표제지
목차
Ⅰ. 과산화수소와 cold plasma 병합 처리를 이용한 플라스틱 용기에 포장된 혼합채소의 미생물 저해 17
1. 서론 18
2. 재료 및 방법 20
2.1. 혼합채소 시료 준비 20
2.2. 미생물 접종원 준비 및 접종 20
2.3. 과산화수소 및 CP 단독 또는 병합 처리 21
2.4. 미생물 분석 24
2.5. 저장 실험 24
2.6. 색도 측정 24
2.7. 호흡률 측정 25
2.8. 항산화능 측정 25
2.9. 관능평가 26
2.10. Shotgun metagenome sequencing 26
2.11. PET 용기의 내분비교란물질(환경호르몬) 용출 확인 27
2.12. 통계 분석 28
3. 결과 및 고찰 29
3.1. CP 처리시간에 따른 토착 호기성 세균 저해 29
3.2. 단독 처리와 병합 처리의 미생물 저해 31
3.3. 저장 중 미생물 생장 33
3.3.1. 토착미생물과 효모 및 곰팡이 33
3.3.2. E. coli O157:H7과 L. monocytogenes 35
3.4. 저장 중 혼합채소의 품질 특성 변화 37
3.4.1. 색도 37
3.4.2. 호흡률 39
3.4.3. 항산화능 39
3.4.4. 관능평가 41
3.5. Shotgun metagenome sequencing 43
3.6. HCP 처리가 플라스틱 용기 환경호르몬 용출에 미치는 영향 46
4. 결론 48
Ⅱ. 신선 편이 셀러리의 미생물 저해를 위한 ultrasound와 plasma-activated water 병합 처리 조건 최적화 49
1. 서론 50
2. 재료 및 방법 52
2.1. 셀러리 시료 준비 52
2.2. Plasma-activated water (PAW) 제조 및 처리 52
2.3. 초음파 처리 및 초음파-PAW 병합 처리 52
2.4. UP 실험설계 54
2.5. 미생물 분석 56
2.6. PAW의 물리화학적 특성 측정 56
2.7. 미생물 저해 메커니즘 연구 56
2.7.1. Lipid peroxidation과 intracellular ROS 측정 56
2.7.2. 세포막 무결성 측정 57
2.8. 통계 분석 58
3. 결과 및 고찰 59
3.1. 방전 시간에 따른 토착 호기성 세균 저해 59
3.2. 초음파 세척 시간에 따른 토착 호기성 세균 저해 62
3.3. 반응표면분석법을 이용한 UP 처리 조건 최적화 64
3.3.1. 처리 조건이 세척수의 물리화학적 특성에 미치는 영향 64
3.3.2. 처리 조건이 토착 호기성 세균 저해에 미치는 영향 64
3.3.3. UP 처리 조건 최적화 64
3.4. 단독 처리 및 병합 처리의 미생물 저해 효과 비교 67
3.5. 미생물 저해 메커니즘 69
3.5.1. Lipid peroxidation과 intracellular ROS 69
3.5.2. 세포막 무결성 71
4. 결론 74
Ⅲ. Ultrasound와 plasma-activated water 병합 처리가 신선 편이 셀러리의 보존성에 미치는 영향 75
1. 서론 76
2. 재료 및 방법 78
2.1. 셀러리 시료 준비 78
2.2. Plasma-activated water (PAW) 제조 78
2.3. 초음파와 PAW의 단독 또는 병합 처리 78
2.4. 저장 실험 78
2.5. 미생물 분석 78
2.6. 색도 측정 79
2.7. 호흡률 측정 79
2.8. 조직감 측정 79
2.9. 관능평가 79
2.10. Shotgun metagenome sequencing 80
2.11. PAW의 물리화학적 특성 측정 80
2.12. 통계 분석 80
3. 결과 및 고찰 81
3.1. 저장 중 셀러리의 토착 중온성 세균 생장 81
3.2. 저장 중 셀러리의 품질 특성 83
3.2.1. 호흡률 83
3.2.2. 경도 83
3.2.3. 색도 85
3.3. 관능평가 87
3.4. Shotgun metagenome sequencing 89
3.5. 저장 중 세척수의 물리화학적 특성 92
4. 결론 94
참고 문헌 95
ABSTRACT 107
Table 1. Effects of the hydrogen peroxide treatment combined with cold plasma (HCP) treatment on the color of kale, cabbage, and paprika during storage at 4 ℃ for 14 days 38
Table 2. Effects of the hydrogen peroxide combined with cold plasma (HCP) treatment on the CO₂ generation and antioxidant activity of mixed vegetables 40
Table 3. Effects of hydrogen peroxide treatment combined with cold plasma treatment (HCP) treatment on sensory attributes of mixed vegetables 42
Table 4. Bacterial diversity in mixed vegetables as assessed by Shannon index 45
Table 5. The concentrations of bisphenol A and phthalates eluted from PET container treated by hydrogen peroxide combined with cold plasma... 47
Table 6. Experimental variables and their values for the determination of the optimum conditions of ultrasound combined plasma-activated water treatment for inactivating indigenous bacteria in fresh-cut celery 55
Table 7. Effects of individual ultrasound (US) and plasma-activated water (PAW), and their combined (UP) treatment on the CO₂ generation and firmness of celery during storage at 4 ℃ and 10 ℃ 84
