UTILIZATION OF PHENOLPHTHALEIN MONOPHOSPHATE TO TO DETERMINE THE PHOSPHATASE ACTIVITY OF MILK1

1972 ◽  
Vol 35 (7) ◽  
pp. 405-409 ◽  
Author(s):  
Dick H. Kleyn
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Rapid Method ◽  
Alkaline Phosphatase Activity ◽  
Collaborative Study ◽  
Correlation Coefficients ◽  
Raw Milk ◽  
New Method ◽  
Chocolate Milk ◽  
Positive Correlations

The properties of alkaline phosphatase as it exists in milk are considered. The more common methods of measuring alkaline phosphatase activity in milk are briefly reviewed, especially those employing substrates possessing “built-in” indicators which produce a chromogen directly upon hydrolysis. The visual procedure employing phenolphthalein monophosphate as the substrate is given. The sensitivity of this method is shown to be far greater than that of the Scharer I (Rapid) method. Results of an AOAC Collaborative study demonstrated that the method yields results that are as precise and either as accurate as or more accurate than those obtained by the Scharer I (Rapid) method. The quantitative spectrophotometric procedure employing the above substrate is presented. Comparison of this method with the Scharer modified spectrophotometric method on milk revealed correlation coefficients (Scharer method: 0.998 and modified new method 0.991) showing very little difference in the positive correlations of absorbance values and % raw milk. For chocolate milk, the values were 0.990 and 0.990 for the respective methods. Collaborative study of this method has demonstrated that the random error of the modified new method is almost twice that of the Scharer technique while the systematic error is only about one-fourth of the latter method.

Refinement of a Quantitative Technique for Estimating Alkaline Phosphatase Activity in Milk

1971 ◽  
Vol 54 (4) ◽  
pp. 857-859
Author(s):  
C L Huaxg ◽  
D H Kleyn
Keyword(s):  
Alkaline Phosphatase ◽  
Linear Relationship ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Spectrophotometric Method ◽  
Correlation Coefficients ◽  
Chocolate Milk ◽  
Modified Method ◽  
Subsequent Measurement ◽  
The Cost

Abstract A procedure for determining alkaline phosphatase activity in milk and chocolate milk, based upon the dialysis of phenolphthalein monophosphate and subsequent measurement of absorbance of the dialysate at 550 nm, has been refined. The modified procedure specifies 3 ml milk, 3 drops (0.04 ml/drop) of substrate, and a 3 hr incubation period. These changes have resulted in a decrease in the cost of reagents and higher, more suitable absorbance values. The Scharer modified Spectrophotometric method was used as a reference. The modified method showed an apparent linear relationship which was verified by calculating correlation coefficients, 0.996 for milk and 0.992 for chocolate milk; both of these values are significant at the 1% level.

Collaborative Study of Alkaline Phosphatase Activity in Filter Paper Disks Impregnated with Skim Milk: Positive Control Sample

1982 ◽  
Vol 45 (2) ◽  
pp. 112-114 ◽  
Author(s):  
G. K. MURTHY ◽  
J. T. PEELER
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Filter Paper ◽  
Room Temperature ◽  
Collaborative Study ◽  
Control Sample ◽  
Skim Milk ◽  
Positive Control ◽  
Colorimetric Test

The rapid colorimetric test was used in a collaborative study to determine alkaline phosphatase activity in filter paper disks impregnated with skim milk then dried and stored for several months at room temperature. Five samples of filter paper disks (0 to 6 μg phenol/disk) in duplicate were sent to six collaborators for analysis. Computations of analytical and analyst errors showed variations of 22.2 to 48.8%. Most of the variations were due to differences among analysts, but some were partly due to differences in the slopes of the calibration curves (a = 0.05 level) they prepared at the time of analysis. Collaborator's performance was evaluated by comparing % correct results that were positive (negative) with the expected results. About 95% of the samples were correctly analyzed.

