ANALISA STABILITAS ZAT WARNA PADA EKSTRAK KULIT BUAH NAGA MERAH MENGGUNAKAN SPEKTROFOTOMETER (Analysis Pigment Stability on Red Dragon Fruit Skin Exstracts Using Spectrophotometer)

Abstract

Red dragon fruit skin (Hylocereus polyrhizus) contain anthocyanin pigment potential as natural dyes. Anthocyanins are pigments that are soluble in water, anthocyanin pigment classified into benzene derivatives. Anthocyanins are one important part of the group after the pigment chlorophyll. Anthocyanins produce color from red to blue. Anthocyanin extraction is done using the solvent water and the addition of citric acid. Comparison of the number of samples with the solvent of 1: 1, in cases where 100 ml sample is dissolved in a solvent 100 ml distilled water. Based variable heating temperature and acidity, color stability a decrease at high temperature occurs because of damage to the chromophore group anthocyanin pigments that cause the degradation of dyes as susceptible to changes in temperature, while decreasing the color stability at acidic pH due flavilium red cations hydrated becomes colorless carbinol so The resulting color is becoming increasingly fadedresults obtained on the dye anthocyanin extract from the bark of the red dragon fruit is stable at pH 5 with stability against temperature resistance heating at 40 o Keywords: Anthocyanins, Dye stability, Red dragon fruit skin