Digitized by Kansas Correctional Industries

The nitrate content of some foods was determined. Canned food, baby food, frozen food, and fresh vegetables were analyzed. Among them spinach and beet were found to have the highest nitrate-nitrogen content and frozen food had higher nitrate-nitrogen content than other food products analyzed. Nitrate-nitrogen of food is partially transferred to the liquid portion whenever the food consists of any liquid. The amount of nitrate in the liquid portion seemed, to be higher than in the solid portion except in bean which has a protective surface layer as a factor of lowering the nitrate found in the liquid portion. The rate of nitrate transferring from solid portion to liquid portion was not the same for all foods and was not the same even from different parts of the same plant. Nitrate-nitrogen was not destroyed by cooking. Even after pouring off cooking water, some nitrate-nitrogen still remained in the solid portion. The distribution of nitrate among different plant parts was not uniform: bean leaves, beet root and spinach petioles were found to have higher nitrate than other parts. Nitrogen fertilization readily increased nitrate-nitrogen content in spinach. The sodium salicylate method was found to be the most reliable method for nitrate determination among different methods used in this study. The determination might be affected by many factors occuring during the procedure of analysis such as procedure of extraction and the spectrophotometer blanks used. Oxidising agents, arid reducing agents do not seem to affect the analysis but pH variation and sucrose which might occur in food probably are factors affecting apparent nitrate content. Cooking did quickly destroy spinach nitrate reductase enzyme activity. This means that nitrite will not be found after cooking unless the enzyme is regenerated, or unless there is microbial activity. / Land and Food Systems, Faculty of / Graduate

Typescript / M.A. Florida State College for Women 1932 / Includes bibliographical references (pages 34-35)

Call number: LD2668 .T4 1961 S77

by Lung Man Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Includes bibliographical references. / ACKNOWLEDGMENT --- p.i / ABSTRACT --- p.ii / Chapter CHAPTER 1 --- GENERAL INTRODUCTION --- p.1 / Chapter 1.1 --- Stationary phases and detectors --- p.2 / Chapter 1.2 --- Internal standardization --- p.5 / Chapter 1.3 --- Common pre-treatment technique --- p.6 / Chapter 1.4 --- Pre-treatment techniques --- p.9 / Chapter 1.5 --- Objectives of this work for the determination of styrene --- p.11 / Chapter CHAPTER 2 --- EXPERIMENTAL --- p.13 / Chapter 2.1 --- Instrumentation --- p.13 / Chapter 2.2 --- Reagents and solutions --- p.16 / Chapter 2.3 --- Preparation of stock solutions --- p.18 / Chapter 2.4 --- Sample preparation --- p.19 / Chapter 2.5 --- Extraction method for food samples --- p.20 / Chapter 2.6 --- Procedure for the analytical finish --- p.22 / Chapter 2.7 --- Assessment of the food matrix effect on the recovery of styrene --- p.23 / Chapter 2.8 --- Confirmatory Procedures --- p.23 / Chapter 2.9 --- Treatment of data --- p.24 / Chapter CHAPTER 3 --- DEVELOPMENT OF METHOD --- p.26 / Chapter 3.1 --- Development of GC method --- p.26 / Chapter 3.2 --- Development of the extraction method --- p.29 / Chapter CHAPTER 4 --- DETERMINATION OF RESIDUAL STYRENE IN POLYSTYRENE POLYMER --- p.50 / Chapter 4.1 --- The proposed method --- p.50 / Chapter 4.2 --- Identification of polymer and one cup for the ice-cream cone --- p.51 / Chapter 4.3 --- Determination of residual styrene monomer in polystyrene container and cup --- p.52 / Chapter CHAPTER 5 --- DETERMINATION OF STYRENE MONOMER MIGRATED INTO FOODSTUFFS --- p.58 / Chapter 5.1 --- Methodolgy and scope --- p.58 / Chapter 5.2 --- Determination of styrene migrated into ice-cream --- p.59 / Chapter 5.3 --- Determination of styrene migrated into Yakult and Yogo --- p.60 / Chapter 5.4 --- Determination of styrene migrated into foodstuff kept at elevated temperature in polystyrene containers --- p.60 / Chapter 5.5 --- Conclusion --- p.74 / REFERENCES --- p.76 / APPENDIX --- p.80

