Lu, Ying. / Thesis submitted in: March 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 142-155). / Abstracts in English and Chinese. / THESIS COMMITTEE --- p.i / ACKNOWLEDGEMENTS --- p.iii / ABSTRACT(ENGLISH) --- p.iv / ABSTRACT(CHINESE) --- p.vi / TABLE OF CONTENT --- p.viii / LIST OF TABLES --- p.xii / LIST OF FIGURES --- p.xiv / ABBREVIATIONS --- p.xvii / Chapter CHAPTER 1: --- LITERATURE REVIEW --- p.1 / Chapter 1.1 --- Background of Sufu --- p.1 / Chapter 1.2 --- Classification of Sufu --- p.2 / Chapter 1.3 --- Production of Sufu --- p.3 / Chapter 1.3.1 --- Preparation of Tofu --- p.7 / Chapter 1.3.2 --- Preparation of Pehtze --- p.7 / Chapter 1.3.3 --- Salting and Brining --- p.8 / Chapter 1.3.4 --- Aging --- p.8 / Chapter 1.4 --- Biological and Chemical Changes during Sufu Production --- p.8 / Chapter 1.4.1 --- Microbial Changes during Sufu Production --- p.8 / Chapter 1.4.2 --- Proteolysis during Sufu Production --- p.9 / Chapter 1.4.3 --- Lipolysis during Sufu Production --- p.10 / Chapter 1.4.4 --- Flavor during Sufu Production --- p.10 / Chapter 1.5 --- Benefits of Sufu --- p.11 / Chapter 1.6 --- Existing Problems --- p.12 / Chapter 1.7 --- Exogenous Enzymes for Acceleration of Sufu Fermentation --- p.13 / Chapter 1.8 --- The Orthogonal Experimental Design --- p.14 / Chapter 1.9 --- Objective of This Study --- p.17 / Chapter CHAPTER 2: --- SURVEY ON PHYSICAL AND CHEMICAL PARAMETERS OF COMMERCIAL SUFU --- p.18 / Chapter 2.1 --- Introduction --- p.18 / Chapter 2.2 --- Materials and Methods --- p.19 / Chapter 2.2.1 --- Crude Protein Analysis --- p.19 / Chapter 2.2.2 --- Crude Fat Analysis --- p.19 / Chapter 2.2.3 --- Texture Profile Analysis (TPA) --- p.20 / Chapter 2.2.4 --- Free Amino Acid Analysis --- p.21 / Chapter 2.2.4.1 --- Chemicals and Standards --- p.23 / Chapter 2.2.4.2 --- Other Materials --- p.24 / Chapter 2.2.4.3 --- Additional Equipment --- p.24 / Chapter 2.2.4.4 --- Sample Pre-treament --- p.24 / Chapter 2.2.4.5 --- Preparing the Eluting Medium --- p.25 / Chapter 2.2.4.6 --- SPE and Derivatization --- p.25 / Chapter 2.2.4.7 --- GC-MS Conditions --- p.26 / Chapter 2.2.4.8 --- Calibration and Standard Curve Set Up --- p.26 / Chapter 2.2.4.9 --- Statistical Analysis --- p.27 / Chapter 2.2.5 --- Free Fatty Acid Analysis --- p.27 / Chapter 2.2.5.1 --- Chemicals and Standards --- p.27 / Chapter 2.2.5.2 --- Equipment --- p.28 / Chapter 2.2.5.3 --- Calibration and Standard Curve Set Up --- p.29 / Chapter 2.2.5.4 --- Free Fatty Acid Extraction --- p.29 / Chapter 2.2.5.5 --- GC-MS Conditions --- p.30 / Chapter 2.2.5.6 --- Statistical Analysis --- p.30 / Chapter 2.2.6 --- Sample Collection: Commercial Brands of Sufu --- p.31 / Chapter 2.3 --- Results --- p.32 / Chapter 2.3.1 --- Results of Crude Protein Contents in Commercial Sufus --- p.32 / Chapter 2.3.2 --- Results of Crude Fat Contents in Commercial Sufus --- p.33 / Chapter 2.3.3 --- Results of Texture Profile Analysis in Commercial Sufus --- p.34 / Chapter 2.3.4 --- Results of Free Amino Acids in Commercial Sufus --- p.37 / Chapter 2.3.5 --- Results of Free Fatty Acids in Commercial Sufus --- p.47 / Chapter 2.4 --- Discussion --- p.55 / Chapter CHAPTER 3: --- SHORTEN THE FERMENTATION TIME USING EXOGENOUS ENZYMES BY THE ORTHOGONAL EXPERIMENTAL DESIGN AND OPTIMIZE RESULTANT PROPERTIES --- p.58 / Chapter 3.1 --- Introduction --- p.58 / Chapter 3.2 --- Materials and Methods --- p.58 / Chapter 3.2.1 --- Laboratory-scale Sufu Production --- p.58 / Chapter 3.2.1.1 --- Preparation of Tofu --- p.58 / Chapter 3.2.1.2 --- Sub-culture Mold Strain --- p.59 / Chapter 3.2.1.3 --- Spore Suspension --- p.59 / Chapter 3.2.1.4 --- Preparation of Pehtze --- p.60 / Chapter 3.2.1.5 --- Inoculation of Tofu --- p.61 / Chapter 3.2.2 --- Brining and Aging with Addition of Enzyme Mixture --- p.62 / Chapter 3.2.3 --- Exogenous Enzymes of Food-grade --- p.62 / Chapter 3.2.3.1 --- Protamex --- p.63 / Chapter 3.2.3.2 --- Palatase --- p.64 / Chapter 3.2.3.3 --- Lipase --- p.64 / Chapter 3.2.3.4 --- Flavorzyme --- p.65 / Chapter 3.2.4 --- The Orthogonal Experimental Design --- p.65 / Chapter 3.2.4.1 --- Factors --- p.65 / Chapter 3.2.4.2 --- Statistical Analysis of Orthogonal Design L9 (34) --- p.66 / Chapter 3.2.5 --- "Crude Protein, Crude Fat and TPA Analysis" --- p.67 / Chapter 3.2.6 --- Free Amino Acid and Free Fatty Acid Analysis --- p.67 / Chapter 3.3 --- Results --- p.68 / Chapter 3.3.1 --- Orthogonal Results of Crude Protein Contents --- p.69 / Chapter 3.3.2 --- Orthogonal Results of Crude Fat Contents --- p.71 / Chapter 3.3.3 --- Orthogonal Results of Texture Profiles --- p.73 / Chapter 3.3.4 --- Orthogonal Results of Free Amino Acids --- p.80 / Chapter 3.3.5 --- Orthogonal Results of Free Fatty Acids --- p.108 / Chapter 3.4 --- Discussion --- p.121 / Chapter 3.4.1 --- Crude Protein of Enzyme Adding Sufu in Orthogonal Experiment --- p.121 / Chapter 3.4.2 --- Crude Fat of Enzyme Adding Sufu in Orthogonal Experiment --- p.122 / Chapter 3.4.3 --- Texture Profiles of Enzyme Adding Sufu in Orthogonal Experiment --- p.123 / Chapter 3.4.4 --- FAAs of Enzyme Adding Sufu in Orthogonal Experiment --- p.124 / Chapter 3.4.5 --- FFAs of Enzyme Adding Sufu in Orthogonal Experiment --- p.128 / Chapter CHAPTER 4: --- DISCUSSIONS AND CONCLUSION --- p.131 / REFERENCE --- p.142 / APPENDIX --- p.156

