CARBOHYDRATES AND TESTS TO DETERMINE THEM.pdf

OUTLINE
Sugars (saccharides)
 monosacharides
 di-, tri- and tetra saccharides
 Polysaccharides
 tests of carbohydrates
Commercial plant derived fibres and products:
Absorbent cotton wool
Starch - Starch application - Sources of starch - Preparation of starch - Sources, composition, uses
of starch (dextrose, mannitol, sorbitol and lactulose).
-Fructans - Inulin - Algal gelling agents - Gums and mucilage - Collection, preparation and
pharmaceutical uses of honey.

CARBOHYDRATES
 Carbohydrates are polyhydroxy aldehydes or ketones, or substances that
yield such compounds on hydrolysis.
 Carbohydrates are compounds of tremendous biological importance:
they provide energy through oxidation
they supply carbon for the synthesis of cell components
they serve as a form of stored chemical energy
they form part of the structures of some cells and tissues

Classes of carbohydrates
 Monosaccharides
 Disaccharides
 Polysaccharides

Monosaccharides
 Monosaccharides contain a single polyhydroxy aldehyde or ketone
unit (saccharo is Greek for “sugar”) (e.g., glucose, fructose,
galactose).
 White crystalline solids in nature, colorless, water-soluble and some
have a sweet taste.
 They are subdivided into two classes- aldose and ketoses.

Monosaccharides
 Aldoses- Sugars containing an aldehyde group are known as aldoses, e.g., Glucose,
galactose, mannose, ribose and glycerose.
 Ketoses- Sugars containing a ketonic group are known as ketoses. e.g.,
Dihydroxyacetone, fructose and seduloheptulose
 They are also classified as a triose, tetrose, pentose, hexose or heptose on the basis of
whether they contain three, four, five, six or seven carbon atoms.
 Hexose is the most important.

Physical characteristics of Monosaccharides
 Most Monosaccharides have a sweet taste (fructose is sweetest; 73% sweeter
than sucrose).
 They are solids at room temperature.
 They are extremely soluble in water:
 Despite their high molecular weights, the presence of large numbers of OH groups
make the Monosaccharides much more water soluble than most molecules of similar
MW.
 Glucose can dissolve in minute amounts of water to make a syrup (1 g / 1 ml H2O).

Physical properties of Monosaccharides
• Asymmetric carbon atoms
It is that carbon atom that is attached to four different groups or atoms.
All Monosaccharides contain one or more asymmetric carbon atoms except ketotriose and
dihydroxyacetone.
• Stereoisomerism
Compounds that have the same structural formula but differ in spatial configuration are known as
stereoisomers.
The number of possible stereoisomer's depends on the number of asymmetric carbon atoms (n) and is
equal to 2n.

Properties
• Epimers
When sugars differ only in the configuration around one specific carbon atom other than the carbonyl
carbon or penultimate carbon, they are called epimers. e.g., Glucose and mannose are epimers at C2
whereas glucose and galactose are epimers at C4.
• Enantiomers:
Non super-imposable mirror images are known as enantiomers. e.g., D and L sugars.
 a monosaccharides can be found in either D or L form. E.g D-glyceraldehyde and L-glyceraldehyde.
Also D-glucose and L-glucose. D sugars most abundant in humans.

Properties
Anomers
Sugars differing at the anomeric carbon atom are known as anomers.
These are monosaccharides that differ in the configuration only around the carbonyl carbon in the
cyclic structure .
A monosaccharide in the cyclic structure can exist either in α or β in configuration.
In α form, the hydroxyl group attached to the carbonyl carbon is on the right.
In β form, the hydroxyl group attached to the carbonyl carbon is on the left.
In monosaccharide solutions, the α and β are in equilibrium and can be easily be converted to each
other.

Properties
Mutarotation
 Change in the specific rotation of an optically active compound (freshly
prepared solutions of sugars with free aldehyde and ketone groups)
without any change in its other properties is knows as mutarotation.
 E.g. Freshly prepared D-glucose solution has an angle of rotation +112o
which gradually decreases and becomes constant at +52.5o

Properties
Optical activity
It is the ability of the compound to rotate plane polarised light to the right or to the left.
• A levorotatory (–) substance rotates polarized light to the left. [E.g., l-glucose; (-)-glucose]
• A dextrorotatory (+) substance rotates polarized light to the right. [E.g., d-glucose; (+)-glucose]
• Molecules which rotate the plane of polarized light are optically active.
• Each optically active substance has a specific angle of rotation. E.g the specific rotation for
glucose is +52.5o and for fructose is -91o.

