Design and performance assessment of a flat-plate solar milk pasteurizer for arid pastoral areas of kenya
Journal of Food Processing and Preservation
National Arid Lands Research Centre, Kenya Agricultural Research Institute, PO Box 147, Marsabit 60500, Kenya; Department of Food Science, Nutrition and Technology, University of Nairobi, Nairobi, Kenya
A solar milk pasteurizer consisting of flat-plate water-heating collector and a 1.5-mm thick stainless steel cylindrical milk vat was designed and tested in an arid pastoral area of northern Kenya. The milk vat had a capacity of 80L and a 50-mm wide hot water jacket insulated with 38-mm thick fiberglass. Hot water produced by the collector was used for pasteurizing milk. The optimum quantity of milk that could be pasteurized by this device under the study conditions was 40L, and the average temperature difference between hot water and milk being pasteurized was 8.1±1.4C. Total bacterial counts in pasteurized milk were less than 10cfu/mL while coliform counts were negative. This low-cost solar milk pasteurizer is appropriate for arid pastoral areas without grid electricity, where milk marketing is an important income source, and where most of the milk is boiled using firewood. © 2012 Wiley Periodicals, Inc.
Flat plate; Grid electricity; Income sources; Marketing IS; Pasteurized milk; Performance assessment; Temperature differences; Total bacterial count; Water; Pasteurization; Bacteria (microorganisms); Lycium andersonii