Resumo

MATERANO, Willian et al. Evaluation of the effect of postharvest protectors in orange juice over the time. Agronomía Trop. [online]. 2007, vol.57, n.2, pp.129-136. ISSN 0002-192X.

The objective of this study was to evaluate the effect of the Primafresh^® wax and cover with polyvinyl policloruro (PVC) of 32 microns of thickness in the content of total carotenoids and the parameters of color (L., Chroma and Hue) of the juice, during the period of commercialization, of 'Valencia' orange fruits, Citrus sinensis L. Osbeck, stored under refrigeration. A group of fruits was submerged in Primafresh^® at the original concentration of 20% and placed in polypropylene trays. Another group was placed in polypropylene trays and covered with PVC. No treated fruits were used as a control. The fruits were stored at 8 °C (±0,5 C), 80-85% HR during 21 days, and the lost of weight, total carotenoids, and color were evaluated at intervals of 7 days. The treatments with covering reduced the lost of humidity (1.22 and 1.11% for Primafresh^® and PVC respectively), and there was a lower lost of weight of the fruits, while in the control group there was lost of humidity of 5.17%. It was found a rate of change of carotenoid concentration of 0.4426 mg l^-1 day^-1 for the control, and of 0.2605 and 0,1991 mg l^-1 day^-1 for the tratments with Primafresh^® and PVC respectively. Moreover, the rate of change of the color was 0.1085 units of Chroma by day^{-1 in the control treatment, and 0.0564 and 0.0480 units day-1} for the tratments with Primafresh^® and PVC. The study shown that the use of Primafresh^® wax and PVC covers influenced the changes of color and carotenoid content of the orange.

Palavras-chave : Orange; Citrus sinensis L; Primafresh^®; PVC; waxes; carotenoids; quality.