Studies on Processing Optimization of Ready-to-Eat Bulgogi for the Long-term Storage using Radiation Technology
- 주제(키워드) Sauce , Irradiation , Autoclave , Xanthan gum , Combination treatments , Ready-to-eat meal , Extreme environment , Long-term storage
- 발행기관 고려대학교 대학원
- 지도교수 Han-Joon Hwang, Ju-Woon Lee
- 발행년도 2011
- 학위수여년월 2011. 2
- 학위구분 박사
- 학과 일반대학원 식품생명공학과
- 원문페이지 238 p
- 실제URI http://www.dcollection.net/handler/korea/000000024944
- 본문언어 영어
- 제출원본 000045633340
초록/요약
Bulgogi is cooked beef marinated with soy sauce and raw vegetables, which may introduce spoilage bacteria into the food. Therefore, a decontamination technology is necessary for not only destruction of spoilage bacteria in Bulgogis but also its long-term storage in extreme environments. This study was conducted to develop ready-to-eat (RTE) Bulgogi for storage in extreme environments, using radiation technology. The studies are composed of three chapters, and the main results of each chapter were as follows: In chapter I, the Bulgogi samples were sterilized (p < 0.05) by different methods such as autoclave (121°C, 15 min) and gamma irradiation up to 20 kGy. The appropriate sterilizing method was determined after microbiological, physicochemical and sensory evaluations during storage at 35°C for 90 day. The bacterial survivals in Bulgogi samples were not observed after treatments of autoclave and gamma ray (15 kGy). However, the adverse effects (lipid oxidation and sensory quality deterioration) were induced by sterilizing treatments, especially the sensory qualities (color, texture and taste) of autoclaved sample were very inferior (p < 0.05) to irradiated samples. The in vitro protein digestibility was not changed by each treatment. The Bulgogi samples were irradiated up to 20 kGy under the conditions of packaging (aerobic or vacuum), antioxidant (vitamin-C and α-tocopherol (0 - 1.0%, w/w)) addition, charcoal teabag attachment (0 and 10 g), or different temperatures (room temperature, -20 and -70°C) for the predominant quality maintenance. The Bulgogi was sterilized (p < 0.05) by gamma irradiation of 20 kGy, the adverse effects (lipid oxidation and sensory property deterioration) were also improved by irradiation (20 kGy) under the conditions such as antioxidant (0.5%), charcoal (10 g), vacuum packaging, or -70oC. Solid-phase microextraction (SPME) gas chromatography/mass spectrometry (GC/MS) analysis identified volatile compounds such as toluene, hexanal, heptane, and 1,3-Bis(1,1-dimethylethyl)benzene that were created by irradiation of Bulgogi. Meanwhile, off-flavor caused by irradiation were reduced (p < 0.05) by each physicochemical treatment. The quality deteriorations (drip spillage, decoloration, lipid oxidation and rancidity) of Bulgogi were continuously induced during storage at 35°C. Thus, the viscosity strengthening of Bulgogi sauce was needed to inhibite quality dectrioration of Bulgogi. In chapter II, the quality of irradiated thickening agent/stabilizer (xanthan gum, guar gum and locust bean gum) was compared by examination of the physicochemical properties (viscosity, molecular weight, reducing end level, water solubility, UV spectrum, pH and