| Autor: |
George C Supplee, B. Bellis |
| Rok vydání: |
1922 |
| Předmět: |
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| Zdroj: |
Journal of Dairy Science. 5:39-50 |
| ISSN: |
0022-0302 |
| DOI: |
10.3168/jds.s0022-0302(22)94132-3 |
| Popis: |
Summary A review of the results recorded herein seem to warrant the following conclusions: 1. The normal variations in results from the same sample of milk powder analyzed by the Roese-Gottlieb (Mojonnier) method should not be over 0.15 per cent when results are expressed on the original powder basis. If results are expressed on the moisture-free basis, the variation between duplicate samples may be increased due to discrepancies in the moisture determinations. 2. There is no positive evidence of less fat being extracted from old milk powder than fresh powder when both samples are expressed on the moisture-free basis. If results are expressed on the original powder basis, there is an apparent decrease in fat content of old powders due to the fact that they may have absorbed moisture. 3. The simple ether extraction method gives results from the double roller process powder which are on an average about 0.25 per cent lower than the Roese-Gottlieb (Mojonnier) method. Duplicate results from the former method are also subject to wider variations than those from the latter method. From sixty-nine comparisons of duplicate determinations by the Roese-Gottlieb (Mojonnier) method there is an average variation of 0.147 per cent; a maximum of 0.49 per cent and a minimum of zero. From the ether extraction method from twenty comparisons there is an average variation of 0.369 per cent; a maximum of 1.29 per cent; and a minimum of .05 per cent. 4. On the basis of results presented herein, the Redmond modification of the Babcock centrifugal method is very unreliable. The wide variations between the two methods is undoubtedly accounted for to some extent by the large multiplication factor required for converting the test bottle reading to percentage fat in the powder. 5. The modified Roese-Gottlieb procedure from which extraction is made from an acid medium instead of an alkaline medium gave higher results in the majority of cases than did the regular extraction from an alkaline medium. The full significance of these higher results cannot be stated however, without further investigation as to the variability of numerous results from the same sample of powder. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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