AS 2300.4.8-1994

1 - AS 2300.4.8-1994 METHODS OF CHEMICAL AND PHYSICAL TESTING FOR THE DAIRYING INDUSTRY - DRIED MILK AND DRIED MILK PRODUCTS - DE
1 - PREFACE
1 - METHOD
1 - 1 SCOPE
1 - 2 REFERENCED DOCUMENTS
1 - 3 PRINCIPLE
1 - 4 REAGENTS (See also Appendix A)
1 - 4.1 General
2 - 4.2 Sodium chloride
2 - 4.3 Amido black dye solution
2 - 4.4 Citric acid monohydrate
2 - 4.5 Sodium chloride, saturated solution
2 - 4.6 Standard dried skim milk powder
2 - 5 APPARATUS (See also Appendix A)
2 - 5.1 Balance
2 - 5.2 Stoppered test tubes
2 - 5.3 Filter funnel
2 - 5.4 Filter papers
2 - 5.5 One- mark pipettes
2 - 5.6 Capillary pipette or pipettor
2 - 5.7 One-mark volumetric flasks
2 - 5.8 Water bath
2 - 5.9 Glass centrifuge tubes
2 - 5.10 Centrifuge
2 - 5.11 Spectrophotometer
2 - 6 TEST SAMPLES
3 - 7 PROCEDURE
3 - 7.1 Determination
3 - 7.2 Zero UDWPN check
3 - 7.3 Standard curve
4 - 8 CALCULATION
4 - 9 REPEATABILITY
4 - 10 TEST REPORT
4 - 11 REFERENCES
5 - APPENDIX A - METHOD FOR DETERMINING THE UDWPN CONTENT OF THE STANDARD DRIED SKIM MILK POWDER
5 - A1 SCOPE
5 - A2 PRINCIPLE
5 - A3 REAGENTS
5 - A3.1 General
5 - A3.2 Sodium chloride
5 - A3.3 Hydrochloric acid solution (8. 5 g HCl/ 100 mL)
5 - A3.4 Reagents for the Kjeldahl determination of nitrogen
5 - A4 APPARATUS
5 - A4.1 Erlenmeyer flasks
5 - A4.2 Erlenmeyer flasks
5 - A4.3 Bulb pipettes
5 - A4.4 Straight pipette
5 - A4.5 Filter funnels
5 - A4.6 Watch- glasses
5 - A4.7 Filter papers
5 - A4.8 Water bath
5 - A4.9 Centrifuge bottles
5 - A4.10 Centrifuge
6 - A4.11 Apparatus for the Kjeldahl determination of nitrogen
6 - A4.12 pH meter
6 - A5 TEST SAMPLE
6 - A6 PROCEDURE
6 - A6.1 Determination
6 - A6.2 Blank test
7 - A7 CALCULATION

This Standard sets out a method for the determination of the undenatured whey protein nitrogen (UDWPN) content of dried skim milk.

This Standard sets out a method for the determination of the undenatured whey protein nitrogen (UDWPN) content of dried skim milk.NOTE: The dye-binding method given is suitable for the testing of a large number of samples. If the number of samples is small, the UDWPN content may be determined directly by the Kjeldahl method described in Appendix A.

First published as part of AS N67-1970.
Revised and redesignated in part as AS 1629-1974.
Revised and redesignated in part as AS 2300.4.8-1994.