Effect of pasteurization, high-pressure processing, and retorting on the barrier properties of nylon 6, nylon 6/ethylene vinyl alcohol, and nylon 6/nanocomposites films.

This study determined the impact of pasteurization, high-pressure processing (HPP), and retorting on the barrier properties of nylon 6 (N6), nylon 6/ethylene vinyl alcohol (N6/EVOH), and nylon 6/nanocomposite (N6/nano) materials. The pasteurized and high-pressure treated films were coextruded with low-density polyethylene (PE) as the heat-sealing layer. The retorted films were coextruded with polypropylene (PP). Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) of the samples were measured after pasteurization (75 degrees C for 30 min), HPP (800 MPa for 10 min at 70 degrees C), and retorting (121 degrees C for 30 min) treatments. These were compared with the thermal characteristics and morphologies of the samples using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Results showed that OTR of N6 and N6/Nano increased after HPP (16.9% and 39.7%), pasteurization (13.3% and 75.9%), and retorting (63.3% and 112.6%), respectively. For N6/EVOH, a decrease in OTR after HPP (53.9%) and pasteurization (44.5%) was observed. The HPP treatment increased the WVTR of N6 (21.0%), N6/EVOH (48.9%), and N6/Nano (21.2%). The WVTR of N6, N6/EVOH, and N6/Nano increased by 96.7%, 43.8%, and 40.7%, respectively, after pasteurization. The DSC analyses showed that the enthalpy and percent crystallinity increased (2.3% to 6.5%) in the N6/Nano when compared with the N6 material after each treatment. Retorting caused a decrease (3.5%) in the percent crystallinity of the polypropylene material. HPP did not cause major morphological changes to the samples. Results of the barrier studies were influenced by the crystallinity changes in the materials as seen in the XRD diffractograms.

Development of a sanitizing fabric wipe for use on food contact surfaces.

A sanitizer was incorporated into disposable sanitary wipes that were used to eliminate microorganisms on plastic and metal surfaces. These surfaces were inoculated with strains of Bacillus subtilis OSU 494, Enterococcus faecalis OSU 48, Escherichia coli ATCC 29181, Listeria innocua ATCC 33090, Pseudomonas aeruginosa OSU 167, Salmonella enteritidis OSU 799, Staphylococcus epidermidis OSU 838), Candida albicans ATCC 10231, and Aspergillus fumigatus ATCC 10894. These inoculated surfaces were cleaned with the wipes for 5, 10, and 30 s, then organisms surviving on the cleaned surfaces and in the wipes were enumerated. Applying the sanitizing wipe to the plastic and metal surfaces reduced the viability of bacteria (> log 4 for 5 s), yeast cells (> log 5 for 10 s), and fungal spores (< log 4 for all times). The use of large pore sized or thick wipes showed better sanitizing result when compared with the use of the small pore sized and slim wipe. There were no significant differences (P > 0.05) between surviving numbers on the surface of the plastic compared with that of the metal.

Efficacy of two acidic sanitizers for microbial reduction on metal cans and low-density polyethylene film surfaces.

This study investigated 2 sanitizer formulations and compared them with hydrogen peroxide (H(2)O(2)). Formulation number 1 contained citric acid and sodium dodecylbenzene sulfonate (SDBS). Formulation number 2 contained SDBS, citric, lactic, phosphoric acids, and benzoic acid. Low concentration levels of the sanitizers (1.0% for formulation 1 and 0.5% for formulation 2) were compared with 35% H(2)O(2) for their efficacies on Escherichia coli, Listeria innocua, and Saccharomyces cerevisiae inoculated onto low-density polyethylene (LDPE) films and metal cans at room temperature (23 +/- 1 degrees C) and 40 degrees C. The results showed that both formulations 1 and 2 required >120 s to sanitize both materials from microbial populations at room temperature, while <15 s was needed for the H(2)O(2). Except for formulation 1 on the E. coli inoculated LDPE film surface, the sanitizers completely eliminated the bacterial populations on both materials in 60 s at 40 degrees C. In general, the formulations were more effective for reduction of the microbial numbers on the can material when compared with the LDPE film. The E. coli showed greater tolerance for the sanitizers when exposed to the process conditions in this study. All sanitizers completely eliminated the test organisms in