Effect of antioxidants and pH on browning and firmness of minimally processed eggplant
Author
Uscanga-Sosa, Diana P.; Pérez-Gago, María B.; Gómez-Merino, Fernando C.; Herrera-Corredor, José A.; Hernández-Cázares, Aleida S.; Contreras-Oliva, AdrianaDate
2020Cita bibliográfica
Uscanga-Sosa, D. P., Pérez-Gago, M. B., Gómez-Merino, F. C., Herrera-Corredor, J. A., Hernández-Cázares, A. S., & Contreras-Oliva, A. (2020). Effect of antioxidants and pH on browning and firmness of minimally processed eggplant. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 48(1), 79-89.Abstract
Minimal processing of eggplants (Solanum melongena L.) generates a rapid onset of enzymatic browning,
tissue softening and water loss that limits their shelf life. The aim of this study was to evaluate the effect of 1%
ascorbic acid and 2% calcium ascorbate in aqueous solution at natural pH of the antioxidant (pH 2.6 and 7.8,
respectively), or adjusted to pH 5 with generally recognized as safe substances, to maintain the quality of
minimally processed eggplant stored at 5 °C for 6 d. Water was used as a control. The colour, firmness,
polyphenol oxidase activity, and visual quality was evaluated in the freshly cut fruit at 3 and 6 d of storage. No
effect of the treatments on firmness or polyphenol oxidase activity was observed. At 3 d of storage, a correlation
was observed between polyphenol oxidase activity and the visual evaluation of the cut product. Samples treated
with 2% calcium ascorbate and the rest of the treatments at pH 5 had a lower browning index than those treated
with 1% ascorbic acid and the control. At the end of the storage period, the visual quality of the eggplant
samples treated with 1% ascorbic acid at pH 5 was evaluated above the marketing limit, whereas those treated
with 1% ascorbic acid at pH 2.6 had the lowest quality indicators. An adjustment to pH 5 helps to preserve the
luminosity and visual quality of the eggplant, however firmness was not affected by calcium ascorbate or the
pH of the medium.