Effect of Packaging Material on the Color Stability of Refrigerated Mandarin Juice During Storage

Introduction: Color is a key quality attribute of mandarin juice, influencing consumer perception of freshness and product acceptability. The bright orange color is mainly associated with carotenoid pigments, which can be affected by storage conditions and packaging barrier properties. This study evaluated the effect of different packaging materials on the instrumental color stability of refrigerated mandarin juice during storage.

Methods: A batch of 100 packaging units per treatment was used. Mandarin juice was packed in three non-transparent multilayer cartons with contrasting inner barrier layers (aluminum foil or ethylene vinyl alcohol copolymer, high to intermediate oxygen barrier) and in a transparent, light-permeable PET bottle (lower barrier), and stored at 4°C for 6 days, consistent with the shelf life reported for non-thermally treated refrigerated citrus juice. Instrumental color (L*, a*, b*, C*, hab) was measured periodically during storage (six replicates), and visible reflectance spectra (400-700 nm) assessed yellow-orange-red region changes. Data were analyzed by ANOVA and Tukey's test (P<0.05).

Results: Packaging material significantly affected (P<0.05) the chromatic stability of refrigerated mandarin juice. All samples showed a progressive decrease in L*, a*, b* and C* values, indicating darkening, loss of reddish-orange intensity, and reduced vividness. High-barrier cartons showed significantly better preservation of the initial orange color than lower-barrier materials. Transparent, light-exposed PET showed the greatest deterioration, with the lowest L* and C* values and a higher total color difference (ΔE*) than the best-performing carton by the end of storage. Reflectance spectra confirmed a greater loss of color intensity in the orange-red region for juices packed in less protective materials.

Conclusions: Packaging material selection is critical for maintaining color quality in refrigerated mandarin juice. High oxygen- and light-barrier packaging (e.g., aluminum-foil-lined cartons) best preserved the bright orange color and reduced chromatic degradation during storage.