Inhibition of orange (Citrus reticulata ) green mold with anti-fungal yeast Debaryomyces hansenii and Aureobasidium pullulans

Abstract

Green mold rot is an important disease that generally affects post-harvest and storage oranges. The attack of this disease quickly causes a decrease in the quality and shelf life of citrus fruits during storage. Post-harvest handling of citrus fruit from green mold attack is generally by coating the fruit using synthetic fungicides so that the fungicide residue often sticks to the orange peel when marketed. Fruit protection with a protective material can be used to increase shelf life and maintain the quality or quality of fruit stored in a room without refrigeration. The use of yeast as a protective material for postharvest fruit is still a little developed. The yeast fructoplan D. hansenii and A. pullulans have anti-fungal properties, so they have the potential to be developed as fruit protective agents. The experiment objective to find out the yeast ability of fructoplan D. hansenii and A. pullulans to protect postharvest citrus fruits with different ripeness levels against pathogens of green mold, storage capacity and quality of citrus fruits. The study was conducted using a two-factor randomized block design with four replications. The first factor, the type of antifungal yeast treatment, consisted of 4 levels; namely treatment without yeast and pathogens as negative control; pathogen inoculation alone, without application of yeast as positive control; A. pullulans application treatment, and D. hansenii application treatment. The second factor was the level of maturity of the citrus fruit, consisting of 3 levels, namely 25% yellow, 75% yellow; and 100% yellow. Measurement variables included disease severity, intensity of green mold rot, fruit storage time, weight loss, fruit hardness, vitamin C content, and total dissolved solids. The results of the experiment proved that the coating treatment of citrus fruits with yeast D. hansenii and A. pullulans was able to maintain the quality of oranges, increase shelf life, and increase the resistance of oranges to post-harvest diseases without reducing the quality of citrus.