Thesis (M.Med.Sc.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 28-32). Also available in print.

From D. K. Brundage's thesis - University of Michigan. / An article, by J. O. Halford and Donald Brundage, reprinted from the Journal of the American Chemical Society, 64, 1942.

Thesis (Ph.D.) - University of St Andrews, May 2008. / Restricted until 29th May 2010.

abstract: Objective: Vinegar consumption studies have demonstrated possible therapeutic effects in reducing HbA1c and postprandial glycemia. The purpose of the study was to closely examine the effects of a commercial vinegar drink on daily fluctuations in fasting glucose concentrations and postprandial glycemia, and on HbA1c, in individuals at risk for Type 2 Diabetes Mellitus (T2D). Design: Thirteen women and one man (21-62 y; mean, 46.0±3.9 y) participated in this 12-week parallel-arm trial. Participants were recruited from a campus community and were healthy and not diabetic by self-report. Participants were not prescribed oral hypoglycemic medications or insulin; other medications were allowed if use was stable for > 3 months. Subjects were randomized to one of two groups: VIN (8 ounces vinegar drink providing 1.5 g acetic acid) or CON (1 vinegar pill providing 0.04 g acetic acid). Treatments were taken twice daily immediately prior to the lunch and dinner meals. Venous blood samples were drawn at trial weeks 0 and 12 to measure insulin, fasting glucose, and HbA1c. Subjects recorded fasting glucose and 2-h postprandial glycemia concentrations daily using a glucometer. Results: The VIN group showed significant reductions in fasting capillary blood glucose concentrations (p=0.05) that were immediate and sustained throughout the duration of the study. The VIN group had reductions in 2-h postprandial glucose (mean change of −7.6±6.8 mg/dL over the 12-week trial), but this value was not significantly different than that for the CON group (mean change of 3.3±5.3 mg/dL over the 12-week trial, p=0.232). HbA1c did not significantly change (p=0.702), but the reduction in HbA1c in the VIN group, −0.14±0.1%, may have physiological relevance. Conclusions: Significant reductions in HbA1c were not observed after daily consumption of a vinegar drink containing 1.5 g acetic acid in non-diabetic individuals. However, the vinegar drink did significantly reduce fasting capillary blood glucose concentrations in these individuals as compared to a vinegar pill containing 0.04 g acetic acid. These results support a therapeutic effect for vinegar in T2D prevention and progression, specifically in high-risk populations. / Dissertation/Thesis / M.S. Nutrition 2013

Rhenium oxides as well as other rhenium compounds are known to display a broad spectrum of catalytic activity,^25 being resistant to attack by acids under nonoxidizing conditions, and showing a remarkable ability to resist poisoning which is a serious limiting factor in many commonly used catalysts. Rhenium catalysts are cheaper than the platinum metals with the exception of palladium. One of the most remarkable properties of the rhenium catalyst is the ability to catalyze the hydrogenation of carboxylic acids and amides to the corresponding alcohols and amines respectively. The carboxyl group (-COOH) is notoriously difficult to reduce catalytically and most of the commonly used catalysts are ineffective in catalyzing the hydrogenation of carboxylic acids. Either hydrogenolysis of the carbon-oxygen bond occurs or the carboxylic acid remains inert. It is for this reason that low molecular weight carboxylic acids are often used as inert solvents in catalytic hydrogenations. This investigation was undertaken to study the effects of various parameters upon product formation in the hydrogenation of carboxylic acids using the catalyst formed from the reduction of rhenium heptoxide i situ. Acetic acid was used throughout the investigation as the representative carboxylic acid. The parameters studied were pressures ranging from 2000 to 3000 psig, temperatures ranging from 115° to 175°, reaction time varied over the range of 0 to 24 hours, the effects on product formation from repeated use of the catalyst, and agitation of reactants during the reaction with emphasis on the optimization of these parameters. In several series of reactions repeated reuse of the catalyst showed that rhenium catalyst can be reused at least 8 times while still achieving greater than 50 per cent reduction. Relative decrease in catalyst activity appears to be greater when temperature and pressure of the hydrogenation are high compared to the range. Experimental data shows that the concentration of ethyl acetate in the product mixture as a function of time passes through a maximum between 1.0 and 1.5 hours. Beyond this maximum there is a relatively rapid decrease in ester concentration. A change in initial hydrogen pressure from 2000 to 3000 psig does not appreciably change the product composition in the reaction mixture while a modest increase, i.e., a temperature increase of 25°, was observed to improve yields of the alcohol by a very significant amount. Moreover, the investigation shows that for a reaction time of 5 hours the "optimum" conditions for reaction are a temperature of 175°, a catalyst to substrate ratio of 1.0 g Re_2O_7/50 g AcOH, and an initial hydrogen pressure of 3000 psig while reactions carried out for only 1.5 hours require a catalyst to substrate ratio of from 1.0 to 2.5 g Re_2O_7/50 g AcOH to effect a quantitative reduction optimally. Whether or not the reaction system was agitated during the warm-up period seemed to have little effect on the composition of the product mixture, however, it was observed that partial reduction takes place during the initial heating period before agitation of the reactor begins. The results of this work have shown that "optimum" conditions for quantitative reduction of acetic acid to the corresponding alcohol are the mildest yet reported and clearly confirm the superiority of the rhenium catalyst over other catalysts in the hydrogenation of carboxylic acids.

