Lemon Products Division, Sunkist Growers, Inc., Corona, CA
Jelly-grade Pectin


Pectin, from lemon rinds, is both hygroscopic and heat sensitive. If heated over 150°F, there is loss of grade, and over 180°F, there is a loss of gelling strength. Over-drying produces undesirable odors. The former drying method was batch drying in a rotary vacuum unit that required constant supervision by several operators to ensure quality. The process was relatively slow, power requirements were considerable, and the processing generated an undesirable amount of air pollution. The two replacement TURBO-DRYER® are 9.5 ft dia x 15 ft high with 28 trays. Operating temperature IS below 150°F. First dryer removes all the isopropyl alcohol and most of the water, reducing 65% volatiles to 25%. Metered-in nitrogen prevents oxidation and prevents fires and explosions. The water-alcohol mix is condensed and recovered in a receiver; the drying gas is recirculated through a steam heater. The second dryer removes water only and uses filtered, heated air as the drying medium. Cost savings due to grade improvement are estimated at 50¢ per Ib, approximately $90,000 per year. Only one operator is required; automatic controls replace constant monitoring. Drying time and power requirements are reduced by 50%. Air pollution, secondary dust collectors and subsequent re-blending facilities are eliminated.


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