March, 1996 September, 2004 - Fresh-cut 2015fresh-cut2015.ucdavis.edu/files/220790.pdf9/22/2015 1...
Transcript of March, 1996 September, 2004 - Fresh-cut 2015fresh-cut2015.ucdavis.edu/files/220790.pdf9/22/2015 1...
9/22/2015
1
Preharvest Factors and Fresh‐cut Quality of Leafy Vegetables
Mabel Gil
Research Group on Quality, Safety and Bioactivity of Fruits and VegetablesCEBAS‐ CSIC, Murcia Spain
September, 2004March, 1996
1. Fresh appearance
2. No discoloration,
3. No decay,
4. Crisp texture,
5. Good flavour (aroma and taste)
Quality characteristics of leafy greens
Main causes of quality loss
1. Browning
2. Off‐ flavours
3. Texture loss
3. Agricultural practices
2. Environmental conditions
1. Genotypes
Pre‐harvest factors that affect quality of leafy greens
4. Maturity at harvest
5. Harvest time
Yield (high plant density, low core lenght, solid midrib),
Visual appearance, flavor,
Resistant to internal defects (tipburn and pinkrib),
Health promoting constituents
1. Genotype
Criteria for the selection
mg
100
g-1 F
W
0
50
100
150
200
250
Monet
Batavia verde
Romana verde
Romana roja
Lollo rosso BerroMizu
na
Rúcula salvaje
Rúcula cultiv
ada
Flavones derv.Cinnamic acid derv. Antocyanin derv.
LSD52 Total polyphenols
0
Monet
Green Batavia
Green Romaine
Red Romaine
Lollo rosso
Watercre
ssMizu
na
Wild rocket
Salad rocket
Individual and total polyphenol content of baby leaves
1. Genotype: Selection based on health promoting constituents
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Yield (high plant density, low core elnght, solid midrib),
Visual appearance, flavor,
Resistant to internal defects (tipburn and pinkrib),
Health promoting constituents
1. Genotype
Criteria for the selection
Selection of cultivars with lower response for cutting
Conditioning
Harvest
Transport to the CEBAS
Raw material cooling
1. Maturity index2. Removal of external leaves
Washing
3. Cutting
Centrifugation
Packaging
Storage
Evaluation and analysis
1. Genotype: Selection based on lower response to cutting
Passive MAPActive MAP
Cultivars
1 2 3 4 5 6 7 8 9 10 11 12
She
lf-L
ife
0
2
4
6
8
10
12
14
PassiveActive
1. Genotype: Selection based on browning potential
Shelf life of 12 cultivars of fresh‐cut Romaine lettuce stored in passive and
active MAP for 3 days at 4ºC plus the rest of storage at 7ºCCut edge browning of fresh‐cut Romaine lettuce cultivars stored
for 11 days at 7ºC
1 = absence, 3 = moderate and 5 = severe
1. Genotype: Selection based on browning potential
CULTIVAR
1 2 3 4 5 6 71
2
3
4
5
+ 24 h in air
Cultivar
1 2 3 4 5 6 71
2
3
4
5
Active MAP
CULTIVAR
Quality attributes
1 4
Vitamin C - +
Phenolic content + -
PAL + -
POD + -
PPO + -
% PPO activation + -
Respiration rate + -
Browning in air + -
Browning in MAP - -
Off-flavours in MAP + -
Harvest dates:
‐ December
‐ January
‐ April
Results:
Cultivar 1 vs cv 4: higher susceptibility to
browning, lower vitamin C, higher
phenolic content and higher enzymatic
activities of browning related enzymes
(PPO and POD)
Tissues studied:
‐ Photosynthetic + midrib
‐Midrib
Differences between two Romaine cultivars
1. Genotype: Selection based on browning potential
UPLC‐MS‐QTOF (Quadrupole + Time of
flight): Non‐targeted metabolomics.