Some important monosaccharides
β-D-ribose: Forms the sugar backbone of ribonucleic acid (RNA).
β-D-deoxyribose: Forms the sugar backbone of deoxyribonucleic acid (DNA).
β-D-galactose: Incorporated with glucose into lactose (milk sugar).
β-D-glucose Also known as dextrose and blood sugar; present in honey and fruits. Glucose
is metabolized in the body for energy.
Other sugars absorbed into the body must be converted to glucose by the liver.
Also known as levulose and fruit sugar.

Some important monosaccharides
Fructose is the sweetest of the monosaccharides.
It is present in honey (1:1 ratio with glucose), fruits, and corn syrup.
It is often used to sweeten foods, since less fructose is needed to achieve the
same degree of sweetness.

DISACCHARIDES
 Disaccharides are Sugars containing two monosaccharide units linked by glycosidic
bond.
 The three most common disaccharides are discussed below:
 Maltose
 Lactose
 Sucrose

DISACCHARIDES
 Maltose
It contains two a-D-glucose units linked by α-1 → 4 glycosidic linkage.
Chemically it is named as α-D-glucopyranosyl-(α-1 → 4)-α-D-glucopyranose.
It is also known as malt sugar.
It is found in germinating grain (such as barley), and is formed during the
hydrolysis of starch to glucose during digestion.
 Because it has a hemiacetal group, it is a reducing sugar.
 It forms star shaped osazone crystals.

Disaccharides
Lactose:
 Made up of β-D-galactopyrasone and α-D-glucopyranose linked through β-1 → 4
glycosidic linkage.
 Chemically it is called as β-D-galactopyranosyl-(β-1 → 4)-α-D-glucopyranose.
 It is present in milk and hence called milk sugar.
 It is a reducing sugar and forms puff shaped osazone crystals.

Disaccharides
Sucrose
 Contains α-D-glycopyranse and β-D-fructofuranose linked through α-1 → 2 glycosidic linkage.
 Its chemical name is α-D-glucopyranosyl-(α-1 → 2)-β-D-fructofuranose.
 It is the common table sugar obtained from sugar cane hence the name cane sugar.
 As it is a non-reducing sugar it does not form osazones.
 It is also known as invert sugar.
 Both anomeric carbons of glucose and fructose are tied together in the glycosidic linkage; thus neither
ring can open, and sucrose is not a reducing sugar.
 Sucrose is abundant in sugar cane and sugar beets; maple syrup contains about 65% sucrose, with
glucose and fructose present as well; caramel is the solid residue formed from heating sucrose.

Disaccharides
 A flavoring agent called invert sugar is produced by the hydrolysis of sucrose
under acidic conditions, which breaks it apart into glucose and fructose; invert
sugar is sweeter than sucrose because of the fructose.
 Some of the sugar found in honey is formed in this fashion; invert sugar is also
produced in jams and jellies prepared from acid-containing fruits.

Polysaccharides
 Carbohydrates made up of 10 or more monosaccharide units are called as
polysaccharides.
 They are also known as glycans.
 They are further classified as: homopolysaccharides and heteropolysaccharides.
 Homopolysaccharides:
 Those polysaccharides which contain only one kind of monosaccharide unit are called
homopolysaccharides. e.g., starch, glycogen, cellulose, dextran, inulin, agar, chitin, etc.
Heteropolysaccharides
Contain two or more different monosaccharides, most naturally occurring heteroglycans contain only
two different ones and are closely associated with lipid and proteins. E.g pectin, agar, peptidoglycan.

Polysaccharides
 Carbohydrates made up of 10 or more monosaccharide units are called as
polysaccharides.
 They are also known as glycans.
 They are further classified as: homopolysaccharides and heteropolysaccharides.
 Homopolysaccharides:
 Those polysaccharides which contain only one kind of monosaccharide unit are called
homopolysaccharides. e.g., starch, glycogen, cellulose, dextran, inulin, agar, chitin, etc.