Chang Pui Sze. / Thesis submitted in: October 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 204-227). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract (In English) --- p.ii / Abstract (In Chinese) --- p.iv / List of Tables --- p.vi / List of Figures --- p.x / Contents --- p.xii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Historical Background of Sufu --- p.1 / Chapter 1.2 --- Nutritional Benefits of Sufu --- p.2 / Chapter 1.3 --- Production Steps --- p.2 / Chapter 1.3.1 --- Preparation of Tofu --- p.5 / Chapter 1.3.2 --- Preparation of Pehtze --- p.5 / Chapter 1.3.3 --- Salting or Brining --- p.8 / Chapter 1.3.4 --- Aging --- p.9 / Chapter 1.4 --- Local Varieties of Sufu --- p.9 / Chapter 1.5 --- Other Types of Sufu Fermentation --- p.10 / Chapter 1.6 --- Biochemical Changes during Sufu Production --- p.11 / Chapter 1.6.1 --- Protein Faction --- p.12 / Chapter 1.6.2 --- Lipid Fraction --- p.14 / Chapter 1.6.3 --- Carbohydrate fraction --- p.14 / Chapter 1.7 --- Sufu Flavor --- p.14 / Chapter 1.7.1 --- "Water-soluble Peptides, Free Amino Acids and Tasty Oligopeptides" --- p.14 / Chapter 1.7.2 --- Nucleotide Contents in the Taste of Sufu --- p.15 / Chapter 1.7.3 --- Effects of Ethanol on Flavor Development --- p.15 / Chapter 1.7.4 --- Volatile Components in Sufu --- p.16 / Chapter 1.8 --- Microbiological Safety of Sufu --- p.18 / Chapter 1.9 --- Existing Problems in Sufu Production --- p.19 / Chapter 1.10 --- Acceleration of Sufu Maturation by Adding Exogenous Lipase --- p.20 / Chapter 1.10.1 --- Proteases --- p.22 / Chapter 1.10.2 --- Problems with Proteases --- p.24 / Chapter 1.10.3 --- Lipases --- p.25 / Chapter 1.10.4 --- Problems with Lipases --- p.26 / Chapter 1.11 --- Replacement of Sodium Salt in Food with Alternative Salts --- p.29 / Chapter 1.12 --- Objectives --- p.33 / Chapter 2 --- Development of Volatile Compounds in Sufu --- p.35 / Chapter 2.1 --- Introduction --- p.35 / Chapter 2.2 --- Materials and Method --- p.36 / Chapter 2.2.1 --- Sufu Production --- p.36 / Chapter 2.2.1.1 --- Preparation of Tofu --- p.36 / Chapter 2.2.1.2 --- Inoculation of Tofu --- p.37 / Chapter 2.2.1.2.1 --- The Mold Strain --- p.37 / Chapter 2.2.1.2.2 --- Spore Suspension --- p.38 / Chapter 2.2.1.2.3 --- Spore Count in Spore Suspension --- p.38 / Chapter 2.2.1.3 --- Preparation of Pehtze --- p.39 / Chapter 2.2.1.4 --- Brining and Aging --- p.41 / Chapter 2.2.2 --- Sampling of Sufu --- p.42 / Chapter 2.2.3 --- Flavor Analysis --- p.42 / Chapter 2.2.3.1 --- Simultaneous Steam Distillation-Solvent Extraction (SDE) --- p.42 / Chapter 2.2.3.2 --- Gas chromatography-mass spectrometry (GC-MS) Conditions --- p.43 / Chapter 2.2.3.3 --- Compound Identification and Quantification --- p.44 / Chapter 2.3 --- Results --- p.45 / Chapter 2.3.1 --- Evolution of Volatiles During Sufu Aging --- p.45 / Chapter 2.3.1.1 --- Esters --- p.46 / Chapter 2.3.1.2 --- Alcohols --- p.51 / Chapter 2.3.1.3 --- Aldehydes --- p.55 / Chapter 2.3.1.4 --- Ketones --- p.55 / Chapter 2.3.1.5 --- Other Nitrogen-containing Compounds --- p.59 / Chapter 2.3.1.6 --- Sulfur (S)-containing and Oxygen (O)-containing Compounds --- p.51 / Chapter 2.3.1.7 --- Pyrazines --- p.61 / Chapter 2.3.1.8 --- Miscellaneous Compounds --- p.63 / Chapter 2.3.2 --- Change in the Concentrations of Sufu Odorous Compounds with Time --- p.65 / Chapter 2.4 --- Discussion --- p.67 / Chapter 2.4.1 --- Quantitatively Important Volatile Components of Sufu --- p.67 / Chapter 2.4.2 --- Esters --- p.59 / Chapter 2.4.3 --- Alcohols --- p.72 / Chapter 2.4.3.1 --- 1-Hexanol --- p.72 / Chapter 2.4.3.2 --- Phenol and 2-Methoxyphenol --- p.74 / Chapter 2.4.4 --- Aldehydes --- p.75 / Chapter 2.4.4.1 --- Hexanal --- p.75 / Chapter 2.4.4.2 --- "(E,E)-2,4-Heptadienal" --- p.77 / Chapter 2.4.4.3 --- (E)-2-Heptenal --- p.78 / Chapter 2.4.4.4 --- Benzeneacetaldehyde --- p.79 / Chapter 2.4.5 --- Ketones --- p.80 / Chapter 2.4.5.1 --- 3-Hydroxy-2-Butanone --- p.81 / Chapter 2.4.6 --- Sulfur-Containing Compounds --- p.82 / Chapter 2.4.6.1 --- 3-(Methylthio)propanal --- p.82 / Chapter 2.4.7 --- Pentylfuran --- p.84 / Chapter 2.4.8 --- Naphthalene --- p.86 / Chapter 2.4.9 --- Contaminants and artifacts generated by A-SDE --- p.87 / Chapter 2.5 --- Conclusion --- p.92 / Chapter 3 --- Acceleration of Sufu Production with Exogenous Lipase Effect on Flavor Development --- p.95 / Chapter 3.1 --- Introduction --- p.95 / Chapter 3.2 --- Materials and Method --- p.96 / Chapter 3.2.1 --- Sufu Production --- p.96 / Chapter 3.2.2 --- The Addition of Lipases --- p.96 / Chapter 3.2.3 --- Sampling of Sufu --- p.97 / Chapter 3.2.4 --- Flavor Analysis --- p.97 / Chapter 3.2.5 --- Statistical Analysis of Sufu Flavor Compounds --- p.98 / Chapter 3.2.6 --- Proximate Analysis --- p.98 / Chapter 3.2.7 --- Freeze-Drying --- p.99 / Chapter 3.2.8 --- Statistical Analysis of Sufu Proximate Contents --- p.99 / Chapter 3.2.9 --- Sensory Evaluation of Experimental Sufu --- p.100 / Chapter 3.3 --- Results --- p.102 / Chapter 3.3.1 --- Experiment I ´ؤ Adding 0.01% (w/w) Lipase from Porcine Pancreas and Candida rugosa --- p.102 / Chapter 3.3.1.1 --- Esters --- p.104 / Chapter 3.3.1.2 --- Alcohols --- p.108 / Chapter 3.3.1.3 --- Aldehydes --- p.110 / Chapter 3.3.1.4 --- 3-Hydroxy-2-Butanone --- p.113 / Chapter 3.3.1.5 --- 3-(Methylthio)propanal --- p.114 / Chapter 3.3.1.6 --- 2-Pentylfuran --- p.115 / Chapter 3.3.1.7 --- Naphthalene --- p.115 / Chapter 3.3.2 --- Experiment II - Adding 0.02% Lipase from Porcine Pancreas and Candida rugosa --- p.117 / Chapter 3.3.2.1 --- Esters --- p.118 / Chapter 3.3.2.2 --- Alcohols --- p.123 / Chapter 3.3.2.3 --- Aldehydes --- p.125 / Chapter 3.3.2.4 --- 3-Hydroxy-2 -Butanone --- p.129 / Chapter 3.3.2.5 --- 3-(Methylthio)propanal --- p.129 / Chapter 3.3.2.6 --- 2-Pentylfuran --- p.131 / Chapter 3.3.2.7 --- Naphthalene --- p.131 / Chapter 3.3.3 --- Sensory Evaluation of Lipase-treated Sufu --- p.132 / Chapter 3.3.4 --- Proximate Composition of Sufu at Different Ages from the 3 Treatments --- p.134 / Chapter 3.3.4.1 --- Addition of 0.01%(w/w) Lipase to Sufu Aging Solution --- p.134 / Chapter 3.3.4.1.1 --- Crude Protein --- p.134 / Chapter 3.3.4.1.2 --- Crude Lipid --- p.135 / Chapter 3.3.4.1.3 --- Moisture --- p.138 / Chapter 3.3.4.1.4 --- Ash --- p.138 / Chapter 3.3.4.2 --- Addition of 0.02% (w/w) Lipase to Sufu Aging Solution --- p.141 / Chapter 3.3.4.2.1 --- Crude Protein --- p.141 / Chapter 3.3.4.2.2 --- Crude Lipid --- p.141 / Chapter 3.3.4.2.3 --- Moisture --- p.144 / Chapter 3.3.4.2.4 --- Ash --- p.144 / Chapter 3.4 --- Discussion --- p.147 / Chapter 3.4.1 --- Adding 0.01 % Lipase from Porcine Pancreas and Candida rugosa --- p.147 / Chapter 3.4.1.1 --- Comparison of Total Odorous Content --- p.147 / Chapter 3.4.1.2 --- Sensory Evaluation of Experimental Sufu --- p.147 / Chapter 3.4.2 --- Adding 0.02% Lipase from Porcine Pancreas and Candida rugosai --- p.150 / Chapter 3.4.2.1 --- Comparison of Total Odorous Content --- p.150 / Chapter 3.4.2.2 --- Sensory Evaluation of Experimental Sufu --- p.151 / Chapter 3.4.3 --- Summary of Sensory and TOC Results of Lipase Experiments --- p.153 / Chapter 3.4.4 --- Impact of Lipase Addition on Different Odorous Volatile Compounds --- p.153 / Chapter 3.4.4.1 --- Esters --- p.154 / Chapter 3.4.4.2 --- Alcohols --- p.155 / Chapter 3.4.4.3 --- Aldehydes --- p.157 / Chapter 3.4.4.4 --- 3-Hydroxy-2-Butanone --- p.159 / Chapter 3.4.4.5 --- 3-(Methylthio)propanal --- p.160 / Chapter 3.4.4.6 --- 2-Pentylfuran and Naphthalene --- p.161 / Chapter 3.4.5 --- Effect of Aging on Chemical Composition of Sufu --- p.161 / Chapter 3.4.5.1 --- Crude Protein --- p.161 / Chapter 3.4.5.2 --- Crude Lipid --- p.162 / Chapter 3.4.5.3 --- Ash --- p.163 / Chapter 3.4.6 --- Effect of Lipase Addition on Chemical Composition of Sufu --- p.163 / Chapter 3.4.7 --- Effect of Lipase Addition on Free Fatty Acid (FFA) Profiles --- p.164 / Chapter 3.4.8 --- Generation of Different Classes of Esters from Animal and Fungal Lipases --- p.168 / Chapter 3.5 --- Conclusion --- p.171 / Chapter 4 --- "Partial Substitution of Sodium Chloride with Potassium Chloride in Sufu Aging Solution - Effect on Proteolysis, Bacterial Growth and Flavor" --- p.174 / Chapter 4.1 --- Introduction --- p.174 / Chapter 4.2 --- Materials and Method --- p.175 / Chapter 4.2.1 --- Sufu Production --- p.175 / Chapter 4.2.2 --- Partial Substitution of NaCl with KC1 --- p.176 / Chapter 4.2.3 --- Sampling of Sufu --- p.176 / Chapter 4.2.4 --- Bacterial Count --- p.176 / Chapter 4.2.5 --- Total and Amino Nitrogen Contents in Sufu --- p.177 / Chapter 4.2.6 --- Sensory Evaluation of Experimental Sufu --- p.177 / Chapter 4.3 --- Results --- p.179 / Chapter 4.3.1 --- Microbial Growth --- p.179 / Chapter 4.3.2 --- Proteolysis --- p.181 / Chapter 4.3.2.1 --- Total Nitrogen Content (TN) --- p.181 / Chapter 4.3.2.2 --- Amino Nitrogen Content (AN) --- p.184 / Chapter 4.3.3 --- Sensory Evalutaion of Control and KCl-Substituted Sufu --- p.186 / Chapter 4.4 --- Discussion --- p.187 / Chapter 4.4.1 --- Microbial Growth --- p.187 / Chapter 4.4.2 --- Proteolysis --- p.189 / Chapter 4.4.3 --- Sensory Tests --- p.194 / Chapter 4.5 --- Conclusion --- p.198 / Chapter 5 --- Overal Conclusion --- p.199 / References --- p.204 / Appendix I --- p.228 / Appendix II --- p.229

Cheung Hiu-Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 140-150). / Abstracts in English and Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENTS --- p.vi / LIST OF FIGURES --- p.xiii / LIST OF TABLES --- p.xv / Chapter CHAPTER 1 --- LITERATURE REVIEW --- p.1 / Chapter 1.1 --- Introduction --- p.2 / Chapter 1.2 --- Soybeans --- p.3 / Chapter 1.2.1 --- Chemistry and nutritional value of soybeans --- p.3 / Chapter 1.2.2 --- Protein composition of soybeans --- p.4 / Chapter 1.2.3 --- Volatile compounds in soybeans --- p.4 / Chapter 1.3 --- Food fermentation --- p.5 / Chapter 1.4 --- Chaw tofu --- p.6 / Chapter 1.4.1 --- Preparation of tofu --- p.7 / Chapter 1.4.2 --- Preparation of chaw tofu --- p.7 / Chapter 1.4.3 --- Microorganisms involved in fermentation of chaw tofu --- p.8 / Chapter 1.4.4 --- Volatile components in chaw tofu --- p.11 / Chapter 1.4.5 --- Proteolytic activity of chaw tofu --- p.12 / Chapter 1.5 --- Stinky brine broth --- p.13 / Chapter 1.5.1 --- The pH value of stinky brine broth --- p.13 / Chapter 1.5.2 --- The salt percentage of stinky brine broth --- p.14 / Chapter 1.5.3 --- Volatile components of stinky brine broth --- p.14 / Chapter 1.5.4 --- Parameters affecting ammonia production of stinky brine --- p.15 / Chapter 1.6 --- Other fermented soy products --- p.16 / Chapter 1.6.1 --- Microorganisms involved in the fermentation --- p.16 / Chapter 1.6.1.1 --- Fermentation of soybean by bacteria --- p.17 / Chapter 