Submitted to: Florida State Horticultural Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 23, 2010
Publication Date: N/A
Technical Abstract: ‘Valencia’ and ‘Hamlin’ oranges were juiced using one of three treatments: fresh squeezed (F), fresh squeezed then pasteurized (FP) or commercially processed/pasteurized (CPP). Headspace volatiles, secondary metabolites, total phenolics, sugar and acid contents were measured right after processing and after 4 days storage at 5 °C, and juice was evaluated by a sensory panel. Cloud loss was monitored during 14 days at 30 °C. Because of the juicing processes, F and FP juice contained 4-8 times higher peel oil in ‘Hamlin’ and ‘Valencia’, respectively, in comparison with CPP. F and FP juices had more stable cloud particles and less insoluble solids than CPP juice. For volatile components in ‘Valencia’ juice, F and FP juices contained higher esters including ethyl acetate, ethyl butyrate, and ethyl hexanoate aldehyde, and peel oil related volatiles such as a-pinene, linalool and octanol. On the other hand, acetaldehyde, octanal, a-terpineol and most terpenes including sabinene, myrcene, a-terpinene and valencene were higher in CPP juice. Total sugar (°Brix) was similar in all samples, however, CPP juice had higher contents of citric, malic and ascorbic acids, followed by F and then FP juice. F and FP juices contained lower levels of flavonoids, limonoids, and alkaloids, but had higher levels of limonin glucoside. The sensory panel perceived the CPP juice to have less peel oil flavor, agreeing with the low peel oil content. There was no significant difference in sensory data for overall preference among the three juice types in both cultivars.