A COLORIMETRIC METHOD FOR THE DETERMINATION OF FAT-PEROXIDES AND ITS APPLICATION IN THE STUDY OF THE KEEPING QUALITY OF MILK POWDERS

1943 ◽  
Vol 21b (7) ◽  
pp. 133-139 ◽  
Author(s):  
R. A. Chapman ◽  
W. D. McFarlane
Keyword(s):  
Colorimetric Method ◽  
Milk Powder ◽  
Ammonium Thiocyanate ◽  
Close Relation ◽  
Peroxide Values ◽  
Keeping Quality ◽  
Quality Of Milk ◽  
Ferrous Ammonium

A colorimetric method based on the oxidation of ferrous to ferric iron and the determination of the latter as ferric thiocyanate has been found suitable for the estimation of fat-peroxides in milk powder. To an acetone extract of milk powder is added a solution consisting of 0.1% of ferrous ammonium sulphate and 0.4% of ammonium thiocyanate in 96% acetone, and the colour is developed by heating. The intensity of the red colour is measured with a Coleman spectrophotometer and is found to bear a close relation to the keeping quality of the milk powder. Peroxide values determined by this method are considerably higher than those obtained by an iodimetric procedure (4).

scholarly journals A METHOD FOR THE DETERMINATION OF THE KEEPING QUALITY OF MILK

1919 ◽  
Vol 40 (2) ◽  
pp. 373-382
Author(s):  
John C. Baker ◽  
Lucius L. Van Slyke
Keyword(s):  
Keeping Quality ◽  
Quality Of Milk

scholarly journals Determination Of Quality Of Milk From Different Genotype Of Dairy Cows

1970 ◽  
Vol 37 (1) ◽  
pp. 52-56 ◽  
Author(s):  
MR Islam ◽  
MN Hassan ◽  
MSR Siddiki ◽  
MAS Khan ◽  
MA Islam
Keyword(s):  
Specific Gravity ◽  
Dairy Cows ◽  
Protein Content ◽  
Milk Sample ◽  
The Other ◽  
Test Protein ◽  
Quality Of Milk ◽  
Genotype A

The present study was conducted to investigate the milk quality from different genotype. A total 48 dairy cows belong to different genotypes such as Holstein cross, Jersey cross, Sahiwal cross and Red Chittagong were selected. Milk compositional viz. specific gravity, Acidity test, Fat test, Protein test, Solids-not-fat (SNF) test and total solids (TS) test were carried out. It was observed that the higher specific gravity of milk was obtained from Jersey cross and Red Chittagong genotype, which was significantly higher (P<0.01) than the other genotype of dairy cows. The highest acidity (%) was observed (0.165±0.014) in Red Chittagong and the lowest acidity (0.118±0.025) in Sahiwal cross. The highest fat (%) was observed from Red Chittagong cows milk which was statistically higher from Jersey cross and Sahiwal cross and the lowest fat (%) was found in the milk of Holstein cross cows. The highest SNF value was obtained from Jersey cross and the lowest from Sahiwal cross. On the other hand, Holstein cross and Red Chittagong was nearly similar. Red Chittagong milk sample showed the highest TS value and the lowest value was observed from Holstein cross. The highest protein value was found from Red Chittagong and the lowest from Holstein cross but the protein content of other two genotypes were nearly similar. DOI: http://dx.doi.org/10.3329/bjas.v37i1.9868 BJAS 2008; 37(1): 53-56

scholarly journals Determination of Total Phosphorus in Foods by Colorimetry: Summary of NMKL Collaborative Study

1996 ◽  
Vol 79 (6) ◽  
pp. 1408-1410 ◽  
Author(s):  
T Katrhna Pulliainen ◽  
Harriet C Wallin
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Content ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Milk Powder ◽  
Molybdenum Blue ◽  
Relative Standard ◽  
Standard Deviations ◽  
Skimmed Milk Powder

Abstract A collaborative study was conducted to validate a spectrophotometric–colorimetric method for determining total phosphorus in foods. The sample was dry-ashed in the presence of zinc oxide, and total phosphorus content was measured colorimetrically as molybdenum blue. Twelve laboratories from the Nordic countries participated in the study. The test materials included potato flour, sausage, cold ham, infant formula powder, cheese, and skimmed milk powder. Participants received 12 randomly coded samples of 2 blind duplicates of each material. Phosphorus contents of materials varied between 0.076 and 0.96 g/100 g. Relative standard deviations for repeatability of the method varied from 1.1% for 0.96 g phosphorus/100 g to 5.4% for 0.29 g phosphorus/100 g. Relative standard deviations for reproducibility varied from 3.6% for 0.96 g phosphorus/100 g to 7.7% for 0.23 g phosphorus/100 g. The colorimetric method for determination of total phosphorus in foods has been adopted first action by AOAC INTERNATIONAL as an NMKUAOAC INTERNATIONAL method.

scholarly journals Keeping Quality of Milk and the Age on Testing for Total Bacterial Count

1931 ◽  
Vol 31 (3) ◽  
pp. 373-374 ◽  
Author(s):  
H. Barkworth
Keyword(s):  
Bacterial Count ◽  
Total Bacterial Count ◽  
Keeping Quality ◽  
Quality Of Milk

During the period 1923–29 inclusive nearly six thousand samples of milk were tested at Wye for both total bacterial count and also keeping quality. An examination of the results shows that on the average the afternoon milks showed nine hours less keeping quality than morning milks of the same total bacterial count, see Table I. The age of the milk on testing for total bacterial count (reckoned from the time of milking) is 27–29 hours for morning milks and 20–24 hours for afternoon milks.

452. Bacteriological tests for milk sampled during distribution to the consumer

1951 ◽  
Vol 18 (3) ◽  
pp. 268-282 ◽  
Author(s):  
A. Rowlands ◽  
Zena Hosking
Keyword(s):  
Lower Incidence ◽  
England And Wales ◽  
Keeping Quality ◽  
Quality Of Milk

1. This survey was undertaken to select a test for the official examination of the keeping quality of milk, both raw and pasteurized, sampled during its distribution to the consumer. Forty-five laboratories in England and Wales collaborated in the survey and together tested 20,159 samples during the year May 1949–April 1950.2. Failures with each test were lower in winter than in summer, and increased with increasing shade temperature. However, the proportion of failures for all samples tested in any one month at maximum shade temperatures up to 70° F., or even 75° F., was not appreciably higher than at temperatures up to 65° F. Of the samples examined during June to September, 62% were taken on days when the maximum shade temperature exceeded 65° F.Whatever test is used for the control of milk it is reasonable to expect that at least 75% of samples taken during a given period should reach the required standard. Because of the lower incidence of failures in winter than in summer, this requirement should apply to tests done during a period of 6 months rather than one of a year.

Keeping quality and raw-milk grading: I. Dye tests as measures of the keeping quality of milk

1950 ◽  
Vol 17 (2) ◽  
pp. 159-191 ◽  
Author(s):  
A. T. R. Mattick ◽  
A. Rowlands ◽  
H. Barkworth ◽  
Zena Hosking ◽  
O. Kempthorne
Keyword(s):  
Raw Milk ◽  
Keeping Quality ◽  
Quality Of Milk

The experiments analysed in this series of papers were undertaken as the result of a discussion on methods of measuring the keeping quality of milk, at a Conference of Advisory Bacteriologists of the Ministry of Agriculture and Fisheries.Owing to the disturbance and difficulty following the outbreak of war and the dislocation of handling and distribution, a serious decline in the keeping quality of raw-milk supplies was threatened.

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