Ameliorative Effect of Zeolite Packaging on Shelf Life of Milk

Abstract

Recently, many trials to perform new films are used as food packaging to better quality and/or higher safety products. Zeolite-X [Faujasite-NaX (ZX)] and ZX modified by ionic exchange with silver nanoparticles (ZX-AgNPs) were characterized by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM), and were then employed in the starch composite films at 0, 0.5, and 1% concentrations. The prepared films were investigated for its effect on the shelf life of laboratory pasteurized milk by detection of pH and using clot on boiling test, the antimicrobial activity, and the migration of silver to milk during refrigeration storage detected using Inductively Coupled Emission Spectrometer (ICAP). Then, we explored the impact of experimental feeding of packaged milk to laboratory rats on the hematological, biochemical parameters, and pathological effects. The results revealed that the ZX-AgNPs films showed significant reduction in the count of aerobic bacteria, psychrotrophes, coliforms, yeast, and mold, and nearly complete inhibition to Staphylococcal count at 5th day at 4 °C of storage period (2 weeks). The highest migration amount of silver recorded at 15th day was 0.497 ± 0.005 mg/l for 1% ZX-AgNPs films. Also, there are non-significant pathological lesions in the liver and kidney or clinicopathological changes of their functions as well as total protein, albumen, globulin, and blood picture at this migration amount. Therefore, the study was recommended to use ZX-AgNPs films at 0.5% as food packaging due to the existence of AgNPs which reinforcement for ZX also, nearly no silver migration occurred and by extension no hazards plus its antimicrobial characteristics which mainly ameliorate the food safety and the expiry duration of food products.