BS EN ISO 6647-2-2020 Rice – Determination of amylose content Part 2: Spectrophotometric routine method without defatting procedure and with calibration from rice standards.
This document specifies two simplified routine methods for the determination of the amylose mass fraction of milled rice, non-parboiled. The main difference between the two methods is the dispersion procedure: method A specifies hot dispersion, and method B specifies cold dispersion.
Both methods are applicable to rice with an amylose mass fraction higher than 5 %.
NOTE These methods describe simplified procedures for the preparation of samples, which are frequently used In routine laboratories. The methods use the same reagents as the reference method (see ISO 6647-1), but omit the defatting step. Rice samples where the amylose mass fraction has been determined by the reference method are used as standards.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendmentsj applies.
ISO 712, Cereals and cereal products — Determination of moisture content — Reference method
ISO 6647-1:2020, Rice — Determination of Amylose content — Reference method — Part 1:
Spectro photometric method with a defatting procedure by methanol and with calibration solutions of potato amylose and waxy rice amylopectin
ISO 7301, Rice — Specification
ISO 8466-1, Water quality — Calibration and evaluation of analytical methods and estimation of performance characteristics — Part 1: Statistical evaluation of the linear calibration function
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6647-1 and ISO 7301 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www’electropedia.org/
4 Principle
Rice is ground to a very fine flour to break up the endosperm structure in order to aid complete dispersion and gelatinization. A test portion is dispersed in a sodium hydroxide solution. An aliquot portion is taken to which is added an iodine solution. The absorbance, at 720 nm, of the colour complex formed is then determined using a spectrophotometer.BS EN ISO 6647-2 pdf download.