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dc.contributor.advisorRichter, Ronald
dc.creatorPerez Hernandez, Gabriela
dc.date.accessioned2005-08-29T14:39:17Z
dc.date.available2005-08-29T14:39:17Z
dc.date.created2005-05
dc.date.issued2005-08-29
dc.identifier.urihttp://hdl.handle.net/1969.1/2344
dc.description.abstractStable retorted whey protein beverages with 5% protein concentration were prepared. The effect of protein concentration, fat concentration and homogenization pressure on the heat stability and the stability of emulsions of sterilized whey protein beverages was determined. Beverages containing >1% protein formed aggregates during the heat treatment. Food grade additives were added to the beverages with >1% protein to determine if the heat stability could be improved. Lecithins and polyphosphates improved the heat stability while hydrocolloids decreased the heat stability. Lecithins improved the heat stability of emulsions better than polyphosphates but polyphosphates were more effective in beverages without fat. Lecithins modified by acetylation or hydrolysis provided more protection against heat denaturation of proteins than regular lecithin. Acetylated lecithin created the emulsions most stable against creaming. Improvement in the emulsion stability by the use of phospholipids was associated with a more negative charge at the interface of the fat droplets. The effect of polyphosphates on the heat stability was related to the chain length of the polyphosphates. Short chain polyphosphates (dp~4) were more effective than other polyphosphates. Polyphosphates probably improved the heat stability of the systems by changing the structure of water and this prevented aggregation of whey proteins. Hydrocolloids decreased heat stability most probably through thermodynamic incompatibility that locally increased the concentration of proteins and promoted aggregation during the heat treatment.The effect of homogenization pressure, concentration of acetylated lecithin, and the concentration of short chain polyphosphate on the storage stability of retorted whey protein beverages containing 5% protein and 3% fat was determined. The creaming index and particle size index changed over 28 d of storage and indicated creaming of the emulsions. The use of homogenization pressures of 55 and 90 MPa compared to 20 MPa reduced the magnitude of the change of the particle size index and creaming index during storage. Inclusion of polyphosphates reduced the storage stability of the emulsions. Optimization of parameters showed that emulsions formulated with 5% protein, 3% fat and 0.3% lecithin without polyphosphates and homogenized at 90 MPa had the best stability after 28 d of storage.en
dc.format.extent979727 bytesen
dc.format.mediumelectronicen
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherTexas A&M Universityen
dc.subjectwhey proteinsen
dc.subjectretort beveragesen
dc.titleUse of ingredients and processing to control the stability of high whey protein concentration retort sterilized beveragesen
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentAnimal Scienceen
thesis.degree.disciplineFood Science and Technologyen
thesis.degree.grantorTexas A&M Universityen
thesis.degree.nameDoctor of Philosophyen
thesis.degree.levelDoctoralen
dc.contributor.committeeMemberCastillo, Alejandro
dc.contributor.committeeMemberCisneros-Zevallos, Luis
dc.contributor.committeeMemberRooney, Lloyd
dc.type.genreElectronic Dissertationen
dc.type.materialtexten
dc.format.digitalOriginborn digitalen


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