color value). The physicochemical properties of xanthan gum were more stable (p < 0.05) than those of other samples after gamma irradiation up to 9 kGy. Therefore, it was determined that a xanthan gum (1%, w/w) must be added for viscosity strengthening of Bulgogi sauce. The effects of sterilizing methods such as gamma irradiation (0 - 40 kGy) and autoclave on microbial, physicochemical and sensory properties of Bulgogi sauce containing xanthan gum (1%, w/w) were compared. The total bacterial populations in sauce were below detection limit (< 1 log CFU/g) after irradiation at more than 10 kGy and autoclave treatments, and viscosity, color values and sensory properties (color, texture, taste, and flavor) could be excellently maintained (p < 0.05) after irradiation up to 40 kGy compared to autoclave treatment induced burnt taste and flavor. In chapter III, the sterilizing dose of RTE Bulgogi made by sauce containing xanthan gum (1%, w/w), treatment of vitamin-C and α-tocopherol (0.5%, w/w), and gamma irradiation under the frozen state (-70°C) were determined. The viable cells of RTE Bulgogi were not observed (p < 0.05) by irradiation of 40 kGy, its sensory properties (taste and flavor) were also superior to other samples (40 kGy-irradiated sample). The mutagenic safety such as Ames test (Salmonella Typhimurium reversion assay) and SOS chromotest (Escherichia coli PQ37), and subacute toxicity study (body weight, organ weight, food consumption, serum biochemical, hematological and urine analysis, and histopathological test) using ICR mice and nutritional change (fatty acid and free amino acid composition) of RTE Bulgogi were evaluated after gamma irradiation at 40 kGy. The RTE Bulgogi exposed to 40-kGy gamma ray revealed negative results in these mutagenicity tests and no subacute toxicity, and its nutritional changes were not observed. The RTE Bulgogi was certificated as space food by the Russian Institute for Biomedical Problems (IBMP) after certification tests for use in the International Space Station (ISS). The certification tests consist of a microbial test (mesophilic aerobic and anaerobic bacteria) and an organoleptic test (color, odor, texture, taste and general impression) during 51-day space environment simulating a temperature fluctuation. Finally, the RTE Bulgogi was certificated for use in space flight conditions of 30 days by the IBMP. These results indicate that irradiation (40 kGy) under the frozen (-70°C) state after combined treatment such as vitamin-C and α-tocopherol (0.5%, w/w), charcoal (10 g) teabag and vacuum packaging were effective for the long term storage (35°C, 90 days) and predominant quality maintenance of RTE Bulgogi. The xanthan gum (1%, w/w) was also helpful to maintain viscosity of sauce irradiated at 40 kGy. Thus, these RTE Bulgogi and sauce can be applied to various foods industry such as combat rations, space foods and emergency/special purpose foods.
more초록/요약
