Co-electrospun-electrosprayed ethyl cellulose-gelatin nanocomposite pH-sensitive membrane for food quality applications.

Anthocyanin from red cabbage is an important biomolecule suitable for pH sensing due to its oxidoreduction potential that leads to a color change at various pH conditions. The pH-sensitive anthocyanin compound was extracted from red cabbage (1785 ± 235 mg/L) and encapsulated with gelatin as the wall material at the nanoscale (350 nm) through electrospraying. By using a simultaneous electrospraying and spinning process at 20 kV, nanoencapsulated anthocyanin was immobilized on ethyl cellulose (EC) nanofibers and formed as a nanocomposite membrane. The surface morphology of developed nanocomposites has shown complex nonwoven nanofiber formation and the immobilized nano encapsulates captured inside the nanofibrous membrane. The pH sensitivity was significantly stable up to 7 days of storage at room temperature. Total color difference has been observed to be statistically significant at different pH conditions of 2 to 12. Also, the application of the nanocomposite strips in pH sensing during milk spoilage was studied and reported.