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23292号 / エネ博第417号 / 新制||エネ||79(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 河本 晴雄, 教授 石原 慶一, 教授 上髙原 浩 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Sodium lactate and acetic acid derivatives were evaluated for their effects on color retention, microbial growth (TPC), oxidation (TBARS), and sensory attributes of hot-boned pork sausage patties that were stored under retail store display conditions over time. Treatments included: (a) 2.5% sodium lactate 60% solids (L), (b) 2.5% buffered vinegar pH 6.5-8.0 (V), (c) 2.5% sodium lactate and vinegar 52/48% mixture (LV), (d) control with 0.02% BHA/BHT (C), and (e) negative control without additives (NC). Overall acceptability of day 17 LV and L treatments were not different (P>0.05) from day 14 treatments. These results revealed that the L and LV sausage patties retained sensory acceptability and microbial quality from day 14 through day 17 as opposed to other treatments. Additionally, sausage patties with 2.5% LV maintained color (redness) and overall acceptability throughout 17 days of shelf-life when held in retail conditions, when compared to other treatments.

In recent years economic, environmental, and strategic concerns over the use of petroleum resources have led to increased interest in renewable resources. Biomass gasification produces a synthesis gas composed of primarily carbon monoxide, hydrogen, and carbon dioxide, which can be fermented into a variety of fuels and chemicals. This study evaluated the performance of a two-stage approach to batch synthesis gas fermentations. The first stage employs a rich medium optimized for cell growth, while the second stage is designed to maximize production of acetic acid from synthesis gas. This two-stage approach is hypothesized to be more metabolically efficient than previous single-stage designs. This study presents the evaluation of known acetic acid producing organisms described in the literature, and efforts to isolate a novel microbial catalyst for synthesis gas fermentations. Finally, new techniques were developed and implemented in order to develop a more effective system for batch synthesis gas fermentations.

Liquid extraction is a means of separating two or more components of a solution. The process involves mixing the solution with an immiscible solvent, separating the two phases, and recovery of the desired materials and of solvent from the solvent phase, usually by distillation. Separation is accomplished if certain of the solution components are more soluble in the extracting solvent employed than in the feed solution. Liquid extraction is used to concentrate aqueous solutions of acetic acid produced in the esterification of cellulose and in other manufacturing processes because acetic acid and water are not easily separated by direct rectification. Liquid extraction of acetic acid must always be followed by solvent-recovery systems. Then the selection of solvents suitable for extraction of acetic acid must be based not only on the relative affinity of the solvents for acetic acid but also on consideration of heat and other energy requirements of the extraction and solvent recovery systems. The purpose of this investigation was to develop a method of evaluating solvent extraction systems for the recovery of acetic acid from aqueous liquors, by comparisons of selected solvent systems on the basis of: (a) theoretical transfer units required for extraction, (b) in the case of solvents boiling below 100 °C, theoretical plates required for distillation of extracts, and (c) heat required for recovery of pure acetic acid and of solvent. / Master of Science

The tannin extract industry disposes of large volumes of condensate liquors evolved during concentration of weak leach liquors obtained by extraction of wood chips. The liquors are highly corrosive due to acetic acid contained therein along with lesser quantities of other organic substances common to woody materials. Recovery of the acetic acid would be desirable from two standpoints: (1) the value of the acetic acid, and (2) reuse of the acid-free condensate in the manufacturing process. The purpose of this investigation was to recover acetic acid from the wastes of tannin extract manufacture. An ion exchange process was given primary consideration to accomplish the recovery by adsorption of the acetic acid from the waste liquor with subsequent elution of the acid from the ion exchange material by use of stronger acid. Tests were conducted using De-Acidite, a synthetic aliphatic amine anion exchange resin produced by the Permutit Company, New York, N.Y.. For all tests 200 ml. of resin were used at temperatures within 20-30°C. A total acid-binding capacity of 19,700 grains CaCO₃/ft.³ was found when De-Acidite was exposed to 0.5 percent acetic acid in batch operation. Optimum rate of flow determinations in column operation within the range of 1 to 5 gal./ft.²/min. were conducted. Variations of flow rates between these limits failed to produce substantial differences in breakthrough capacities. To prepare the De-Acidite bed in the ion exchange column between runs regeneration was effected with 1 percent sodium hydroxide. Rinse was by downflow operation until data was obtained which indicated its unsuitability; thereafter backwash rinse was used and found more satisfactory. The waste liquor used in the investigation was obtained from the 2nd and 3rd effects of a triple effect evaporator employed in the Mead Corporation Plant at Lynchburg, Virginia. Successive exposures of De-Acidite to the waste liquor resulted in sharp reduction of breakthrough capacity, discoloration of the De-Acidite, and deterioration of the resin with the formation of fines. It was found that the extremely small quantities of tannin present in the waste liquor were the cause of the rapid depreciation of the De-Acidite. / M.S.