Return to search

Processing Effects on Physiochemical Properties of Natural and Reformulated Creams

Skim, sweet buttermilk, and butter-derived aqueous phase components were used to re-emulsify low-melt butteroil into creams with a desired 20% milkfat. The implications of pasteurization process, homogenization sequence, and formulation on the physicochemical properties of reformulated and natural creams were investigated.

Creams homogenized prior to pasteurization had significantly (p<0.05) greater amounts of milkfat surface material per gram of cream and per gram of lipid compared to creams homogenized after pasteurization. Significantly (p<0.05) higher percentages of available phospholipid also were associated with the milkfat surface material of creams homogenized prior to pasteurization. Phosphodiesterase, a marker enzyme within the native milkfat globule membrane, was in significantly (p<0.05) higher activity relative to protein on lipid globule surface when cream was homogenized prior to pasteurization. Creams that underwent pasteurization prior to homogenization had significantly (p<0.05) higher protein load associated with the milkfat surface material.

Natural cream homogenized prior to pasteurization had significantly (p<0.05) greater milkfat surface material per gram lipid than natural cream homogenized after pasteurization and buttermilk / aqueous phase (AP) reformulated cream homogenized after pasteurization. In contrast, natural cream homogenized after pasteurization and BM / AP reformulated cream homogenized after pasteurization had significantly (p<0.05) greater amounts of protein per 10 mg of milkfat surface material than all other formulation / homogenization sequence combinations. In addition, natural cream homogenized prior to pasteurization, and skim milk (SM) reformulated cream pasteurized prior to or after homogenization had significantly (p<0.05) higher percentages of available phospholipid associated with the milkfat surface material than natural cream homogenized following pasteurization.

Pasteurization temperature had a significant (p<0.05) effect on apparent viscosity of natural and reformulated creams. All UHT pasteurized natural and reformulated creams had significantly (p<0.05) greater apparent viscosities at all shear rates monitored than HTST pasteurized natural and reformulated creams. At a failing curve shear rate of 692 s-1 UHT pasteurized cream reformulated with BM / AP had significantly (p<0.05) greater viscosity than UHT pasteurized natural cream and cream reformulated with skim component.

HTST pasteurized natural cream had significantly (p<0.05) greater viscosities than HTST pasteurized cream reformulated with skim component. Moreover, at a shear rate of 2769 s-1 and a rising shear rate of 1384 s-1 HTST pasteurized natural cream had significantly (p<0.05) greater viscosity than HTST pasteurized cream reformulated with buttermilk and aqueous phase.

Creams formulated with skim component showed significant differences in creaming stability after 7 days of storage. On the other hand, natural cream and cream reformulated with buttermilk and aqueous phase showed significant differences in creaming stability after 9 days of storage. HTST pasteurized creams had greater creaming stability than UHT pasteurized creams. All creams feathered in a pH range of 5.09 to 5.31. Homogenization prior to UHT pasteurization resulted in creams rated "out of specification" because of poor sensory quality on day 1. Other processing sequences resulted in creams within sensory specifications. / Master of Science

Identiferoai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/31565
Date08 May 2001
CreatorsBolling, James Coleman
ContributorsFood Science and Technology, Duncan, Susan E., Keenan, Thomas W., Eigel, William N. III
PublisherVirginia Tech
Source SetsVirginia Tech Theses and Dissertation
Detected LanguageEnglish
TypeThesis
Formatapplication/pdf
RightsIn Copyright, http://rightsstatements.org/vocab/InC/1.0/
RelationCole.pdf

Page generated in 0.0023 seconds