cereal grains Flashcards
why are cereal grains important
widely available at a low cost
nutrition, energy
feed for livestock use
economic important to farmers
fuel
grain is durable- long term storage
different grains grow in different climates
food, staple in diet
food security
enviroment
what is a cereal grain
starchy grains from plants
what is a cereal grain used for?
breakfast foods, flours, breads, pastas, starches, fermented beverages, etc
what is a whole grain?
contains endosperm, bran, and germ,
when processed it should still have the same rich balance as the origianal grain
humans need atleast 3 servings of whole grain per day
examples of whole grains (with gluten)
wheat, rye, barley, oats, triticale
examples of gluten free whole grains
amaranth, buckwheat, millet, quinoa, teff, rice, corn, sorghum
three parts of canadas food guide
fruits and vegetables, protein, whole grains
refined or white vs enriched
refined, bran and germ are removed, leaving only the endosperm
enriched, bran and germ are removed, then vitamins/minerals are added back in after processing
how much of the calories in a human diet come from cereal grains, how much protein
75% of each
what are kernels of cereal grains called?
fruits
the fruit is a dry, single seeded _________ that remains intact on maturity
caryopsis
what is the bran
pericarp or fruit coat acts to protect and support the growth of the endosperm and embryo
seed coat (testa) - pigmented layer
what is the endosperm
aleurone is a single layer at the inner cite of the bran. it contains most of the minerals, vitamins, phenolic antioxidants, and lignans of the wheat grain
the starchy endosperm is the major storage tissue, storing both starch and protein. supplies nutrients for plant growth, yield and quality
what is the germ
where new wheat sprouts occur, rich in nutrients
compostion of cereal grain
65-70% starch
10-15% protein
10-30% fibre
2-10% lipid
2-4% minerals
what causes variation in composition
genetics, environment, agronomic practices
what is dry milling
to separate fruit structures from seed
how many million tons of wheat does Canada produce in a year (2017)
30
two most important commercial species are
triticum aestivium L (common wheat)
triticum durum desf (durum wheat)
Characteristics of kernels
deep ventral crease, 9-15% protein 65-70% starch, 2%lipids
utilization of wheat
roller milled into flour or semolina
by-products are bran and germ
flour/semolina +water+mixing= gluten development=dough
fermentation = fuel alcohol, beer, distilled beverages
wet milling = gluten and starch
objectives of roller milling
seperation of bran 23% germ embryo2% and starchy endosperm 75%
reduction of starchy endosperm to semolina ie coarsely milled durum wheat or flour
refined flour
has enhanced appearance, palatability, quality(shelf life) and functionality
loss of nutritional value fibre protein lysine vitamins and minerals
grading and qualtity of wheat
quality is the degree to which something is suitable for a particular end use
the quality of wheat is determined by both genetics and the enviroment
wheat is segregated into market classes on the basis of growth habit colour hardness protein content gluten strenght and end use functionality
market classees of wheats
durum wheats highest protein pasta CWAD
hard wheats high protein pan breads
medium hardness, medium protein wheats french breads, oriental noodles,
soft, low proteins
grading system is largely visual
principal grading factors are test weight and degree of soundness, test weight is positively correlated with flour yield
degree of soundness is related to __________
flour yield, flour colour, dough handling properites, loaf volume and height, crumb and crust colour
soundness factors
frost damage, maturity, bleaching, springing, sprouting, disease, insect damage
flour protein is ____________ with bread loaf volume
positively correlated
corn
native to central and south america
world production in 2017 just under 1.39 billion tons
leading producers= USA 371 million, china 259 million, brazil=98
corn large kernel size ____ times of wheat
10
_______ embryo in corn
large
naked caryopsis in corn means?