Fluorometric Determination of Alkaline Phosphatase in Fluid Dairy Products: Collaborative Study

1990 ◽  
Vol 73 (6) ◽  
pp. 842-849 ◽  
Author(s):  
Richard M Rocco
Keyword(s):  
Alkaline Phosphatase ◽  
Dairy Products ◽  
Collaborative Study ◽  
Skim Milk ◽  
Raw Milk ◽  
Chocolate Milk ◽  
Phenyl Phosphate ◽  
Whole Milk ◽  
Standard Deviations

Abstract Official methods for the measurement of alkaline phosphatase (ALP) in dairy products use either phenyl phosphate or phenolphthaleln monophosphate as substrate. Quantitation of results requires butanol extraction of the Indophenol (Scharer) or 3-h dialysis of the liberated phenolphthaleln (Rutgers). The Advanced Fluorophos® assay Is based on a self-indicating substrate which, when acted upon by ALP, loses a phosphate radical and becomes a highly fluorescent compound. The rate of fluorophore formation Is monitored for 3 mln In a fluorometer and the enzyme activity In mU/L Is calculated. Eight laboratories participated in a collaborative study to evaluate the Fluorophos® assay for determining ALP activity In whole milk, skim milk, chocolate milk, and cream (half and half). The comparative method was the AOAC quantitative phenyl phosphate method, 16.121-16.122 (14th Ed.). Mixed herd raw milk was added to pasteurized samples at 0.05, 0.1, and 0.2% (v/v). Method performance at 0.1% (v/v) added raw milk as measured by repeatability and reproducibility standard deviations (sr and sR) and relative standard deviations (RSDr and RSDR), respectively, were: whole milk, sr = 21.7%, sR = 34.6%, RSDr = 4.4%, RSDR = 7.0%; skim milk, sr = 19.2%, sR = 31.4%, RSDr = 3.8%, RSDR = 6.2%; chocolate milk, sr = 27.6%, sR = 45.8%, RSDr = 5.3%, RSDR = 8.8%. The method has been adopted official first action by AOAC for determination of alkaline phosphatase in whole milk, skim milk, and chocolate milk.

scholarly journals Phosphatase Activity of Microbial Populations in Different Milk Samples in Relation to Protein and Carbohydrate Content

2014 ◽  
Vol 6 (4) ◽  
pp. 465-469
Author(s):  
Sosanka Protim SANDILYA ◽  
Anuradha GOGOI ◽  
Pinky Moni BHUYAN ◽  
Dip Kumar GOGOI
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Microbial Population ◽  
Raw Milk ◽  
Carbohydrate Content ◽  
Cow Milk ◽  
Activity Maximum ◽  
Milk Samples ◽  
Acid And Alkaline Phosphatase

Cattle milk is a rich source of protein, carbohydrate, vitamins, minerals and all other major and micro nutrients. At a moderate pH, milk is an excellent media for the growth of microbes and thus, intake of raw milk is precarious. In this study, attempt was made for a qualitative study of eight raw milk samples of different varieties of cow and goat milk, collected from Jorhat district of Assam, India, on the basis of nutritional value and microbial population. The highest microbial population was found in the milk collected from cross hybrid variety of cow, whereas microbial contamination was the least in Jersey cow milk. Samples of C1 (Jersey cow) variety showed presence of the highest amount of protein and carbohydrate content as compared to the others. Almost all the milk samples showed positive acid and alkaline phosphatase activity. Maximum acid phosphatase activity was observed in cross hybrid cow milk, whereas local cow milk exhibited the highest alkaline phosphatase activity. Phosphatase activity did not show any co-relationship with microbial population of the milk samples. Similarly, the protein and carbohydrate content of the samples did not have any significant impact on both acid and alkaline phosphatase activity.

Effect of pulsed light on total microbial count and alkaline phosphatase activity of raw milk

2014 ◽  
Vol 39 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Nadia Innocente ◽  
Annalisa Segat ◽  
Lara Manzocco ◽  
Marilena Marino ◽  
Michela Maifreni ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Raw Milk ◽  
Microbial Count ◽  
Pulsed Light

Influence of Brand of Dialysis Tubing on a Quantitative Technique for Determining Alkaline Phosphatase Activity of Milk

1974 ◽  
Vol 57 (3) ◽  
pp. 710-712
Author(s):  
Dick H Kleyn ◽  
Joseph Jakubowski
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Analysis Of Variance ◽  
Alkaline Phosphatase Activity ◽  
Raw Milk ◽  
Regenerated Cellulose ◽  
Dialysis Tubing ◽  
Quantitative Technique ◽  
Modified Method

Abstract A study was conducted to determine the influence of brand of dialysis tubing on the official first action method for alkaline phosphatase activity of milk, 16.B01—16.B05. Two brands of tubing were compared: seamless regenerated cellulose tubing and membrane tubing. Analyses were performed in quintuplet on 8, 5, and 5 samples of milk containing about 0.10, 0.25, and 0.50% raw milk, respectively. Two trials were also conducted to compare the rates of dialysis, using about 0.25% raw milk. An analysis of variance of the data showed that the brand of tubing did have a significant ( P< 0.05) influence on resulting absorbance values, particularly at the higher levels of phosphatase activity. Rates of dialysis were found to agree within ± 0.07 μg phenolphthalein/hr during the 3 hr incubation specified. The modified method has been adopted as official final action.

