Preparation of a thermosensitive nanofibre membrane for blackberry preservation

Blackberries provide multiple health benefits. However, they deteriorate easily during harvesting, storage, and transportation (temperature-changing). Therefore, to extend their shelf-life under variable temperature conditions, a temperature-sensitive nanofibre-based material with good preservation attributes was developed, composed of polylactic acid (PLA) electrospun fibres, loaded with lemon essential oil (LEO) and covered with poly (N-isopropylacrylamide) (PNIPAAm). Compared with PLA and PLA/LEO nanofibres, PLA/LEO/PNIPAAm exhibited good mechanical properties, oxidation resistance, antibacterial ability, and controlled release of LEO. The PNIPAAm layer prevented rapid LEO release below the low critical solution temperature (32 °C). When the temperature exceeded 32 °C, the PNIPAAm layer underwent a chain-to-globule transition and accelerated LEO release (slower than PLA/LEO). The temperature-controlled release of LEO via PLA/LEO/PNIPAAm membrane prolongs its action time. Therefore, PLA/LEO/PNIPAAm effectively maintained the appearance and nutritive quality of blackberries during variable storage temperatures. Our research demonstrated that active fibre membranes have great potential applications in preserving fresh products.