Study of Terigas Tangerine Degreening Originate from Sambas Regency of West Kalimantan

Abstract

Terigas tangerine peel is still green even when it has reached acceptable internal maturity, meanwhile the green peel indicated immature fruit. Improving tangerine uniform yellow peel will also improve its aesthetic quality and price which could be taken by ethylene degreening technique. The objectives of this research were: (1) to study the ethylene concentration and trigger time of Terigas tangerine (Citrus nobilis var. chrysocarpa) degreening process, (2) to investigate influences of degreening on physicochemical and organoleptic changes of Terigas tangerine, (3) to determine the best ethylene consentration and trigger time of Terigas tangerine degreening process. Initial tangerine quality were analyzed before the tangerine were arranged inside box layered by LLDPE 0.06 mm plastic. After that the plastic was closed with the top of box remained open. Each box contained of 3 kg tangerines which finally exposed by 1000, 1500, and 2000 ppm of exogenous ethylene and without ethylene (control), with trigger time for 10, 20, and 30 hours. Soon after each trigger time was reached, the plastic was then opened and tangerines were placed at room temperature until their peel turned to be yellow. After that, quality of tangerines were analyzed which consisted of color changes, firmness, juice misture content, pH value, vitamin C content, total of chlorophyll and carotenoid, total soluble solid, and organoleptic. Results of the research showed that ethylene enhanced color of tangerine, increased total of carotenoid, and decreased total of chlorophyll. However it did not affect internal quality such as moisture content, firmness, total soluble solid, and vitamin C. Postharvest degreening also increased panelists preference of tangerine external color, nevertheless it did not affect sweetness, texture, and aroma of Terigas tangrine. The best treatment was 1000 ppm ethylene with trigger time for 30 hours. Uniform yellow peel of Terigas tangerine occured on the fourth day of storage at room temperature.