Standard No.:	SN/T 4260-2015
English Name:	Determination of crude polysaccharides in plant source foods for export. Phehol-sulfuric acid colorimetry
Chinese Name:	出口植物源食品中粗多糖的测定 苯酚-硫酸法
Professional Classification:	SN    Professional Standard - Import&Export Inspection
Source Content Issued by:	AQSIQ
Issued on:	2015-05-26
Implemented on:	2016-1-1
Status:	valid
Target Language:	English
File Format:	PDF
Word Count:	3000 words
Translation Price(USD):	120.0
Delivery:	via email in 1 business day

Determination of crude polysaccharides in plant source foods for export— Phenol-sulfuric acid colorimetry 1 Scope This standard specifies the colorimetry determination of crude polysaccharide content in plant source foods for export. This standard is applicable to the determination of crude polysaccharide content in plant source foods such as edible fungi, wolfberries, grapes, jujubes and fruit juices. This standard is not applicable to foods with starch and dextrin components. The detection limit of this standard method is 0.5 mg/kg. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 crude polysaccharides a series of macromolecular compounds with β-D-glucan or α-D-glucan or other carbon sugars as the main chain, with general formula of the molecule is (C6H12O6)n 4 Principle Polysaccharides are hydrolyzed into monosaccharides under the action of concentrated sulfuric acid, and rapidly dehydrated to form glycoaldehyde derivatives. They react with phenol to form an orange-yellow solution, have characteristic absorption at 490 nm, and then are quantified through comparison with the standard series.   5 Reagents and materials Unless otherwise specified, only analytical pure reagents shall be used, and the test water shall meet the requirements of Grade-III water specified in GB/T 6682-2008. 5.1 Sulfuric acid (H2SO4); ρ = 1.84 g/mL. 5.2 Anhydrous ethanol (C2H6O). 5.3 Phenol (C6H6O); re-distillation. 5.4 80% ethanol solution. 5.5 Glucose (C6H12O6); before use, it shall be dried at a constant temperature of 105°C to constant weight.

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Principle 5 Reagents and materials 6 Apparatus 7 Sample preparation and preservation 8 Determination steps 9 Calculation 10 Repeatability Annex A (Informative) Qualitative identification of starch and dextrin