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

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.

2014 ◽  
Vol 6 (4) ◽  
pp. 465-469
Author(s):  
Sosanka Protim SANDILYA ◽  
Anuradha GOGOI ◽  
Pinky Moni BHUYAN ◽  
Dip Kumar GOGOI

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.


1972 ◽  
Vol 35 (7) ◽  
pp. 405-409 ◽  
Author(s):  
Dick H. Kleyn

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.


2014 ◽  
Vol 39 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Nadia Innocente ◽  
Annalisa Segat ◽  
Lara Manzocco ◽  
Marilena Marino ◽  
Michela Maifreni ◽  
...  

1977 ◽  
Vol 60 (6) ◽  
pp. 1389-1391
Author(s):  
Dick H Kleyn ◽  
Chia-Lu Ho

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.


1971 ◽  
Vol 54 (4) ◽  
pp. 857-859
Author(s):  
C L Huaxg ◽  
D H Kleyn

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.


1960 ◽  
Vol XXXV (IV) ◽  
pp. 575-584 ◽  
Author(s):  
C. Borel ◽  
J. Frei ◽  
A. Vannotti

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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