Tests for carbohydrates
1. Reduction of Fehling's solution.
 To a heated solution of the substance add drop by drop a mixture of equal parts of Fehling’s solution No. I and No.
2.
 In certain cases reduction takes place near the boiling point and is shown by a brick-red precipitate of cuprous
oxide.
 Reducing sugars include all monosaccharides many disaccharides (e.g. lactose, maltose, cellobiose and
gentiobiose).
 Non-reducing substances include some disaccharides (sucrose and trehalose the latter a sugar found in some fungi)
and polysaccharides.
 Non-reducing carbohydrates will on boiling with acids be converted into reducing sugars, but students are reminded
to neutralize any acid used for hydrolysis before testing with Fehling's solution, or cuprous oxide will fail to
precipitate.

Tests
2. Molisch's test.
All carbohydrates give a purple colour when treated with o-naphthol and concentrated
sulphuric acid.
With a soluble carbohydrate this appears as a ring if the sulphuric acid is gently poured
in to form a layer below the aqueous solution.
With an insoluble carbohydrate such as cotton-wool (celluiose) the colour will not
appear until the acid layer is shaken to bring it in contact with the material.

Tests
3. Osazone formation.
Osazones are sugar derivatives formed by heating a sugar solution with phenylhydrazine hydrochloride,
sodium acetate and acetic acid.
If the yellow crystals which form are examined under the microscope they are sufficiently characteristic
for certain sugars to be identified.
It should be noted that glucose and fructose form the same osazone( glucosazonem. .p. 205oC).
Before melting points are taken, osazones should be purified by recrystallization from alcohol.
Sucrose does not form an osazone but under the conditions of the above test sufficient hydrolysis takes
place for the production of glucosazone.

Tests
4. Resorcinol test for ketones.
This is known as Selivanoff's test.
A crystal of resorcinol is added to the solution and warmed on a water-bath with an
equal volume of concentrated hydrochloric acid.
A rose colour is produced if a ketone is present (e.g. fructose, honey or hydrolysed
inulin).

Tests
5. Test for pentoses.
Heat a solution of the substance in a test-tube with an equal volume of hydrochloric acid
containing a little phloroglucinol.
Formation of a red colour indicates pentoses.
6. Keller-Kiliani test for deoxysugars.
Deoxysugars are found in cardiac glycosides such as those of Digitalis and Strophanthas .
The sugar is dissolved in acetic acid containing a trace of ferric chloride and transferred to the
surface of concentrated sulphuric acid.
At the junction of the liquids a reddish-brown colour is produced which gradually becomes blue.

Tests
7. Enzyme reactions.
Since certain carbohydrate reactions are only brought about by certain specific enzymes,
such enzymes may be used for identification.
8. Chromatography .
Chromatographic methods are particularly suited to the examination of drug extracts, which may contain
a number of carbohydrates often in very small amounts.
Not only are they applicable to carbohydrates originally present in the plant, but also they may be used
to study the products of hydrolysis of polysaccharide complexes such as gums and mucilages.
As standards for comparison many pure sugars, uronic acids and other sugar derivatives are
commercially available.

Chromatography
Experimental details and Rf values of sugars in different systems are to be found in standard books on
chromatography.
The carbohydrate spots obtained after separation are identified by their positions and by reagents.
It may be useful to examine them in ultraviolet light.
A non-specific reagent for reducing sugars is a freshly prepared ammoniacal silver nitrate solution.
More specific reagents giving coloured spots with different sugars include aniline hydrogen phthalate( in
water-saturated n-butanol) and naphthoresorcinol (ln acetone, water and phosphoric acid).
These are applied to the chromatogram with a spray.
Although sugars are nonvolatile, it is possible by suitable treatment to render the satisfactory for gas
chromatography (q.v.)

COMMERCIAL PLANT DERIVED FIBRES AND PRODUCTS

Absorbent cotton wool
Cotton Wool is mainly prepared from linters, card strips, card fly and comber waste.
Bales of these short-fibred cotton wastes pass from the yam manutacturers to the makers
of cotton wool.
For best quality cotton wool the comber waste of American and Egyptian cottons is
preferred.
In this the fibres are reasonably long and twisted and thus suitable for producing a cotton
wool having an average staple as specified in the BP, which will offer appreciable
resistance when pulled and not shed a significant quality of dust when shaken gently.

