The Development of Intelligent Film From Crosslinked–Acylation Cassava Starch and Purple Sweet Potato Anthocyanin for Monitoring Indian Mackerel Fish Freshness

Abstract

Edible coatings and films have gained significant interest due to their ability to extend the shelf life of fresh products. This research aimed to develop a novel indicator film using crosslinked–stearic acid acylation-modified cassava starch and anthocyanin extracts, both of which can be utilized to create solid matrices that are safe for consumption. The physical properties of the films improved with the use of modified starch, exhibiting a stronger tensile strength (from 0.96 to 1.02 MPa). Additionally, flexibility increased from 121% to 129%, and the water vapor transmission rate was significantly reduced from 5.86 to 1.79 g/m²/h. Anthocyanin extracts also contributed to improvements in flexibility and reductions in water vapor transmission rate. Differential scanning calorimetry analysis indicated an increase in the film's thermal stability, with a transition temperature shifting from 276°C to 299°C, attributing to changes in the starch characteristics following modification. Fourier transform infrared spectroscopy revealed alterations in the molecular interactions between the CH and CC groups. The application of these edible films for storing and monitoring Indian mackerel fish meat demonstrated consistent results, particularly in terms of color change due to an increase in pH levels (from 7 to 8.5 over 2 days). Furthermore, TVB-N levels in fish meat covered with the edible film were successfully reduced from 71 to 46 mg/100 g over the same period. These findings indicate that the films can function as intelligent food packaging, possessing antioxidant properties beneficial for human health while being biodegradable, thus reducing their environmental impact.