1.6.1.1.1 --- Natto --- p.17 / Chapter 1.6.1.1.2 --- Kinema --- p.18 / Chapter 1.6.1.1.3 --- Soy daddawa --- p.19 / Chapter 1.6.1.1.4 --- Hawaijar --- p.20 / Chapter 1.6.1.1.5 --- Thua nao --- p.21 / Chapter 1.6.1.2 --- Fermentation of soybean by moulds --- p.21 / Chapter 1.6.1.2.1 --- Tempe --- p.21 / Chapter 1.6.1.2.2 --- Sufu --- p.22 / Chapter 1.6.1.2.3 --- Soy sauce --- p.22 / Chapter 1.6.1.2.4 --- Soy paste --- p.23 / Chapter 1.6.2 --- Formation of volatile compounds during Bacillus fermentation --- p.24 / Chapter 1.6.3 --- Biochemical changes during fermentation --- p.21 / Chapter 1.7 --- Methods of flavor analysis --- p.30 / Chapter 1.7.1 --- Headspace Analysis --- p.31 / Chapter 1.7.2 --- Aroma characterization --- p.32 / Chapter CHAPTER 2 --- IDENTIFICATION OF ODOROUS COMPOUNDS IN COMMERCIAL CHAW TOFU BASED ON ODOR ACTIVITY EVALUATION --- p.42 / Chapter 2.1 --- Introduction --- p.43 / Chapter 2.2 --- Materials & Methods --- p.46 / Chapter 2.2.1 --- Experimental samples --- p.46 / Chapter 2.2.2 --- Headspace-Gas Chromatography-Mass Spectrometry (GC-MS) --- p.46 / Chapter 2.2.3 --- Conditions of the Gas Chromatography-Mass Spectrometry (GC-MS) --- p.47 / Chapter 2.2.4 --- Compound identifications --- p.48 / Chapter 2.2.5 --- Quantification of compounds --- p.48 / Chapter 2.2.6 --- Statistical analysis --- p.48 / Chapter 2.2.7 --- Calculation of odor activity value (OAV) --- p.49 / Chapter 2.3 --- Results & Discussion --- p.50 / Chapter 2.3.1 --- Odor activity value (OAV) --- p.51 / Chapter 2.3.2 --- Volatile compounds in fresh samples --- p.51 / Chapter 2.3.2.1 --- Comparison of odorous compounds in fresh samples among different locations --- p.52 / Chapter 2.3.3 --- Volatile compounds in deep-fat fried samples --- p.53 / Chapter 2.3.3.1 --- Comparison of odorous compounds in deep-fat fried samples among different locations --- p.54 / Chapter 2.3.4 --- Comparison between fresh and deep-fat fried samples --- p.55 / Chapter 2.3.5 --- Odorous compounds of chaw tofu based on OAVs --- p.56 / Chapter 2.3.6 --- Possible ways for formation of odorous compounds --- p.58 / Chapter 2.3.6.1 --- Protein degradation --- p.58 / Chapter 2.3.6.2 --- Lipid degradation --- p.59 / Chapter 2.3.7 --- Comparison between volatile compounds in chaw tofu and others fermented soybean products --- p.60 / Chapter 2.4 --- Conclusion --- p.61 / Chapter CHAPTER 3 --- IDENTIFICATION OF ODOROUS COMPOUNDS IN COMMERCIAL CHAW TOFU BASED ON GAS CHROMATOGRAPHY-OLFACTOMETRY --- p.67 / Chapter 3.1 --- Introduction --- p.68 / Chapter 3.2 --- Materials & Methods --- p.71 / Chapter 3.2.1 --- Experimental samples --- p.71 / Chapter 3.2.2 --- Gas Chromatography-Mass Spectrometry-Flame Ionization Detection-Olfactometry (GC-MS-FID-O) --- p.71 / Chapter 3.2.3 --- Conditions of the Gas Chromatography-Mass Spectrometry --- p.72 / Chapter 3.2.4 --- Detection of odor active compounds --- p.73 / Chapter 3.2.5 --- Compound identifications --- p.73 / Chapter 3.3 --- Results & Discussion --- p.74 / Chapter 3.3.1 --- "Fecal, rancid and putrid odor" --- p.74 / Chapter 3.3.2 --- "Cabbages, sulfurous and meaty odor" --- p.76 / Chapter 3.3.3 --- Green odor --- p.77 / Chapter 3.3.4 --- Other odor contributing compounds --- p.77 / Chapter 3.3.5 --- Odor generate during deep-fat frying --- p.78 / Chapter 3.3.6 --- Comparison between GC-O and OAVs --- p.79 / Chapter 3.3.7 --- Comparison between volatile compounds in chaw tofu and others fermented soybean products --- p.80 / Chapter 3.4 --- Conclusion --- p.82 / Chapter CHAPTER 4 --- EVALUATION OF CHAW TOFU MODEL FERMENTATION BROTH --- p.86 / Chapter 4.1 --- Introduction --- p.87 / Chapter 4.2 --- Materials & Methods --- p.90 / Chapter 4.2.1 --- Model fermentation broth preparation --- p.90 / Chapter 4.2.2 --- Tofu sample preparation --- p.91 / Chapter 4.2.3 --- Gas Chromatography-Mass Spectrometry --- p.91 / Chapter 4.2.3.1 --- Conditions of Gas Chromatography-Mass Spectrometry (GC-MS) --- p.92 / Chapter 4.2.3.2 --- Compound identification --- p.93 / Chapter 4.2.3.3 --- Quantification of compounds --- p.93 / Chapter 4.2.4 --- Viable cell counts --- p.93 / Chapter 4.2.5 --- pH value and soluble content --- p.94 / Chapter 4.2.6 --- Proteolytic activity --- p.94 / Chapter 4.2.7 --- Statistical analysis --- p.95 / Chapter 4.3 --- Results & Discussion --- p.96 / Chapter 4.3.1 --- Headspaces analysis --- p.96 / Chapter 4.3.1.1 --- Changes in volatile composition in model fermentation broths --- p.97 / Chapter 4.3.1.2 --- Comparison of volatile compositions between the broths --- p.98 / Chapter 4.3.1.3 --- Comparison of volatile compositions among the three deep-fat fried fermented tofu with different broths --- p.101 / Chapter 4.3.1.4 --- Comparison of volatile compositions of deep fat fried fermented tofu with that of the commercial chaw tofu --- p.102 / Chapter 4.3.2 --- Liquid samples analysis --- p.104 / Chapter 4.3.2.1 --- "Changes in viable cell counts, pH values, protease activities and soluble solid contents within model fermentation broths during fermentation" --- p.106 / Chapter 4.3.2.2 --- Viable cell counts --- p.107 / Chapter 4.3.2.3 --- Soluble solid content --- p.108 / Chapter 4.3.2.4 --- Proteolytic activity --- p.106 / Chapter 4.3.2.5 --- pH value --- p.110 / Chapter 4.4 --- Conclusion --- p.112 / Chapter CHAPTER 5 --- GENERAL CONCLUSION --- p.127 / APPENDIX --- p.130 / IDENTIFICATION OF MICROORGANISMS PRESENTED IN THE MODEL CHAW TOFU FERMENTATION BROTHS BY MICROBIAL IDENTIFICATION SYSTEM (MIDI) --- p.130 / Materials & Methods --- p.130 / Model fermentation broth preparation --- p.130 / Viable cell counts --- p.131 / Microbial Identification System (MIDI) --- p.131 / Results --- p.133 / Suggestion on further investigation --- p.134 / REFERNECES --- p.141

