Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/6/2006
Publication Date: 4/11/2007
Citation: Pinnavaia, S., Baldwin, E.A., Plotto, A., Narciso, J.A., Senesi, E. 2007. ENZYME-PEELING OF VALENCIA ORANGES FOR FRESH-CUT SLICES. Proceedings of Florida State Horticultural Society. 119:335-339. Interpretive Summary: Oranges that are peeled using natural enzymes that digest the peel or infiltration of water without enzymes result in an easy-to-eat product. However, commercialization of this system has not been successful. One reason is that the enzyme keeps digesting the fruit tissue, making it softer and causing juice leakage. Another reason is the perception that this method of infiltration could result in higher microbial counts in the fruit tissue. This research tested some further treatments to both inhibit residual enzyme activity and reduce microbial loads as well as documenting the effect of enzyme peeling on softening and juice leakage. Results showed that juice leakage was minimal, and that even though the cut fruit slices were softer, they were preferred in an informal sensory evaluation. Microbial counts were not higher than with manual peeling.
Technical Abstract: In spite of the booming market for fresh cut fruit, fresh cut citrus has not been successful commercialized due to technical difficulties in peeling the fruit. The USDA and the FDOC have developed a process using enzyme infiltration under vacuum to facilitate citrus peeling. However, the enzymes (cellulase and/or pectinase) continue their lytic action on the slices after the peeling process, hence degrading the slices during storage. The objective of the present study was to investigate an acid solution (0.1 N HCl) rinse and cold conditioning (2 °C for 24 h) to slow down enzymatic activity after peeling of ‘Valencia’ oranges. In addition, the infiltration system was used to compare two commercial enzymes and water infusion. Quality factors including juice leakage, firmness, pH, titratable acidity and soluble solids were evaluated over three different harvests.