Organic Pea Starches – I. Comprehensive Investigation of Morphological and Molecular Properties

Abstract

The comparatively high amylose (AM) content in native pea starch leads to a good functionality in food and non‐food products. Nevertheless, it has also been reported that pea starch tends to cause manufacturing problems more often than other starches. It has been suggested that this is due to substantial variation of the starch qualities originating from different pea starch varieties. Therefore, additional research which explores morphological, physicochemical, molecular, and techno‐/functional properties of starches from multiple pea varieties is necessary. Here, a large variety of pea starches are analyzed. The structure and size of the starch granules is studied using scanning electron microscopy (SEM), laser particle sizing (LPS), and image analysis of optical microscopy (IAOM). The morphological appearance and size do not differ significantly between the pea cultivars. The AM content is determined with two methods, both based on iodine interaction with the AM helix. The method suggested here (SEC‐prep) results in systematically higher AM content. This is due to better solubilization of the starch. Nevertheless, only small differences between the pea cultivars are observed. No differences in morphological appearance, particle size, and only minor differences in AM content, significant variations in the molar mass distribution of the total starch fraction (MwST) and of the AM fraction (MwAM) are found.