Edible pH sensor based on immobilized red cabbage anthocyanins into bacterial cellulose membrane for intelligent food packaging

An edible pH sensor has been developed based on anthocyanins of red cabbage (Brassica oleraceae var capitata L.) (ARC) immobilized on a bacterial cellulose (BC) membrane. The polivinyl alcohol (PVA) (1%) was added into the membrane to reduce swelling and water solubility. The edible pH sensor exhibited a various distinctive colors from red to purple, blue‐gray, and then to yellow in the pH range (pH 1–14), with good linearity between pH 1–6, and pH 8–12, with a sensor response time of 4 min and reproducibility of