Fruits and Vegetables Flashcards
Parts of the plant cell:
cytoplasm, cell wall, vacuoles, plastids, intercellular air
cytoplasm:
water and salts
cell wall:
indigestible fibres
plastids:
contain leucoplasts, chloroplasts, chromoplasts
leucoplasts:
non-pigmented
chloroplasts:
chlorophyll containing
chromoplasts:
carotenoids
vacuole:
water, anthocyanin, flavour compounds, organic acids
intercellular air:
crispness and volume
photosynthesis: ___+___–>___+___ (–> = ___)
CO2/H2O/C6H12O6/O2/sunlight energy
plant fibres:
cellulose, hemicellulose/pectin, lignin, gums
cellulose:
major component of cell walls, provides structural support and strength
pectin: (include types)
cement within cell walls, provides elasticity and firmness, large polysaccharides, used as thickness in the food industry
- protopectin: immature fruit, no gel
- pectin: ripe fruit, gel
- pectic acid: overripe fruit, no gel
lignin:
non-CHO, made from phenolic alcohols, provides strength, concentration increases over time
gums:
able to absorb water and swell, often used as thickening agents
fruits:
seed bearing structure of flowering plant, protects seeds
seeds:
can create new plants, high in CHO
flowers:
male/female parts, responsible for reproduction and pollination
leaves:
active, metabolizing parts, contain large amount of water
stems:
transfer water and nutrients, support
roots:
draw nutrients and moisture from soil, high in CHO
tubers:
storage vessels, meant to propagate new plants, high in CHO
bulbs:
storage organ during dormancy, high in CHO
legumes:
- leguminosae
- seeds from pods
- high in CHO, PRO, Fe
what are the classifications of fruits?
- simple: formed from single ovary on single flower, ex. apple
- aggregate: formed from several ovaries on one flower, ex. raspberry
- multiple: formed from many flowers in a mass, ex. pineapple
what are some fruits that are naturally high in fat?
coconut, avocado, olive
nutritive vales of fruit (generally): kcal=___, water=___%, fat=___, PRO=___, CHO=___, fibre=___
low/70-90/low/low/relatively low/fairly high
vitamin C
enzymatic cofactor, antioxidant, immunity
- citrus, bell pepper, tomato
folate
DNA synthesis, repair, methylation, reduces NTD risk
- legumes, dark/leafy greens
riboflavin
metabolism, antioxidant
- leaf greens, mushroom, sea vegetables
K
fluid balance
- most vegetables
Ca
promotes bone health
- dark/leafy greens, broccoli
Fe
component of blood cells
- dark/leafy greens, legumes
phenolic compounds
aka tannins
- in unripe fruit
- responsible for browning/bruising
organic acids:
volatile (vaporize when heated) and non-volatile (leach into cooking water)
- citric acid, magic acid, tartaric acid, oxalic acid, benzoic acid
functional foods:
have potential health benefits beyond basic nutrient needs
phytochemicals:
non-nutritive component in plants thought to have health benefits
what is in cruciferous vegetables?
indole glucosinolate (may protect against cancers)
allium vegetables contain ___
allicin (antimicrobial)
lycopene:
red carotenoid, antioxidant, may reduce cancer risk, maximized when cooked in fat
- tomato, water melon
lutein:
yellow carotenoid, antioxidant, prevents macular degeneration, bright light sensitivity, and cataracts
- leafy greens, broccoli, pumpkin
luteolin:
antioxidant, may decrease cancer cell growth, anti-inflammatory
- broccoli, herbs
soybeans contain ___
genistein ( may decrease breast/uterine cancer risks)
moist cooking methods:
simmering, steaming, braising, stewing, blanching, microwaving
dry cooking methods:
baking, roasting, stir-fry, deep fry, grilling, broiling
textural changes during cooking:
reduction in crunch
- protopectin–>pectin, gelatinization, softening of cellulose, dissolving of hemicellulose, cell membrane PRO denature
- prevented by adding Ca2+
flavour changes during cooking:
- volatile compounds are lost (dulls flavour)
- caramelization (adds flavour)
- degorging (removal of bitter compounds)
odour changes during cooking:
sulphur compounds create undesirable odours which are reduced by
- short cook time
- adding vinegar
- removing lid frequently
- refrigerating onions before cutting
colour changes during cooking:
- pigments are sensitive to heat, pH, metals, light
- caramelization, Maillard, and enzymatic browning reactions cause browning
other changes during cooking:
reduction in pathogens, loss of nutritive value, increased bioavailability
tips for retaining nutrients during cooking:
short cook time, minimal water, consume leftover cooking liquid, cook with skin on, cook in big pieces, avoid baking soda
Changes during ripening: minimal change in ___, ___, and ___, ___ are maximized, ___ and ___ decrease, ___ change, texture ___, starch –> ___
PRO/fat
minerals/vitamins/organic acids/phenolic compounds
softens/sugar
unripe fruits should be left at ___ temperature in a paper bag to ripen
room
oxidative enzymatic browning
- caused by: phenolic compounds, O2, and polyphenol oxidase
- enzymes are denatured by: acid, boiling
- process is slowed by: low storage temperatures, salt water
- O2 can be blocked by: coating with sugar or wax, antioxidants
what are the two key factors of storing fresh fruit?
reducing respiration rate and reducing moisture loss
refrigeration/freezing: reduces ___ rate, must be ___ before freezing, loss of quality is cause by ___
respiration/blanched
cellular membrane rupture
dry storage: retains ___ and ___, speeds up ___
flavour/texture/ripening
potatoes should be stores away from ___ because it creates ___ (green, toxic)
light
solanine
what type of storage is used commercially to prevent respiration?
controlled atmospheric storage
additives for longer shelf life:
- cutin (plant wax) and commercial waxes (protection)
- sulphites (prevent browning)
- ascorbic acid (prevent browning)
- sorbets/benzoates (antimicrobial)
what must be included on a food label of an imported fruit?
country of origin
grading is ___, based on …
difficult
- uniformity, maximum and minimum size, minimum length, colour, maturity, freedom from disease, defects, injury, etc.
do processed foods also need grading? (ex. apple juice)
yes
canning, freezing, drying, and juicing allow what?
year round consumption
Pigments include:
chlorophyll, carotenoids, flavonoids
chlorophyll:
green, porphyrin ring with central Mg, essential for photosynthesis, heat sensitive, degrades over time
chlorophyll a
blue/green, methyl group
chlorophyll b
green, more common, aldehyde group
what happens when you heat chlorophyll?
H+ ions displace the Mg2+ ion, creating pheophytin (olive coloured)
carotenoids
yellow/orange/red, fat soluble, polymers of isoprene, provitamin A
carotenes
yellow/orange
lycopenes
red/orange
xanthophylls
yellow
flavonoids
flavylium-ion structure, water soluble, in vacuoles, pH sensitive
anthocyanins
blue/red; red in acid, purple in neutral, blue in base
anthoxanthins
cream/white; white in acid, yellow in base, blue/brown/black when overheated, with Cu or Fe
betalins
red/yellow; acid=purple/red, base=red/yellow
