Name: Rice
Rice – Oryza sativa L.
Known only in cultivation in the tropical, subtropical and warm zones of both hemispheres. Ancient culture of China and India (4-5 millennia). More than 1 billion people of Southeast Asia eat rice (grain). Cultivated varieties (within 7000 of them) of rice are associated with wild species: in Asia – with O. perennis Moench, in Africa – with O. glaberrima Steud., in South America – with O. sabulata Nees.
Rice is a monsoon climate plant with abundant rainfall and cloudiness. Rice was originally cultivated with natural rainfall. Subsequently, thanks to high irrigation technology, it began to be cultivated in fields artificially flooded as soon as the plants reached 15-20 cm in height. Irrigation flowing water moves very slowly along bunded areas. Water is drained 2-3 weeks before harvest.
The fruit is a caryopsis, laterally compressed, covered with lemmas. Sizes of grains depending on the ecotype: length 5.3-11.8 mm, width 1.9-3.1 mm.
Rice contains the highest percentage of starch among cereals. Grains of rice starch are among the smallest – their size is 4-6 microns. Prior to processing rice for starch, they are in the form of complex, easily disintegrating grains. Small grain sizes make rice starch indispensable in the preparation of medicinal and cosmetic (powder) powders.
The plant is starchy.
K starch-bearing plants
Starch is not a chemically individual substance. For 96-98% it consists of polysaccharides (amylase and amylopectin), accompanied by minerals, solid fatty acids, etc.
Starch-bearing plants are conditionally divided into two groups: plants of the cereal family and plants of other families. Cereal starches serve as raw materials for the production of the main types of starch: wheat (Amylum Tritici), maize or corn (Amylum Maydis) and rice (Amylum Oryzae).
From plants of other families, a lot of starch is obtained from potato tubers (Amylum Solani). In tropical countries, other varieties of starch are used; of which the main ones are:
– starch from sweet potato tubers – Amylum Batatae;
– Australian arrowroot – Amylum Cannae;
– Indian arrowroot – Amylum Curcumae;
– Westind Arrowroot – Amylum Marantae;
– cassava (cassava, tapioca) – Amylum Manihot.
Sago, or Amylum Sagi, is a starch obtained from the core of some palm trees.
All types of starch have the same use – in the form of mucous extracts (Mucilago, Decoctum) as an enveloping and emollient. Sago and cassava are also popular dietary aids for convalescents.