Effect of microwave treatment on the quality of the Averrhoa bilimbi

Abstract

Averrhoa bilimbi which commonly known as bilimbi is belongs to the family of the Oxalidaceae. A. bilimbi is less commercialize compare to the A. carambola because of the taste of this fruits is too sour. A. bilimbi has been categorized to be rich in oxalic acids, phenols, vitamin C, tannins and minerals. In this study, microwave energy to facilitate partition of analyses fr om the sample matrix into the solvent. The specific parameter (power, time and ratio of solvent) of the microwave treatment would affect the quality of A. bilimbi extract. Therefore, this study was conducted using a modified microwave assisted extraction method. The modified microwave was not changed the microwave properties. The optimum parameter of mid crowave treatment on the quality of A. bilimbi was analyzed using Box-Behnken method under design of experiment to evaluate the parameters based on the selected range and limitation. Vitamin C, total phenolic content (TPC) and total flavonoid content (TFC) were evaluated to determine the quality of the A. bilimbi. The vitamin C contents were carried out by the titrimetric method with 2, 6-dichlorophenolindophenol (DCPIP) reagent. The TPC was analyzed using Folin-Ciocalteau assay and the TFC was carried out using aluminum chloride colorimetric assay. The optimum for time was 3 min, power was 20 W and sample to solvent ratio was 1:3. The validation process occur by using optimum parameter that given by Box-Behnken. The predicted and experimental value was compared by using optimum parameter for the validation process.