Call number: LD2668 .T4 1986 H645 / Master of Science / Grain Science and Industry

Thesis (M.B.A.)--Chinese University of Hong Kong. / Bibliography: leaves 120-121.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1977. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographical references. / Ph.D.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

A method was developed for the extraction of rennet from fresh frozen vells. Frozen vells were partially thawed and minced in a Hobart "Wonder worker." The tissue was treated with 2.0 per cent potassium alum and allowed to stand for 20 hours before sufficient 0.45 M disodium phosphate was added to bring the pH of the mixture to 5.7. Dry sodium chloride was added until the salt concentration in the moisture of the mixture was 10 per cent. The tissue was then mixed with 3/4-inch pumice gravel in a volume ratio of 1 to 2 and packed into extractor columns. The tissue was extracted continuously with a 10 per cent sodium chloride solution. The yield of enzyme and extract viscosity from 60 undried vells was compared with that from 60 dried vells. The undried vells yielded 2. 99 x 106 R.U. in 86 liters of extract and the dried vells yielded 3.03 x 106 R.U. in 74 liters of extract. The viscosities of the initial extracts were 5.8 and 6.2 centipoise respectively. Drying temperature, moisture content and pH had no effect on extract viscosity . Viscosities of extracts were viii reduced by aging the dried vells prior to extraction, adjusting sodium chloride to 10 per cent in extracting solutions, and adding 2 to 3 per cent potassium alum to undried vell tissue and holding for 20 hours before neutralizing to pH 5.7 %plusmn; 0.2 with disodium phosphate. The mean activity value of extracts representing 96,000 vells was 45.5 R.U. with a standard deviation of ± 19.57 for individual vells. This variation in enzyme content precluded useful comparisons of yield based on small numbers of individual whole vells.

Kinetics of the reactions of amoxycillin sodium and potassium clavulanate alone and in combination were investigated in the liquid and frozen states at selected pH values of 2.0, 4.6 and 7.0. A stability indicating HPLC assay was developed to perform simultaneous quantification of these compounds validated under stressed conditions.Amoxycillin and clavulanate degradation obeyed first-order kinetics under all conditions of this study. The effect of temperature, buffer, concentrations and complexation were investigated. Both compounds showed acceleration in rates due to general acid catalysis from buffer species. The buffer catalysis rate constants due to total phosphate and total acetate at 55 degrees celsius were 5.84x10(subscript)-1 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 and 1.53 X10(subscript)-1 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 for amoxycillin, 2.33 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 and 4.4x10(subscript)-1 mol dm(subscript)-3)(subscript)-1 h(subscript)-1 for clavulanate respectively. The buffer independent rate constant values were obtained and interpreted according to the available literature data. Increase in the initial concentration of amoxycillin or clavulanate did not change the first-order rate constant values of these antibiotics significantly at liquid state temperatures. However in the buffer systems, the rate of hydrolysis of amoxycillin in the combination was significantly subject to clavulanate catalysis. This novel finding was influenced by phosphate buffer concentration. A kinetic model was proposed and the second-order catalytic rate constant values at pH 7.0 and 55 degrees celsius were estimated for clavulanate catalysis of amoxycillin (k(subscript)cvc) to be k(subscript)cvc = 1.75 X10(subscript)2 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 and for phosphate catalyzed of clavulanate catalysis of ++ / amoxycillin (k(subscript)phccv) as k(subscript)phccv = 2.87 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1.The temperature dependence of the rate of amoxycillin sodium degradation over the pH range evaluated did not change significantly. However the E(subscript)a values of potassium clavulanate decreased slightly with increase in pH. Both the compounds showed similar E(subscript)a values at pH 4.6 in acetate system. Hence 71.2 kJ mol(subscript)-1 for amoxycillin and 75.1 kJ mol(subscript)-1 for clavulanate.The investigation on complexation effects by HPbetaCD on the rate of hydrolysis of amoxycillin and clavulanate indicated no significant change in the rate of reaction of amoxycillin in the acetate buffer system. But the rate of clavulanate hydrolysis in combination was decreased by approximately 10%. The rate constant within the cyclodextrin complex and the stability constant of the complex obtained for clavulanate at pH 4.6 and 55 degrees celsius were k(subscript)c = 1.54x 10(subscript)-1 h(subscript)-1 and K(subscript)c = 74.2 (mol dm(subscript)-3)(subscript)-1.Extrapolation of the rate constant values to the frozen state from the liquid state data indicated marked acceleration of the rate of amoxycillin and clavulanate in all the pH values investigated. The highest acceleration in rate recorded was 15.0 fold for clavulanate in the hydrochloric acid system and the lowest value was 4.4 fold for amoxycillin at -7.3 degrees celsius. The rate constant values obtained were interpreted in terms of the concentration model (Pincock and Kiovsky 1966), phase-temperature relationship of the solutes, buffer catalysis, pH change and polymerization reactions.In the hydrochloric acid system a kinetic model was deduced providing adequate explanation of the experimental results. The stabilizing effect of sodium chloride used for maintaining constant ionic strength (mu=0.5) was ++ / enormous in this system. The shelf-life of amoxycillin was increased from 2.2 h to 58.3 h at -7.3 degrees celsius when sodium chloride was included in the system. It also stabilized the rates of the reactions significantly in the buffer systems.The buffer systems used in this study stabilized the rates of the reaction of both the drug compounds considerably. The shelf-life of amoxycillin in phosphate buffer was 621.3 h at -13.5 degrees celsius and in acetate buffer the shelf-life of clavulanate was 71.9 h at the same temperature. These are the highest shelf-life values recorded so far in the literature for amoxycillin and clavulanate at this frozen temperature.

