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starch
Polysaccharide made up entirely of glucose present as granules or grains in amyloplasts/leucoplasts of plants (seeds, roots, cereals, legumes)
starch
A carbohydrate which is produced by photosynthesis
starch
Second most abundant organic substance; From Leafy green plants, roots, fruits, grains
Native starch
originally derived from its plant source
modified starch
altered by treatment w/ physical or chemical agents
starch molecules
are present in plant cells as granules or grains, laid down in concentric rings & deposited in a radial fashion
starch granules
consist of water-compatible, amorphous (consists of amylose & those parts of amylopectin where branching occurs) & partially crystalline (branches of amylopectin) polymers
water compatible amorphous & partially crystalline
starch granules consist of
glucose units
are linked through the C1 of one glucose unit to C4 of the next glucose unit w/ the ring oxygen all on the same side
amylose
A LINEAR STARCH MOLECULE
amylopectin
BRANCHED STARCH MOLECULE
A chains
outer unbranched chains
B chains
inner branched chains
c chains
head chain that contain the single reducing group
starch granules
Arranged radially & contain both crystalline & non-crystalline regions in alternating layers (onion-like or “growth rings”)
cassava starch
irregular shapes w/ truncated round & concave granules
wheat starch
w/ small spherical & large lenticular granules
rice
small polygonal granules
corn
both round & larger polygonal granules
potato
smooth ovoid granules of irregular sizes
starch granules
Arranged radially & contain both crystalline & non-crystalline regions in alternating layers (onion-like or “growth rings”)
100% amylopectin
waxy starches (malagkit)
amylose and amylopectin
associate through hydrogen bonding, forming crystalline bundle (micelles – hold the granules together during swelling in heated water)
native starches
insoluble solids (swell very slightly when suspended in water)
gelatinization
When starch solution is heated to a critical temperature, an irreversible reaction occurs
BIREFRINGENCE
Property of starch to rotate polarized light
Melting of crystalline region
causes starch molecules to lose birefringence
viscocity
•Resistance to flow when shear is applied
•“consistency”; thickness/thinness of dispersions
high viscocity gel
(firm & resists flow)
Low viscosity gel
flows
Agitation or stirring
results in a weaker gel & the mixture becomes gluey (eg. Tikoy or kalamay)
kind of starch
root starch gelatinizes at lower temperature than cereal starch; large molecules gelatinize sooner then smaller ones; more amylopectin – more viscous; more amylose (firmer gel)
Concentration of starch
high concentration turns viscous more readily
effects of added ingredients
Addition of sugar at the start of cooking delays gelatinization but makes swollen granules more resistant to mechanical rupture
acids
delay gelatinization & results in softer gel
fats
lower gelatinization temperature
milk and egg
increase firmness of the gel
method of cooking
more viscous due to rapid & direct heating; i.e. cooking on top of the double boiler produces tender or soft gel; dry heat
Endpoint temperature
wherein starch reaches optimum gelatinization; incomplete – not attain viscosity; over gelatinization – decreased viscosity
cooled to fast
no time to form micelles
cooled too slowly
liquid portion not be trapped in micelles weeping & syneresis
retrogadation
ocess which causes drying & hardening of cooked starch; reassociation of the linear amylosechains by hydrogen bonding upon cooling, creating structure that holds water
syneresis
occurs when concentration of sugar is 50%; changing temperature, adding salt
• Example: lumpia sauce left
thickening
Ability to gelatinize without setting / solidification
•More amylopectin (waxy), more thickening property
•Corn starch has twice thickening property as flour
dextrinization
Partially hydrolyzed starches prepared by dry roasting starch
dextrins
Dry heat cooking at 160ºC changes starch to smaller fragments called ———- (water-soluble thus decreases the ability to starch to gelatinize & thicken)
hydrolysis
Involves breaking up of the glycosidic bonds
•Acids & enzymes (amylases) can catalyze this reaction
modified starches