불고기는 한국의 대표적인 전통식품 중의 하나로서 근래에는 세계 각국의 외국인들에게 널리 알려진 한국 식품중 하나로 손꼽히고 있다. 산업화와 핵가족화 및 여성의 사회진출에 따라 ready-to-eat/ready-to-cook 불고기 제품이 대량 생산 및 유통되고 있는데, 제조회사가 대부분 소규모 시설이며 영세하여 제조 및 유통과정 중 산화와 부패에 의한 품질 및 상품성 저하로 문제가 되고 있다. 따라서 본 연구에서는 사막 및 우주와 같은 극한 환경하에서 저장 및 고품질 유지가 가능한 ready-to-eat 불고기의 제조공정 최적화 확립을 위해 방사선 기술과 식품공학 기술을 융복합하였으며, 저장기간에 따른 불고기의 미생물학적, 이화학적 및 관능적 품질 변화를 측정하였다. 본 연구는 상기 연구목표를 달성하기 위해 총 3개의 chapter로 구성하였고, 각 chapter별 주요 결과는 다음과 같다. Chapter I 에서는 autoclave(121°C, 15분) 및 감마선 조사(0 - 20 kGy) 처리가 상법으로 제조된 불고기의 저장 안전성, 이화학적 및 관능적 품질에 미치는 영향을 비교하였다. 불고기 샘플의 autoclave 및 감마선(15 kGy) 처리에 의해 1 log CFU/g의 검출한계에서 미생물 증식이 관찰되지 않았다 (p < 0.05). 한편, 살균 처리로 인해 관능적 품질 저하가 발생하였으며, 특히 autoclave 처리된 불고기의 관능적 품질(외관, 조직, 맛 및 풍미) 저하가 매우 심했다 (p < 0.05). 즉, 고온 고압 처리로 인해 지방이 녹은 후 굳으면서 외관 기호도(greasy appearance)가 저하되었고, 조직이 무르고 잘 부서졌으며(brittle texture), 느끼한 맛(oily taste)이 강해졌다. Autoclave 및 irradiation 처리에 따른 시료의 in vitro 단백질 소화율 분석 결과 멸균 처리에 따른 유의적인 차이는 없었다. 또한, 상법으로 제조된 불고기에 대한 방사선 병용처리의 최적 조건 설정을 위해 포장방법(함기/진공), vitamin-C와 α-tocopherol(0 – 1.0%, w/w), 활성탄(0/10 g) 또는 조사 온도(실온/-20/-70°C)를 달리하여 방사선 조사를 실시하였다. 그 결과, 불고기의 미생물학적 안전성과 저장중 관능적 품질 유지를 위해 vitamin-C와 α-tocopherol(0.5%, w/w), 활성탄(10 g), 진공포장 및 -70°C 냉동 조건에서 방사선 조사(20 kGy)를 하는 것이 효과적이었다 (p < 0.05). Solid-phase microextraction (SPME) gas chromatography/mass spectrometry (GC/MS)에 의한 irradiated Bulgogi의 off-flavor 분석 결과 toluene, hexanal, heptane와 1,3-Bis(1,1-dimethylethyl)benzene 같은 irradiation off-flavor가 검출되었고, 이들 off-flavor들은 각각의 병용처리에 의해 감소되었다. 그러나 35°C에서 저장중 불고기 소스의 물성(점도) 저하로 인해 제품의 드립 유출 및 탈색 등 외관 기호도가 매우 저하되었다. 따라서, 방사선 조사된 불고기 소스의 물성 강화를 위한 gum류 (농후제/ 안정제)첨가 연구가 추가적으로 수행되어야 할 것으로 판단되었다. Chapter II에서는 방사선 조사된 불고기 소스의 물성(점도) 강화를 위해 다양한 gum류(농후제/안정제) 수용액(1%, w/w)을 대상으로 방사선 조사 영향 평가를 실시하였다. 즉, 잔탄검, 구아검 및 로커스트빈검 수용액(1%, w/w)에 대한 방사선 조사 영향평가를 실시했을 때, 잔탄검 수용액의 물성이 가장 안정적인 것으로 나타났다 (p < 0.05). 따라서 방사선 조사된 불고기 소스의 점도 강화를 위해 잔탄검(1%, w/w)을 첨가하기로 결정하였다. 한편, 잔탄검(1%, w/w)이 첨가된 불고기 소스(완제품)의 멸균처리(irradiation과 autoclave)에 따른 물성학적 및 관능적 품질을 비교하였다. 총균수는 10 kGy 이상 조사 및 autoclave 처리를 할 경우 저장기간 동안 1 log CFU/g 검출한계에서 검출되지 않았다 (p < 0.05). 한편, 소스의 점도, 색도 및 관능적 품질(색, 조직, 맛 및 풍미)은 40 kGy의 고선량 조사에 의해 저장기간 중 우수하게 유지되었으나, autoclave 처리된 소스의 경우 고온 (121°C) 처리로 인해 탄맛과 탄내가 크게 증가하여 관능적 품질이 매우 저하되는 것으로 나타났다. Chapter III에서는 선행결과를 바탕으로 ready-to-eat 불고기 완제품을 제조하였다. 즉, 초벌구이된 소고기와 잔탄검 1%가 함유된 불고기 소스를 혼합하였다. 그 후 항산화제(vitamin-C와 α-tocopherol) 0.5%를 처리하여 통조림 포장하였고, -70°C 의 냉동조건에서 감마선 조사(0 – 40 kGy)를 실시하였다. Ready-to-eat 불고기는 20 kGy의 선량에서 멸균되지 않았고, 샘플 유래 분리 미생물(Bacillus atrophaeus spore)의 D10 및 12D10 values는 각각 2.52 and 30.31 kGy인 것으로 나타나 불고기의 완전멸균을 위해 40 kGy의 선량을 적용하기로 결정하였다. 한편, 40 kGy로 조사된 Ready-to-eat 불고기 시료는 유전독성 시험결과 음성 판정을 받아 유전독성학적으로 돌연변이원성이 없음을 확인하였고, 12주간 ICR 마우스에 급여 후 나타나는 아급성 독성을 평가한 결과에서도 시험물질 투여에 의한 임상증상이나 폐사동물은 나타나지 않았으며, 혈액학적, 혈청학적 검사 및 조직병리학적 검사에서도 특이적인 변화는 관찰되지 않았다. 또한, 고선량 조사로 인한 불고기 내 지방산 및 유리아미노산 조성 변화도 없었다. 본 연구를 통해 제조된 Ready-to-eat 불고기는 완전멸균 제품으로 러시아에서 요구하는 까다로운 우주식품 인증 테스트를 모두 통과하여, Russian Institute for Biomedical Problems(IBMP)를 통해 국제 우주정거장(International Space Station)에서 우주비행 조건에서 사용할 수 있게 되었다. 결론적으로 사막 및 우주와 같은 극한 환경하에서 저장 안전성과 우수한 관능적 품질을 유지할 수 있는 ready-to-eat 불고기를 제조하기 위해 방사선 기술과 식품공학 기술을 융복합하였으며, 최적 공정은 항산화제(vitamin-C와 α-tocopherol(0.5%, w/w)), 활성탄(10 g), 진공포장 및 -70°C 냉동조건하에서 40 kGy의 선량으로 방사선 조사하는 것이었다. 또한 불고기 소스의 물성 강화를 위해 잔탄검(1%, w/w)을 첨가하였다. 본 연구를 통해 제조된 불고기 및 소스는 향후 전투식량, 우주식품, 구호식품 및 특수목적 식품 등 다양한 식품 산업에 적용 가능할 것으로 판단된다.
