Characterization of active and pH-sensitive poly(lactic acid) (PLA)/nanofibrillated cellulose (NFC) films containing essential oils and anthocyanin for food packaging application by Zabidi, Nurul 'Afifah, Nazri, Farhana, Mohamed Amin Tawakkal, Intan Syafinaz, Mohd Basri, Mohd Salahuddin, Kadir Basha, Roseliza, Othman, Siti Hajar