Studies on factors affecting beef taste and the effects of dietary glycerin on growth performance and carcass characteristics in Korean cattle steers

학위논문 (박사)-- 서울대학교 대학원 : 농업생명과학대학 농생명공학부, 2018. 2. 백명기.Beef marbling score and quality grade positively affect meat sensory characteristics, including tenderness, juiciness, flavor, and overall palatability. Korean cattle beef is well known for good palatability because of the high quality grade and thus high marbling. Limited information is available and variability exists in data on the associations among marbling score/quality grade, meat characteristics, and sensory traits in Korean cattle beef. Korean consumers prefer Korean cattle beef to domestic Holstein and imported beef because they believe that the palatability of Korean cattle beef is superior to that of other breeds. Limited information is available on the factors that affect the preference of Korean consumers for Korean cattle beef over other breeds. Two studies (study 1 and 2) were conducted to elucidate 1) the associations among quality grade/marbling and various carcass characteristics and sensory traits in Korean cattle beef, and 2) the factors that contribute to differences in the sensory traits of longissimus thoracis of different breeds. Glycerol, a by-product with biodiesel, also known as glycerin, serves as gluconeogenic substrate in the liver and kidney, and it has an energy value similar to corn on a pound-for-pound basis in dairy and feedlot cattle. Although many studies were conducted for the effect of glycerin on carcass composition and characteristics in various animal diets, the outcomes were not consistent. Also, limited information is available for effects of glycerin supplementation on meat characteristics in Korean cattle steers. Two studies (study 3 and 4) were conducted to identify 3) the effects of dietary glycerin replacement on growth performance, carcass characteristics and sensory traits in Korean cattle steers fed diets based on the similar TDN level between experimental diets, and 4) the effects of crude glycerin supplementation on growth performance and carcass characteristics in Korean cattle steers fed diets based on the different TDN level between experimental diets. 1. Comparison of carcass and sensory traits, fatty acid profiles and volatile compounds among quality grades in longissimus dorsi and semimembranosus muscles of Korean cattle steer This study was performed to compare carcass traits, sensory characteristics, physicochemical composition, nucleotides and collagen content, free amino acids, content and composition of fatty acids (FA), and volatile compounds among four quality grades (QG1++, 1+, 1, and 2), and to understand their association with carcass characteristics in longissimus dorsi (loin) and semimembranosus (rump) cuts of Korean cattle steers. This study confirms that marbling score (MS) and intramuscular fat (IMF) content are major positive determinants of QG in Korean cattle beef. Numeric values of tenderness, juiciness, and overall acceptability in loin tended to be highest in QG1++, and those of juiciness and overall acceptability tended to be lowest in QG 2. Juiciness and overall acceptability were strongly correlated with QG. Our results demonstrated that QGs are linked to sensory traits. However, the nucleotide contents including inosine monophosphate (IMP) may not be major factors determining meat palatability of Korean cattle beef in this study. Glutamic acid and proline were significantly associated with tenderness, juiciness, and overall acceptability, although they did not differ significantly among QGs. In addition, beef QGs affected the compositions and contents of FAs and volatile compounds in loin and rump. Loin FA percentages, especially those of oleic acid (C18:1n9) and monounsaturated FA (MUFA), generally increased with increasing QGs. Some volatile compounds in loin and rump varied with QGs and were positively or negatively correlated with flavor. 