Development of Biodegradable Smart Packaging for Virgin Olive Oil Utilizing Cellulose Nanofiber, Methylene Blue and Vitamin C

In this study, four types of cellulose (Cel) nanofiber films modified with methylene blue (MB) and vitamin C (VC) were prepared and examined using scanning electron microscopy (SEM). This study evaluated four packaging types for virgin olive oil (control; Cel/MB; Cel/VC; Cel/MB/VC) over 30 days. Packaging with MB and VC, alone or in combination, significantly mitigated increases in acidity and peroxide value (PV) and preserved total phenols compared with control ( p < 0.05). Acidity (mg KOH/g): Control increased from 0.18 to 0.69; Cel/MB/VC delayed increase to 0.44 ( p < 0.05 vs. control). PV (mEq O 2 /kg): Control PV rose from 1.00 to 6.55; Cel/MB/VC packaging yielded significantly lower PV at Day 30 (4.20) ( p < 0.05). Total phenols (mg GAE/kg): Retention was highest in Cel/MB/VC, with values differing significantly from control at Day 30 (4.95 vs. 3.80, p < 0.05). After 30 days, Cel/MB/VC showed the smallest deterioration in colour parameters (L*, a*, b*) and sensory scores. Also, the Cel/MB/VC kit in olive oil packaging with antioxidant properties can estimate the shelf life of the oil by changing its colour from white to blue due to oxidation. A strong linear relationship between storage time and the colorimetric sensor reading (b*) was observed (b* = −0.1367 × Days + 0.5506, R 2 = 0.997), enabling shelf‐life estimation from colour changes alone. The colour changes of the sensor are easily visible, and using colour software, the colour factor b can be recorded and the exact shelf life of the oil can be calculated.