Chau Wing-sze. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 238-262). / Abstracts in English and Chinese. / Abstract (in English) --- p.i / Abstract (in Chinese) --- p.iv / Acknowledgement --- p.vi / Contents --- p.ix / List of Figures --- p.xv / List of Tables --- p.xvi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Introduction of samples --- p.2 / Chapter 1.3 --- Flavor of Chinese salted-dried fish --- p.4 / Chapter 1.4 --- Objectives of the study --- p.5 / Chapter 2. --- Literature review --- p.7 / Chapter 2.1 --- Introduction --- p.7 / Chapter 2.2 --- Volatile compounds in fresh fish --- p.8 / Chapter 2.2.1 --- Groups of volatile compounds --- p.9 / Chapter 2.2.2 --- Variation in fresh fish flavor --- p.12 / Chapter 2.2.2.1 --- Intrinsic factor --- p.12 / Chapter 2.2.2.2 --- Environmental factors --- p.15 / Chapter 2.2.2.3 --- Post harvest conditions --- p.16 / Chapter 2.3 --- Fish preservation --- p.17 / Chapter 2.3.1 --- Preservation methods --- p.18 / Chapter 2.3.1.1 --- Drying --- p.19 / Chapter 2.3.1.2 --- Salting --- p.19 / Chapter 2.3.1.3 --- Fermentation --- p.21 / Chapter 2.3.2 --- Theory of drying and salting --- p.21 / Chapter 2.3.3 --- Different protocols in the world --- p.23 / Chapter 2.3.3.1 --- European methods --- p.24 / Chapter 2.3.3.2 --- Southeast Asian methods --- p.25 / Chapter 2.3.3.3 --- Thai methods --- p.27 / Chapter 2.3.3.4 --- Chinese method --- p.28 / Chapter 2.3.3.5 --- Local method --- p.29 / Chapter 2.3.4 --- Consumption procedures --- p.31 / Chapter 2.3.5 --- Advantages of drying besides preservation --- p.31 / Chapter 2.3.5.1 --- Convenience in transportation --- p.32 / Chapter 2.3.5.2 --- Flavorization --- p.32 / Chapter 2.3.5.3 --- Nutritional values --- p.33 / Chapter 2.4 --- Flavor of salted-dried fish --- p.34 / Chapter 2.4.1 --- Taste of salted-dried fish --- p.35 / Chapter 2.4.2 --- Aroma of salted-dried fish --- p.35 / Chapter 2.4.3 --- Flavor of Chinese salted-dried fish --- p.37 / Chapter 2.4.4 --- Parameters affect the flavor and quality of salted-dried fish --- p.38 / Chapter 2.4.4.1 --- Freshness --- p.38 / Chapter 2.4.4.2 --- Temperature --- p.39 / Chapter 2.4.4.3 --- Post harvest freezing and thawing --- p.40 / Chapter 2.4.4.4 --- Gutting --- p.42 / Chapter 2.4.4.5 --- Salt quality --- p.43 / Chapter 2.5 --- Biological deterioration in salted fish --- p.46 / Chapter 2.6 --- Salted-dried fish in Hong Kong --- p.47 / Chapter 3. --- Materials and methods --- p.55 / Chapter 3.1 --- Materials --- p.55 / Chapter 3.1.1 --- Abbreviation of names of samples --- p.55 / Chapter 3.1.2 --- Handling of samples --- p.56 / Chapter 3.2 --- Method --- p.58 / Chapter 3.2.1 --- Modified Simultaneous steam distillation-solvent extraction (SDE)-Steaming --- p.58 / Chapter 3.2.2 --- Concentration --- p.59 / Chapter 3.2.3 --- Gas chromatography-mass spectrometry (GC-MS) --- p.59 / Chapter 3.2.4 --- Compound identification --- p.60 / Chapter 3.2.5 --- Quantification of compounds --- p.60 / Chapter 3.2.6 --- Moisture analysis --- p.62 / Chapter 3.2.7 --- Texture analysis --- p.62 / Chapter 3.2.8 --- Statistical analysis --- p.63 / Chapter 3.2.9 --- OAV calculation --- p.64 / Chapter 4. --- Results and Discussion --- p.66 / Chapter 4.1 --- Threadfin --- p.66 / Chapter 4.1.1 --- Overall description of volatile compounds in salted-dried threadfin --- p.66 / Chapter 4.1.2 --- Characteristic compounds in delayed (D) groups of samples --- p.68 / Chapter 4.1.3 --- Characteristic compounds in regular (R) groups of samples --- p.70 / Chapter 4.1.4 --- Common compounds found in the eight groups of samples --- p.71 / Chapter 4.1.5 --- Comparison of common compounds among individual groups of salted-dried fish --- p.78 / Chapter 4.1.5.1 --- Comparison between delayed and regular salting methods --- p.78 / Chapter 4.1.5.2 --- Comparison between locations of purchase --- p.80 / Chapter 4.1.5.3 --- Comparison between samples from different years (2000 and 2001) --- p.81 / Chapter 4.1.6 --- Exclusive compounds found in delayed salted (D) or regular salted (R) fish --- p.83 / Chapter 4.1.7 --- Conclusion of threadfin --- p.84 / Chapter 4.2 --- White herring --- p.85 / Chapter 4.2.1 --- Overall description of volatile compounds in salted-dried white herring --- p.85 / Chapter 4.2.2 --- Characteristic compounds in delayed (D) groups of samples --- p.87 / Chapter 4.2.3 --- Characteristic compounds in regular (R) groups of samples --- p.88 / Chapter 