腐乳是中國傳統豆類發酵製品，具有綿軟的口感和特殊的風味。其是豆腐通過真菌固態發酵，并加入鹽，米酒和香料等進行後期熟化而成的產品。本文的研究分為兩部份，第一部份對腐乳發酵過程中的毛胚，鹽胚，熟化第一天，熟化一個月以及熟化六個月的腐乳樣本進行採樣，并採用傳統微生物培養法和克隆文庫法對每個階段真菌和細菌的生態結構和動態變化進行研究。第二部份重點比較了四株腐乳產品中分離的微生物和購自台灣生物資源保存及研究中心的四株細菌的產揮發性含硫化合物能力，并挑選了最高產的一株微生物進行紫外誘變，最後獲得理想的突變株。本研究的結論如下： / 1. 真菌和細菌的總數均是在毛胚階段為最高，在進入熟化階段后開始下降。在傳統微生物培養方法下分別分離出了三株真菌和九株細菌，通過18S rDNA和16 rDNA測序，發現絲孢酵母屬（Trichosporon spp.）是真菌中的優勢菌種，蠟狀芽孢桿菌（Bacillus cereus）和解澱粉芽孢桿菌（Bacillus amyloliquefaciens）為細菌中的優勢菌種； / 2. 本研究建立了五個真菌18S rDNA克隆文庫和五個細菌16 rDNA克隆文庫用于研究真菌和細菌的生態結構和動態變化。通過聚合酶鏈式反應-限制性片段長度多態性（PCR-RFLP）的研究，分別在真菌和細菌克隆文庫中發現23和38種圖譜類型，并計算其相應比例。在進行真菌細菌測序之後，對優勢菌群進行了定性和定量分析； / 3. 在對比傳統微生物培養方法和克隆文庫技術的結果后發現，二者的結果存有差異，有些在克隆文庫中鑒定到的微生物在傳統培養方法中未能分離鑒定，而有些微生物則只能在傳統培養方法中被分離鑒定。因此，本研究中將這兩種方法結合有助於我們更為全面、客觀地研究腐乳發酵過程中真菌和細菌的生態結構和多樣性。 / 4. 對四株腐乳中分離純化的微生物和四株外來購入細菌的產揮發性含硫化合物能力進行比較，結果發現，從腐乳產品中分離純化的B-1菌株擁有最高的產揮發性含硫化合物能力，通過紫外誘變后，突變株#3在產揮發性含硫化合物以及L-蛋氨酸代謝酶活力都比初始菌株有了顯著的提升。B-1菌經測序比對后鑒定為絲孢酵母（Trichosporon sp.）。 / 本研究結果對于傳統腐乳發酵的有效控制和現代腐乳生產工藝的建立有一定指導意義，並且對於腐乳產品中的風味物質，特別是揮發性含硫化合物的產生和優化提供信息。 / Sufu (fermented soybean curd) is a soft creamy cheese-type product with a pronounced flavor and is made by fungal solid state fermentation of tofu (soybean curd) followed by aging in brine containing salt and alcohol. In first part of this research, the eco-structure and the dynamic changes of microbes during sufu production process (Pehtze, Salted pehtze, 0 Month sufu, 1 Month sufu and 6 Month sufu sample) were studied by combined microbiology techniques, including plate culture, 16S rDNA and 18S rDNA clone library and restriction fragment length polymorphism (RFLP) analysis. The second part of this research focus on the comparison of volatile sulfur-containing compounds (VSCs) production ability within isolated strains in sufu product and bacteria purchased commercially, the strain that possessed highest ability was selected and followed by a UV mutation experiment, finally obtained the desired mutant. The results of this research are as followed: / 1. The population of both fungi and bacteria were all at highest number in Pehtze stage and started to decrease in ripening stages. A combined total of three and nine living strains of fungi and bacteria were obtained from the plate culture, respectively. Through 18S rDNA and 16S rDNA sequencing, Trichosporon spp. was the dominant fungi and Bacillus cereus and Bacillus amyloliquefaciens were the dominant bacteria; / 2. Five 18S rDNA clone libraries and five 16S rDNA clone libraries from different stages of sufu production were constructed to analyze the structure and dynamic changes of fungi and bacteria. A total of 23 and 38 RFLP patterns were found, and the ratio of each pattern were calculated. After sequencing, qualitative and quantitative analysis on the dynamic changes of dominant strains was performed; / 3. After comparing the results of plate culture and clone library, it was found that there were some differences between the two. Some strains were only found in clone library while some only found in plate culture approach. Therefore, the combination of the two microbiology methods will help us to objectively and completely analyze the structure and dynamic changes of microbes in the sufu production process; / 4. The ability to produce VSCs within four strains (B-1, B-2, B-3 & B-4) isolated from a commercial sufu manufacturing process and four commercial strains (B. acetylicum, L. Lactics, S. thermophilus and L. Paracasei) were compared. Results showed that B-1 possessed both the highest VSCs production ability and L-methionine metabolism enzymatic activities among the eight strains. After UV light mutagenesis of B-1 strain, its mutant #3 significantly increased in DMDS and DMTS production and all four L-methionine-related enzymatic activities in reference to that of the starting strain (B-1). B-1 was identified as Trichosporon sp. by sequencing. / These results would make a profound significance on the control of traditional sufu production and the development of new technology for modern sufu manufacturing. They will also help to provide some important information of optimal production of VSCs in sufu ripening and the overall flavor in sufu product. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Huang, Ruolan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 106-117). / Abstracts also in Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgement --- p.v / Table of contents --- p.vi / List of Figures --- p.x / List of Tables --- p.xiii / Chapter Chapter 1 --- : Introduction --- p.1 / Chapter 1.1 --- Sufu --- p.1 / Chapter 1.1.1 --- Classification --- p.1 / Chapter 1.1.1.1 --- Classified by processing technology --- p.1 / Chapter 1.1.1.2 --- Classified by color and flavor --- p.1 / Chapter 1.1.1.3 --- Other classifications --- p.2 / Chapter 1.1.2 --- Typical commercial manufacturing process --- p.2 / Chapter 1.1.2.1 --- Production process of naturally fermented sufu --- p.2 / Chapter 1.2.2.2 --- Production process of traditional mold-based