Anthocyanin-rich pectin-chitosan edible coatings from blackcurrant pomace and purple cabbage for chilled strawberry quality preservation
摘要
Strawberries (Fragaria × ananassa) are highly perishable, resulting in significant postharvest losses. Edible coatings, particularly those enriched with anthocyanins, offer a promising method to extend fruit shelf life. This study investigated the effects of a pectin-chitosan (PC) coating infused with 0%, 0.125%, 0.25%, and 0.50% freeze-dried blackcurrant pomace-purple cabbage (BPPC) anthocyanin extract on the preservation of strawberries. Strawberries were coated, dried, and stored at 4 ± 2 ℃ for 21 days. The PC + 0.50% BPPC coating exhibited the highest total monomeric anthocyanin content (TMAC) (78.18 mg/100 g), total phenolic content (TPC) (560.17 mg GAE/100 g), and scavenging activity (70.46%). It also demonstrated the highest water vapor permeability (1.49 × 10⁴ g·m/m²·day·Pa), opacity (2.76 Abs·mm⁻¹), and lowest transmittance (2.80%). After 21 days, PC, PC + 0.25%, and PC + 0.50% BPPC retained the highest TMAC, while PC showed the highest TPC (4801.04 mg GAE/100 g). All PC + BPPC coatings significantly reduced weight loss, with control and PC + 0.50% BPPC showing the highest weight loss. Microbial and fungal growth were also suppressed, with PC + BPPC coatings maintaining the lowest counts. PC + 0.25% BPPC exhibited better overall performance than PC only, PC + 0.125%, and PC + 0.50% in preserving strawberry quality. Therefore, this work provides a sustainable approach to preserving perishable strawberries.
Graphical Abstract