Starches Leguminous

French bean starch (Plate II, Fig. 20). The granules have the form typical of leguminous starches, They are elliptical car bean- or kidney-shaped and all show a hilum fantastically fringed the narrow striation is always plainly apparent. Mean length of granules, about 60 ft. 

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. 

It is thus possible to settle microscopically if a wheaten loaf contains rye (but not the converse) or if potato, maize and leguminous starches are present. It is, however, far more difficult to detect in this way the presence of barley, oats or rice, the swollen and deformed starch granules of these being virtually indistinguishable from those of wheaten flour. 

Starch is obtained from cereals, from leguminous and other seeds, from potatoes and other tubers, and from certain roots. The starches which are most commonly used are those of wheat, maize, rice, potatoes, sago, manioc and maranta. 

It is likely that in the near future, starch, oilseed, or leguminous plants will be used to produce PHAs. Other plant materials such as cellulose and starch are already used to make plastics or plastic-like materials. Hemicelluloses have been used directly and/or converted to organic acids for PHA production at a laboratory scale. Thus any waste from the separation of PHA from plants could be hydrolyzed, fermented to lactic, acetic, and propionic acids, and then fed into bioreactors for the production of specialty PHAs. Polylactides and other polymers of organic acids could be produced in the same plant as could polysaccharides. Plant materials may become a major source of plastic materials in the next century with PHAs leading the way. 

Fig. 3.10. (A) Changes in dry weight (x) and content of starch ( ) and chlorophyll (o) during development of pea cotyledons. (B) Changes in fresh weight ( ) and protein content (a) during development of pea cotyledons. Vertical arrows indicate the stages of development at which the storage proteins vicilin and legumin can first be detected. (C) Changes in DNA (o) and RNA ( ) content during development of pea cotyledons. After Millerd and Spencer, 1974 [122]...

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