Unit 4 Flashcards
What is water activity (aw)
the amount of free water in a food vs bound water
True or false: Water activity is the same thing as the moisture content
false
Foods with higher or lower water activity are at risk for microbial spoilage
higher
The presence of _____ determines water hardness
mineral salts
What is temporarily hard water
contains bicarbonate salts
what is permanently hard water
contains calcium and magnesium sulfates
How do you temporarily and permanently hard water
temporary = boiling permanent = exchanging sodium ions for the Ca and Mg
Is hard water acidic or alkaline
alkaline
Fluoride is important for ____
teeth and bone formation
Chlorine and ozone is added to water to ___
kill microorganisms
Why would nitrates be found in water
from fertilizer, manure, or sewage
Why would lead be found in water
from old lead pipes
Why would organic chemicals be found in water
pesticide contamination
2 examples of molecules that water is a solvent for
flavour molecules (tea) sugars (juice, syrup)
____ is an example of water being used as a vehicle for heat transfer
Boiling
(hexose/pentose) sugars such as glucose, mannose, fructose, and galactose are the building blocks of (starches/ fibers+gums)
hexose
starches
(hexose/pentose) sugars such as ribose, xylose, and arabinose are the building blocks of (starches/ fibers+gums)
pentose
fibers + gums
What is the most abundant sugar
Glucose
____ is the form of sugar that circulates the bloodstream
Glucose
3 products of glucose
Energy
Water
Carbon dioxide
glucose is widely used in what industry
baking
What is the sweetest sugar
Fructose
True or false: fructose easily crystallizes
false, it is very soluble
True or false: Galactose is not normally found in its free form in foods
true
What is the basic unit of vegetable gums
galactose
Glucose + fructose =
sucrose
glucose + glucose =
maltose
glucose + galactose =
lactose
table sugar is referring to ____
sucrose
sucrose is extracted from ____
sugar cane + sugar beats
maltose is a product of ____ hydrolysis
starch
raffinose and stachose are examples of ____
oligosaccharides
raffinose and stachose are found in _____
dried beans
what is the difference between homo-polysaccharides and heterosexual-polysaccharides
homo = same type of monosaccharide hetero = 2+ types of monosaccharide
True or false: polysaccharides must be branched chains
False: can be straight chains or branched
True or false: starch is water soluble
False
amylose and amylopectin are both _____ molecules
starch
what is the difference between amylose and amylopectin
amylose = linear amylopectin = branched
Is starch composed of either just amylose or amylopectin, or a mixture of the two?
a mixture
Is starch made of more amylose or amylopectin
amylopectin
what is gelatinization
the swelling of starch granules when heated in water
What are dextrins
polysaccharides that are derived from starch
How are dextrins produced
starch is broken down by enzymes, acid, or dry heat
what type of polysaccharide can be used as a fat replacer in food
Dextrins
What is the difference between starch and glycogen
starch = plant storage of glucose glycogen = animal storage of glucose
True or false: Glycogen chains are longer and more branched than starch
True
True or false: Glycogen is rapidly degraded upon the animals death
True
Surplus glucose in the body is converted to either ____ or _____
fat or glycogen
Glycogen is temporarily stored where (2)
liver and muscles
What are the 2 types of plant fibre
soluble fibre and insoluble fibre
what type of fibre forms a gel-like solution, what type swells?
soluble = gel insoluble = swells
Is cellulose a homoglucan or a heteroglucan
homo
is hemicellulose a homoglucan or a heteroglucan
hetero
is beta-glucan a homoglucan or a heteroglucan
hoo
what is the most abundant type of fibre
cellulose
what type of fibre is used to improve the water binding of flour
hemicellulose
Are beta-glucans more or less water soluble than cellulose
more
Oats and barley are rich in what type of fibre
beta-glucans
what type of fibre traps cholesterol in the body
beta-glucans
what type of fibre slows starch digestion and glucose absorption
beta-glucans
what type of fibre is found both in cell walls and the space between plant cells
Pectins
Galacturonic acid is the building block of what type of fibre
Pectins
5 types of vegetable gums
- seaweed extracts
- plant seed gum
- plant exudates
- microbial gums
- modified cellulose
3 parts of a wheat kernel
bran
germ
endosperm
Wheat bran properties
high in vitamins, minerals, and fibre
Wheat germ properties
high in vitamins and fat
Wheat endosperm properties
high in carbohydrates
Flour is made of what part of the wheat kernel
endosperm
Semolina is derived from ____
Durum wheat
5 ingredients of beer
- cereal grains
- saccharomyces yeast
- carbon dioxide
- hops
- water
What do hops do in beer
intensify flavour and colour
beer mash =
cereals + water
beer wort =
liquid portion of the mash
beer wort is high in ____
fermentable sugars
10 steps in making beer
- make mash
- extract wort, move to kettle
- wort + hops, settle
- wort is filtered through hops
- cool wort, + yeast
- fermentation for 9 days
- Chill beer, filter to remove yeast
- storage in tanks (months) to develop flavour
- CO2 during storage
- final filtration, bottled
What are prebiotics
indigestible dietary carbs that stimulate growth of probiotics
Fructo-oligosaccharides are used as food by which bacteria (3)
- Faecium
- Acidophilus
- Bifidus
What is inulin
A plant extract composed of linear fructose changes with 1 terminal glucose
What is the only place inulin can be digested in humans and how
large intestine
via anaerobic fermentation by bacteria
Calorie content of inulin
1.5 calories /gram
True or false: excess inulin is excreted in the stool
false
Inulin can be used in low fat foods to provide what texture
creamy
3 other carb prebiotics
oligofructose
lactulose
beta-glucans
