Page 187 - Pharmaceutical Analytical Chemistry III
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Rancidity
Kreis-Kerr test
The presence of aldehyde as epihydrine aldehyde (measured by Kreis-Kerr
test) indicates Progressive Rancidity
Test
Oil or fat sample + phloroglucinol/ conc HCl → pink color indicate
rancidity
Epihydrin aldehyde + phloroglucinol/ conc HCl → condensation product
"pink color
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