Ultrafiltration (UF), using Romicon pilot-scale hollow-fiber cartridges (Model HFXS-MK11) in the batch mode, was investigated as a possible procedure for clarifying, stabilizing and preserving White Riesling (WR) and Thompson Seedless (ThS) grape juice. The effect of UF processing of SO₂-treated or untreated juice, of process temperature and membrane molecular weight cut-off (MMWCO) on UF juice composition and quality, was determined. "Sparkling clear" pale light-colored UF permeates were obtained and subjected to storage stability trials at different temperatures. Juice parameters evaluated included proteins, phenolics, polyphenol oxidase (PPO), microorganisms, browning, haze and sensory properties. UF at elevated temperatures of up to 50°C, compared to lower temperatures, had the advantage of increased rate of filtration with decreases in browning or haze of clarified permeates and of markedly reduced microbial loads. UF of SO₂-treated juices (13- 20 ppm free) had several advantages including further reduction in browning, haze, and microbial load, and complete inhibition of PPO activity. More proteins (34% - 92%) than phenolics (2% - 27%) were retained by UF membranes. However, more proteins and less phenolics were retained in SO₂-treated than untreated juices. Increasing MMWCO from 10,000 to 100,000 had no effect on the retention of browning, haze, or microorganisms but decreased the retention of proteins from 58 percent to 34 percent in SO₂-treated WR juice. A MMWCO of 50,000 or less retained essentially all PPO. ThS juice browned more than WR during juice preparation and UF processing, yet its clarified permeates were lighter. It contained less phenolics, more proteins and more PPO activity, and higher percentages of its proteins and phenolics were retained by UF membranes. UF juices processed with or without low concentrations of SO₂ (13-20 ppm free) could be stored for at least one year at 1°C without fermentation spoilage. At 21°C only the treated juices could be stored for this long, untreated juices fermenting within one week. At 1°C, there was no increase in browning, but a gradual increase in haze upon storage, the latter being greater in untreated juices. At 21°C, browning increased gradually, resulting in pale golden juices but haze formation was markedly less than in juices stored at 1°C. Similar but accelerated changes occurred with storage at 38°C. The above changes correlated with the disappearance of free SO₂. Although juices were preserved for up to one year, "absolute juice sterility" was never obtained. Leakages around the cartridge gaskets, rather than failure of membranes, was believed to be responsible. Sensory analysis detected no significant differences (p = 0.05) in color, aroma and taste between juices processed with SO at 30°C and 50°C. Juices processed without SO₂ were not significantly different in color, but demonstrated small differences (p = 0.05) in aroma and taste. The SO₂-treated and untreated juices at both processing temperatures, as well as treated juices stored at 21°C and 1°C for twelve months, were significantly different (p = 0.01) in color, aroma and taste. Although these juices had different flavor "characters," only small or no significant differences (p = 0.05) in desirability were detected. It is concluded that good quality clarified grape juice but of different flavor "character" can be produced by UF, either in the presence or absence of SO₂. Both juice "styles" (± SO₂) may find preferred use, but juices processed with SO₂ have the advantage of ambient storage, retaining good quality after one year at 21°C. Recommended optimum processing conditions are 50°C, in the presence of minimal amounts of SO₂ (13-20 ppm free), using membrane molecular weight cut-off of 30-50,000. However, application of the process to "cold-sterilization" of grape juice requires further evaluation. / Graduation date: 1983

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xxi., 190 p.: ill. Includes abstract and vita. Advisor: David B. Min, Dept. of Food Science and Nutrition. Includes bibliographical references (p. 179-190).

v, 144 leaves : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 1971

Thesis (Ph.D.) -- University of Adelaide, Dept. of Medicine, 1971.

Thesis (Ph. D.)--University of Chicago, 1917. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." "From the Hull Physiological Laboratory of the University of Chicago." "Reprinted from the American journal of physiology, vol. 55, nos. 2 and 3, March and April, 1921." Bibliography at end of each study.

Thesis (M.S.)--Ohio State University, 1975. / Includes bibliographical references (leaves 64-68).

No description available.

No description available.

Thesis (M.S. in food science)--Washington State University, December 2008. / Title from PDF title page (viewed on July 10, 2009). "Department of Food Science." Includes bibliographical references (p. 84-94).

Unpasteurized (condition A) and pasteurized (condition B) orange juice samples were stored frozen for eight months. In addition, pasteurized samples were also aseptically packaged and stored at +1°C in polyethylene bags (condition C). Nine quality parameters were monitored during the eight months of storage: sedimentation of the pulp, cloud measurement, aroma volatiles, ascorbic acid concentration, viscosity, density, colour, sugar content (sucrose, glucose and fructose), organic acids (malic and citric), in addition to sensory analysis. The optimum storage condition for freshly processed orange juice was the unpasteurized frozen storage method (condition A). The juice retained most of its chemical and physical properties and was rated by a sensory panel to have the highest sensory score.