Biological source
 It is the epidermal hairs of the seeds of cultivated species of Gossypium
herbaceum or other species of Gossypium.
 Family; Malvaceae
 Chemical nature. Raw cotton consists of cellulose approximately 90% and
moisture 7% the remainder being wax. fat, remains of protoplasm and ash.
 The cellulose molecule is built up of glucose residues united by 1,4-B-
glucosidic links (contrast starch).

Preparation:
Raw cotton discarded by the textile industry as combers waste consists of about
90% cellulose, 3% fat, wax and 7% moisture.
This cotton is subjected to combing process so as to separate short fibres are
spun and woven as cloth.
The combers waste consisting mainly of short fibres is boiled with dilute caustic
soda and soda ash solution for 10-15 hours at a pressure of 1-3 atmospheres.
This treatment will remove fatty cuticle of the trichomes making the wall
absorbent.

It is then thoroughly washed with water.
Bleaching is done by treatment with sodium hypochlorite solution and dilute hydrochloric acid.
It is washed with water and dried.
This cotton is then carded into flat sheets.
The carding machine forms thin continuous films of cotton wool.
Several such thin films are placed one above the other and packed into packages, which are finally
sterilized.
Uses
It employed as a surgical dressing; it serves as a mechanical protection to absorb blood, mucus or pus
and to keep bacteria from infecting wounds.

Starch
• Starch constitutes the principal form of carbohydrate reserve in the green plant and is to
be found especially in seeds and underground organs.
• Starch is a polymer consisting of D-glucose units.
• It can be seperated into two fractions i.e Amylose and Amylopectin .
• Natural starches are mixture of amylose (10-20%) and Amylopectin (80-90%).
• Amylose ( beta amylose) consists of long, unbranched chains of glucose (from 1000 to
2000 molecules) connected by α(
1→ 4) glycosidic linkages.
• It is water soluble and gives blue color with iodine.

Starch
Amylopectin (alpha amylose) consists of long chains of glucose (upto 105 molecules)
connected by α(
1→ 4) glycosidic linkages, with α(
1→ 6) branches every 24 to 30 glucose
units along the chain.
It is water insoluble nd gives a bluish black coloration.
Biological sources;
A number of starches are recognized for pharmaceutical use. They include
Maize (Zea mays L.).
Rice (Oryza sativa L.),

Starch
Biological sources;
Wheat (Triticum aestivum L .) and potato (Solanum tuberosum L.) (EP, BP).
 Maize, wheat and potato starches are official in the USNF (1990).
Tapioca or Cassava starch ( Manihot utilissima) may be used in place of the above.
The more important commercial starches are
 Rice starch; simple- polyhedral 2-12micrometer in size, compound 12-30Micrometer.
 Maize starch; polyhedral or rounded in shape, 5-31micrometer in size
 Wheat starch; simple lenticular hranules, circular or oval compound granules, 2-4 components.
 Potato starch; sphericl, flattened, irregularly ovoid in shape 30-100micrometer.

Uses of Starch
 used as nutritive
Demulcent
Binding agent
Disintegrant
Absorbant

Preparation of maize starch
The grain is first softened by soaking at 50'C for about 2 days in a 0.2% solution of
sulphurous acid.
This assists disintegration, enabling the embryo or germ to be easily liberated intact and
permitting the starch to be readily freed from fiber.
During this time lactic acid bacteria are active and metabolize soluble sugars extracted
from the maize.
The grain, in water, is then disintegrated by attrition mills; these do not break the
liberated oil-containing embryos .

The germs are continuously separated from the suspension by liquid cyclones
(hydroclones) which operate in batteries of about 12.
The germs are used for the preparation of germ oils. which are an important source of
vitamins.
The remainder of the grain is ground wet and the starch and gluten separated from
fibrous material in rotating, slightly inclined stainless steel reels covered with perforated
metal sheets.

