Effect of packaging with nano-composite clay/LDPE film on the quality of rainbow trout (Oncorhynchus mykiss) fillet at refrigerated storage

In recent years, application of nanotechnology in the food packaging industry has become more widespread and is progressively being commercialized. Adding nano-materials improves polymers` barrier properties for gases such as O2 and Co2, and increases UV rays barrier, mechanical strength, stiffness, stability, and heat resistance of the base polymer. In this study, low density polyethylene film (LDPE) with 5 wt % nanoparticles of clay was used as the experimental treatment and low density polyethylene film as control treatment. These films were used for packaging of rainbow trout fillets and keeping them in the refrigerator. Then to investigate the quality of packed fillets, samples were taken in days 0, 5, 10, 15, 20 and 25, and were evaluated using chemical (pH, PV, TBA, TVB-N), microbial (TVC, PTC, LAB, EBC and H2S producing bacteria) and sensory tests. Based on the results, significant differences (p<0.05) were observed between control and experimental treatments in different days. The sensory attributes of rainbow trout fillets correlated well with the microbiological analyses (r=0.91). With regards to sensory scores and the microbiological analysis, the shelf-life of rainbow trout fillets has been determined in the control and experimental treatments, 13 to 15 and 18 to 20 days, respectively.