Abstract

This study observed the antifungal activity of crude coffee extract (CCE) and crude spent coffee ground extract (CSCGE) against Aspergillus, Penicillum and Eurotium on the surface of an areca palm leaf sheath (Areca catechu). The extraction of CCE and CSCGE could be performed twice to obtain extracts containing aromatic compounds such as caffeine capable of inhibiting mould growth on an areca palm leaf sheath.This study observed the antifungal activity of crude coffee extract (CCE) and crude spent coffee ground extract (CSCGE) against Aspergillus sp., Aspergillus flavus, Aspergillus niger, Penicillum citrinum, Penicillum chrysogenum and Eurotium amstelodami on the surface of an areca palm leaf sheath (Areca catechu). The agar dilution method was employed to determine the minimal inhibitory concentration (MIC) of the CCE for the first, second and third extractions and CSCGE for the first and second extractions in malt extract agar at concentrations from 50 to 500 μg/ml. A mould test was then performed on durian paste product wrapped with the areca palm leaf sheath treated with the second CSCGE at its MIC. Gas chromatography-mass spectrometry (GC-MS) was performed to find the major components of the CCE and CSCGE and to measure the total phenolic content. For the second CSCGE treatment on the areca palm leaf sheath, the following qualities were studied: mould growth, wettability, measurements of hardness and thickness and a Fourier transform infrared spectroscopy scan. It was found that the CCE and CSCGE MICs from the first and second extractions ranged from 100 to 230 μg/ml and from 300 to 460 μg/ml, respectively. In addition, the MICs showed the capability of CCE and CSCGE to provide protection against mould growth on the leaf sheath for at least 21 days in comparison with the control (3 days) during storage at accelerated conditions (25 C and 100% relative humidity). Shelf life of durian paste product wrapped with areca palm leaf sheath treated with the second CSCGE at 460 μg/ml was extended from 3 days to 21 days under storage condition of 30 C. Caffeine was the main constituent of CCE (79.69%) and CSCGE (84.92%). Also, the total phenolic content of CCE and CSCGE measured were 0.640 and 0.981 mol ferulic acid 100 g^-1, respectively. This study has demonstrated that the first and second CCE and CSCGE were capable of inhibiting mould growth under both in vitro and in vivo tests.