more목차
ABSTRCT I
LIST OF CONTENTS V
LITERATURE REVIEW 1
1. GENERAL INTRODUTION 2
2. BULGOGI 5
3. FOOD IRRADIATION 9
4. READY-TO-EAT MEAL AND IRRADIATION 19
CHAPTER I EFFECTS OF DIFFERENT STERILIZING TREATMENTS AND RADIATION-COMBINED TREATMENTS ON QUALITY OF BULGOGI 23
ABSTACT 24
1. INTRODUCTION 26
2. MATERIALS AND METHODS 28
2.1. Materials 28
2.2. Preparation of Bulgogi 28
2.3. Different sterilizing treatments of samples 30
2.4. Radiation-combined treatments of samples 30
2.5. Total bacterial populations 32
2.6. Evaluation of physicochemical properties 32
2.6.1. pH 32
2.6.2. Hardness 32
2.6.3. 2-Thiobarbituric acid values 32
2.6.4. Volatile basic nitrogen 33
2.7. Sensory evaluation 34
2.8. In vitro protein digestibility 34
2.9. Volatile compounds 35
2.10. Statistical analysis 35
3. RESULTS AND DISCUSSION 37
3.1. Effects of different sterilizing treatments on Bulgogi 37
3.1.1. Total bacterial populations 37
3.1.2. Evaluation of physicochemical properties 39
3.1.2.1. pH 39
3.1.2.2. Hardness 41
3.1.2.3. 2-Thiobarbituric acid values 43
3.1.2.4. Volatile basic nitrogen 45
3.1.3. Sensory property 47
3.1.4. In vitro protein digestibility 50
3.2. Radiation effect on aerobic or vacuum packaged
Bulgogi 52
3.2.1. Total bacterial populations 52
3.2.2. 2-Thiobarbituric acid values 54
3.2.3. Sensory property 57
3.2.4. Volatile compounds 59
3.3. Radiation effect on antioxidants added Bulgogi 61
3.3.1. Sensory evaluation for determination of the optimal
addition level 61
3.3.2. Total bacterial populations 63
3.3.3. 2-Thiobarbituric acid values 65
3.3.4. Volatile compounds 67
3.4. Radiation effect on Bulgogi packaged with charcoal
teabag 69
3.4.1. Total bacterial populations 69
3.4.2. 2-Thiobarbituric acid values 71
3.4.3. Sensory property 73
3.4.4. Volatile compounds 76
3.5. Effect of different irradiation temperature on Bulgogi 78
3.5.1. Total bacterial populations 78
3.5.2. 2-Thiobarbituric acid values 81
3.5.3. Sensory property 83
3.5.4. Volatile compounds 86
3.5.5. Sensory property and volatile compounds of
combination treated samples 88
4. CONCLUSION 91
CHAPTER II STUDY OF BULGOGI SAUCE HAVING STABLE RHEOLOGY AFTER EXTREME STERILIZING TREATMENTS 93
ABSTACT 94
1. INTRODUCTION 95
2. MATERIALS AND METHODS 97
2.1. Materials 97
2.2. Evaluation of rheological stability of various gums 97
2.2.1. Preparation of gum solutions 97
2.2.2. Gamma irradiation 97
2.2.3. Viscosity 98
2.2.4. Molecular weight 98
2.2.5. Reducing end level 98
2.2.6. Water solubility 99
2.2.7. UV spectrum 99
2.2.8. pH 100
2.2.9. Hunter's color value 100
2.3. Application of xanthan gum into Bulgogi sauce 100
2.3.1. Preparation of sauce containing xanthan gum 100
2.3.2. Gamma irradiation and autoclave treatments 101
2.3.3. Total bacterial populations 102
2.3.4. Evaluation of physicochemical properties 102
2.3.4.1. pH 102
2.3.4.2. Viscosity 102
2.3.4.3. Water solublity 102
2.3.4.4. Hunter's color value 102
2.3.4.5. Appearance 102
2.3.5. Sensory evaluation 103
2.4. Statistical analysis 103
