햄버거 패티에 L. monocytogenes cocktail을 인위적으로 접종한 후 UV-C 조사 처리에 따른 저장 중 미생물 수 변화를 조사하였다. 햄버거 패티에 접종된 L. monocytogenes의 초기 균수가 6-7 log CFU/mL가 되게 하였고, 사용된 UV-C 조사선량은 1, 5, 10 kJ/이었으며 조사된 시료는 에서 7일 동안 저장하였다. UV-C 조사는 L. monocytogenes 수에 있어서 조사선량이 증가할수록 유의적으로

Trypsin inhibitors occur in a wide range of foods, they have been studied extensively in plants such as soybean (Glycinemax) as the majority of species are considered as important food sources. Selected soybeans were subjected to various treatments including microwave heating, supercritical fluid CO2 de-fatting, ultrasound incubating by different treat time (5min-120min) to determine the effect on soybean trypsin inhibitor (STI) activities compared to the non-treatment. The results indicated that microwave reduced trypsin inhibitors ranged from 20.57±1.40 TIU/mg to 14.60±1.48 TIU/mg compared to the control (21.44±1.04 TIU/mg) respectively (p<0.05). The inactivation of STI activities by ultrasound ranged from 28.47±0.16 TIU/mg to 19.86±0.78 TIU/mg compared to the control (28.87±0.18 TIU/mg) respectively (p<0.05). While the observed STI activities by supercritical CO2 de-fatting was not significant compared to the control. This study signifies the effective potential of inactivation of trypsin inhibitor by several applicable treatments which might be benefit in the food manufacture and livestock feeding industry.

세척 당근에 E. coli O157:H7과 L. monocytogenes를 인위적으로 접종한 후 UV-C 조사 처리에 따른 저장 중 미생물수 변화를 조사하였다. 당근에 접종된 E. coli O157:H7과 L. monocytogenes의 초기 균수가 6-7 log CFU/mL가 되게하였고, 사용된 UV-C 조사선량은 1, 3, 5, 이었으며 조사된 시료는 에서 8일 동안 저장하였다. UV-C 조사는 E. coli O157:H7과 L. monocy

We investigated how supercritical affected sterilization and enzyme inactivation in dongchimi, a conventional Korean fermented food. The growth of bacteria, including lactic acid bacteria, in dongchimi juice tended to decrease with increased pressure and temperature during treatment with supercritical . D values were affected by pressure more than by temperature. The lowest total number of cells and D values of lactic acid bacteria were observed after treatment with supercritical at 25 MPa and ; these conditions also reduced polygalacturonase activity in radishes by approximately 40.3%. Supercritical can be used as an alternative method of sterilization and enzyme inactivation, minimizing sensory loss and textural changes in vegetable materials.

This study was performed to evaluate the inactivation and microbial regrowth of heterotrophic and nitrifying bacteria using chloramine as a secondary disinfectant for drinking water distribution system. Three sets of the three reactors filled with the Cl2/NH3-N ratio of 3:1, 4:1 and 5:1 were used in these experiments. Chloramine concentration were applied to each set of the reactors with 1㎎/ℓ, 2㎎/ℓ and 3㎎/ℓ, respectively. For the set with 1㎎/ℓ was applied, all the reactors showed that the residual chloramine concentration gradually decreased with elapsed time and reached to zero level after 7 days. Heterotrophic bacteria remarkably increased and nitrification occurred after 11 days. For the sets with 2㎎/ℓ and 3㎎/ℓ, however, the residual chloramine was maintained through the experimenatal period (21 day). Furthermore the regrowth of heterotrophic bacteria and nitrification were not found. More than 2㎎/ℓ of chloramine with Cl2/NH3-N ratio of 3:1, the nitrification could be inhibited by 2 days of contact time.

In order to develovpment of new sterilizing method applied to food industry, effects of ozone treatment on microorganisms, associated with food hygiene were investigated. Microorganisms were immersed in water and sparged with ozonised air(ozone concentration, 3mg liter-1) at an air flow rate of 5 liter min-1. When organisms were treated with benzoic acid and sorbic acid of 0.4∼1.0g/, respectively, they were not dectable perfectly. Sodium benzoate had an effect on Penicillium islandicum. When bacteria were sparged with ozonised air, Pseudomonas aeruginosa completely inhibited at 60 minutes, and the killing Aspergillus flavus and Penicillium islandicum. Also, all of bacteria were inactivated after immersed with ozonated water for 10minutes, but two fungal species were not effective.