This ppt will give information of different properties of carbohydrate

1. PROPERTIES OF FOOD
CARBOHYDRATES

4. • The term carbohydrate (sugars) is derived from the
french : HYDRATE DE CARBON.
• They have a central role in the metabolism of animals
and plants.
• Sugar acts as a preservative as well as a sweetening
agent, EXAMPLE: Jams, Jellies etc.
• It is mainly used as a sweetening agent in beverage such
as tea, coffee, fruit drinks, frozen desserts such as ice
cream etc.
• Confectionaries sugar is the major ingredient
responsible for its shape and structure.

6. • The word hygroscopic means water attracting.
• Sugar absorbs moisture from air, when it is
exposed to air and are known to be very
hygroscopic in nature, hence sugar should be
stored in airtight container.
• Sugar and confectionaries made from sugar tend
to absorb moisture and become sticky when
exposed to air.

7. • Sugar are soluble carbohydrates.
• The solubility of mono- and oligosaccharides in water is
good.
• Solubility decreases as the sugars come together, as
often happens in sugar powders or granulates.
• The sugar arranged in descending order of solubility are-
fructose, sucrose, glucose, maltose and lactose.
• This property is important to obtain a particular product
when mixture of sugar is used.

8. • The ability of sugar to dissolve and reform
crystals.
• Sugar is dissolved in a liquid and heated, the
liquid evaporates, concentrating the sugar solution.
As the solution cools, the sugar re-form into
crystals.
• Crystals of sugar thus obtained are very desirable
in sugar coated preparations like sugar coated nuts
and other such as icings and candies.

9. ½ thread 1 ½ thread
1 thread Soft ball

10. • Crystallization depends upon a number of
factors include
1. Nature of the crystallizing medium,
2.Concentration of sugar in the preparation,
3.Temperature at which crystallization takes
place,
4.Agitation of the sugar preparation and the
addition of other ingredients such as butter,
ghee, egg etc.
• The greater the concentration of the sugar in the
sugar preparation the faster is the rate of
crystallization.

11. • When starch is mixed with water and heated the starch
granules swell and eventually rupture, absorbing liquid
which thickens the mixture. On cooling, if enough starch is
used, a gel forms.
• Gelatinization can take place in different temperature
range, commonly it take place at 88⁰C – 90⁰C.
• Common thickening agents : plain wheat flour, cornflour
etc.
• Two factors affect the qualities of the gel produced. These
are the ratio of amylose to amylopectin and the method
used to prepare the food.

12. •Wheat flour and cornflour = More amylose,
meaning a thick but cloudy gel.
• Gelatinization may be partial or complete.
1. PARTIAL GELATINIZATION (gummy):
When the starch granules are dextrinized prior to
being cooked in water. EXAMPLE : upma, sheera.
2. COMPLETE GELATINIZATION : complete
mix of starch with water and then cooling will
lead to complete gelatinization.

13. • Gelation is the method of solidification mainly through
freezing is the creation of gel or the solidification of any
gelation solution.
• The gelatin is used for gelation. The gelatin liquid form a
thick sugar solution and constantly thickens when freezed.
There is no any definite setting point.
• In some food gel is produced on cooling and in some it
may be formed on heating.
•Gels can either be thermo-irreversible or thermo-
reversible, it all depends on the type of gelation occurred.
EXAMPLE: cooling- gelation in gelatin, heating- egg white.

14. • Vicosity is a fluid’s resistance to flow or fluid thickness. The
thicker the liquid, more is its viscosity.
• The viscosity of a fluid can be measured by
1. Seeing how far a fluid can flow down an incline.
2. Viscometer- measures the force necessary to move
through a liquid.
3. Household instruments- measuring how far a liquid
can move on a slight incline after a certain amount of time.
• Measuring of viscosity is to determine how resistant that
material is to following
1. Flow down a slight incline very quickly – very little
resistance to flow.

15. 2. Lot of force to move through a liquid, it has a lot of
resistance to flow.
• A fluid will be more resistant to flow the more internal
friction it has.
• Many food industries check for vicosity. There is an
acceptable range of vicosity if it is not in the range then it
will not be sold.

16. • Colloidal are formed when one substance is dispersed
into another, but does not combine to form a solution.
• There are many types of colloidal systems based on the
state of two substances mixed together.
GEL, SOLS, FOAM AND EMULSIONS.
• Most colloidal are stable, but the two substance may
separate over a period of time because of an increase in
temperature or by physical force. Sometime will be
unstable when frozen or heated, especially if they contain
emulsion of fats and water.

17. • Sol and gel both are liquid loving colloids
• Sol- solid particles are dispersed in liquid
phase when the mixture is heated or cooled
the sol changes to gel, which resembles solid
rather than a liquid.

18. OIL+ WATER= EMULSION
• Emulsion is unstable. The two liquids are immiscible. A
stable emulsion is formed when two immiscible liquids are
held stable by a third substance called as an Emulsifying
Agent.
• There are two type of emulsifying agent, HYDROPHILIC
(water loving) and HYDROPHOBIC ( water hating).
• Emulsion may be
1. oil-in-water(o/w) – small oil droplets in water(milk)
2. water-in-oil(w/o) – small water droplets in oil (butter)

19. • When small bubbles of gas dispersed in a
liquid they form foaming. EXAMPLE : egg
white foam, as liquid egg white is whisked, air
bubbles get incorporated.
• If egg white is heated, protein coagulates
and moisture is driven off. This form a solid
foam.