Exact molecular weight and chemical
formula. High sensitivity. Authentic
standards for identification
Agilent QTOF 6550 Agilent QQQ 6460
Biomarkers of enzymatic browning (AGL2013‐48529‐R)
Plant metabolites including phenolic compounds and other primary and secondary metabolites evaluated using a metabolomic approach
UPLC‐MS‐QQQ (Triple Quadrupole):
Targeted metabolomics. High
sensitivity. Authentic standards
for quantitation
1. Genotype: Selection based on browning potential
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UnbrownedBrowned
Browned
Unbrowned
Biomarkers of enzymatic browning (AGL2013‐48529‐R)
1. Genotype: Selection based on browning potential
Selection of specific groups of metabolites by clustering and principal component analysis
The untargeted metabolomic study was able to differentiate three groups ofmetabolites that were able to explain differences in the browning process
Barracuda Greenforest
Compound0 Days of storage
5 Days of storage
0 Days of storage
5 Days of storage Class
PS(20:5(5Z,8Z,11Z,14Z,17Z)/0:0) Phospholipids
LysoPE(15:0/0:0) Phospholipids
PE(18:0/0:0) Phospholipids
LysoPE(0:0/18:4(6Z,9Z,12Z,15Z)) Phospholipids
PS(18:3(6Z,9Z,12Z)/0:0) Phospholipids
PI(18:3(6Z,9Z,12Z)/0:0) Phospholipids
LysoPE(0:0/18:3(9Z,12Z,15Z)) Phospholipids
PS(18:2(9Z,12Z)/0:0) Phospholipids
Camila tesela
Compound0 days of storage
5 days of storage
0 days of storage
6 days of storage Class
PIP(16:1(9Z)/18:0) Phospholipids
PI(18:2(9Z,12Z)/0:0) Phospholipids
PI(18:3(6Z,9Z,12Z)/0:0) Phospholipids
LysoPE(0:0/20:2(11Z,14Z)) Phospholipids
PE(19:0/0:0) Phospholipids
LysoPE(0:0/20:2(11Z,14Z)) Phospholipids
LysoPE(0:0/20:3(8Z,11Z,14Z)) Phospholipids
LysoPE(0:0/18:0) Phospholipids
LysoPE(18:3(6Z,9Z,12Z)/0:0) Phospholipids
LysoPE(0:0/18:3(9Z,12Z,15Z)) Phospholipids
LysoPE(0:0/16:0) Phospholipids
LPA(18:2(9Z,12Z)/0:0) Phospholipids
PA(18:3(9Z,12Z,15Z)/0:0) Phospholipids
Biomarkers of enzymatic browning (AGL2013‐48529‐R)
1. Genotype: Selection based on browning potential
Phospholipids, Fatty acids and Phenylpropanoids
Days of storage0 2 4 6 8 10 12 14 16
kP
a
0
2
4
6
8
10
12
14
16
4ºC 7ºC
Days of storage
O2
CO2
0 2 4 6 8 10 12 14 16
Off
-od
ours
1
2
3
4
5Var 5Var 6Var 7Var 8Var 9Var 10
Gas composition (left) and off‐flavors (right) of fresh‐cut Iceberg cultivars
stored in Active MAP for 3 days at 4ºC + 13 days at 7ºC
1. Genotype: Selection based on low off‐flavor potential
septum
juice
fiber
Incubation15 min at 35 ºC
Time (min.)
