Shelf life extension of grapes through chitosan coating reinforced zinc oxide nanoparticles containing phytocompounds from lemon pomace

• Lemon pomace is an excellent source of bioactive compounds such as phenolic acids and flavonoids. • Microwave-assisted extraction was conducted to recover the phenolic compounds from lemon pomace extract. • Ethanol concentration and extraction time were found to be effective on TPC and RSA. • SEM and TEM stated the agglomeration of spherical nanoparticles with sizes ranging from 15 to 30 nm. • Green synthesis of zinc oxide nanoparticles has the potential to be scaled up, cost-effective, easily controlled and requires no sophisticated instruments. Lemon pomace is a byproduct containing bioactive compounds which can be extracted using Microwave-assisted extraction (MAE). The parameters for MAE were ethanol concentration (30–70% v/v), microwave power (300–700 W), and extraction time (1–5 min). The optimal results for MAE were estimated at an ethanol concentration of 70 %, extraction time of 3 min, and microwave power of 600 W, with the Total Phenolic Content (TPC) yield of 1.101 mg GAE/ g and 63.42% Radical Scavenging Activity (RSA) of RSA. The utilization of lemon pomace extracts for the green synthesis of Zinc Oxide Nanoparticles (ZnO NPs) has been extensively researched. FTIR examined the ZnO and phenolic compounds-based functional groups. The NPs exhibited are hexagonal wurtzite crystals in nature analyzed through XRD. Nanoparticle sizes range from 15 to 30 nm. This study revealed that 0.4 % ZnO NPC coating retained a shelf life of around 12 days while the uncoated grapes lost their freshness within 6 days.