Крахмал химические свойства, назначение, производство
Химические свойства
Starch occurs as an odorless and tasteless, fine, white to off-white
powder. It consists of very small spherical or ovoid granules or
grains whose size and shape are characteristic for each botanical
variety.
Использование
corn starch is used as a thickener in cosmetics and in face powders. Corn starch absorbs water and is soothing to the skin. It can cause allergic reactions such as inflamed eyes, stuffy nose, and perennial hay fever. A natural material obtained from corn kernels.
Определение
A polysaccharide that occurs exclusively
in plants. Starches are extracted
commercially from maize, wheat, barley,
rice, potatoes, and sorghum. The starches
are storage reservoirs for plants; they can
be broken down by enzymes to simple sugars
and then metabolized to supply energy
needs. Starch is a dietary component of animals.
Starch is not a single molecule but a
mixture of amylose (water-soluble, blue
color with iodine) and amylopectin (not
water-soluble, violet color with iodine).
The composition is amylose 10–20%,
amylopectin 80–90%.
Методы производства
Starch is extracted from plant sources with specific processes
according to the botanical origin. Typical production steps are
steeping (corn), wet milling (corn, potato), dry milling (wheat), or
sieving and physical separation with hydrocyclones. The last
production step is usually a centrifugal separation from the starch
slurry followed by drying with hot air. The starch separation
process may use sulfur dioxide or peroxides as a processing aid,
improving the separation process and the microbial quality of the
final product.
Общее описание
Fine, white, odorless powder. Note that granules from different vegetable sources vary in shape, size, and general appearance. A mixture of the carbohydrate polymers amylose amylopectin varying according to the vegetable source. Principally used for food.
Профиль реактивности
Starch is combustible. Presents a dust explosion hazard if dispersed as a fine dust in air in sufficient concentrations. Granules swell greatly in water and produce a colloidal suspension. Incompatible with oxidizing agents, acids, iodine, bases. Reacts with nitric acid/sulfuric acid mixtures to give nitroStarch, an explosive.
Опасность
Dermatitis. Questionable carcinogen.
Профиль безопасности
A nuisance dust. Mildly toxic by intraperitoneal route. A skin irritant. An allergen. Flammable when exposed to flame; can react with oxidizing materials. Moderately explosive when exposed to flame.
Безопасность
Starch is an edible food substance, considered a food ingredient and
not a food additive. It is regarded as an essentially nontoxic and
nonirritant material. Starch is therefore widely used as an
excipient in pharmaceutical formulations.
Both amylose and amylopectin have been evaluated as safe and
without limitation for daily intake. Allergic reactions to starch
are extremely rare and individuals apparently allergic to one
particular starch may not experience adverse effects with a starch
from a different botanical source. The wheat proteins (gluten) are
problematic for conditions such as celiac disease.
Contamination of surgical wounds with the starch glove powder
used by surgeons has resulted in the development of granulomatous
lesions.
LD50 (mouse, IP): 6.6 g/kg
хранилище
Dry starch is stable if protected from high humidity. Starch is
considered to be chemically and microbiologically inert under normal storage conditions. Starch solutions or pastes are physically
unstable and are readily metabolized by microorganisms; they
should therefore be freshly prepared when used for wet granulation.
Starch should be stored in an airtight container in a cool, dry
place.
Несовместимости
Starch is incompatible with strongly oxidizing substances. Colored
inclusion compounds are formed with iodine.
Регуляторный статус
GRAS listed. Included in the FDA Inactive Ingredients Database
(buccal tablets, oral capsules, powders, suspensions and tablets;
topical preparations; and vaginal tablets). Included in nonparenteral
medicines licensed in the UK. Included in the Canadian List of
Acceptable Non-medicinal Ingredients.
Крахмал препаратная продукция и сырье
сырьё
препарат