sufu --- p.5 / Chapter 1.2.2.3 --- Production process of traditional bacteria-based sufu --- p.5 / Chapter 1.2.2.4 --- Acceleration of sufu ripening process --- p.6 / Chapter 1.1.3 --- Important ingredients in sufu production --- p.6 / Chapter 1.1.4 --- Flavor components in sufu --- p.7 / Chapter 1.1.4.1 --- Volatile flavor components --- p.7 / Chapter 1.1.4.2 --- Essential odor in sufu product --- p.8 / Chapter 1.1.4.3 --- Volatile sulfur compounds in sufu --- p.9 / Chapter 1.1.4.4 --- Using Head Space-Solid phase Microextraction (HS-SPME) to analyze the volatile sulfur components --- p.9 / Chapter 1.1.5 --- Relationship between microbes and sufu --- p.12 / Chapter 1.1.5.1 --- Microbes involved in fermentation process --- p.13 / Chapter 1.1.5.2 --- Microbial changes during the production of sufu --- p.14 / Chapter 1.1.6 --- Study on microbial ecology in food product --- p.15 / Chapter 1.1.6.1 --- PCR-based molecular techniques --- p.16 / Chapter 1.1.6.2 --- Non-PCR based molecular techniques --- p.16 / Chapter 1.1.6.3 --- The common techniques used in microbial ecology research --- p.17 / Chapter 1.1.6.4 --- Microbial ecology study by molecular biological techniques --- p.18 / Chapter 1.2 --- Objectives --- p.19 / Chapter Chapter 2 --- : Analysis of fungi diversity during sufu fermentation process --- p.21 / Chapter 2.1 --- Introduction --- p.21 / Chapter 2.2 --- Materials and methods --- p.21 / Chapter 2.2.1 --- Sample collection and preparation --- p.22 / Chapter 2.2.2 --- Plate count of fungi during sufu fermentation process --- p.22 / Chapter 2.2.3 --- Change of pH values and moisture content --- p.22 / Chapter 2.2.4 --- Total DNA extraction from fungi --- p.23 / Chapter 2.2.5 --- Preparation of competent cell --- p.23 / Chapter 2.2.6 --- 18S rDNA PCR amplification and construction of 18S rDNA clone library --- p.24 / Chapter 2.2.7 --- RFLP analysis of 18S rDNA clone library --- p.25 / Chapter 2.2.8 --- DNA sequencing for fungi identification --- p.26 / Chapter 2.2.9 --- Analysis of the diversity of 18S clone library --- p.26 / Chapter 2.2.10 --- Frequency percentage analysis --- p.27 / Chapter 2.2.11 --- Enzyme Solutions --- p.27 / Chapter 2.2.12 --- Determination of protease activity --- p.28 / Chapter 2.2.13 --- Determination of lipase activity --- p.29 / Chapter 2.2.11 --- Microtox test --- p.30 / Chapter 2.2.12 --- Statistical analysis --- p.30 / Chapter 2.3 --- Results and discussion --- p.30 / Chapter 2.3.1 --- Fungi growth on plate counting result --- p.30 / Chapter 2.3.2 --- Changes in pH and moisture content of sufu during production --- p.33 / Chapter 2.3.3 --- Construction and selection of 18S rDNA clone library --- p.35 / Chapter 2.3.4 --- Fungal diversity based on 18S rDNA clone library analysis --- p.38 / Chapter 2.3.5 --- Protease and lipase activities in Actinomucor elegans and Trichosporon japonicum --- p.45 / Chapter 2.3.5.1 --- Protease activity --- p.46 / Chapter 2.3.5.2 --- Lipase activity --- p.47 / Chapter 2.3.6 --- Toxicity of Actinomucor elegans and Trichosporon japonicum --- p.49 / Chapter 2.3.7 --- Analysis of fungi eco-structure and function during sufu fermentation process --- p.50 / Chapter 2.3.8 --- The influence of PCR bias and artifact --- p.53 / Chapter 2.2 --- Summary --- p.55 / Chapter Chapter 3 --- : Analysis of bacteria diversity during sufu fermentation process --- p.57 / Chapter 3.1 --- Introduction --- p.57 / Chapter 3.2 --- Materials and methods --- p.57 / Chapter 3.2.1 --- Sample collection and preparation --- p.57 / Chapter 3.2.2 --- Plate count of bacteria during sufu fermentation process --- p.57 / Chapter 3.2.3 --- Total DNA extraction from bacteria --- p.58 / Chapter 3.2.4 --- Preparation of competent cell --- p.58 / Chapter 3.2.5 --- 16S rDNA PCR amplification and construction of 16S rDNA clone library --- p.58 / Chapter 3.2.6 --- RFLP analysis of 16S rDNA clone library --- p.59 / Chapter 3.2.7 --- DNA sequencing for bacteria identification --- p.60 / Chapter 3.2.8 --- Analysis of the diversity of 16S rDNA clone library --- p.60 / Chapter 3.3 --- Results and discussion --- p.60 / Chapter 3.3.1 --- Bacteria growth on plate counting result --- p.60 / Chapter 3.3.2 --- Construction and selection of 16S rDNA clone library --- p.63 / Chapter 3.3.3 --- 16S rDNA clone library analysis of bacteria diversity --- p.65 / Chapter 3.3.4 --- Analysis of bacteria eco-structure and function during sufu fermentation process --- p.74 / Chapter 3.4 --- Summary --- p.77 / Chapter Chapter 4 --- : Screening the mutant possess higher capacity of forming volatile sulfur compounds (VSCs) from non-starter microbes of sufu product --- p.80 / Chapter 4.1 --- Introduction --- p.80 / Chapter 4.2 --- Materials and methods --- p.82 / Chapter 4.2.1 --- Strains and culture conditions --- p.82 / Chapter 4.2.2 --- Head space-solid phase microextraction (HS-SPME) analysis --- p.83 / Chapter 4.2.3 --- Gas Chromatography-Mass Spectrometry (GC-MS) analysis --- p.84 / Chapter 4.2.4 --- UV mutation --- p.85 / Chapter 4.2.5 --- Ellman’s method --- p.86 / Chapter 4.2.6 --- Preparation of cell-free extracts (CFE) for enzymatic assays --- p.86 / Chapter 4.2.7 --- Enzymatic assay --- p.86 / Chapter 4.2.7.1 --- L-methionine aminotransferase activity assay --- p.86 / Chapter 4.2.7.2 --- L-methionine demethiolase activity assay --- p.87 / Chapter 4.2.7.3 --- α-keto