Of wrinkled pea

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). 

Wrinkled pea has a reduced starch level 66-75% of that seen in the normal round seed. The amylose content is about 33% in the wild-type round form, but is 60—70% in the wrinkled pea seed. Edwards et measured several enzyme activities involved in starch metabolism at four different developmental stages of wrinkled pea and found that branching enzyme activity at its highest level was only 14% of that observed for... 

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

Smith, A. M., Neuhaus, H. E., and Stitt, M. 1990. The impact of decreased activity of starchbranching enzyme on photosynthetic starch synthesis in leaves of wrinkled-seeded peas. Planta. 181, 310-315. 

Protein Composition of Peas (Reduced Data Set) (a) 1 = Smooth Pea Cultivars 2 = Wrinkled Pea Cultivars (b) LaurelPs Technique (c) Ultracentrifugation... 

Soon after Cori and Cori showed the existence of a branching factor, Haworth, Peat, and Bourne reported the isolation from potato juice of an enzyme fraction termed Q-enzyme, which, in association with potato phosphorylase, produced a polysaccharide having the properties of amylopectin. Peat and his collaborators also presented evidence that the Q-enzyme was capable of converting linear amylose to branched amylopectin without the participation of inorganic phosphate in the reaction. They therefore concluded that the Q-enzyme is a nonphos-phorolytic enzyme. Besides being present in the potato, Q-enzyme has also been found in the wrinkled pea,the broad bean, Neisseria perfiava, and Polytomella coeca. " ... 

Fig. 3. (A) Wheat starch. (B) Wheat starch under polarized light. (C) Com starch. (D) Cora starch under polarized light. ( ) Potato starch. (P) Potato starch under polarized light. (G) Regal lily starch. (H) Navy bean starch. I) Rice starch. (J) Wrinkled pea starch. (K) Cassava starch. (L) Oat starch, lowing a large compound granule. Magnification x 235. All photographs kindly provided by Professor R. M. Sandstedt of the University of Nebraska.

A. represents the lesser amount of the starch constituents in the - starch granules, about 15-35% in the normal starches from maize, wheat, potato, maniok and rice. Special varieties of plants exhibit enhanced contents of a. ->amylomaize starches (50-80%) and - wrinkled pea (50-78%) are the most promising carriers of high-amylose starch for industrial utilization. 

Wrinkled - pea starches The starches of most legumes generally show somewhat enhanced amylose contents of >28-35% (- broad bean starch, - pea starches). Naturally occurring wrinkled pea (Pisum sativum, convar. medullae ALEF) contains starches with 50% amylose. Plant breeders intend to generate a wrinkled pea with up to 90% amylose. 

P. are starch granules that are deposited in the cotyledons of different pea species as reserve polysaccharide, together with oligosaccharides and proteins. Industrial or pilot-plant products, obtained by ->wet milling and raffination from either Pisum sativum convar. sativum L. (smooth pea) or Pisum sativum convar. medullae ALEE (wrinkled pea). The first one contains 47-54% starch, 5-7% oligosaccharides, 21-34% protein and fiber, the second contains 30-37% starch, 25-36% protein, oligosaccharides and fiber. 

Introduction of special properties by breeding and genetic engineering high-amylose starches from wrinkled pea and amylocom amylopectin starches from waxy com, waxy rice, waxy sorghum, potatoes. 

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