Smart Nanosensor Technology for Fruit Preservation: In vivo Papaya Model with Ethylene Scavenging and Colorimetric Indication
Ricardo dos Santos Medeiros, Ana Carolina Gava de Barros da Silveira, Giovanna Maia, Matheus Godoy Reimberg Amaral, Ramon Peres Brexó, Ednaldo José Ferreira, Elaine Cristina Paris, Marcos David FerreiraAbstract
A nanosilica-permanganate colorimetric nanosensor (NS) was developed for ethylene scavenging in postharvest papaya, offering sustainable shelf life extension. Incorporated in a polyethylene nonwoven pouch (tag), NS was compared to control (CO) and vermiculite (VR) treatments. NS particles measured 15–25 nm, negatively charged, and characterized by FTIR, SEM-FEG, SEM-EDS, and zeta potential. GC-FID analysis showed ethylene release at climacteric peak: CO = 0.50 μL/kgh, VR = 0.49 μL/kgh, NS = 0.35 μL/kgh, confirming NS’s superior scavenging. Ripening was monitored over 17 days at 16 °C. Deconvolution revealed ethylene peak at day 15 for NS vs day 13 for CO/VR. Firmness declined (peel: ∼30–6 N; pulp: ∼11–0.5 N), pH rose (5.4–5.9), titratable acidity (∼0.085–0.052%), and soluble solids rose (∼10.0–12.7). Statistical analysis did not demonstrate a significant difference among treatments. Hue angle in NS changed from 240° to 320° (violet to brown), indicating continued ethylene adsorption, unlike VR. NS color shift aligned with fruit ripening, supporting its use in smart packaging.