Carboxymethyl cellulose – Polyvinyl alcohol bioactive films loaded with green extracted date seed polyphenols for active packaging of Shiitake mushrooms
Kehinde Ganiyat Lawal, Raouf Aslam, Akmal Nazir, Balan Sundarakani, Constantinos Stathopoulos, Sajid Maqsood
Abstract
This study investigated the use of a natural deep eutectic solvent-based polyphenolic extract (DSE) from date fruit seed as a bioactive and functional component for the development of carboxyl methylcellulose-poly(vinyl)alcohol (CMCPVA) packaging films. The impacts on the physicochemical, structural, water barrier and bioactive properties of the CMCPVA films were studied. Different concentrations of DSE (1.5%, 2%, 2.5%, and 3%) incorporated into CMCPVA film increased the total phenolic content (0.08–0.17 mg GAE/mL), DPPH scavenging activity (4.08–5.11 mmol GAE/mL), and ferric ion-reducing antioxidant power (0.82–1.46 μmol TE/mL) of the films. The antibacterial activities against S. aureus , L. monocytogenes , S. typhimurium, and E. coli were also improved. In particular, a 4–5 log reduction was recorded for CMCPVA film incorporated with 3% DSE. Also, the presence of DSE enhanced elongation at break (25.53%–93.23%) and film thickness (0.10–0.19 mm), whereas tensile strength (6.39–1.40 MPa) and Young's modulus (25.89–2.85 MPa) decreased. Furthermore, UV-shielding performance improved, opacity decreased from 2.93 to 0.86, while the water vapor permeability was not significantly affected which ranged from 3.01 to 5.83 (X 10 −10 g/m.s.Pa). The application of CMCPVA film incorporated with 3% DSE (CMCPVA_3) as a bioactive film for preserving sliced and whole shiitake mushrooms at refrigeration temperature for 8–12 days was studied. The CMCPVA_3 film preserved the mushrooms' color, browning degree, and texture compared to the cling film-covered samples. There is a potential for the successful application of NADES-based polyphenolic extract in biopolymer films for food preservation. • CMCPVA film was incorporated with NADES-based polyphenolic extract from date seed. • The NADES extract improved the film's antioxidant and antibacterial properties. • NADES-based extract increased the elongation at break and reduced tensile strength. • The film's opacity and UV-shielding ability were improved. • The bioactive film slowed the quality deterioration of sliced and whole mushrooms.