신선편의 채소류의 품질 및 안전성확보를 위한 전해수효능 및 생육예측모델 개발 = Effect of Electrolyzed Water on the Quality and Safety of Produce and Predictive Model of Foodborne Pathogene

다국어 초록 (Multilingual Abstract)

The tissues of fresh ready-to-eat vegetables are easily wounded during washing, sanitizing, peeling and cutting up, which will cause the changes in respiration and enzymes and increase the probability of food-borne bacteria contamination. Thus, it is important to prevent and inhibit microbial growth during processing, storage and transportation. Therefore, natural antimicrobial agents were investigated to 1)evaluate the microbiological safety of ready-to-eat vegetables; 2)predict the model of food-borne bacteria growth, electrolyzed water and citric acid by using either alone or in combination with different dipping time, treatments and temperatures; 3) the optimal condition of antimicrobial and anti-browning was also investigated; 4)extend the shelf life, optimal packaging condition was tested and measured the changes of contaminated E. coli O157:H7 and L. monocytogenes in head lettuce. Then, a secondary model was developed by using specific growth rate and lag time which was based on the previous data. The results followed,
1. Dipping for 5 min had better effect on microbial population than that of 3 min, and no significant difference was observed between 5 and 10 min. Shaking showed similar effect as compared with static. The lowest microbial population was found when the ready-to-eat vegetables were treated at 40~50℃.
2. The microbial population was comparable in the ready-to-eat vegetables when they were treated by electrolyzed alkali water, 100 ppm NaClO or 1% citric acid. The highest inhibition of microbial was observed when the ready-to-eat vegetables were treated by in combination of electrolyzed alkali water and 1% citric acid. The strongest antimicrobial activity was shown at 50℃ in cabbage and carrot, whereas at 40℃ in head lettuce. The total count of microbial was completely depressed when cabbage, carrot and head lettuce were treated with electrolyzed alkali water and 1% citric acid at mild heat for 5 min.
3. The packaging of modified atmosphere(MA) at 10% CO2 concentration showed the best growth inhibited activity, which also had similar effect as compared with the packaging of polyethylene terephthalate(PET). However, PET was considered as the best packaging method because unfreshed odor was not noticed as compared with MA.
4. Combination of electrolyzed alkali water and 1% citric acid at mild heat showed the strong inhibition activity on contaminated E. coli O157:H7 and L. monocytogenes in cabbage, carrot and head lettuce and have the same anti-browning activity with the agent of antibrown갈변. Therefore, combination of electrolyzed alkali water and 1% citric acid could be considered as one of natural antimicrobial agents in the ready-to-eat vegetables.
5. The slelf-life was calculated by using the equation of slelf-life based on the data collected from the changes of microbial population in the cabbage, carrot and head lettuce packaged with PET when they were stored in room and low temperatures.
6. The changes of contaminated E. coli O157:H7 and L. monocytogenes in the head lettuce were analyzed by the models of Gompertz and Logistic, and the specific growth rate and lag time were obtained. A secondary model of SGR and LT was developed by the square rate model, and tested by Mean square error(MSE), Bias factor(BF) and Accuracy factor(AF). Based on the above results, this second model was very suitable for predicting the growth of E. coli O157:H7 and L. monocytogenes in vegetables.

목차 (Table of Contents)

• Ⅰ. 서론 = 1
• Ⅱ. 연구사 = 6
• Ⅲ. 재료 및 방법 = 16
• 1. 실험재료 = 16
• 1) 채소류 = 16
• 2) 사용균주 = 16
• 3) 전해수 제조 = 16
• 2. 실험방법 = 17
• 1) 전처리 = 17
• 2) 미생물 균총 분석 = 18
• 3) 시험균주 배양 및 야채류에 균주접종 및 분석 = 19
• 4) 포장재료 및 포장방법 = 19
• 5) 저장온도에 의한 미생물 생육변화 = 20
• 6) 갈변도 및 색도 = 20
• 7) PPO(Polyphenol oxidase)활성 = 21
• 8) 관능검사 = 21
• 9) 야채류 shelf-life 예측 = 21
• 10) 성장예측모델 개발 = 23
• 3. 통계분석 = 26
• Ⅳ. 결과 및 고찰 = 27
• 1. 침지 시간이 전해수의 효능에 미치는 영향 = 27
• 2. 침지 방법이 전해수의 효능에 미치는 영향 = 36
• 3. 침지 온도가 전해수의 효능에 미치는 영향 = 43
• 4. 품목별 병용 전처리 효과 = 52
• 5. 병원성 식중독균에 대한 저감효과 = 60
• 6. 알칼리 전해수와 구연산의 병용전처리에 의한 품질변화 억제효과 = 69
• 7. 유통 중 hurdle concept를 이용한 채소류의 선도유지 연장 = 81
• 1) 천연항균제에 의한 선도유지 효능 = 81
• 2) CO2농도에 따른 선도유지효능 = 84
• 3) 포장지종류에 따른 선도유지 효능 = 89
• 4) 저장온도에 따른 선도유지 효과 탐색 = 93
• 5) 품목별 최적 포장조건에 따른 선도유지효과 탐색 = 104
• 8. 수학적 모델을 이용한 채소류의 유통기간 설정 = 112
• 9. 성장예측모델 개발 = 115
• 1) 병원성 미생물 생육변화 조사 = 115
• 2) Growth-fitting curve = 121
• 3)모델식에 의한 식중독 미생물의 Specific Growth Rate와 Lag Time = 129
• 4) 온도변화에 따른 식중독미생물의 이차성장예측 모델 개발 = 133
• 5) 모델 검증 = 139
• Ⅴ. 결론 = 145
• Ⅵ. 참고문헌 = 147
• Ⅶ. Summary = 179
• Ⅷ. 감사의 글 = 183