Thesis--Wisconsin. / Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 30-32).

Thesis (M.S.)--University of Wisconsin--Madison, 1981. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 72-74).

Sweet whey is the liquid that separates from the cheese curd during manufacture of cheeses like Edam and Cheddar. Though highly nutritious, problems associated with whey utilizations include variability of desired functional attributes and lack of thermostability (TS), an attribute that is imperative in retort or pasteurization stable high protein drinks. The objective of this study was to determine the influence of pre-heat treatment (thermization) of fresh sweet whey and/or addition of casein hydrolyzate on the subsequent TS of whey protein concentrates (WPC). Fresh sweet wheys were obtained from the Mississippi State University Dairy Plant, separated, thermized for different time periods (5-30 min) at 70°C, vacuum evaporated, and spray dried to obtain WPC. Thermization of Edam and Cheddar whey for 5 and 10 min significantly enhanced TS across all pH (3-7.5) levels studied. Addition of the hydrolyzate to thermized and not thermized Edam whey significantly enhanced the TS.

No description available.

No description available.

Sweet whey powder is mainly used as an ingredient in foods and has a potential for increased use with the development of new foods. In view of the many whey powder producers, there is need to establish the quality of the whey powders currently on the market in terms of conformance to specifications, consistency over different seasons, and keeping quality. Selected sweet whey powder from different processors was analysed for microbiological, physicochemical and sensory quality. The whey powder was in most the cases within specifications. There was suggestive evidence of seasonal variability in the cooked flavor and sweet taste. In regard to storage, there was no significant difference in the flavor and aroma of the whey powder with storage except for the oxidized flavor which was marginally significantly different in at least one product. Most of the variation was in the microbiological and physicochemical properties. Of three products considered, rate of deterioration by the Maillard reaction, one was significantly different from the other two, having lower activation energy. Accelerated shelf-life testing deterioration rates compared well with those at ambient conditions for two products, implying that ASLT can be used for shelf-life determinations only if Maillard reaction inhibitors are absent. The flavor and aroma of sweet Cheddar cheese whey powder from one processor over 12 months, was consistent. However, the physicochemical, and microbiological properties were variable mainly between the fall and summer production with the fall production being higher in L* (lightness) and pH, but low in solubility index, and conversely, the summer production being high in solubility index and titratable acidity but low in L*. / Graduation date: 2005

Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 29, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Bioresource and Food Engineering, Department of Agricultural, Food and Nutritional Science, University of Alberta. Includes bibliographical references.

Acid whey is a by-product of the quarg production and arises in large volumes in dairies. A considerable disposal problem arises due to the lack of obtainable proceeds from acid whey utilisation. Additionally, sustainable and energy efficient treatment methods for high strength liquid wastes from dairies cleaning operation are needed to reduce the costs of wastewater treatment. Samples of acid whey and spent cleaning solutions from a quarg cheese production plant were collected. The composition and physical properties were analysed and evaluated against waste treatment process requirements. The occurrence of different waste streams, their volumes and frequencies were also investigated. A laboratory scale membrane nanofiltration plant was designed, and built for investigation of the volume reduction of cleaning process effluents with emphasis to treatment options for the filtration concentrates. The examination of the rheological properties of alkaline CIP wastewaters at different volume reduction ratios clearly shows that these effluents are Newtonian fluids even at high concentrations. The anaerobic biodegradability of acid whey and mixtures containing portions of alkaline CIP wastewaters at different volume reduction ratios was tested. Characteristic process kinetics for acid whey fermentation in batch mode was observed. The occurrence of a second lag-phase in mixtures containing larger portions of acid whey was identified as phase separation- due to rapid acidification of lactose. Anaerobic digestion (AD) was identified as a suitable treatment option for acid whey and alkaline CIP wastewaters. Four anaerobic digester types were designed with regard to their suitability for high strength waste treatment and were built and operated at laboratory scale. The reactors tested were: a) A Continuous Stirred Tank Reactor (CSTR); b) An Anaerobic Membrane Reactor (AMR); c) An Upflow Anaerobic Sludge Blanket (UASB) re- actor; and d) A novel two-stage process design consisting of a combined acidification and crystallization stage and a gaslift driven fluidised bed methanogenic stage. The operation of the AMR process and also of the UASB process with internal circulation and pH-control using alkaline CIP effluents was evaluated at high loading rates of 7.7 g•L-1•d-1 and 10.2 g•L-1•d-1 respective. However, in the experiments it was demonstrated that even with perfect biomass retention the operation of one stage anaerobic digestion at high loading rates caused process upsets. Precipitation and accumulation of milk minerals within the sludge was observed in all one stage experiments. The conclusions drawn from one stage studies led to the design of a novel high-rate diges- tion system to meet the demands of anaerobic digestion of acid whey and effluents from dairy plant cleaning. The design based on different high-rate industrial reactor designs and incorporate the ideas of staging, crystallisation of calcium salts prior to anaerobic di- gestion, fluidised bed and internal circulation reactors, and also jet-loop or gaslift reactors. The performance of the novel system when treating acid whey is comparable to the results of well designed, two-stage digesters treating cheese whey which is easier to digest.

In this work, glucose isomerase (GI) activity was measured with several sugar substrates. Lactase was also used with several carbohydrate substrates to observe its hydrolytic action. In order to observe the enzymes' action, a small batch reactor was designed and used in the entire project. Paper partition chromatography, was the analytical method of choice to measure the reaction end products. It proved to be a valuable technique in combination with other analytical methods for determination of various carbohydrates. GI showed positive activity with glucose, fructose, xylose and L-sorbose but none with mannose, galactose, lactose, maltose, melibiose and cellobiose. Lactase was active on maltose, cellobiose, raffinose, lactose and sucrose but not with maltiol, melibiose or melezitose. Whey proteins were removed either by ultrafiltration or heat precipitation. This deproteinized whey was treated with the two enzymes to produce a syrup composed mainly of galactose, glucose, fructose and small amounts of oligosaccharides. The syrup had a predominantly sweet taste with a slight salty attribute. The proper utilization of whey lactose has potentially valuable features in the production of a sweetening ingredient for foods. This is especially true after the lactose has been hydrolyzed by lactase and then the glucose in the hydrolyzate isomerized to fructose with glucose isomerase.