Structural and functional properties of starches from field peas

• Published in: Food chemistry 2011-06, Vol.126 (4), p.1546-1552
• Main Authors: Wang, Shujun, Sharp, Peter, Copeland, Les
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; C-type crystallinity; Field peas; Food industries; Fundamental and applied biological sciences. Psychology; Pisumsativum; Starch and starchy product industries; Starch structure and function; Thermal transitions
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2010.11.154

► Starch was characterised from seven varieties of field peas (Pisumsativum). ► The starches had similar amylose content but differed in crystallinity. ► The starches differed significantly in swelling, pasting and thermal properties. ► Fine structure of starch molecules is important for functional properties. Starch was isolated from seven varieties of field peas (Pisumsativum L.) and characterised using a combination of physical, chemical and functional tests. The total starch content of the peas ranged between 34% and 42.7% of dry matter, and the amylose content of the starch was between 35% and 38%. Average particle diameter of the seven starches varied between 21.4 and 26.1μm. All of the pea starches gave a typical C-type X-ray diffraction pattern, with relative crystallinity ranging between 36% and 55% and the proportion of B-type crystallites between 3.8% and 30.4%. Although there were only small differences between the starches in amylose content, they displayed significant variability in functional properties, including swelling power, pasting characteristics, thermal transition temperatures in the differential scanning calorimeter, and in susceptibility to invitro attack by α-amylase. The results indicate the importance of structural characteristics of starch molecules, particularly amylopectin, as determinants of the properties of native starch granules.