Determination of microbial contamination of plastic cups for dairy products and utilization of electron beam treatment for sterilization

Abstract

Packaging materials are often considered a critical control point in HACCP systems of food companies. Methods for the determination of the microbial contamination rate of plastic cups, especially for dairy products, must reliably detect single moulds, yeasts or coliforms. In this study, a comparison of a specially adapted coating method, impedance method, direct inoculation and membrane filter technique was carried out to determine contamination with yeasts, moulds, coliforms and total bacterial counts using the appropriate agar in each case. The coating method is recommended for determining yeasts, moulds and coliforms as it allows the localization of the microorganisms as well as the determination of single microorganisms. For total bacterial count, a direct inoculation technique is proposed. The employing of simple measures in the production and during transport of packaging materials, such as dust-prevention or tight sealing in polyethylene bags, heavily reduces microbial contamination rates of packaging material. To reduce contamination rates further, electron beam irradiation was applied: plastic cups sealed in polyethylene bags were treated with 4-5 kGy, a dose that already leads to sterile polystyrene and polypropylene cups without influencing mechanical characteristics of the packaging material.

Physicochemical-Microbiological Studies on Irradiated Date Fruits with Studying Migration Monomers of Packages Materials

“…Irradiation at 3.0 and 5.0 kGy which was considered a factor for improving the health side of date's samples for consumers' health was less in irradiated date fruits even after nine months, especially during freezing storage. Irradiation in all doses improved the healthy for human health; same results were obtained by workers [30].…”

“…Physical, chemical analysis of Polyethylene low density LDPE-blue layer and colorless-were used. γ-rays caused some increase of significance in the mechanical characters as elongation [7,[12][13][14]30], but insignificant as gas permeability [30,31].…”

Radiation treatment for sterilization of packaging materials

“…The coating method is recommended, as it allows the localization of the microorganisms as well as the determination of single microorganisms. For total bacterial count, a direct inoculation technique is proposed (Tacker et al, 2002). The employment of simple measures in the production and during transport of packaging materials, such as dust-prevention or tight sealing in polyethylene bags, heavily reduces microbial contamination rates of packaging material.…”