acid decarboxylase activity assay --- p.87 / Chapter 4.2.7.4 --- C-S lyase activity --- p.88 / Chapter 4.2.8 --- Statistical analysis --- p.88 / Chapter 4.3 --- Results and discussion --- p.89 / Chapter 4.3.1 --- Optimization of SPME extraction condition --- p.89 / Chapter 4.3.2 --- Selecting the start strain --- p.90 / Chapter 4.3.4.1 --- Comparison of VSCs production ability --- p.90 / Chapter 4.3.4.2 --- Comparison of enzymatic activity in L-methionine metabolism --- p.92 / Chapter 4.3.3 --- Optimization of UV exposure time --- p.95 / Chapter 4.3.4 --- Screening the mutants --- p.96 / Chapter 4.3.4.1 --- Comparison of VSCs production ability among the mutants --- p.96 / Chapter 4.3.4.2 --- Comparison of the L-methionine related enzymatic activities among the mutants --- p.99 / Chapter 4.3.4.3 --- Identified of strian B-1 --- p.101 / Chapter 4.4 --- Summary --- p.102 / Chapter Chapter 5 --- : General conclusions and future work --- p.103 / References --- p.106

Kam, Shuk Fan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 124-134). / Abstracts in English and Chinese. / Abstract --- p.ii / Abstract in Chinese --- p.iv / Acknowledgements --- p.vi / List of Figures --- p.xi / List of Tables --- p.xii / Chapter Chapter 1 --- Literature Review --- p.1 / Chapter 1.1 --- Soybeans as Food --- p.1 / Chapter 1.1.1 --- Backgrounds --- p.1 / Chapter 1.1.2 --- Soybean Composition --- p.1 / Chapter 1.1.3 --- Diseases Prevention of Soybean Consumption --- p.3 / Chapter 1.1.4 --- Traditional Soyfoods --- p.3 / Chapter 1.2 --- Sufu --- p.5 / Chapter 1.2.1 --- Historical Information and Synonyms --- p.5 / Chapter 1.2.2 --- Features --- p.5 / Chapter 1.2.3 --- Manufacturing Techniques --- p.5 / Chapter 1.2.4 --- Types and Varieties of Sufu --- p.10 / Chapter 1.2.5 --- Compositional Changes during Fermentation and Ripening --- p.11 / Chapter 1.2.5.1 --- Proteins and Amino Acids --- p.11 / Chapter 1.2.5.2 --- Fats and Free Fatty Acids --- p.13 / Chapter 1.2.5.3 --- Carbohydrates --- p.14 / Chapter 1.2.5.4 --- Isoflavones --- p.15 / Chapter 1.2.6 --- Volatile Flavor Compounds --- p.15 / Chapter 1.3 --- Accelerated-Ripened Sufu --- p.17 / Chapter 1.4 --- Objectives of Project --- p.18 / Chapter Chapter 2 --- Contribution of Lipid to the Fatty Acids and Ethyl Esters in Model Plain Sufu --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials and Methodology --- p.23 / Chapter 2.2.1 --- Sufu Preparation --- p.23 / Chapter 2.2.1.1 --- Preparation of Tofu --- p.23 / Chapter 2.2.1.2 --- Preparation of Inoculum --- p.23 / Chapter 2.2.1.3 --- Spore Count in Spore Suspension --- p.24 / Chapter 2.2.1.4 --- Preparation of Pehtzes --- p.25 / Chapter 2.2.1.5 --- Brining and Ripening --- p.26 / Chapter 2.2.1.6 --- Sampling --- p.26 / Chapter 2.2.1.7 --- Free Fatty Acid Analysis --- p.26 / Chapter 2.2.1.7.1 --- Extraction --- p.26 / Chapter 2.2.1.7.2 --- Gas Chromatography-Mass Spectrometry Analysis (GC-MS) for Free Fatty Acid Analysis --- p.27 / Chapter 2.2.1.7.3 --- Compounds Identification and Quantification --- p.28 / Chapter 2.2.1.8 --- Ethyl Ester Analysis --- p.29 / Chapter 2.2.1.8.1 --- Extraction --- p.29 / Chapter 2.2.1.8.2 --- Gas Chromatography-Mass Spectrometry Analysis (GC-MS) for Ethyl Ester Analysis --- p.29 / Chapter 2.2.1.8.3 --- Compounds Identification and Quantification --- p.30 / Chapter 2.2.1.9 --- Enzymatic Activities --- p.30 / Chapter 2.2.1.9.1 --- Enzyme Extracts --- p.30 / Chapter 2.2.1.9.2 --- Lipase Activity Measurement --- p.31 / Chapter 2.2.1.9.3 --- Lipoxygenase Activity Measurement --- p.32 / Chapter 2.2.1.10 --- Determination of Peroxide Value --- p.33 / Chapter 2.2.1.11 --- pH Value Determination --- p.34 / Chapter 2.2.1.12 --- Moisture Content --- p.34 / Chapter 2.2.1.13 --- Statistical Analysis --- p.34 / Chapter 2.3 --- Results and Discussions --- p.35 / Chapter 2.3.1 --- Change of Free Fatty Acids with Sufu Processing Stage --- p.35 / Chapter 2.3.2 --- Change in Ethyl Esters with Sufu Processing Stage --- p.41 / Chapter 2.3.3 --- Activity of Lipase in the Sufu Enzyme Extracts --- p.47 / Chapter 2.3.4 --- Activity of Lipoxygenase in the Sufu Enzyme Extracts --- p.50 / Chapter 2.3.5 --- Lipid Oxidation determined by Peroxide Value --- p.50 / Chapter 2.3.6 --- pH Value Change during Sufu Production --- p.54 / Chapter 2.3.7 --- Moisture Content during Sufu Production --- p.56 / Chapter 2.3.8 --- Overall Discussions --- p.58 / Chapter 2.3.8.1 --- Lipolysis and Ester Synthesis --- p.58 / Chapter 2.3.8.2 --- Lipid Oxidation --- p.58 / Chapter 2.4 --- Conclusion --- p.61 / Chapter Chapter 3 --- A Study on Ripening Model Systems of Sufu --- p.63 / Chapter 3.1 --- Introduction --- p.63 / Chapter 3.2 --- Materials and Methodology --- p.68 / Chapter 3.2.1 --- Partial Purification Lipase from Mucor hiemalis --- p.68 / Chapter 3.2.1.1 --- Inoculum --- p.68 / Chapter 3.2.1.2 --- Culture --- p.68 / Chapter 3.2.1.3 --- Protein Precipitation --- p.68 / Chapter 3.2.1.4 --- Gel Filtration Column Chromatography --- p.69 / Chapter 3.2.1.5 --- Enzyme Assay --- p.69 / Chapter 3.2.1.6 --- Lipase Activity Confirmation --- p.70 / Chapter 3.2.1.7 --- Protein Determination --- p.70 / Chapter 3.2.2 --- Model Studies of the Formation of Free Fatty Acids and Ethyl Esters --- p.70 / Chapter 3.2.2.1 --- "A System with Lipid, Alcohol, and Lipase" --- p.70 / Chapter 3.2.2.2 --- A System with