SOP: Modified Villavecchia Test for Sesame Oil

GIFSQ — Global Institute for Food Safety & Quality

Principle

Sesame oil is detected by the crimson colour formed when the oil is treated with a dilute furfural solution and concentrated hydrochloric acid (the AOAC-adopted modification of the Baudouin test). A confirmatory shake with water distinguishes the sesame reaction, since the colour disappears when sesame oil is absent.

Apparatus required

• Test tube

Reagents

a. Furfural solution: add 2 ml of distilled furfural to 100 ml of alcohol (a very dilute solution is specified, since furfural gives a violet colour with HCl).

b. Concentrated HCl.

c. Distilled water.

Procedure

To 10 ml of oil or melted fat in a test tube, add 10 ml of conc HCl and 0.1 ml of furfural solution

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Mix for 15 seconds and allow the mixture to stand for 10 min; appearance of a crimson colour indicates the presence of sesame oil

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Add 10 ml of water, shake and observe the colour; if the colour disappears, sesame oil is absent

References

Ranganna, S., Handbook of Analysis and Quality Control for Fruit and Vegetable Products, 2nd edition. (Test adopted by AOAC.)