brain removed
corn is higher in _________ and __________
starch 75% and oil 5%
corn is lower in __________ 9-10%
protein
___________ is of lower nutritional quality (low in lysine, theronine, and tryptophan
protein
gluten free: used to prepare ____ (dough prepared from alkali-treated corn
masa
corn us _________ into germ, starch and by-products (fibre, protein, solubles)
wet milled
germ of corn is extracted to produce oil and meal
starch - food starch (native and modified) - sweeteners (glucose, syrups), adhesives, textile processing aid etc
by products of corn wet milling
feed - corn gluten meal
_________________ ground whole grain and refined starch
fuel alchohol
for fuel alcohol production by-products are dried distillers grains DDG and dried distiller grains with solublesDDGS for feed
corn can be _____________ into bran, germ, grits, meal, flour
roller milled
grits/meal/flour
snack foods, tortillas, chappatis, RTE breakfast cereals, brewing and distilling, grain alcohol
ground whole grain as feed grain and cob
dent corn is
field corn, yellow and white varieties, two regions in the endosperm, various starch types
flint corn
very hard endosperm, insect ad disease resistent, many colours
popcorn
a small kernel flint corn, explosive expansion when heated, grown for use as a snack food,
flour corn
soft endosperm throughout the kernel, easy to grind, maily used to make corn flour
sweet corn
a mutant of dent corn, sugary when immature, starchy when mature
corn bean and squash were known as _________ by the iroquois
three sisters
rice (oryza sativa L.)
world production in 2017 was 984 million tons
leading producers china 213 million, india169, indonesia 81, bangladesh 49
staple food for the half the worlds population
long and short grain rice, as well as intermediate types in usa
jasmine and basmati rice
rice protein is high in sulfur containing AA but low in _______
lysine
rice protein is often combined with pea protein
about 7%
glutenins represent _____________ of the total proteins , typically are extensively aggregated, has a lot of disulfide bridging and glycosated
60-80%
promalins represent _____ , globulins 5-13%, and albumins 4-22% of the total proteins
1-5%
proteins are mostly water insoluble due to the high degree of disulfide bonding and higher MW
rise is harvest ______________________
with the hull intact
kernel characteristics of rice
smaller than wheat in size, hard quartz like texture, no ventral crease, dehulled grain 10% protein, 80% starch, gluten free
dehulling of rice
removal of glumes, yields brown rice
brown rice is abrasion milled and pollished, yields
white rice and fines
white rice is processed into grits and flour that can be used in brewing, snack foods, RTE cereals, wet-milled into starch
fines used as feed; extracted to yield rice bran oil,
polished rice involved removing bran from brown rice, and gently rubbing the rice kernes together to remove dust
paddy rice may be converted (parboiled) prior to dehulling or milling
drives nutrients from bran into starchy endosperm reduces losses on milling
results in a darker coloured polished rice product, limited acceptance
barley, world production in 2017 was 149 million tons
leading producers were ruusia, australia, gerany, france, ukraine, canada, and united kingdom
primary uses of barley
fees, malting and brewing
barley has limited use as a food grain
most barley production is hulled, hulless types in limited production have advantages with respect to energy, transportation, storage
main steps of barley malting
cleaning, steeping, germination, kilning
limited (controlled) germination to activate/synthesizes the enzymes for germination : _______
amylases
partial hydrolsis of the starchy endosperm
kilning:
terminate germination and develop characteristic flavours aroma and colour
brewing with barley
fementation by yeast of simple sugars derived from starch into alcohol(beer)
main steps are mashing, wort filtration (lautering), boiling/hopping, fermentation and finishing
how is distilled alchol made
entire mash is fermented and then distilled to achieve an alcoholic content of 40-50% by volume 80-100 proof in the condensed vapour
products may be aged, blended, flavoured, etc
fuel alcohol from barley
mash of wheat corn rye etc is hydrolyzed with bacterial and fungal amylases, entire mash is fermented and then distilled to 95% alcohol (100% if dehydrated: using molecular sieve)
stillage is dried to produce distillers dried grains or dried distillers grains with solubles
food use of barley
abrasion milled into pot and pearled barley
pearled product may be gronud into flour
flour is specky in appearance
pearled- barley has been processed to remove its fibrous outer hull polished to remove all the bran layer
hulless types of barley may be _____________
roller milled
glucan content (soluble dietary fibre is considered _______ for human nutrition but ____________ in feeding and brewing
positive; detrimant
