Penentuan Kondisi Operasi Optimum Proses Ekstraksi Zat Warna Alami Dari Daun Senduduk (Melastoma malabathricum) Serta Penentuan Jenis Dan Konsentrasi Pengawet Ekstrak

Senduduk (Melastoma malabathricum) is a common wild plant found in shrubs. This plant has the potential to be a natural dye source, as its leaves contain tannins, flavonoids, saponins, anthocyanins, and carotenoids. The use of natural dyes in textiles needs to be massively enhanced to reduce the negative impact of synthetic dyes on the environment. This experiment aims to determine the optimum operating conditions for extraction and to determine the effective concentration of preservatives to inhibit biodegradation reactions in natural dye extracts from Senduduk leaves. Variables observed in the extraction process include time, temperature, and the ratio of the weight of the material to the solvent. The content of natural dyes in the extract was analyzed using gravimetric methods. The optimization of natural dye content with time, temperature, and the ratio of the weight of the material to the solvent volume was performed using Response Surface Methodology (RSM) with the Box-Behnken model. To determine the concentration of preservatives, chitosan and tannic acid were added to the natural dye extract, and storage was conducted for 20 days. Every 2 days, the extract was taken for analysis of natural dye concentration using gravimetric methods. The results of the study indicate that the optimum operating conditions for extraction were 45 minutes of time, 90°C temperature, and a ratio of the weight of the material to the solvent volume of 1:10 g/mL resulted in a natural dye content of 19.164%. The most effective preservative used to preserve natural dye extracts from Senduduk leaves is 0.50% tannic acid.