Effects of Zein-Lecithin-EGCG nanoparticle coatings on postharvest quality and shelf life of loquat (Eriobotrya japonica)

Abstract

The loquat (Eriobotrya japonica) has high nutritional and economic values. However, loquat easily rots at room temperature, resulting in the loss of commodity value. In this study, zein, lecithin, and (−)-epigallocatechin gallate (EGCG) were used to prepare Zein-Lecithin-EGCG (Z-L/E) nanoparticles, and the effects of these nanoparticles on loquat quality were studied. EGCG addition affected the zeta potential values of the nanoparticles, which increased from −11.80 mV to −23.34 mV. The Fourier transform infrared (FTIR) results showed that electrostatic interactions and hydrogen bonding formed among lecithin, zein, and EGCG. The Z-L/E nanoparticles showed great antioxidant activity with the DPPH radical scavenging rate of 84.76% and the ABTS radical scavenging rate of 80.95% for Z-L/E4:1 sample, and had good antibacterial ability by decreasing the growth rate of E. coli. The coating treatment with Z-L/E nanoparticles for loquats reduced the weight loss and the decay rate by 13.3% and 1.4%, respectively, during the storage at 25 °C for 22 days, and the decrease of titratable acidity (TA) and vitamin C (VC) content in loquats were also effectively delayed. The coating treatment with Z-L/E nanoparticles for loquats could significantly prolong the storage life of fruits and maintain the quality of fruits.