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Some physico-chemical properties of nine commercial or semi-commercial whey protein concentrates, isolates and fractions.
- Source :
-
International Journal of Food Science & Technology . Oct-Dec99, Vol. 34 Issue 5/6, p587-601. 15p. 1 Color Photograph, 3 Charts, 6 Graphs. - Publication Year :
- 1999
-
Abstract
- Summary The physico-chemical properties are reported for a group of whey protein powders prepared on a commercial or semi-commercial scale by three companies and chemically characterized as described elsewhere (Holt et al., 1999). The dependence of the apparent β-lactoglobulin % on the recovered % showed that the nine samples could be placed in three distinct groups with β-lactoglobulin weight % of 70.9 ± 1.1 (Group 1), 62.0 ± 3.4 (Group 2) and 39.5 ± 4.9 (Group 3). Measurements by 1H-NMR spectroscopy, on 3 of the samples confirmed that the native fold still predominated in the β-lactoglobulin. β-lactoglobulin could be crystallized from all the powders and the normal space group and cell dimensions were determined for the 8 samples that gave crystals of good enough quality for X-ray studies. Differential scanning microcalorimetry of samples dispersed in a phosphate buffer showed a clear difference between Goups 1 and 2 with a more prominent peak due to α-lactalbumin in the Group 2 samples. Light scattering and size exclusion chromatography showed that two types of aggregates were present to a variable extent in all the samples and after a heat treatment, the larger aggregates tended to predominate in Group 2. The rheology measurements, also made in the phosphate buffer, showed a difference of gel stiffness during heat treatment between the Group 1 and Group 2 samples with the exception of the BORCwpc+ sample. Within each group, gel stiffness increased with the degree of lactoslylation of the β-lactoglobulin. Interfacial measurements on samples dispersed in water presented a more complex pattern of behaviour although surface tension measurements at the air water interface of the Group 2 samples showed a two-step pattern of surface tension decrease with time, compared to a single step pattern in the Group 1 samples. [ABSTRACT FROM AUTHOR]
- Subjects :
- *WHEY products
*PROTEINS
*GLOBULINS
Subjects
Details
- Language :
- English
- ISSN :
- 09505423
- Volume :
- 34
- Issue :
- 5/6
- Database :
- Academic Search Index
- Journal :
- International Journal of Food Science & Technology
- Publication Type :
- Academic Journal
- Accession number :
- 2664714
- Full Text :
- https://doi.org/10.1046/j.1365-2621.1999.00326.x