The retained fibre is washed and the total mixture of starch and protein (mill starch) is
fractionated into gluten and starch by the use of special starch purification centrifuges;
separation depends on the fact that gluten is lighter than starch.
The starch suspension from the centrifuge is further purified in other centrifuges and
hydroclones.
which reduces the protein level.
The subsequent drying process may involve flash dryers or a moving-belt dryer:
considerable flexibility in drying time is required to accommodate various modified
starches which are now produced.

Preparation of rice starch
Rice is soaked in successive quantities of 0.47% caustic soda until the material can be easily
disintegrated.
The softened grain is ground (the compound grains separating into their components) made into
a dilute suspension which is repeatedly screened and the starch separated by standing or by
means of a centrifuge.
The damp starch is next cut into blocks and dried at 50-60"C for 2 days.
The brown outer layer which forms is then scraped from the blocks and drying is continued at a
lower temperature for about 14days, during which time the blocks gradually crack into irregular
masses.
For pharmaceutical use this 'crystal' starch is powdered.

Preparation of potato starch
The potatoes are washed and reduced to a fine pulp in a rasping machine or in a disintegrator of the
hammer-mill type.
Much of the cell debris is removed from the pulp by rotary sieves and the milky liquid which passes through
the sieve contains starch, soluble proteins and salts, and some cell debris.
On standing, the starch separates more rapidly than the other, insoluble matter and again high-speed
centrifugal separators for use with potato starch (and cassava starch),are now employed for separation
and washing.
At two or three points during the isolation, sulphurdioxide is added to prevent discoloration of the product
by the action of oxidative enzymes.
The washed starch is collected, dried to contain about 18% moisture and packaged.

Preparation of Wheat Starch
Wheat being the major article of food is restrictedly used for preparation of
starch.
In this process, the wheat flour is converted into dough and kept for-awhile.
The gluten in the dough swells and the masses are taken to grooved rollers,
wherein water is poured over them with constant shaking.
The starchy liquid coming out of the rollers is processed conveniently to take
out the starch, which is then dried and packed suitably.

Dextrose
• Dextrose is the name of a simple sugar that is made from corn and is chemically
identical to glucose or blood sugar.
• Dextrose is often used in baking products as a sweetener and can be commonly
found in items such as processed foods and corns.
• Dextrose also has medical purposes.
• It is dissolved in solutions that are given intravenously, to replace lost fluids and
provide carbohydrates to the body therefore used to treat low blood sugar
(hypoglycemia), insulin shock or dehydration (fluid loss)

Lactulose
 Lactulose solution is used by mouth or rectally to treat or prevent
complications of liver disease (liver encephalopathy) - improves
mental status not cure.
 It is a colonic acidifier that works by decreasing the amount of
ammonia in the blood.

Mannitol
 Mannitol is used as a medication.
 As a sugar it is often used as a sweetener in diabetic food, as it is poorly absorbed from the intestines.
 Also used as excipient in chewable tablets.
 Mannitol, sorbitol are a common sugar alcohols are manufactured from sources such as corn cobs,
sugar cane bagasse (stalk residue remaining after sugar extraction.
 Sorbitol
 It is converted to fructose by sorbitol-6-phosphate 2-dehydrogenase. Sorbitol is an isomer of mannitol,
another sugar alcohol; the two differ only in the orientation of the hydroxyl group on carbon 2. while
similar, the two sugar alcohols have very different sources in nature, melting points and uses.

Sorbitol
 Sorbitol is mainly got from corn syrup but also found in nature in apples, pears, peaches and prunes.
 Uses
 As sweetener, Sorbitol is a sugar substitute and used in food.
 Its 60% as sweet as sucrose .
 Also its referred to as a nutritive sweetener because it provides dietary energy.
 As a laxative when taken orally or as an enema.
 Also used as excipient in chewable tablets
 Sorbitol is used in bacterial culture media to distingiush the pathogenic Escherichia coli O157:H7, from
other E.coli strains because it is usually unable to ferment sorbitol unlike 93% of known E.coli strains

Sorbitol
 Uses
 In treatment of hyperkalemia.
 Sorbitol is often used in modern cosmetics as a humectant and thickener.
 Also in mouthwashes, toothpaste and gel.

