Using Anthocyanin Extracts from Butterfly Pea as pH Indicator for Intelligent Gelatin Film and Methylcellulose Film

Among variety of intelligent food packaging, pH indicator packaging is becoming more popular, which can be made from synthetic and natural compounds. The search for natural pH indicator dyes that can be used in intelligent food packaging systems has recently focused on anthocyanins extracted from plants. Thus, this work aimed to develop and characterize an intelligent tag for pH indicator based on gelatin and methylcellulose-film with butterfly pea extract (BPE). The results showed that the colors of BPE solutions had a tendency to change from red to blue in a pH range of 4.0 to 8.0. The maximum absorption peak moved to a higher wavelength was observed at around 627 nm at pH 8.0 and shifted…