Calcium as an Adjuvant for Spray-Drying Acid Whey

Abstract

Cottage cheese whey was treated with calcium compounds to reduce sticking in dryer box and cyclone while spray drying (inlet air of 178 to 180 C; exit air of 70 to 74 C). Concentrated whey (22 to 24% solids) neutralized to pH 6.0 with an aqueous suspension of 4% calcium oxide (wt/vol), dried easily, but it was chalky, bitter, and stringent with a high solubility index. The neutralized whey was clarified with desludging centrifuge to remove insoluble calcium salts. This greatly improved flavor, decreased solubility index, increased product clarity upon reconstitution, decreased ash content, and reduced wear on drying equipment. The precipitate formed from calcium addition occupied up to 20% of the bowl volume and reduced yield of protein during clarification. In addition, the protein content of the powder also was reduced. Samples neutralized to pH 5.5 with calcium oxide plus .05% calcium chloride and samples containing only .3% calcium chloride dried more easily than control, but some caking occurred in cyclone. Although clarification of these latter samples improved the solubility index and flavor, they were unacceptable due to bitter and astringent flavors. © 1978, American Dairy Science Association. All rights reserved.