Sperm survival in frozen semen appears to be determined largely by the amount of intracellular enzymes during freezing and thawing. Data is presented to show the effects of different diluents, temperature and glycerol as well as egg yolk concentrations, on glutamic-oxaloacetic-transaminase release. Summary in Chinese and in English

No description available.

This study determined the effects of sucrose and sorbitol as cryoprotectant (CR) on the quality and sensory attributes of bone-in hams (N=90) injected (20% of weight) with following brine treatments (BT): control (2% sucrose; CNT), 2% CR (1% sucrose, 1% sorbitol), 4% CR (2% sucrose, 2% sorbitol). Hams that were frozen and injected with CNT after thawing (FZ I) were used as a negative control. After reaching the designated ST all bone-in hams were thawed under refrigeration (4oC) and FZ I hams were then injected with CNT (n=8). Hams were cooked to 70oC, chilled (7oC), sliced, vacuum packaged and analyzed for lipid oxidation, color, protein solubility and purge at 0, 28, and 56 of refrigerated storage while sensory evaluation and shear force determinations were conducted at 28 d. Color, pH, and lipid oxidation values tended to remain similar or decrease as frozen storage time increased. Water holding capacity (percent bound water) and protein solubility increased as frozen storage increased. The 4% CR BT exhibited the lowest shear force value (4.04 N/g) but was not statistically different than CNT or FZ I on ham knuckle muscles. Trained sensory panelists found hammy and salty were the strongest flavor and basic taste attributes. The results of this study confirm that quality attributes and protein functionality were maintained but not significantly improved by injecting a brine solution with cryoprotectants prior to freezing.

An average American consumes 52 kg of Frozen food, while an European consumes 40 kg, and a Japanese consume 12 kg. Compared to these advanced nations, China¡¦s consumer behavior and power can be viewed as uncultivated and full of potential. Thus, taking in China¡¦s long culinary history and long tradition of its cuisine, if food technology can be integrated into these specialties, there will be a bright future for China¡¦s frozen food market. This report collects its data from Access Asia Limited: Frozen Food In China Market Analysis and from focusing on frozen prepared food , investigates the growth, size, selection and advantage of the frozen food market in China The city of Shanghai is the most prosperous, goverened and educated city in China. With a well developed infrastructure and modernized malls, Shanghai provides the best environment for fostering a frozen food market. Thus, this report picks Shanghai as the main city of observation and arrives at the following conclusions ¡G 1. The Frozen Food Market in Shanghai will enjoy a promising 5% growth rate, a potential market for any new investors . 2. From observing the sales of dumplings and meat , one notices that frozen cooked food will enjoy a bigger market share because it meets the consumer¡¦s need of basic nutrition intake . 3. Sanitation and safety are two primary concerns on the consumer. Thus establishing a good brand image is vital to any company¡¦s success. Selling products through supermarket is also a crucial channel that vendors need to establish . 4. Due to the common use of microwave in the common household, microwavable frozen food not only provides variation but is also convenient for the consumer, thus raising its overall value. A majority of the consumer believe that microwavable frozen food can maintain a dish¡¦s original flavor while saving time. As this market is merely in its fledgling state, it is advised that all companies should pay attention to this market .