The Effect of Preparation Method on Anthocyanin Contents from Lpomoe Batatas (L.) Lam as Intelligent PH Indicator

Intelligent pH indicators have been gain interested in food industry as its acts as intelligent packaging where can be monitored and providing information and warning customer on the food condition in real time pH indicator. Calorimetric pH indicator used as indicator system in the packaging as in the most cases, pH changes can be detected when food deterioration occurs. However, the current pH indicator has lower colour changes and lower stability. In this research, new pH indicator was produced and have pronounced colour changes in wide range of pH that have higher stability to temperature and light from natural colorant sources. Two method of extract’s preparation was conducted to evaluate the effect of anthocyanin contents which is with or without steaming. The characterization was done by observing the physical appearance, total anthocyanin contents, UV-Vis analysis and colour response of anthocyanin to various PH solution. As the results, steaming of sweet potatoes preparation method was found able to produce dark purple colour with high value of total anthocyanin contents. Anthocyanin colour produced using steaming process results more intents colour at pH 1 to pH 13 compared to without steaming. These finding was supported with UV-Vis peak that showing different wavelength which corresponding to the various colour produced. The results obtained show the anthocyanin extracts is a promising component to be used as pH indicator since its stimuli responsive with the pH of the environments.