Formulation and Evaluation of Ethanolic Extract of Black Fruit (Haplolobus sp.) Leaves and Chitosan-Tripolyphosphate Mixture as Antioxidant and Antibacterial Agents

This study investigated the mixture system comprising an ethanolic extract of black fruit (Haplolobus sp.) leaves and chitosan-tripolyphosphate (TPP), hereinafter called extract-chitosan-TPP mixture (ECTM), with a focus on its an antioxidant and antibacterial properties. The solution was prepared by adding the extract to the chitosan solution followed by the addition of TPP and then subsequent sonication. The resulting ECTM was centrifuged and then its encapsulation efficiency was determined based on the phenolic content using gallic acid method. The results showed that the ECTM particle size ranged from 190.7 to 496.8 nm with a polydispersity index of less than 0.5, which indicated that the suspension was homogeneous. The statistical results based on Taguchi method showed that the smallest possible size was 187.08 nm at a chitosan:TPP ratio of 0.2, extract concentration of 15% and ultrasonic time of 10 min. Encapsulation efficiency ranged from 75.45-80.43%. The antioxidant activity, expressed as IC50 values, ranged from 0.54 to 25.77, while the antibacterial activity was highest for sample E, showing inhibition of 15.63% against Staphylococcus aureus and 14.70% against Escherichia coli, relative to the antibacterial activity of chloramphenicol.