Cuticle, seed coat

The reproducibility of the results for heated filament pyrolysers (CDS Pyroprobe 1000) and Curie point pyrolysers (Horizon Instruments) was reported for several samples [34]. This included several synthetic polymers, dammar resin, chitin, an insect cuticle, a hardwood (cherry), a seed coat (water lily), lycopod cuticle (fossil Eskdalia), as well as several organic geological samples. All samples were pyrolysed at 610° C for 5 s in a flow of helium. The residence time in the pyrolyser before pyrolysis was kept constant and the temperature of the sample housing was 250° C. Other parameters such as the temperature of the transfer line to the analytical instrument were also the same. Both systems were connected to a GC/MS system for the pyrolysates analysis. 

The seed coat is the outermost tissue layer which protects the embryonic structure and consists of approximately 7-8 % of the total dry weight in the mature bean with a protein content of 5% (db) (3 and 4). Two external anatomical features include the hilum and micropyle which each have a role in water absorption. The major components in the seed coat structure include a waxy cuticle layer, palisade cell layer, hourglass cells and thick cell-walled parenchyma cells. The cuticle is the outermost portion of the seed coat and its... 

Sediments of higher plant remains like seeds, pollen, cuticle, bark, and wood remains, indicated that their fossilization was comprised of highly resistant biopolymers like cutan, suberin, and lignin. In most cases only the seed coats are found in the geological record, because the outer layers of seeds contain resistant compounds to protect the genetic material against physical and chemical processes such as temperature and humidity changes and bacterial... 

Importantly, it has been stated that permeability of the seed coat may be affected by the mechanical properties of the cuticle (Ma et al., 2004 Zeng et al., 2005). The mechanical properties of a material are influenced by the pol)nners that are present in the material (i.e. their chemical composition, molecular arrangement, and interadion of the molecules) along with temperature and moisture content (Hoseney, 1994). As noted, the glass transition temperature (Tg) is a pol3mier science concept that has been applied to food science research for studying the material properties of biopol)nners (Brent et al., 1997 Perdon et al., 2000). 

Ma, F. Cholewa, E. Mohamed, T. Peterson, C.A. Gijzen, M. (2004). Cracks in the Palisade Cuticle of Soybean Seed Coats Correlate with their Permeability to Water. Annals of Botany, Vol.94, pp. 213-228. 

Cotton. Cotton is furnished by the down surrounding the seeds of various species of Gossypium. This fibre, which is unicellular and closed at only one end, is always isolated, and appears under the microscope as a ribbon twisted at intervals on its own axis like a spiral (Fig. 68, Plate VI). The wall is comparatively thin and sometimes somewhat raised like a rim the lumen is wide—three or four times as wide as the walls. This lumen is mostly empty, but sometimes contains granulations representing the original protoplasm in a dried state. The cotton fibre, which consists solely of cellulose, is coated in the raw state with a very thin cuticle, which is readily seen in a dry microscopic preparation. When raw cotton is treated with ammoniacal cupric oxide solution, whilst the cellulose of the fibre first swells and then dissolves, the cuticle remains almost intact, so that the fibres assume characteristic microscopic forms. The section of the cotton fibre (see Fig. 69, Plate VI) is elliptical, curved or reniform, with a fissure-like lumen. 

---