The granular structure of C‐type pea starch and its role in gelatinization

Pea Starch: Composition, Structure and Properties — A Review

“…This causes the central part of the granule to swell. However, the crystallites of the A polymorphs, which are situated in the outer part of the granule are not disrupted at this stage, but are disrupted only at a higher temperature [74].…”

“…Most legume starches exhibit a 'C' type [30,34,39,67,73] diffraction pattern, which is intermediate between the A type (cereal) and the B type (tuber). Bogracheva et al [74] and Buléon et al [75] reported that all granules from wild type pea starches contain both A and B polymorphs and that the B polymorphs are arranged centrally with the A polymorph located peripherally within the granules. However, wrinkled pea starch has been shown to exhibit a 'B' type X-ray pattern with peaks that are both broad and weak [42].…”

“…Pea starches exhibit a weak peak at 5.6°2θ (characteristic of B type polymorphs) [74], strong peaks at 17.9°2θ (characteristic of A type polymorphs) and 17.0°2θ (characteristic of both A and B type polymorphs) [74]. The position (2θ angle) of the small peak, which is characteristic of the 'B' polymorph could lie anywhere between 5 and 6°g onimeter angle and different authors have reported different 2θ angle locations for this specific peak (5.4° [ 73], 5.45° [31], 5.5° [42,75], 5.6° [74], 5.75° [39], or 5.8° [ 79]). It seems that the exact position of the "B-peak" in the diffractogram depends on the instrumental settings and the experimental conditions.…”

The Effects of Environmental Conditions on the Structural Features and Physico-chemical Properties of Starches

“…Early work on starch crystalline polymorphic form [25,26] showed that elevation of growth temperature caused little change in the polymorphic form of rice (A-type) or potato (B-type) although in vitro the B-type crystallite form could be converted to the A-type. However, in some plants (sweet potato and soybean seedlings) the polymorphic form could be shifted from the B-(or C-type, traditionally viewed as the intermediate form between B-and A-type, although now regarded by some authors as a mixture of A-and B-type polymorphs [58,59]) to the A-type due to influence of growth temperature. This appears logical.…”

In situ Imaging of Pea Starch in Seeds

“…3 Such methods can be used to probe the effects of starch structure on gelatinisation of the starch on heating. [3][4][5] Various staining procedures using iodine 4,6-7 or fluorescent labelling [8][9] can be used to locate amylose molecules and visualise the growth ring structure within the granule, for intact granules, or for sectioned material. Phosphate-binding dyes have also been used with CSLM to probe the distribution of phosphate in native granules.…”