Antibacterial and amine scavenging properties of silver–silica composite for post-harvest storage of fresh fish

Polypropylene (PP) films containing silver–silica (AgSiO₂) were prepared using hot pressing. Incorporating AgSiO₂ into PP films enhanced the antimicrobial properties, and tensile and compressive strengths of the composite by 5.85 MPa, 4.08 MPa respectively. The pH of the fresh chub mackerel with PP + AgSiO₂ composite increased from 6.17 to 6.76 during storage at 2 ± 0.5 °C for seven days, whereas the pH of the control sample initially increased from 6.17 to 6.55, and then decreased to 6.48. The control-sample thiobarbituric acid (TBA) value increased during storage, but remained low in the PP + AgSiO₂ composite. Total psychrophilic counts for fish stored in the composite containing 5.0% and 10.0% AgSiO_2, were 3.06 and 3.11 log CFU/g, respectively, whereas the count reached 4.81 log CFU/g in the control sample. Trimethylaimne values of the control sample increased from 1.6 to 2.5 mg TMA/100 g; however, there was no change in the composite sample. The hue angle increased from red to yellow for the control sample, while remaining between the red and yellow zones for composite samples, indicating that the quality of the treated fish was retained.