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Apparent chemical composition of nine commercial or semi‐commercial whey protein concentrates, isolates and fractions
Author(s) -
Holt Carl,
McPhail Deborah,
Nevison Ian,
Nylander Tommy,
Otte Jeanette,
Ipsen Richard H.,
Bauer Rogert,
Ōgendal, Lars,
Olieman Kees,
Kruif Kees G.,
Léonil Joëlle,
Mollé Daniel,
Henry Gwénaële,
Maubois Jean Louis,
Pérez M. Dolores,
Puyol Pilar,
Calvo Miguel,
Bury Stella M.,
Kontopidis George,
McNae Iain,
Sawyer Lindsay,
Ragona Laura,
Zetta Lucia,
Molinari Henriette,
Klarenbeek Bert,
Jonkman Margrethe J.,
Moulin Jacques,
Chatterton Dereck
Publication year - 1999
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1046/j.1365-2621.1999.00323.x
Subject(s) - lactalbumin , chromatography , whey protein , chemistry , fraction (chemistry) , casein , composition (language) , chemical composition , capillary electrophoresis , bovine serum albumin , food science , philosophy , linguistics , organic chemistry
Summary Analytical results are given for whey powders prepared on a commercial or semi‐commercial scale by three companies. Altogether, five preparations enriched in β‐lactoglobulin, four whey protein isolates and a fraction enriched in α‐lactalbumin were analyzed for protein composition, including %β‐lactoglobulin, α‐lactalbumin, bovine serum albumin, casein (glyco) macropeptide and the main triglycerides. Protein composition was determined by high pressure gel permeation and reversed phase liquid chromatography and by capillary zone electrophoresis. The extent of modification of the native β‐lactoglobulin structure was also measured through the degree of lactosylation and the fraction of accessible free sulphydryl groups. One significant finding was that the calculated recovery of protein following quantitation of the chromatogram or electropherogram was seldom above 90% and occasionally below 60% of that loaded onto the column or capillary, raising doubts as to the reliability of the analytical results. Extrapolation by linear regression to 100% recovery allowed estimates to be made of the true β‐lactoglobulin composition of the samples. The nine samples could be placed into three distinct groups with estimated true β‐lactoglobulin weight % of 70.9 ± 1.1, 62.0 ± 3.4 and 39.5 ± 4.9. Physico‐chemical properties of the group of samples are reported elsewhere (Holt et al ., 1999).