Scribd
Upload
1K views1 page

Aoac 947.05

This document provides a titrimetric method for determining the acidity of milk by measuring the amount of lactic acid present. The method involves diluting a test portion of milk with water, adding a pH indicator, and titrating with sodium hydroxide solution. The volume of sodium hydroxide used is then used to calculate and report the percentage of lactic acid by weight in the milk sample.

Uploaded by

Ederson [BRQuality Consultoria]
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
1K views1 page

Aoac 947.05

This document provides a titrimetric method for determining the acidity of milk by measuring the amount of lactic acid present. The method involves diluting a test portion of milk with water, adding a pH indicator, and titrating with sodium hydroxide solution. The volume of sodium hydroxide used is then used to calculate and report the percentage of lactic acid by weight in the milk sample.

Uploaded by

Ederson [BRQuality Consultoria]
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 1

33.2.

06
AOAC Official Method 947.05
Acidity of Milk
Titrimetric Method
First Action 1947
Final Action
Measure or weigh test portion (ca 20 mL or 20 g) into suitable dish
and dilute with twice its volume CO2-free H2O. Add 2 mL
phenolphthalein and titrate with 0.1M NaOH to first persistent pink.
If measured volume was used, determine its weight from specific
gravity of test sample. Report acidity as % lactic acid by weight. (1
mL 0.1M NaOH = 0.0090 g lactic acid.) If Babcock milk pipet,
989.04C(b) (see 33.2.27), is used, mL 0.1M NaOH required ÷ 20 =
% acid as lactic acid.
Results may also be expressed as mL 0.1M NaOH/100 g test
portion.
References: JAOAC 30, 130(1947); 34, 239(1951).

 2005 AOAC INTERNATIONAL

You might also like