Technology and
Livelihood Education
Quarter 1 - Grade 10
Ma. Danica D. Losito
Cereals
• Cereals are usually starchy pods or grains.
• Cereal grains are the most important group of
food crops in the world named after the Roman
Goddess of harvest, Ceres.
• Rice, wheat and corn are the three most
cultivated cereals in the world.
Starches
• Starch is the second most abundant
organic substance on earth.
• Starch exists in nature as the main
component of cereals and tubers.
• It is found in all forms of leafy green
plants, located in the roots, fruits or
grains.
Tools and Equipment
Preparing Cereals and Starches
Mixing bowl – used when
preparing cake mixture,
salads, and sauces.
Sifter – used for separating coarse
particles of flour, sugar, baking
powder, and powdered ingredients
to retain finer textures.
Wire Whip – used for beating
egg whites, egg yolk,
creams and mayonnaise.
Wooden Spoon – used for
mixing creams, butter and
for tossing salads.
Slotted Spoon – used to separate solid
particles for soup; also, for string purposes,
such as making egg white fine in texture for
bird’s nest soup and mock nido soup.
Blending Fork – used for testing the
tenderness of meat, combining big cuts
and particles of meat and vegetables, and
for blending other ingredients with flour.
Rubber Scraper – used for
scraping off mixtures of butter,
sugar, and egg from the sides of
the mixing bowl.
Strainer – used for separating
liquids from fine or solid food
particles, such as coco cream from
coconut and tamarind extract.
Tong – used for
handling hot foods.
Measuring Cups – used for
measuring dry and liquid
ingredients.
Measuring Spoon – used for
measuring dry and liquid
ingredients which require a little
amount
Sauce Pan and Pots – used
for cooking meat and fish
dishes with gravy and sauce
Kettle and Rice Cooker –
used for cooking rice and
other foods
Pressure Cooker – used for
tenderizing or cooking meat,
chicken, and other grains or
legumes in lesser time
Double Boiler – used for
preparing sauces which easily
get scorched when cooked
directly on the stove
Steamer – used for
cooking food by steaming
Colander – a perforated bowl of varying
sizes made of stainless steel, aluminum
or plastic, used to drain, wash, or cook
ingredients from liquid
Canister – a plastic or metal
container with a lid that is used
for keeping dry products
Butcher Knife – used for
cutting, sectioning, and
trimming raw meals
Channel Knife – a small hand
tool used generally in
decorative works such ad
making garnishes
Sources of The parts of plants that
store most starch are seeds,
Starch
roots, and tubers. Thus, the
most common sources of
food starch are:
• Cereals grains, including corn, wheat, rice, grain, sorghum,
and oat;
• Legumes; and
• Roots or tubers, including potato, sweet potato, arrowroot,
and the tropical cassava plant (marketed as tapioca)
Common Sources
of Manufactured Food Starch
1.Corn
2.Potato
3.Tapioca (cassava)
Starches are named
after its plant sources
• Corn starch from corn
• Rice starch from rice
• Tapioca from cassava
Classification
of Starches
1. Native or Natural Starch refers to the starches
as originally derive from its plant source
2. Modified Starches are starches that have been
altered physically or chemically, to modify
one or more of its key chemicals and/or
physical property
3. Purified Starch may be separated from grains
and tubers by a process called wet milling.
Starch Composition
and Structure
THE STARCH MOLECULE
Starch is polysaccharide made up of
hundreds or even thousands of glucose
molecules joined together. The molecules
of starch are two general types, called
fractions: amylose and amylopectin.
AMYLOSE
Amylose is a long chain-like molecule, sometimes
called the linear fraction, and is produced by
linking together 500 to 2, 000 glucose molecules.
AMYLOPECTIN
Amylopectin has a
highly branched, bushy
type of structure, very
different from the long,
string-like molecules of
amylose.
Property Amylose Amylopectin
Structure Linear Branched
Proportion 20-30% of starch 70-80% of starch
Texture Effect Firm, less sticky Soft, sticky
Gel Strength Strong/firmer gels Weaker gels
Together, amylose and amylopectin determine how a starch
behaves during cooking.
THE STARCH GRANULE
THE STARCH GRANULE
In the storage areas
of plants, notably
the seeds and roots,
molecules of starch
are deposited in
tiny, organized units
called granules.
THE STARCH GRANULE
Amylose and amylopectin molecules are placed together in tightly
packed stratified layers formed around a central spot in the granule
called the hilum.
If the starch granules, in a
water suspension, are
observed microscopically
under polarized light, the
highly oriented structure
causes the light to be This phenomenon is called
rotated so that a Maltese birefringence.
cross pattern on each
granule is observed.
THE STARCH GRANULE
The sizes and shapes of granules differ among
starches from various sources, but all starch
granules are microscopic in size.
THE STARCH GRANULE
Starch Properties and
Reaction
STARCH PROPERTIES AND REACTIONS
Gelatinization. The sum of
changes that occur in the first
stages of heating starch granules
in a moist environment which
includes swelling of granules as
water is absorbed and disruption
of the organized granule structure
STARCH PROPERTIES AND REACTIONS
Viscosity. The resistance to flow; increase in
thickness or consistency. When the newly
gelatinized starch is stirred, more swollen
granules break and more starch molecules
spill causing increase in viscosity or
thickness.
STARCH PROPERTIES AND REACTIONS
Retrogradation. It is the process in which
starch molecules, particularly the amylose
fraction, re-associate or bond together in an
ordered structure after disruption by
gelatinization; ultimately a crystalline order
appears
STARCH PROPERTIES AND REACTIONS
Syneresis. Oozing of liquid from gel
when cut and allowed to stand (e.g.
jelly or baked custard). The oozing of
liquid from a rigid gel; sometimes
called weeping.
STARCH PROPERTIES AND REACTIONS
Dextrinization. It is the process of
forming dextrin.
Dextrins - are partially hydrolyzed
starches that are prepared by dry
roasting.
STARCH PROPERTIES AND REACTIONS
Hydrolysis. Starches undergo hydrolysis
during cooking or processing and during
storage of food where a chemical reaction
in which a molecular linkage is broken and
a molecule of water is utilized
