Low-temperature Packaging Research Articles

Reduction of Bacillus Subtilis and Aspergillus Niger spores using nonthermal atmospheric gas discharges

Nonthermal gas discharges at atmospheric pressure, such as dielectric barrier discharges are currently investigated for low-temperature packaging sterilization in order to reach the conditions required for aseptic food packaging. In particular, understanding the basic sterilization mechanisms and the enhancement of the main bacterial reduction pathways are the goals of our investigations. For this purpose, germ reduction experiments were carried out with Bacillus Subtilis and Aspergillus Niger spores using different gas mixtures and plasma conditions with the direct and the indirect influence of barrier discharges. In order to analyze the contribution of UV radiation during plasma germ deactivation, experiments with different excimer UV lamps, also driven by barrier discharges in special UV-emitting gas mixtures, have been carried out. Results of germ reduction experiments using barrier discharges and prospects for atmospheric discharge systems, suitable for industrial packaging sterilization, are presented in this paper.

Food irradiation and combination processes

International approval of food irradiation is being given for the use of low and medium doses. Uses are being permitted for different categories of foods with maximum levels being set between 1 and 10 kGy. To maximize the effectiveness of these mild irradiation treatments while minimizing any organoleptic quality changes, combination processes of other technologies with irradiation will be useful. Combinations most likely to be exploited in optimal food processing include the use of heat, low temperature, and modified-atmosphere packaging. Because irradiation does not have a residual effect, the food packaging itself becomes an important component of a successful process. These combination processes provide promising alternatives to the use of chemical preservatives or harsher processing techniques.