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Thesis (Ph. D.)--Washington State University, May 2007. / Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 41-45).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 272-279.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1953. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Phage-insensitive Streptococcus cremoris starter strains were selected by assaying cheese whey against potential starter strains. Six strains were selected and characterized for continual use in cheesemaking. Upon phage-infection, strains were removed from the blend. Cheesemaking continued with remaining strains. A phage-insensitive, fast-acid-producing mutant of the infected strain was isolated and characterized. This mutant, similar to the parent, was returned to the strain mixture. Multiple-blend starters were also used in cottage cheese and cultured buttermilk manufacture. Individual strains were used as antigens for a rapid detection test for lactic-streptococcal agglutinins in cheese milk. When sedimentation was encountered, agglutinin-sensitive strains were identified and replaced instead of an entire culture blend. Phage-insensitive mutants were compared to their respective parent strains. Traits examined included acid-producing activity, optimum temperature, generation time, proteolysis, phosphate and NaCl tolerance, phage adsorption, agglutination, morphology, and induction. Mutant strains showed variations in individual characteristics, but no general pattern of variation was observed. Bulk starters, prepared by growing then freezing individual strains in a commercial internal-pH-control medium (PHASE 4), were stored for 3 mo with and without glycerol. Strains varied in storage survival at -20 C. Glycerol enhanced cell viability and activity at -20 C. Storage in PHASE 4 at -40 C and -80 C preserved activity and viability without glycerol. Unfrozen PHASE 4 cultures retained original activity and viability after 1 mo refrigerated storage. Frozen and refrigerated PHASE 4 starters have been used in Cheddar and cottage cheese manufacture for more than 1 yr. Exclusive use of defined-strain cultures resulted in significant manufacturing and economic improvements including elimination of culture rotations and starter failure from phage infection, no ripening period, greater cheese uniformity, predictable starter activity, standardized manufacture, and improved cheese quality. Grade-A cheese production was increased by almost 10%. This technology enabled some factories to increase cheese yields by adding whey cream to cheese milk. The combined improvements, based on defined-strain technology, have enabled factories to increase production—some by nearly 50%. To date, more than 150 million lb of Cheddar cheese have been manufactured with defined-strain cultures. / Graduation date: 1983

Flavor problems associated with the use of cheddar cheese whey in the formulation of ice cream and other food products were investigated. During spray drying of whey, which transforms bulky liquid whey into an easily transportable and storable powder, various degrees of off-flavor development may occur depending on the care with which the processing is carried out. Flavor problems present in the dry whey, which usually take the form of heated, stale, or sometimes burned notes, may then manifest themselves in mildly flavored frozen dessert products in which the powder is incorporated. Additional heating given such a finished frozen dessert during pasteurization may also contribute to the whey related off-flavors present by continuing heat induced flavor reactions (mainly Malliard non-enzymic browning and Strecker degradation reactions) initiated in the original processing of the whey powder. An ice cream mix model system was used to study the effects of varying whey quality, whey quantity, and heat processing load on ice cream flavor profile. The mix consisted of 27 samples, three parameters (whey quality, whey quantity, and heat processing load) using three levels of intensity within each parameter. There were three control samples containing no whey. Whey "fingerprint" compounds were identified by headspace GLC/MS analysis of a poor quality whey powder which was later used with two other better quality wheys in the formulation of the model system. Comparison of the identified and some unidentified compound peaks in the "fingerprint" portion of the whey chromatogram to peaks present in the chromatograms obtained from model system analysis provided qualitative correlation. Subsequent quantitation of "fingerprint" compounds in the model system revealed data trends indicating that whey quality and product processing conditions may adversely effect the flavor profile of a frozen dessert product containing whey powder. The quantity of whey added (at least up to the level of substitution used in this work: 25%) did not set trends indicating adverse product effect with increased concentration. These numerical trends were established by using relative quantitation of the whey "fingerprint" or "indicator" compounds to establish a peak area total for each model system member. When grouped by model parameter, trends in the peak area data were elucidated. The conclusions reached from the data presented in this work are that whey flavors do carry through from powder to ice cream mix, are detectable, and may effect flavor profile of the ice cream. Also it became obvious that the flavor quality of the ingredient whey and careful selection of heat load for pasteurization of the ice cream mix are of primary importance in maintaining excellent flavor quality in frozen desserts employing whey to reduce manufacturing costs. Sensory evaluation of the model system members was unable to establish direct off-flavor correlation with increased volatile compound concentration. / Graduation date: 1978

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2001. / Includes bibliographical references.