Preparation of corn starch/polyvinyl alcohol-based citric acid-phloretin nanofiber membranes for fresh-cut asparagus lettuce and carrot slices preservation.

This study used corn starch (CS) and polyvinyl alcohol (PVA) as the membranes-forming matrix, combining citric acid (CA) and phloretin (PL) as functional components with antibacterial and anti-whitening properties. The electrospinning method was employed to prepare the membranes (CS/PVA/CA-PL). Mechanical properties, thermal stability and antibacterial activity of composite membranes were characterized, and their fresh-keeping capacity was evaluated. The results showed that compared with the pure CS/PVA membranes, the CS/PVA/CA-PL exhibited a 2.36-fold increase in elongation at break and a 2.25-fold improvement in tensile strength. Meanwhile, thermal stability and antibacterial activity of the composite membranes were both significantly enhanced. The membranes could be degraded in soil within 30 days. For fresh-cut asparagus lettuce, the membranes reduced the weight loss rate by 4.93% and browning index by 20.87, suppressed TVC by 2.89 log CFU/g, and maintained vitamin C levels 2.89 mg/100 g above CK. For fresh-cut carrots, the membranes lowered weight loss by 1.98%, raised carotenoid content by 0.26 mg/kg, inhibited TVC by 3.15 log CFU/g and reduced whitening index by 14.77 versus CK. At 4 °C, the shelf lives of fresh-cut asparagus lettuce and carrot slices were prolonged by 4 days and 6 days, respectively. This study provides a novel biodegradable packaging option for the food industry.