2. Comparison of reducing sugar content, sensory traits, and fatty acids and volatile compound profiles of longissimus thoracis among Korean cattle, Holsteins, and Angus steers This study was performed to compare intramuscular fat (IMF) and reducing sugar contents, sensory traits, and fatty acid (FA) and volatile compound profiles in longissimus thoracis (LT) among Korean cattle (KC), Holstein (HO), and Angus (AN) steers. The IMF, reducing sugar content, and sensory traits of the LT varied among KC, HO, and AN steers. The KC LT had the highest IMF and reducing sugar contents, and the best sensory traits (flavor, tenderness, juiciness, and overall acceptance). The IMF and reducing sugar contents were positively correlated with all of the sensory traits, suggesting that these factors may positively affect beef flavor. Palmitic acid (C16:0), oleic acid (C18:1n9), and monounsaturated FA (MUFA) may positively affect sensory traits, whereas linoleic acid (C18:2), and polyunsaturated FA (PUFA) may negatively affect sensory traits. The percentages of different volatile compounds in the LT also varied among the three breeds. The KC had the highest percentage of volatile compounds, including acetaldehyde, 3-methyl butanal, and 3-hydroxy-2-butanone, and these compounds were positively correlated with flavor. Our results demonstrated that variations in IMF, reducing sugar content, and FA and volatile compound profiles may contribute to differences in the sensory characteristics of the LT among breeds. The results of this study enhance our understanding of the association of reducing sugar and volatile compound contents with the sensory traits of beef. This information may help in determining beef palatability. 3. Effects of dietary glycerin replacement on growth performance and rumen and carcass characteristics in Korean cattle steers The study was performed to evaluate the effect of 3% dietary glycerin replacement on growth performance, blood metabolites, ruminal fermentation characteristics, carcass characteristics and sensory traits, hepatic gluconeogenic gene expression, and muscle glycogen contents in Korean cattle steers. Glycerin replacement in the finishing diet of Korean cattle steers had no impact on weight gain, average daily gain, and feed efficiency except for increase in average daily concentrate intake. This increased intake may be attributed to the sweet taste of glycerins property. Glycerin replacement did not affect carcass characteristics, chemical and physico-chemical composition, reducing sugar, glycogen, collagen, nucleotides, fatty acid, volatile compounds, and sensory traits in the longissimus thoracis. These results indicate that the glycerin inclusion level (3%) may be not enough to improve animal performance and carcass characteristics. In addition, feeding concentrate containing 3% of glycerin did not result in detrimental effects on growth performance, ruminal fermentation, animals physical condition, and metabolism. This is important not only on animal performance and carcass characteristics but also for sustainable and economic aspects because glycerin is a biodiesel residue and it can potentially partially replace some expensive ingredients such as corn, molasses, distillers dried grains with solubles as an energy source for beef cattle. 4. Effect of dietary crude glycerin supplementation on performance, blood metabolites, ruminal fermentation parameters, and carcass characteristics in Korean cattle steers This study was performed to evaluate the effect of dietary glycerin supplementation on growth performance, blood metabolites, ruminal fermentation characteristics, carcass characteristics and sensory traits, glycogen content in liver and muscle, and hepatic gluconeogenesis gene expression in Korean cattle steers finished in feedlot. This study confirms that dietary glycerin supplementation at 6.4% of DM did not lead to detrimental effect on feed intake in Korean cattle steers. Both glycerin and corn starch supplementation did not improve average daily gain and feed efficiency