Evaluation of Nanocomposite Packaging Containing Ag and ZnO on Shelf Life of Fresh Orange Juice
Nanocomposite LDPE films containing Ag and ZnO nanoparticles were prepared by melt mixing in a twinscrew extruder. Packages prepared from the films were then filled with fresh orange juice and stored at 4 °C. Microbial stability, ascorbic acid (AA) content, browning index, color value, and sensory attributes of them were evaluated after 7, 28, and 56 days of storage. Packages containing the nanomaterials, expect 1% nano- ZnO, kept the microbial load of fresh juice below the limit of microbial shelf life (6 log cfu/ml) up to 28 days The least degradation of AA (80.50 mg/100 g), development of brown pigments (OD=0.23) and losing of color (ΔE=6.0) were observed in pouches containing 0.25% nano-ZnO, after the same time. Sensory attributes were also ranked highest for the juice thus packed in the recent packages after 28 days (pb0.05). Packages containing nanosilver increased shelf life of fresh juice although part of its sensory attributes were lost.