Interest in the use of intelligent packaging systems for food products has increased in recent years. Intelligent packaging
systems are those that monitor the condition of packaged foods to give information regarding the quality of the packaged
food during transport and storage. The potential of HEC/PANI film as pH indicator and pH sensor were evaluated. HEC/
PANI film was prepared by solution blending and casting method. Fourier transform infrared (FTIR) spectroscopy showed
that there was no chemical interaction between HEC and PANI. The film properties were retained chemically. The electrical
conductivity increment from 1.14×105 to 2.2 ×105
S/cm was observed when PANI was incorporated into the HEC film matrix.
Field emission scanning electron microscopy (FESEM) showed that the electrical conductance network of PANI was formed
in HEC/PANI film. The electrical sensitivity of the film has been studied with I-V characterization. The changes in color and
current of HEC/PANI film on interaction to pH buffer 1-14 shows its suitability as pH indicator and pH sensor for food.
Nata de coco or bacterial cellulose produced by Acetobacter xylinum is a unique type of biocellulose. It contains more than 90% of water. Dried nata was preferred compared to wet form since it is more convenient and portable with stable properties. Therefore, drying process is necessary in order to produce dried nata de coco. Drying method is a key factor that influenced the properties of dried nata de coco produced. The aim of this study was to investigate the effect of different drying methods on morphology, crystallinity, swelling ability and tensile strength of dried nata de coco. Nata de coco samples were dried using three physical drying methods such as oven, tray dryer or freeze dryer until it achieved 3-5% moisture content. Obviously, the three drying techniques produced web-like structured nata de coco and quite similar crystallinity which was in range between 87 and 89%. Freeze dried sample showed the largest swelling capacity and tensile strength which was found to be 148 MPa. Different drying method gave different properties of nata de coco. Therefore, the present work proposed the most suitable drying method can be utilized based on the properties of end product needed.