4.2.4 --- Common compounds found in the eight groups of samples --- p.89 / Chapter 4.2.5 --- Comparison of common compounds among individual groups --- p.94 / Chapter 4.2.5.1 --- Comparison between delayed and regular salting methods --- p.94 / Chapter 4.2.5.2 --- Comparison between locations of purchase --- p.96 / Chapter 4.2.5.3 --- Comparison between samples from different years --- p.97 / Chapter 4.2.6 --- Conclusion of white herring --- p.98 / Chapter 4.3 --- Pawak croaker --- p.100 / Chapter 4.3.1 --- Overall description of volatile compounds in salted-dried pawak croaker --- p.100 / Chapter 4.3.2 --- Characteristic compounds in delayed (D) groups of samples --- p.102 / Chapter 4.3.3 --- Characteristic compounds in regular (R) groups of samples --- p.105 / Chapter 4.3.4 --- Common compounds found in the eight groups of samples --- p.106 / Chapter 4.3.5 --- Comparison of common compounds among individual groups of salted-dried fish --- p.111 / Chapter 4.3.5.1 --- Comparison between delayed and regular salting methods --- p.111 / Chapter 4.3.5.2 --- Comparison between locations of purchase --- p.114 / Chapter 4.3.5.3 --- Comparison between two batches of samples from different years --- p.115 / Chapter 4.3.5.4 --- Characteristic compounds of pawak croaker --- p.117 / Chapter 4.3.6 --- Conclusion of pawak croaker --- p.118 / Chapter 4.4 --- Overall comparison of compounds of the three species --- p.120 / Chapter 4.4.1 --- Introduction --- p.120 / Chapter 4.4.2 --- Comparison of three species of fishes --- p.121 / Chapter 4.4.2.1 --- Delayed- and regular- smell contributors --- p.122 / Chapter 4.4.3 --- The difference among the groups of fishes --- p.123 / Chapter 4.4.3.1 --- Effect of different body compositions of fishes --- p.124 / Chapter 4.4.3.1.1 --- Lipid originated volatile aldehydes --- p.125 / Chapter 4.4.4 --- Common compounds detected in all three species of salted-dried fishes --- p.126 / Chapter 4.4.4.1 --- Compounds with high calculated aroma values (OAV) --- p.127 / Chapter 4.4.4.2 --- Compounds with low calculated aroma values (OAV) --- p.130 / Chapter 4.4.5 --- Effect of treatment methods --- p.132 / Chapter 4.4.6 --- Effect of locations of collection of samples on the composition --- p.134 / Chapter 4.4.7 --- Effect of time of collection of samples on the composition --- p.135 / Chapter 4.4.8 --- Characteristic compounds found only in one species --- p.135 / Chapter 4.4.8.1 --- Characteristic compounds of threadfin --- p.136 / Chapter 4.4.8.2 --- Characteristic compounds of white herring --- p.136 / Chapter 4.4.8.3 --- Characteristic compounds of pawak croaker --- p.138 / Chapter 4.5 --- Texture --- p.139 / Chapter 4.5.1 --- Introduction --- p.139 / Chapter 4.5.2 --- Results and Discussion --- p.141 / Chapter 4.5.2.1 --- Comparison between regular and delayed salted-dried fishes --- p.141 / Chapter 4.5.2.1.1 --- Effects of enzymatic reaction --- p.141 / Chapter 4.5.2.1.2 --- Effects of fermentation --- p.142 / Chapter 4.5.2.1.3 --- Frozen period before regular salting --- p.143 / Chapter 4.5.2.2 --- Comparison between raw and steamed salted-dried fishes --- p.145 / Chapter 4.5.2.3 --- Moisture content of salted-dried fishes --- p.146 / Chapter 4.5.3 --- Conclusion --- p.147 / Chapter 5. --- Conclusion and Significance --- p.233 / Chapter 5.1 --- General conclusion --- p.233 / Chapter 5.2 --- Significance of the study --- p.235 / References --- p.238 / Appendix I --- p.263 / Appendix II --- p.264

No description available.

No description available.

First grade and second grade Nampla, commercially produced Thai fish sauces, were analyzed for their chemical and microbiological composition. First grade commercially produced Nampla contained higher amounts of total nitrogen, formol nitrogen, free and total amino acids compared to second grade sauce. Most of the essential amino acids were present in both grades of sauces. Low microbial counts of halotolerant microorganisms were observed in both sauces. The use of trypsin and chymotrypsin to accelerate the rate of fish sauce fermentation produced from herring, one of the underutilized fish species in Quebec, was investigated. Results showed that supplementation with trypsin and chymotrypsin increased significantly the rate of proteolysis, the amounts of total nitrogen, formol nitrogen and free amino acids in the final fish sauces (p 0.05). (Abstract shortened by UMI).

No description available.