Pengujian aktivitas antifungi kitosan, nanokitosan, dan nanokitosan-Cu secara in vitro terhadap Colletotrichum gloeosporioides pada buah mangga (Mangifera indica)

Abstract

Colletotrichum gloeosporioides, a pathogen of anthracnose disease, can significantly reduce the quality of mango (Mangifera indica) fruits. Chitosan as an antifungal agent can reduce fungal growth on post-harvest agricultural products. In its development, chitosan has been widely improved through its transformation into nanochitosan and its formulation with metals. One of the metals that has a large affinity and can be formulated with chitosan is copper (Cu). This study aimed to compare and determine the optimal concentration of chitosan, nanocithosan, and nanochitosan-Cu in suppressing the growth of C. gloeosporioides that cause decay on mango fruits. The synthesis of nanochitosan and nanochitosan-Cu was carried out by the ionic gelation method, while the characterization was performed using particle size analyzer (PSA). The antifungal activity assay was conducted through the poisoning method by mixing 500, 750, and 1000 ppm (w/v) chitosan, nanochitosan and nanochitosan-Cu into the growth media of C. gloeosporioides. The results of PSA analysis showed that chitosan, nanochitosan, and nanochitosan-Cu had an average size of 606.5, 386.8 and 254.1 nm, respectively. The formulation of chitosan into nanochitosan and nanochitosan-Cu increased the fungal activity on C. gloeosporioides with the inhibition percentage of chitosan, nanochitosan, and nanochitosan-Cu at 750 ppm was 35%, 70%, and 100%, respectively.

Keywords

• ionic gelation
• poisoning food
• copper