Pea starch

Pea starch granules are oval, sometimes fissured, with a diameter of 20-40 ym (13). Molecular and structural characteristics of the two main components of field pea starch—amylose and amylopectin—are important in determining functional properties (25,26). Smooth field pea starch concentrate contains 97.2% starch of which 30.3-37.8% is amylose (9,23,25-27), and wrinkled pea starch concentrate contains 94.8% starch, which is 64% amylose (26). The gelatinization temperature of smooth pea starch is between 64 to 69 C, and that of wrinkled pea starch is greater than 99 C to 115 C. Gelatinization temperature depends on maturity of field pea seed and amylose content (26,27). 

Colonna, P. and Mercier, C. (1985). Gelatinization and melting of maize and pea starches with normal and high-amylose genotyrpes. Phytochemistry 24,1667-1674. 

Colonna, R, Mercier, C. (1984). Macromolecular structure of wrinkled- and smooth-pea starch components. Carbohydrate Research, 126,233-247. 

Chick peas starch (Plate III, Fig. 22). The granules of this starch are rounded oval in form and are among the smallest of the leguminous starches, the maximum length being about 28-30 ft. A hilum is not frequent, whilst striation is fairly evident. 

Lentil starch (Plate III, Fig. 24). These granules resemble in contour those of pea starch, but the hilum is more frequently seen and represents an irregular cavity striation is almost always observed. The mean diameter of the granules is 38-40 /x,... 

Figure 5.9 Distribution of the crystalline domains in pea starch (a) optical micrograph of a typical sample of smooth pea starch after a 7 im step irradiation with an x-ray beam of 2p,m diameter, each step consisting of a 1 6s exposure (b) set of microfocus x-ray diffraction patterns recorded on a smooth pea starch granule. Each diagram corresponds to a diffraction area of " 3 xm2 steps of 7pm separate the diagrams. (Reproduced with permission from reference 41)...

For example, 1.5M KCl elevates the DSC transition in pea starch, and separates the transition into a lower temperature B-type starch transition, and a higher A type. 

Doublier, J. L. 1987. A rheological comparison of wheat, maize, feba bean and smooth pea starches. J. Cereal Sci. 5 247-262. 

Fig. 37.—G, corn starch H, rice starch I, corn dextrin J, pea starch K, cassava starch L, bean starch. Explanation in text.

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