Submitted to: Florida State Horticulture Society and Citrus Industry
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2006
Publication Date: 6/4/2006
Citation: Pinnavaia, S., Plotto, A., Baldwin, E.A., Narciso, J.A. 2006. Enzyme-peeled oranges for fresh-cut slices. Florida State Horticulture Society and Citrus Industry. Paper No. 41.
Technical Abstract: Oranges can be satisfactorily processed for fresh slices using a process of enzyme infiltration under vacuum. Scored ‘Valencia’ and ‘Hamlin’ oranges were placed under 90 kPa vacuum in a 0 ppm (water-infused) or 1000 ppm enzyme solution (Ultrazyme) at 30 °C for 2 min, followed by 30 min incubation in air. Peel was then removed, peeled fruit were washed, blotted dry, cut, and slices were then dipped in water or 1% citric acid (CA) for 2 min. Drained slices were then placed in 16 oz deli containers and stored at 5 °C for up to 21 d. One additional treatment involved vacuum infiltrating scored oranges in 1% CA, without further dipping the cut slices. All ‘Valencia’ slices had <1.0 log10(cfu/g) after 7 d storage, and fruit infused without enzyme but with CA had <1.0 log10(cfu/g) after 21 d storage. For ‘Hamlin’, CA controlled bacterial growth on slices from water-infused oranges, except at 14 days. Enzyme-infused oranges resulted in slices with lower counts in both experiments. CA –treated sliced (post enzyme treatment or by infusion) had higher titratable acidity initially (‘Hamlin’) and after 14 days (‘Valencia’). When presented to a taste panel, ‘Valencia’ slices from enzyme-peeled fruit were preferred for texture after 2 and 8 d in storage. In contrast, slices from fruit infused with water or citric acid were least preferred, were firmer, and had thicker membrane. Appearance of enzyme-treated fruit was preferred for ‘Hamlin’ oranges. Enzyme or CA treatments did not affect overall flavor of ‘Valencia’ or ‘Hamlin’.