Browsing by Author "KINSELLA, JE"

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    COMPRESSION STRENGTH OF DAIRY GELS AND MICROSTRUCTURAL INTERPRETATION
    (1991) AGUILERA, JM; KINSELLA, JE
    Contour plots were developed for the compression stress (at 20% deformation) of single-component, mixed and filled protein gels. Samples were made by heating and acidification from skim milk powder, SMP (0-20% TS), whey protein isolate, WPI (0-10% TS), and recombined cream, within pH 3.6-3.9, 4.6-4.8 and 5.1-5.3. At higher pH, WPI gels were stronger than SMP gels. WPI had a reinforcing effect on SMP gels, while small additions of SMP to WPI gels resulted in weaker mixed gels. Filled gels containing cream had higher compression strengths than mixed gels. Micrographs showed linking of casein chains by WPI strands in mixed gels and compatibility of fat globules with casein micelles in the protein network of filled gels.
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    EMULSIFIED MILKFAT EFFECTS ON RHEOLOGY OF ACID-INDUCED MILK GELS
    (INST FOOD TECHNOLOGISTS, 1991) XIONG, YL; AGUILERA, JM; KINSELLA, JE
    Reconstituted skim milk formed by a gel by acidification to < pH 5.2 and heating to 60-degrees-C. The gel compressive stress (sigma-c) was influenced by the heating process, increased with milk-nonfat-solids (MNFS) and reached a maximum at pH 4.0. The addition of emulsified fat facilitated gelation, increase gel sigma-c and shear modulus, and decreased gel deformability. At an equal fat concentration, emulsions containing small-sized fat globules (i.e., more globules) reinforced the gels more markedly than emulsions comprised of large globules reflecting the importance of number of globules in the gels. Electron micrographs revealed crosslinkages between fat globules and casein particles in the gel network, which may have caused reinforcement of milk gels by milkfat.