Fructans
 Fructans are D–fructose polymers each chain being terminated by a single D-glucosyl residue.
 They are found in nature as oligosaccharides with up to l0units and as polysaccharides with up
to 50units.
 The best-known fructan and the most important pharmaceutically, is inulin, a reserve
carbohydrate found in many roots of members of the Compositae and Campanulaceae.
 The tubers of the Jerusalem artichoke(Helianthus tuberosus) and loots chicory (Cichorium
intybus) are particularly rich sources.
 Other fructans are the phleins found in grasses e .g. in Phleum pratense,a gropyrene in couch
grass and sinistrin a component of Urginea maritima.

Inulin
 Inulin BP is obtained from the tubers of Dahliua variabilis.
 Helianthus Tuberosus and other genera of the Compositae ;it derives
its name from the dahlia, Inula helenium from which it was first
isolated in the 19th century.
 It occurs either in solution in the cell sap (cf. starch granules which are
formed in plastids) or in alcohol-preserve material as sphaerocrystalline
masses.

Inulin
 It is sparingly soluble in cold water but readily dissolves at around
70'C without gelatinizing.
 It is neither stained by iodine solution nor hydrolysed by mammalian
enzymes
 Uses
 High blood fats, cholesterol and triglycerides.
 Also used for weight loss, constipation, diarrhea and diabetes.

Algal Gelling Agents
 Alginates are salts of alginic acid a viscous gum formed by the cell walls of brown algae.
 Alginic acid is a polyuronic acid composed of reduced mannuronic and glucoronic acids,
which are obtained from the algal growth of the species of family Phaeophyceae.
 The common species are Macrocystis pyrifera, Laminaria hyperborea, Laminaria digitata,
Ascophyllum nodosum and Durvillaea lessonia.
 It is a purified carbohydrate extracted from brown seaweed (algae) by treatment of
dilute alkali.
 They have a very high gel strength, and when dissolved in water the gelation process is
reversible at 85oC.

Algal Gelling Agents
 High and medium viscosity grades of sodium alginate are used in the
preparation of paste, creams and for thickening and stabilizing
emulsions.
 It is a good suspending and thickening agent, but a poor emulsifying
agent.
 It is used as binding and disintegrating agent in tablets and lozenges.
 In food industry, it is used for the preparation of jellies, ice cream, etc

Agar
Botanical Source
 It is the dried gelatinous substance obtained by extraction with water
from Gelidium amansii or various species of red algae like Gracilaria
and Pterocladia, belonging to family Gelidaceae (Gelidium and
Pterocladia), Gracilariaceae (Gracilaria).

Agar
Uses of Agar
 Agar is used to treat chronic constipation, as a laxative, suspending agent, an emulsifier,
a gelating agent for suppositories, as surgical lubricant, as a tablet excipient,
disintegrant, in production of medicinal encapsulation and ointment and as dental
impression mold base.
 It is extensively used as a gel in nutrient media for bacterial cultures, as a substitute for
gelatin and isinglass, in making emulsions including photographic, gel in cosmetic, as
thickening agent in food especially confectionaries and dairy products, in meet canning;
sizing for silk and paper; in dying and printing of fabrics and textiles; and in adhesive.

Gums and mucilages
• Gums are considered to be pathological products formed following injury
to the plant or owing to unfavorable conditions, such as drought, by a
breakdown of cell walls (extracellular formation; gummosis)
• while, mucilages are generally normal products of metabolism, formed
within the cell (intracellular formation) and/or are produced without injury
to the plant. Gums readily dissolve in water, whereas, mucilage form slimy
masses.
• Gums are pathological products, whereas mucilages are physiological
products.

Gums and mucilages
 Acacia, tragacanth, and guar gum are examples of gums while
mucilages are often found in different parts of plants.
 For example, in the epidermal cells of leaves (senna), in seed coats
(linseed, psyllium), roots (marshmallow), barks (slippery elm) and
middle lamella (aloe).

Acacia (Gum acacia)
• It is a dried gummy exudate obtained from the stem and branches of Acacia
arabica belonging to the family leguminosae
• Odorless, soluble in water, insoluble in alcohol
Uses
• Demulcent
• Suspending agent
• Emulsifying agent
• Binding agents preparation of microencapsulation.