Rapid Method for Determining Alkaline Phosphatase Activity in Serum with Thymolphthalein Monophosphate

1970 ◽  
Vol 16 (5) ◽  
pp. 431-436 ◽  
Author(s):  
A V Roy
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Rapid Method ◽  
High Precision ◽  
Alkaline Phosphatase Activity ◽  
Present Method ◽  
Standard Procedure ◽  
Effects Of Ph

Abstract The use of sodium thymolphthalein monophosphate in measuring alkaline phosphatase activity of serum is described. Thymolphthalein liberated in the reaction is conveniently measured by raising the pH of the medium, which produces a color and also stops the hydrolysis. The effects of pH, kind and molarity of buffer, temperature, and enzyme and magnesium con-centrations were studied. Results by this procedure correlate well with those obtained by a standard procedure in which liberated p-nitrophenol is de-termined. Advantages of the present method include excellent linearity, high precision, short incubation, and reagent stability.

Rapid Determination of Alkaline Phosphatase Reactivation

1977 ◽  
Vol 60 (6) ◽  
pp. 1389-1391
Author(s):  
Dick H Kleyn ◽  
Chia-Lu Ho
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Rapid Determination ◽  
Screening Method ◽  
Raw Milk ◽  
Relative Increase ◽  
Negative Results

Abstract A study was conducted to determine the feasibility of using the qualitative screening method specifying phenolphthalein monophosphate for differentiating reactivated and residual alkaline phosphatase activity. The relative increase in activity of the enzyme in the presence of MgCl2 serves to distinguish reactivated and residual alkaline phosphatase activity. Ten samples each of pasteurized (172°F for 24 sec), sterilized (about 300°F for a minimum of 2 sec) half-and-half and heavy cream were analyzed. Most samples yielded negative results initially but demonstrated activity after incubation 1 hr at 34°C. The average values, in terms of + marks, for the half-and-half and heavy cream in samples without MgCl2 were <1 and 2.4, respectively ; for samples treated with MgCl2, the values were 2.18 and 4.6, respectively, indicating reactivated phosphatase activity. In samples containing various levels of raw milk, the activity observed in the diluted, Mg2+-containing samples was less than in the undiluted samples containing no Mg, indicating residual phosphatase activity.

Rapid Screening Method for Alkaline Phosphatase Activity in Cheese: Collaborative Study

1978 ◽  
Vol 61 (5) ◽  
pp. 1035-1037
Author(s):  
Dick H Kleyn
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Collaborative Study ◽  
Screening Method ◽  
Rapid Screening ◽  
Butanol Extract ◽  
Rapid Screening Method

Abstract The method developed for determining alkaline phosphatase activity in cheese, in which phenolphthalein monophosphate is used as the substrate, was collaboratively studied. A 7.5% butanol extract of cheese is reacted with phenolphthalein monophosphate; phenolphthalein is released and yields a red solution that is compared visually with a standard (s) prepared from the same extract. Seven collaborators analyzed 8 samples of cheese, in duplicate, by the screening method and Scharer I method. Of the 208 observations returned, only 4 were incorrect. The alkaline phosphatase method has been adopted as official first action.

LEUCOCYTE METABOLISM IN PREGNANCY

1960 ◽  
Vol XXXV (IV) ◽  
pp. 575-584 ◽  
Author(s):  
C. Borel ◽  
J. Frei ◽  
A. Vannotti
Keyword(s):  
Alkaline Phosphatase ◽  
Oxygen Consumption ◽  
Pregnant Women ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Lactate Production ◽  
Glucose Consumption ◽  
In Pregnancy

ABSTRACT Enzymatic studies, on leucocytes of pregnant women, show an increase of the alkaline phosphatase activity and a decrease of the glucose consumption and lactate production, as well as of proteolysis. The oxygen consumption, with succinate as substrate, does not vary.

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