3. RESULTS AND DISCUSSION 104
3.1. Effect of irradiation on physicochemical properties of
various gums 104
3.1.1. Viscosity 104
3.1.2. Molecular weight 107
3.1.3. Reducing end level 109
3.1.4. Water solubility 111
3.1.5. UV spectrum 113
3.1.6. pH 115
3.1.7. Hunter's color value 117
3.2. Effects of different sterilizing treatments on Bulgogi
sauce containing xanthan gum 119
3.2.1. Total bacterial populations 119
3.2.2. Evaluation of physicochemical properties 121
3.2.2.1. pH 121
3.2.2.2. Viscosity 123
3.2.2.3. Water solubility 125
3.2.2.4. Hunter's color value 127
3.2.2.5. Appearance 129
3.2.3. Sensory property 131
4. CONCLUSTION 133
CHAPTER III DETERMINATION OF PROCESS TO PRODUCE RTE SPACE BULGOGI 134
ABSTRACT 135
1. INTRODUCTION 136
2. MATERIALS AND METHODS 137
2.1. Materials 137
2.2. Preparation of RTE Bulgogi 137
2.3. Evaluation of sterilizing dose and qualities of RTE
Bulgogi 139
2.3.1. Total bacterial population 139
2.3.2. Isolation, D10 and 12D10 value of microorganisms
from on RTE Bulgogi 139
2.3.3. 2-Thiobarbituric acid values 141
2.3.4. Sensory evaluation 142
2.3.5. Volatile compounds 142
2.4. Toxicological and nutritional wholesomeness test of
RTE Bulgogi 142
2.4.1. Mutagenic safety 142
2.4.1.1. Ames test 142
2.4.1.2. SOS chromotest 143
2.4.2. Subacute toxicity test 145
2.4.2.1. Clinical observation, body weight, and food
consumption 147
2.4.2.2. Hematology and serum biochemistry analysis
147
2.4.2.3. Tissue preparation and histopathologic
examination 148
2.4.3. Changes of nutritions 148
2.4.3.1. Analysis of fatty acid composition 148
2.4.3.2. Analysis of free amino acid composition 149
2.5. Space food certification test of RTE Bulgogi 150
2.5.1. Microbiological analysis by Russian Institute 150
2.5.2. Organoleptic analysis by Russian Institute 151
2.6. Statistical analysis 151
3. RESULTS AND DISCUSSION 152
3.1. Sterilizing dose and qualities of RTE Bulgogi 152
3.1.1. Total bacterial population 152
3.1.2. Isolation, D10 and 12D10 value of microorganisms
from on RTE Bulgogi 152
3.1.3. 2-Thiobarbituric acid values 156
3.1.4. Sensory property 158
3.1.5. Volatile compounds 160
3.2. Toxicological and nutritional wholesomeness test of
RTE Bulgogi 162
3.2.1. Mutagenic safety 162
3.2.1.1. Ames test 162
3.2.1.2. SOS chromotest 164
3.2.2. Subacute toxicity test 166
3.2.2.1. Body weight and food consumption 166
3.2.2.2. Organ weight 166
3.2.2.3. Leukocyte values 166
3.2.2.4. Erythrocyte and thrombocyte values 167
3.2.2.5. Serum biochemical values 167
3.2.2.6. Histopathological examination 167
3.2.3. Changes of nutritions 175
3.2.3.1. Analysis of fatty acid composition 175
3.2.3.2. Analysis of free amino acid composition 177
3.3. Space food certification test of RTE Bulgogi 179
3.3.1. Microbiological analysis 179
3.3.2. Organoleptic analysis 180
4. CONCLUSTION 182
SUMMARY 183
REFERENCE 187
KOREAN ABSTRACT 208
ACCOMPLISHMENTS OF PUBLISHED RESEARCH PAPERS AND PATENTS DURING COURSE WORK (SEP. 2007 ~ FEB. 2011) 213
KOREAN ACKNOWLEDGEMENT 221
