepared airline (Flight Kitchen) food dishes.

iv) In India under the current situation it is not economical and technically feasible to use Liquid Nitrogen for low cost food items like Vegetables, Fruits, Milk etc. but it can be used for marine products and select fruits like Cherries, Lichees etc. at village level. It is desired to use this technology for processing of high value marine products to avoid dehydration and drip loss.

At urban centers, it is possible to increase its usage for distribution of ice-creams and in airline flight kitchens for storage of prepared dishes.

v) Milk preservation has been found to be much economical by Ammonia Refrigeration & transportation in insulated tanks. At village level no significant application for milk storage is possible even though the Animal Husbandry department have established utility of Cryogenic fluid for semen preservation.

vi) At village level, conventional refrigerator or solar coolers are found to be the most economical for drug storage. Cryogenic technology can complement drug storage facilities if cryo-batch coolers are established for animal or marine products.

vii) The use of Liquid Nitrogen for various other products needs creation of experimental data about its suitability and design parameters for equipment.

None of the Cryogenic research establishments in the country have done any substantial work in this area and it is desired to take up such projects in collaboration with commodity bodies.