Topic 2 Flashcards
carb forms include
starch
sugar
fliber
glycogen
carbs contain what elements?
H, C & O
how are carbs formed
photosynthesis
food sources of carbs include:
o Cereal grains & flours, Ex: wheat, rye, corn & rice
o Legumes, Ex: peas, beans & lentils
o Starchy roots , Ex: potatoes, yam & cassava
o Fruits, Ex: orange, apple & banana
o Sugars, Ex: Honey, jam & molasses
how are carbs classified?
number of basic sugar molecules
monosaccharide
simple sugar
Fructose, galactose, glucose
disaccharide
simple sugar
Maltose (malt sugar), sucrose (table sugar), lactose (milk)
Oligosaccharide
simple sugars
3-10 units
polysaccharides
complex sugars
many units
which carbs are simple sugars
mono
di
oligo
what sugar isn’t considered a simple sugar?
polysaccharides
monosaccharide sugar units consist of:
hexose & pentose
hexose
6C, sugars such as: glucose, mannose, fructose & galactose
Building blocks of polysaccharides
pentose
5C, such as: ribose, xylose & arabinose
Building blocks of fibers & gums
how do glucose & galactose differ?
positioning of the H-OH bond on the
what is the most abundant sugar in the world?
glucose
glucose food source
fruits, plant juices & honey
what form of sugar circulates in the blood?
glucose
what are the 3 products of glucose?
E
water
CO2
what is the storage form of glucose & where is it located?
glycogen
liver & muscles
what is the sweetest sugar?
fructose
solubility of fructose? & how does that influence its baking use?
very soluble & doesn’t crystallize easily –> not good for making candies
it reduces the freezing point too much thus not an ideal sugar to be used in frozen desserts
how is HFCS made?
glucose is changed to fructose by adding glucose isomerase
glucose isomerase
breaks down fructose & changes the isomer of glucose
fructose causes ___ times more cell damage than glucose
7
fructose is only metabolized by what organ? & what does it lead to the production of?
liver
uric acid –> oxidative damage
sucrose contains how much fructose?
50%
HFC-42 contains how much fructose?
42%
galactose
glucose - galactose
galactose is found where?
not free form in foods, fermented in milk where lactose is hydrolyzed into galactose & glucose
disccharides occur from what rxn?
condensation
common disaccharides include
sucrose (cane/beet sugar)
maltose (corn syrup)
lactose (milk sugar)
what sugar unit is accessible to absorption in the blood stream?
monosaccharide
hydrolysis
a water molecule enters the region of the functional group of a larger molecule & splits
what happens if disaccharides aren’t digested?
lead to gas production in the lower gut causing flatulence & abdominal cramps or discomfort
lactose intolerance
pancreas doesn’t produce lactase
if not enough lactose isn’t broken down by bacteria then it leads to abdominal pain
sucrose food source
table sugar
extracted from sugar cane & sugar beets
present in fruits, honey & vegetables
sucrose composition
glucose & fructose
highly concentrated sucrose solutions act as
preservatives & cryoprotectants
cryoprotectants
Protects fluid from freezing by lowering the freezing point (lower the temperature at which the liquid would freeze)
lactose food source
milk & milk products
lactose composition
glucose & galactose
maltose composition
2 glucose molecules
maltose food source
malt sugar
gaunt in germinating grain & corn syrup
what product is used for hydrolysis in malting & how is it made?
alpha-amylase
made by bacteria
reducing sugar
a sugar capable of acting as a reducing agent b/c it has a free aldehyde or ketone grp
reducing sugars include:
all monosaccharides some disaccharides (not sucrose), oligosaccharides polysaccharides
is sucrose a reducing sugar?
no
Dextrose (glucose) equivalent
a measure for the amount of reducing sugars present in a food/solution
when do we use Dextrose (glucose) equivalent
making corn syrup to determine its sweetness
determine the level of degradation of starch
increase reducing sugar = ___ hydrolysis = ___ glucose
more & more
why is glucose aded to a food?
for its functional properties
sweetness is then adjusted with alternative sweetness
sucrose 10% sol’n sweetness
100
Glucose syrup 62 DE sweetness
59