Composition, structure and physicochemical properties of three coloured potato starches

• Published in: International journal of food science & technology 2018-10, Vol.53 (10), p.2325-2334
• Main Authors: Yang, Liping, Xia, Yuesheng, Junejo, Shahid Ahmed, Zhou, Yibin
• Format: Article
• Language: English
• Subjects: Amylose; Chain branching; Chain length distribution; Chains; Composition; Crystal structure; crystalline structure; Crystallinity; Light transmittance; molecular weight; Morphology; Physicochemical properties; potato starch; Potatoes; Properties (attributes); Rheological properties; Starch; Starches; Vegetables
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/ijfs.13824

Summary Composition, structure and physicochemical properties of starch from red‐ and purple‐fleshed potatoes were investigated and compared to those of typical yellow‐fleshed potatoes. The starch from yellow has highest amylose (25.23%) content, following by purple (23.30%) and red (20.26%). The growth ring of the three starches differed, but granule morphology was largely similar. Each potato starch exhibited B‐type crystalline patterns, with crystallinity ranging from 20.33% to 22.25%. The molecular weights and z‐average radius of gyration exhibited significant difference among the three starch samples. The branch chain length distribution showed that purple potato starch had highest population of A chains and lowest population of B1 chains. Moreover, the pasting properties of the three samples differed remarkably. The purple (90.92%) and red (86.41%) potato starches presented extremely good light transmittance compared with the yellow potato starch (34.03%). Dynamic rheological analysis showed that all samples possessed a weak elastic gel‐like structure. Composition, structure and physicochemical properties of starch from red‐ and purple‐fleshed potatoes were investigated and compared to those of typical yellow‐fleshed potatoes. Each potato starch exhibited B‐type crystalline patterns, with crystallinity ranging from 20.33% to 22.25%. The molecular weights, z‐average radius of gyration and chain length distribution exhibited significant difference among the three starch samples. Moreover, the three samples presented remarkably different pasting properties and the properties of starch paste. The purple and red potato starches presented extremely good light transmittance compared with the yellow potato starch. The results can provide further information on how sourcing of coloured potato starch can be applied to food and other industrial applications.