Tragacanth(Gum tragacanth)
 It is a dried gummy exudation obtained by incision from stems and branches of
Astragulus gummifer, family leguminosae
 Uses
 Demulcent
 Emmolient
 Thickening agent
 Suspending agent
 Emulsifying agent
 Adhesive

Mucilages
 Intracellular mucilages; E.g; Aloe- succulent plant, Musa paradisiacal- pulp, etc
 Cell membrane mucilage; E.g Althaea officinalis, L.- root, Cinnamomum sp.- bark, etc
 Uses
 Mucilages are most commonly used as adjuvant in pharmaceutical preparations, with
wide range of applications such as thickening, binding, disintegrating, suspending,
emulsifying, stabilizing and gelling agents. Mucilages may be used as sustained and
controlled release formulations.
 It is used in the process of ‘granulation’ for the manufacturing of tablets

Pectin
 Pectin, is a group of polysaccharides found in nature in the primary cell walls
of all seed bearing plants and are invariably located in the middle lamella.
 Biological source
 Pectin is a purified polysaccharide substance obtained from the various plant sources
such as inner peel of citrus fruits, apple, raw papaya, etc
 One of the richest sources of pectin is lemon or orange rind which contains about 30%
of this polysaccharide.

Pectin
 Pectin is used as an emulsifier, gelling agent and also as a thickening agent.
 It is a major component of anti-diarrheal formulation.
 Pectin is a protective colloid which assists absorption of toxin in the gastro-intestinal tract.
 It is used as haemostatic in cases of haemorrhage.
 As a thickener it is largely used in the preparation of sauces, jams and ketchups in food industry.
 One of the best characterized effects of pectin supplementation is its ability to lower human
blood lipoprotein levels.
 Pectin supplements appear to act as ‘enteroabsorbents’, protecting against the accumulation of
ingested radioactivity.

Honey
Biological source:
• Honey is the saccharine liquid prepared from the nectar of the flowers by the
hive-bee Apis mellifera, Apis dorsata, Apis florea, Apis indica and other species of
Apis, belonging to family Apideae (Order: Hymenotera).
Chemical constituents;
• Honey consists chiefly a mixture of dextrose and levulose (70-80%) and water
(14-20%). contains sucrose (1.2-4.5), Dextrin (0.06-1.25%), volatile oil, pollen
grains enzymes, Vitamins, Amino acids, Proteins, Colouring matters.

Honey
 Preparation:
 Nectar of the flowers is mainly watery solution of sucrose and contains about 25% sucrose and
75% water. The worker bee sucks the nectar by means of a long hollow tube of the mouth
(proboscis).
 The saliva of the bee contains enzyme invertase. Sucrose along with invertase goes to the honey
sac, which is located in the abdomen of the bee and is hydrolyzed by invertase into invert sugar.
 Some invert sugar is utilized by the bee for its nutrition.
 The bee reaches the honeycomb and regurgitates the remaining invert sugar and deposits it into
a special cell prepared earlier.

Honey
 In the next three days at the temperature of honeycomb, invert sugar is converted into
honey and then water is lost by evaporation and in this process, honey contains about
80% invert sugar and 20% water.
 When the honey cell is completely filled, the bee closes it by a cap of wax.
 Honey comb is smoked to remove the bees and honey is obtained by applying the
pressure to it or allowing it to drain naturally.
 The wax cap is removed and honey is separated by keeping hive-comb in a centrifuge.
Sometimes honey is separated by means of pressure.
 By this method honey comb breaks and wax finds its way in honey as in impurity.

Honey
Uses
• Honey is used as nutritive.
• Demulcent
• Mild laxative.
• It is used as an important component of linctuses and cough mixtures.
• It is a sweetening agent.
• It is used as antiseptic and bactericidal.
• This is also used as a vehicle in Ayurvedic and Unani preparations.
• As a pill recipients
• Recently, it is used in the preparation of creams, lotions, soft drink and candies also.

Honey
 It is used for cold, cough, fever, sore eye and throat, tongue and
duodenal ulcers, liver disorders, constipation, diarrhea, kidney and other
urinary disorders, pulmonary tuberculosis, marasmus, rickets, scurvy and
insomnia.
 It is applied as a remedy on open wounds after surgery.

CARBOHYDRATES AND TESTS TO DETERMINE THEM.pdf

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