Simple picrate paper kit for determination of the cyanogenic potential of cassava flour

✍ Scribed by Egan, Sylvia V; Yeoh, Hock Hin; Bradbury, J Howard

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 245 KB
• Volume: 76
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(199801)76:1<39::aid-jsfa947>3.0.co;2-m

✦ Synopsis

A simple picrate paper kit method was developed for the semiquantitative determination of the cyanogenic potential for cassava Ñour. The method involved the addition of linamarase and pH 8 phosphate bu †er (absorbed in a Ðlter paper disc) to 100 mg of Ñour ]0É5 ml water placed in a small vial. A rectangle of yellow picrate paper attached to a plastic strip was added and the vial capped and left overnight. The yellow paper changed colour towards brown and its colour was compared with that of a standard colour card with 10 shades of colour which corresponded with cyanogenic potentials of 0È 800 mg HCN equivalents kg~1 Ñour (ppm). To obtain a more accurate measure of cyanogenic potential (^20%) the paper was eluted with water and the absorbance measured at 510 nm. The cyanogenic potential in ppm was determined from a calibration graph. The methodology is available in kit form. The simple method may be used in the Ðeld by a relatively unskilled person. The more accurate method requires a spectrophotometer and is suitable for use in simple laboratories in developing countries.

1998 SCI.