Ultrasound-Assisted Anthocyanins Extraction from Purple Cabbage for Optical Biosensor of Wound Healing Monitoring

The ethanol-water based extraction of phenolic bioactive components, anthocyanins, from purple cabbage (PC) was carried out. Ultrasound assisted extraction was performed and each cycle was set to 3 minutes. UV-visible absorbance was evaluated at each cycle (total 3 cycles) and the intensity of absorbance at 546~550 nm was interpreted as the extraction efficiency of anthocyanin. The pH sensibility of PC extracts was evaluated at pH 4, 5, 6, 7, and 8 and measured with UV-Visible spectrometry. Each pH condition, the extracts presented different color shades and wavenumbers of maximum absorbance proving their pH sensibility. Antioxidant activity of PC extract was evaluated and the excellent inhibition capacity was observed (~98%). PC extract was then embedded in alginate membrane to use as wound dressing materials. Alginate membrane with PC extract also presented high pH sensibility showing remarkable color changes after exposure to different pH environments.