Table 8. Effects of individual ultrasound (US) and plasma-activated water (PAW), and their combined (UP) treatment on the color of fresh-cut celery during storage at 4 ℃ and 10 ℃ 86
Table 9. Effects of ultrasound treatment combined plasma-activated water (UP) treatment on sensory attributes of fresh-cut celery 88
Table 10. Changes in the physicochemical properties of PAW during storage at 4 ℃ and 25 ℃ for 7 days 93
Figure 1. The images of the dielectric-barrier discharge cold plasma treatment chamber used in the study. 23
Figure 2. Effects of cold plasma (CP) treatment time on the inactivation of indigenous bacteria in mixed vegetables. The CP treatment voltage... 30
Figure 3. Inactivation of indigenous bacteria, Escherichia coli O157:H7 and Listeria monocytogenes in mixed vegetables by hydrogen peroxide... 32
Figure 4. Effects of the hydrogen peroxide treatment combined with cold plasma (HCP) treatment on the number of indigenous bacteria (a) and yeast and molds (b) in mixed vegetables during storage at 4 ℃ and 10 ℃. 34
Figure 5. Effects of the hydrogen peroxide treatment combined with cold plasma (HCP) treatment on the number of Escherichia coli O157:H7 (a)... 36
Figure 6. Taxa relative abundance in phylm (a) and genus (b). NT and HCP: untreated and HCP-treated mixed vegetables, respectively. NTS and... 44
Figure 7. Schematic diagram of plasma-activated water treatment system (a) and ultrasound treatment system (b). 53
Figure 8. Effects of plasma discharge time on the inactivation of indigenous bacteria by plasma activated water (PAW) treatment. The... 60
Figure 9. The pH (a), oxidation-reduction potential (b; ORP), and electrical conductivity (c; EC) of plasma activated water (PAW). The... 61
Figure 10. Effects of treatment time on the inactivation of indigenous bacteria in fresh-cut celery treated by ultrasound (US). The US... 63
Figure 11. Response surface plot for microbial inactivation in fresh-cut celery as a function of plasma discharge time (X₁) and ultrasound... 66
Figure 12. Inactivation of indigenous bacteria in fresh-cut celery by ultrasound (US), plasma activated water (PAW), and US-PAW (UP)... 68
Figure 13. Lipid peroxidation values (a) and intracellular ROS values (b) in Escherichia coli O157:H7 and Listeria monocytogenes treated by... 70
Figure 14. Cellular uptake of propidium iodide (PI) values in Escherichia coli O157:H7 and Listeria monocytogenes treated by plasma-activated... 72
Figure 15. Fluorescence microscopy images of (A), (B) Escherichia coli O157:H7 and (C), (D) Listeria monocytogenes treated by plasma activated... 73
Figure 16. Effects of the ultrasound (US), plasma-activated water (PAW), sodium hypochlorite (NaClO), and US-PAW (UP) treatment on the number of indigenous bacteria in fresh-cut celery during storage at 4 ℃ (a) and... 82
Figure 17. Bacterial distribution pattern at the phylum (a) and genus (b) level. NT and UP: untreated and UP-treated celery, respectively. NTS... 90
Figure 18. Rarefaction curves for species richness of fresh-cut celery. NT and UP: untreated and UP-treated celery, respectively. NTS and UPS:... 91