Starches that have been altered physically or chemically to modify one or more of its chemical and/or physical property
Adding of carboxymethyl group
makes starch less prone to damage by heat & bacteria, more hydrophylic (water loving), aids in cross linking, prevents from recrystallizing; can keep bread fresh for a longer period
resistant starches
•Defined as sum of starch & products of starch degradation not absorbed in SI
•Cannot be digested
•Fermented in large intestine producing SCFA, lactic acids & gases
RS1
with intact cell walls (beans, legumes)
RS2
banana raw potato
RS3
undergone heating then retrograded (bahaw)
RS4
heavily chemically modified starches
FUNCTIONS OF STARCH COOKERY
Thickening,Gelling,Structural,binding & filling,stabilizing, moisture retaining, coating or ducting, diluent , coloring
thickening
sauces, gravy, pie filling & soups
gelling
puddings, maja, bibingka
structural
breads, cakes, framework of baked products
binding & filling
meat extenders
stabilizing
salad & cooked salad dressings, beverages, syrups
coating or dusting
breads, candies
moisture retaining
cakefillings, candies
diluent
baking powder
PROBLEMS IN STARCH COOKERY
Lumping,Thinning of gel – when using acid,Weak gel – if too much liquid, sugar, fats,Skin formation – loss of water from starch & protein,Scorching – control temperature & constant stirring (use bain marie),Raw starch flavor (ungelatinized starch)
PREVENTING LUMPS
Dissolve in cold water first to keep grains dispersed
•Mix with sugar, cocoa powder or dry milk while dry to aid dispersion
•Coat with fat – roux as thickener (mixture of fat/butter & flour)
•Keep stirring while cooking
•Maintain uniform temperature
PREVENTING RAW STARCH
Starches are cooked 5 minutes more after reaching gelatinization point (90ºC) to be sure that complete swelling & cooking; some prescribed 100ºC
MARKET FORMS OF STARCHES
●Corn starch
●Rice flour (high amylose)
●Malagkit rice flour (pure amylopectin)
●Wheat flour
●Cassava flour
●Potato flour
●Arrowroot & taro flour
pasta
– italian for dough; unleavened dough formed from liquid (eggs/water) mixed w/ flour & cut/extruded into shapes & sizes
noodles
ribbons or strands of boiled dough made w/ a starchy ingredient & eggs/water
noodles and pasta
Made from hard wheat flour (durum wheat or semolina); dough is shaped, then dried in hot air
●Examples: spaghetti, macaroni, vermicelli, lasagna
●Those made from rice, soft wheat, soybean, cassava & other legumes or rootcrops do not hold their shapes well when cooked
pancit canton
egg noodles made from flour and duck eggs ,salt & soda
pancit canton
dough is shaped,boiled, then drianed & deep fried before packaging
sotanghon
long thin,round, translucent noodles made from mungbean & cassava starch
sotanghon
also called cellophane noodles, bean threads, NYLON or SILK NOODLES
sotanghon
the starch paste is first cooked then extrude into thin stands, the sun dried
bihon
made from rice or corn flour, the dough is extruded then boiled,cooled & dried
first class ——is made from rice
fresh—— is also available but shell life is shorter & used for pancit palabok or luglug
misua
made from caassava & wheat flour
hairy noodles, usually salted : cheapest noodle
miki
flat yellowish noodles made from wheat flour,lye & salt, egg, kasui
the mixture is flattened,boiled, drained: oil is applied on the surface
bigger and heavier
shing a ling
dried miki
instant noodles
made from rice orr wheat flour, usually packageed with flavorings, require 2 minuts to cook in boiling water
mami
thin egg noodles
wonton noodles; used in soups
pansit molo
squaree stuffed noodles
somen
thin noodles served cold always
cha somen w/ green tea, tomago soman w/ egg yolks
soba (japan)
tan, thick flat chewy noodles
rice sheets
used for dimsum; used as lumpia wrapper ; amy also be in ribbons
•Tubular (macaroni)
•Strand (spaghetti)
•Ribbons (fettuccine)
•Fancy shapes (bows, wheels)
•Soup pasta (alphabet)
•Stuffed pasta (ravioli)
PASTA - 6 basic chapes:
PANCIT GUISADO, BAM-I, MAMI, PANCIT LUGLUG, PANCIT MALABON, PANCIT MARILAO , PANCIT HABHAB, PANCIT MOLO, INSTANT NOODLES
FILIPINO PANCIT DISHES
lumping/thinning gel
when using acid
weak gel
if too much liquid,sugar,fats
skin formation
loss of water from starch & protein
scorching
control temperature & constant stirring
raw starch flavor
ungelatinized starch