in Korean cattle steers. Glycerin supplementation also did not affect rumen fermentation characteristics, carcass characteristics, IMF content, reducing sugar content, glycogen content in both liver and muscle, and sensory traits of Korean cattle steers. Both glycerin and corn starch supplementation did not affect serum glucose concentration at initial and 8th week, but glycerin supplementation slightly increased the average serum glucose concentration at 16th week. Although glycerin supplementation had no impact on carcass and meat quality, glycerin could be potentially considered as a good energy source to maintain the animals metabolism in finishing Korean cattle.CHAPTER ONE 1 GENERAL INTRODUCTION 1 CHAPTER TWO 4 LITERATURE REVIEW 4 1. Overview of Korean cattle 4 1) History of Korean cattle 4 2) Korean cattle industry 5 3) Beef quality grading system in Korea 7 4) Characteristics of Korean cattle beef 8 2. Factors affecting sensory traits 12 1) Tenderness 12 2) Flavor 13 3) Juiciness 17 4) Precursors of flavor 17 3. Glycerin as feedstuff 20 1) Properties of glycerol 21 2) Glycerol as energy source 22 3) Glycerol fermentation in rumen 25 4) Glycerol metabolism in ruminants 28 5) Effect of glycerol on carcass characteristics and sensory traits 30 4. References 33 CHAPTER THREE 43 Comparison of carcass and sensory traits, fatty acid profiles and volatile compounds among quality grades in longissimus dorsi and semimembranosus muscles of Korean cattle steers 43 1. Abstract 43 2. Introduction 45 3. Materials and methods 49 3.1. Animals and sampling 49 3.2. Proximate composition, cooking loss, shear force, pH, and color 53 3.3. Nucleotide content 53 3.4. Total and insoluble collagen contents 54 3.5. Free amino acids 55 3.6. Sensory evaluation 56 3.7. Fatty acid composition 57 3.8. Volatile compounds 58 3.9. Statistical analysis 60 4. Results and discussion 60 5. Conclusion 119 6. References 120 CHAPTER FOUR 127 Comparison of reducing sugar content, sensory traits, and fatty acids and volatile compound profiles of longissimus thoracis among Korean cattle, Holsteins, and Angus steers 127 1. Abstract 127 2. Introduction 128 3. Materials and methods 130 3.1. Beef sample preparation 130 3.2. Proximate composition, color, pH, shear force, and collagen content 133 3.3. Reducing sugars 133 3.4. Sensory evaluation 134 3.5. Fatty acid composition 135 3.6. Volatile compounds 136 3.7. Statistical analysis 137 4. Results and discussion 138 5. Conclusion 164 6. References 165 CHAPTER FIVE 169 Effects of dietary glycerin replacement on growth performance and rumen and carcass characteristics in Korean cattle steers 169 1. Abstract 169 2. Introduction 170 3. Materials and methods 173 3.1. Animals, housing, and diets 173 3.2. Blood, rumen fluid collections and measurements 177 3.3. Slaughter procedures and tissue sample collections 178 3.4. mRNA level in the liver 180 3.5. Chemical and physicochemical composition, color, pH, and shear force 181 3.6. Reducing sugar content 181 3.7. Sensory evaluation 181 3.8. Glycogen concentration 181 3.9. Fatty acid profile 182 3.10. Volatile compound 183 3.11. Statistical analysis 183 4. Results and discussion 184 5. Conclusion 208 6. References 209 CHAPTER SIX 215 Effect of dietary crude glycerin supplementation on growth performance, blood metabolites, ruminal fermentation parameters, and carcass characteristics in Korean cattle steers 215 1. Abstract 215 2. Introduction 216 3. Materials and methods 219 3.1. Animals, housing, and diets 219 3.2. Blood, rumen fluid collections and measurements 222 3.3. Slaughter procedures and tissue sample collections 223 3.4. mRNA level in the liver 225 3.5. Chemical and physicochemical compositions, color, pH, shear force, and water holding capacity 225 3.6. Reducing sugar content 226 3.7. Sensory evaluation 226 3.8. Glycogen concentration 226 3.9. Statistical analysis 226 4. Results and discussion 227 5. Conclusion 248 6. References 249 CHAPTER SEVEN 254 General conclusion 254 SUMMARY IN KOREAN 259Docto

