Improving mango shelf-life using PVA composite films prepared with Zn-doped carbon quantum dots derived from crayfish shells

Food packaging plays a vital role in preserving various agricultural and food commodities for postharvest management. This study aimed to investigate postharvest preservation technologies for mangoes using composite films made from polyvinyl alcohol (PVA) and Zn-doped carbon quantum dots (Zn-CQDs). The results showed a marked increase in the antibacterial potential of the composite films after Zn doping. Furthermore, the addition of Zn-CQDs significantly improved the mechanical properties, thermal stability and ultraviolet absorption of the Zn-CQDs/PVA composite films. In addition, the mango preservation experiment demonstrated that the 5% Zn-CQDs/PVA composite film was effective in delaying the decline in mango hardness (the composite film group was 63.2% higher than the control), VC content (the composite film group was 27.5% higher than the control), titratable acid content (the composite film group was 149% higher than the control), and the incline of disease index (the composite film group was 23.1% lower than the control), total soluble solids (the composite film group was 27.3% lower than the control), and weight loss rate (the composite film group was 25.7% lower than the control). These findings suggest that the Zn-CQDs/PVA composite films hold great potential as a new type of active packaging in the food industry. • Zn-CQDs were synthesized from crayfish shell and zinc acetate and characterized. • Zn-CQDs were incorporated into PVA matrix to prepare Zn-CQDs/PVA composite films. • 5% Zn-CQDs/PVA film showed excellent characteristics compared to PVA films. • 5% Zn-CQDs/PVA films exhibit significant efficacy during fruit preservation. • 5% Zn-CQDs/PVA films were utilized as active packaging to preserve mangoes.