Abstract
Summary A rapid colorimetric method using α-naphtholphthalein originally developed by Roberts et al . (6) has been modified to eliminate certain inherent weaknesses. For convenience, the modified procedure is designated as the ANP test. The method may be applied to butter to give a roughly quantitative measure within an accuracy of 100mg. per 100g. fat of water-insoluble fatty acids below a concentration of 400mg. acid per 100g. of fat. With extra precautions greater accuracy may be achieved, since color changes may be detected with variations of 25mg. water-insoluble acids at concentrations of less than 400mg. per 100g. fat. The ANP method is not affected by the presence of butyric and lactic acids, but does measure caproic and higher fatty acids. The results indicate a close agreement between the ANP method and the WIA method of Hillig (4).
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