Microbiology aetioloty of halitosis

학위논문 (석사)-- 서울대학교 대학원 : 치의학과, 2011.2. 김영구.Maste

측두하악장애 통증 환자의 통증 기원 및 외상 병력에 따른 임상적 특징에 관한 연구

학위논문 (석사)-- 서울대학교 대학원 : 치의학과 구강내과·진단학 전공, 2016. 2. 정진우.Temporomandibular disorder(TMD) is a multifactorial disease with chronic pain that was related with physical and psychological symptoms. Pain is the most common TMD symptom and showed different psychosocial and clinical patterns depending on the origin in the previous studies. Trauma on the orofacial or neck region potentially lead to increase severity and frequency of tempormandibular joint pain and to aggravate psychological factors. The aims of this study were to compare the differences in the clinical pain and psychological condition between the patients with and without history of trauma on the orofacial or neck region, and among the myogenous, arthrogenous, and mixed pain origin of TMD pain patients. A total of 1052 patients (mean age 34.4±15.7 years, 791 women and 261 men) with TMD who visited the Orofacial Pain Clinic of Seoul National University Dental Hospital were evaluated. Patients were divided into trauma and non-trauma groups according to the history of trauma in the orofacial or neck region, and the patients with TMD pain were categorized into three groups (Myogenous, Arthrogenous, and Mixed) according to the pain origin based on the RDC/TMD axis I diagnostic guidelines. Each patient was evaluated the clinical characteristics according to the RDC / TMD axis I and axis II questionnaires. The psychological characteristics were evaluated by the Symptom Checklist-90-R (SCL-90-R). The obtained results were as follows: 1. There were no significant differences in age and gender among the TMD pain groups and between trauma and non-trauma groups. 2. Myogenous pain group showed significantly higher SOM, GSI, PSDI, and PST scores than arthrogenous pain group. Mixed pain group showed significantly higher SOM, I-S, DEP, ANX, HOS, PHOB, PAR, PSY, GSI, PSDI, and PST scores than arthogenous pain group. 3. Trauma group has significantly higher SOM, ANX, PSY, GSI, PSDI, and PST scores than non-trauma group. 4. Mixed pain group showed significantly higher intensity of pain than two other groups and the percentage of high disability group in GCPS was higher in the order to mixed pain group, myogenous pain group, arthrogenous pain group. 5. Trauma group showed significantly higher intensity of pain and higher percentage of high disability group. There were no significant differences in duration of pain among the each group. 6. Arthogenous pain group showed lowest prevalence of headache, subjective insomnia, and tinnitus among the TMD pain groups. Myogenous pain group had highest prevalence of sleep bruxism. 7. Trauma group showed significant high prevalence of headache than non-trauma group. There were no significant differences in the prevalence of subjective insomnia, sleep bruxism, and tinnitus between non-trauma and trauma groups. 8. Patients who had both myogenous origin and history of trauma showed highest scores in the most SCL-90-R dimensions among the groups. Trauma history and pain origin could affect the clinical symptoms and psychological characteristics of patients with TMD pain and should be considered for the establishment of treatment.Ⅰ. INTRODUCTION 1 Ⅱ. MATERIALS AND METHODS 2 1. Subjects 2 2. Evaluation of psychological characteristics 3 3. Evaluation of Clinical pan characteristics and contributing factors 4 Ⅲ. RESULTS 4 1. Evaluation of psychological characteristics 5 2. Evaluation of clinical pan characteristics and contributing factors 5 3. Comparison of pain intensity, pain duration, and psychological profiles among groups combined with pain origin subtypes and trauma history 5 Ⅳ. DISCUSSION 6 Ⅴ. CONCLUSIONS 8 Ⅵ. REFERENCES 9 TABLES 12 KOREAN ABSTRACT 23Maste

The effect of proton pump inhibitor on endoscopic finding of larynx and esophagus in patients with laryngopharygeal reflux symptom

