The potential of postharvest silicon dips to regulate phenolics in citrus peel as a method to mitigate chilling injury in lemons

Abstract

This study investigated the ability of silicon dips to enhance the phenolic content in order to reduce the incidence of chilling injury in lemon fruit. Fruits were obtained from two farms and dipped in 0, 50, 150 and 250 mg L^-1 solutions of K2SiO3 for 30 min and afterward, fruit were air dried and waxed. Thereafter, fruits were stored at -0.5°C and sampled after 28 days for evaluation of phenolic content and chilling injury symptoms. Chilling susceptible fruit sourced from Ithala farm had significantly lower phenolics and flavonoids concentration when compared with chilling resistant lemons from Ukulinga farm. Phenolic and flavonoids content was improved by dipping fruit in silicon for almost all the concentrations. Moreover, 50 mg L^-1 reduced the occurrence of chilling injury symptoms whilst high silicon concentrations increased chilling injury. In conclusion, silicon dips have an ability to reduce chilling injury symptoms in lemons; however, low concentrations should be used.

Keywords: Silicon, lemon, antioxidants, phenolics, chilling injury

African Journal of Biotechnology, Vol. 12(13), pp. 1482-1489