Different Lipase Concentrations --- p.71 / Chapter 3.2.2.3 --- A System with an Exogenous Fatty Acid --- p.71 / Chapter 3.2.3 --- Characterization of the Crude Lipase from Mucor hiemalis Culture on the Formation of Free Fatty Acids and their Ethyl Esters --- p.72 / Chapter 3.2.3.1 --- Effect of a Phospholipid --- p.72 / Chapter 3.2.3.2 --- Effect of Ethanol Concentration --- p.72 / Chapter 3.2.3.3 --- Effect of Sodium Chloride Concentration --- p.72 / Chapter 3.2.3.4 --- Effect of initial pH --- p.73 / Chapter 3.2.4 --- Orthogonal Design Experiment L9 (33) --- p.73 / Chapter 3.2.5 --- Free Fatty Acids Identification and Quantification --- p.76 / Chapter 3.2.5.1 --- Extraction --- p.76 / Chapter 3.2.5.2 --- Gas Chromatography-Mass Spectrometry Analysis (GC-MS) --- p.76 / Chapter 3.2.5.3 --- Compounds Identification and Quantification --- p.77 / Chapter 3.2.6 --- Ethyl Esters Identification and Quantification --- p.77 / Chapter 3.2.6.1 --- Extraction --- p.77 / Chapter 3.2.6.2 --- Gas Chromatography-Mass Spectrometry Analysis (GC-MS) --- p.78 / Chapter 3.2.6.3 --- Compounds Identification and Quantification --- p.78 / Chapter 3.2.7 --- Statistical Analysis --- p.79 / Chapter 3.3 --- Results and Discussions --- p.80 / Chapter 3.3.1 --- Lipase Partial Purification --- p.80 / Chapter 3.3.2 --- Lipase Activity Confirmation --- p.80 / Chapter 3.3.3 --- Model Studies on the Formation of Free Fatty Acids and Ethyl Esters --- p.84 / Chapter 3.3.3.1 --- "A System with Lipid, Alcohol and Lipase" --- p.84 / Chapter 3.3.3.2 --- A System with Different Lipase Concentrations --- p.84 / Chapter 3.3.3.3 --- A System with an Exogenous Fatty Acid --- p.89 / Chapter 3.3.3.4 --- Summary --- p.92 / Chapter 3.3.4 --- Characterization of the Crude Lipase from Mucor hiemalis Culture on the Formation of Free Fatty Acids and their Ethyl Esters Formation --- p.92 / Chapter 3.3.4.1 --- Effect of a Phospholipid --- p.92 / Chapter 3.3.4.2 --- Effect of Ethanol Concentration --- p.96 / Chapter 3.3.4.3 --- Effect of Sodium Chloride Concentration --- p.103 / Chapter 3.3.4.4 --- Effect of initial pH --- p.109 / Chapter 3.3.5 --- Orthogonal Design Experiment L9 (33) Optimizing the Ethyl Esters Formation --- p.114 / Chapter 3.4 --- Conclusion --- p.118 / Chapter 4 Overall Conclusions --- p.120 / References --- p.124

Thesis (MscAgric (Animal Sciences))--University of Stellenbosch, 2007. / The effect of a multiple-enzyme combination in mash and pelleted vegetarian maize-soya diets for broilers was evaluated in terms of apparent excreta- and ileal nitrogen- and amino acid digestibility and production performance. Two separate digestibility trials and one performance trial were conducted. For Trial 1, the apparent nitrogen (N) - and amino acid (AA) digestibility was determined by the collection of the excreta (total collection method) and in Trial 2 from digesta collected at the terminal ileum (ileal digestibility method). Production performance was also recorded in Trial 1. In Trial 3, the effect of the multipleenzyme combination in potentially improving performance of broilers in commercial conditions was evaluated. Broilers were fed a balanced- and low apparent energy (AME) vegetarian maize-soya diet with the addition of the multiple-enzyme combination. The addition of enzymes improved the apparent excreta- and ileal N digestibility of the mash diets during the period 14-21 d, and the ileal N-digestibility of the pelleted diets at 28 and 35 d of age. Conflicting results with regard to apparent excreta- and ileal AA digestibility were found. By both methods the digestibilities of threonine (Thr), methionine (Met) and phenylalanine (Phe) (14-21 d) and Cys (22-28 d and 29-35 d) were improved by the addition of the enzyme combination to the mash diets. Over the entire experimental period (14-35 d) the ileal digestibilities of histidine (His), Cys and leucine (Leu)of the mash diets were improved by 0.2 %, 0.2 % and 1.9 % respectively, following enzyme addition. By both methods the digestibilities of Thr, arginine (Arg), Met, Cys, Phe and Leu (14-21 d), serine (Ser), Arg, glutamic acid (Glu), Val, His, aspartic acid (Asp), lysine (Lys), proline (Pro), Met, tyrosine (Tyr), Phe and Leu (22-28 d), and Pro (29-35 d) were improved by the combination of enzymes and pelleting. For the entire experimental period (21-35 d), the ileal digestibilities of Ser, His, Lys, Met, Tyr, Cys, Phe and Leu was improved by the combination of enzymes and pelleting, indicating enzymatic activity was not destroyed by cold pelleting at 60 - 80º. The improvements in apparent nitrogen- and AA digestibilities were, in most cases, not reflected in production performance, although the combination of enzymes and pelleting resulted in improved body weight gain (BWG) for the first two weeks of chicks life and significantly improved the feed conversion ratio (FCR) during the second week of the chicks’ life. The effect of the multiple-enzyme combination on the production performance of broilers on a low AME- and commercial diet was mostly non-significant except for a significantly lower feed iii intake of the balanced diet for the fourth and fifth week of chick’s life following enzyme addition. A financial calculation showed, however, that the enzyme combination might increase profitability of a nutritionally balanced vegetarian maize-soya diet for broilers.