Organic acids, protein changes and flavour violatiles Flashcards
role of protein in fruit
functional (enzymatic)
% of protein in
fruit
vege
fruit 1%
vege 2%
% of lipids in F & V
1%
which F & V have 11-15% lipids
olive
avocado
what types of lipids are found in F & V
polar lipids
triglycerides
where are polar lipids found
in the membrane and endo sperm
what type of lipids are polar lipids
phospholipids
glycolipids
what fruit and vege are triglycerides found in
nuts, oil seeds, pulses
where are organic acids stored
vacuole
what do organic acids contribute to fruit and veg
taste (esp fruit)
when do organic acids decline q
during ripening
what are the types of acids that usually dominate
citric and malic
types of F and V with citric
berries
citrus
leafy veg
beetroot
types of f and v with malic acid
broccoli
melon
apple
carrot
3 main types of pigments
flavonoids
carotenoids
chlorophyll
what is the synthesis/degeneration of pigments influenced by
ethylene and storage conditions
describe chlorophylls
green
used in photosynthesis
found in chloroplast
describe flavonoids
anthocyanins are the main flavonoids
found in the vacuole
describe carotenoids
yellow/orange
found in chloroplast and chromoplasts
describe the degradation of chlorophyll in the presence of Mg2+
chlorophyll -> pheophytin -> Chlorins, purpurins (O2) or pheophorbide (H+)
colour of pherophorbide
brown
colour of chlorins/purpurins
colourless
describe the degradation of chlorophyll in the presence of chlorophyllases
chlorophyll-> phytol or chlorphyllin
colour of pheophytin
olive green
what can form during the formation of pheophorbide from pheophytin?
phytol in the presence of H+
describe the degradation of chlorophyll in the presence of chlorophyllase
chlorophyll-> phytols or chlorophyllin -> pheophorbide (H+) or chlorin/purpurins (O2/H+)
why does the colour sometimes become brighter in fruit and vege
disruption of the cell membrane results in chlorophyll exposure
MW of volatiles
<250
forms of volatiles
ESTERS, ALCHOLS, ACIDS, CARBONYL COMPOUNDS
how many different volatiles are in f and v
> 100
What happens to volatiles as fruit ripens
they change
why does the odour description of the same compound change between f and v
the presence of other compounds
what are phytochemicals
compounds found in plants that are not required for normal functioning of the body but have a beneficial affect
health benefits to phytochemicals
immune function
act against bacteria and viruses
reduce inflammation
anti-cancer properties
prevent CVD
examples of dietary antioxidants
carotenoid s
vitamins
flavonoids/phenolic compounds
trace elements
sulphur compounds
