Berry and Froscher: Foam-mat and Freeze Dried

Cold pressed peel oil was added to high quality 50°Brix commercial orange concentrate and foam-mat dried, or diluted to single strength juice and freeze-dried using different platen temperatures. Amounts of peel oil ranged from 0.026% to 0.106% for samples to be foam-mat dried, and from 0.011% to 0.109% for freeze drying. For foam-mat drying, previously de veloped standard commercial conditions were used and for freeze-drying, samples were pre pared using different platen temperatures. Among the foam-mat dried samples, that to which the lowest oil had been added yielded 62% retention in the dried product. The sample to which 0.054% oil had been added yielded 56% retention and the sample to which 0.106% oil had been added retained 73% in the dried product. Among the freeze-dried samples, proportions of retained oil were higher in powder prepared from concentrations with the highest initial oil levels. With a given initial oil level, although variable, there was no consistent difference in oil retention between samples dried at different platen temperatures so long as they did not melt. In the freeze-dried samples, COD of volatiles ranged from 19 to 28% of original values, while only 7% were retained in foammat dried samples.