학위논문 (석사)-- 서울대학교 대학원 : 의학과(이비인후과전공), 2013. 8. 이철희.서론: 인후두역류증은 이비인후과 영역에서 흔한 질환으로 최근 병태생리를 이해하는데 위-식도 역류에 주목하고 있다. 인후두 역류증 환자에서 후두 및 식도에 대한 내시경적 소견이 양성자 펌프 억제제를 사용한 후 어떻게 변하는지 확인하고 증상과 어떤 관련성을 보이는지 연구하였다. 방법: 2012년 10월부터 2013년 3월까지 인후두역류증으로 이비인후과를 내원한 환자 36명을 대상으로 이루어졌다. 내원 시 설문지를 통한 역류 증상 점수와 후두 내시경을 통한 역류 소견 지수를 얻었다. 경비식도내시경 검사를 통해 위식도역류 여부를 확인하고 Los Angeles 분류에 따라 역류성 식도염을 분류하였다. 양성자 펌프 억제제를 2개월간 복용한 후 설문지, 후두 내시경, 경비강 식도내시경을 시행하여 치료 전과 동일한 방법으로 자료를 얻었다. 결과: 총 36명의 환자 중 2개월 후 검사를 종료한 22명을 대상으로 분석하였다. 평균 연령은 52.8세이었으며, 남자는 4명, 여자는 18명이었다. 주된 증상은 경부 이물감이었다. 치료 전에 비해 치료 후 인후두 역류 증상, 역류 소견 지수와 역류성 식도염의 소견의 호전율은 각각 50%, 45%, 27%이었으며, 증상 및 후두 소견은 통계적으로 유의하게 호전되었다(p=0.003, 0.018). 그러나 역류 증상의 호전 여부, 역류 소견의 호전 여부, 역류성 식도염의 호전 여부 사이에는 상관관계가 보이지 않았다. 역류 증상의 호전이 된 11명 중에 4명은 후두 및 인두의 내시경적인 변화를 보이지 않았다. 결론: 인후두 역류증에서 양성자 펌프 억제제가 증상 호전에 도움을 주지만, 후두 및 식도의 내시경적 소견의 호전과 연관성을 보이지 않는다.Introduction: layrngopharyngeal reflux(LPR) is a common disorder. The mechanism of LRP is not clear until now. Here, we evaluated the endoscopic findings of larynx and esophagus after proton pump inhibitor(PPI), and analyzed the relationship with patients symptom. Methods: The 36 patients who complained of LPR symptom were enrolled. The reflux symptom, larynx finding and esophageal finding were assessed by reflux symptom index, reflux finding score and Los angeles classification, respectively. The data were collected at pre-treatment and 2 month after PPI treatment. Results:. Of the 36 patients with LPR, the 22 patients who finished all examinations were analyzed. Mean age was 52.8 years and 4 patients were male. The most common symptom was foreign body sensation on throat. The symptom, laryngeal finding and esophageal finding were improved significantly at 2 months after PPI treatment. There was no correlation between symptom, laryngeal finding and esophageal finding. Of patients whose symptom improved, the laryngeal and esophageal finding did not improve. Conclusions: Although symptom, laryngeal finding and esophageal finding may be improved after PPI treatment, the improvement of symptom may not correlate the improvement of endoscopic finding of larynx and esophagus.초록 i 목차 iii 표 및 그림 목록 iv 서론 1 대상환자 및 방법 3 결과 11 고찰 21 결론 24 참고문헌 25 초록 (영문) 28Maste

Effects of synchronization of carbohydrate and protein supply in total mixed ration with Korean rice wine residue on ruminal fermentation, nitrogen metabolism and microbial protein synthesis in holstein steers

학위논문 (석사)-- 서울대학교 대학원 : 농생명공학부, 2011.8. 하종규.Maste

Review On Weak Convergence of Diffusion Processes Generated by Energy Forms

학위논문 (석사)-- 서울대학교 대학원 : 수리과학부, 2014. 2. Gerald Trutnau.We prove weak convergence of a sequence of stationary measures associated with Dirichlet forms using Mosco-convergence and Prokhorov's theorem. We explain explicitly the details in Uemura's paper, [5] 『On Weak Convergence of Diffusion Processes Generated by Energy Forms (1995)』.Abstract 1 Introduction 2 Statement of Theorem 3 Conservativeness and Tightness 4 Mosco-Convergence 5 Theorem 7 of Albeverio-Hegh-Krohn-Streit, [1] 6 Proof of Main Theorem 7 An Example References 국문 초록Maste

Macroscopic Phase Separations to Prepare Functional Polyemr Particles, Fibrils, and Patterns

1