0 2 4 6 8 10 12 14
0
1e+6
2e+6
3e+6
4e+6
5e+6
Ace
tald
eh
yde
Dim
eth
yl s
ulfi
de
Eth
yl a
ceta
te
Eth
an
ol
Inte
rna
l Sta
nd
ard
He
xan
al
Tra
ns-
2-h
exe
na
l
1-h
exa
no
lC
is-3
-he
xen
-1-o
lT
ran
s-2
-he
xen
-1-o
l
Tra
ns-
cary
op
hyl
len
e
2-m
eth
yl b
uta
na
l3
-me
thyl
bu
tana
l
Pe
nta
na
l
Lim
on
ene
Iso
am
yl a
lco
ho
l
Sulfides Aldehydes Alcohols Terpenes
Analysis of volatiles by GC‐MS Solid Phase Micro
Extraction (SPME)
1. Genotype: Selection based on low off‐flavor potential
Day 0
1. Acetaldehyde2. Dimethyl sulfide3. 2‐Methyl propanal4. Ethyl acetate5. 2‐Methyl butanal6. 3‐Methyl butanal7. Ethanol8. α‐ Pinene9. 3‐Methyl‐pentanal10. Toluene11. Butanoic acid 2‐methyl ethyl ester12. Butanoic acid 3‐methyl ethyl ester13. Hexanal14. 1‐Undecane15. Heptanal16. Limonene17. Trans‐2‐hexenal18. Styrene19. 1‐hexanol20. 2‐ethyl‐1,6‐dioxaspiro [4,4]nonane
21. 2‐ethyl‐1,6‐dioxaspiro [4,4]nonane22. 3‐Hexen‐1‐ol23. 2‐nonanone24. 2‐Hexen‐1‐ol25. 2,4‐Hexadienal26. 2,4‐Hexadienal27. 2‐Methoxy‐3‐(1‐methylethyl)‐pyrazine28. 1‐Octen‐3‐ol29. Acetic acid30. 2‐Ethyl‐1‐hexanol31. 2‐Methoxy‐2‐(1‐methylpropyl)‐pyrazine32. 2‐Methoxy‐2‐(2‐methylpropyl)‐pyrazine33. 2‐Nonenal34. 1S‐(‐)Camphor35. Benzaldehyde36. β‐Elemene37. 2,6‐Nonadienal38. Caryophyllene39. Benzeneacetaldehyde40. 2,4‐nonadienal41. 2,4‐nonadienal42. Siloxanes derivatives
1. Genotype: Selection based on low off‐flavor potentialDay 0
Day 13, Damaged tissue
Day 13, Fermented tissue
0 5 10 15 20
Abundan
ce
0
5e+6
1e+7
2e+7
2e+7
0 5 10 15 20
Abundan
ce
0
5e+6
1e+7
2e+7
2e+7
123
5
67 8
9
11
14
15
21
10
13
20
242516 1817
12
1 2
5
67
8
9 10
12
1415 22
11 1619
3
3
0 5 10 15 20
Abundan
ce
0
5e+6
1e+7
2e+7
2e+7
12 3 4
56
7
8
9 10
11
121314
15161718
20
21
22 2423
Day 0
Time
0 5 10 15 20
Abu
ndan
ce
0
5e+6
1e+7
2e+7
2e+7
1
2
5
6
7
IS
13 17
22
2737
19
24
33
4139
303231 38
439 15 23 35
4011
122914 2021
2526 28
Synthetic
Aspirin
Honeydew
melon
Strawberry
Rawalm
ond
Sea, fishy
Candy
Aspirin
Mushroom
Bitter, burny
Good, intense
Mowngrass
Familiar
Red
pep
per, intense
Sweetmelon
Sweaty, p
ungent
Fruity, candy
Cheesy
Acid, m
ild
Rotten
fish
Leather
Combination of gas chromatography‐coupled olfactometry techniques (GC‐O) and gas chromatography–mass spectrometry (GC–MS)
GC‐O AROMAGRAM
GC‐MS CHROMATOGRAM
1. Genotype: Selection based on low off‐flavor potential
Biomarkers of gaseous and volatile compounds (AGL2013‐48529‐R)
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Selection of cultivars is critical because of the strong influence in the
“freshness” of the fresh‐cut product
Advantages
Consistency of the stability of the shelf life
Consistency of the rawmaterial
Consistency of the quality of fresh‐cut product
1. Genotype selection
Conclusions
1. Genotype selection
Breeding program for lettuce
1. Genotype selection 1. Genotype selection
Other factors such as environmental and cultural practices influence
shelf life
Storage conditions influence shelf life. Experimental design: Active
MAP (0.5% O2 + 8‐10% CO2) + 24 h in air
Results must be confirmed in different seasons and years
Seed companies must provide the selected cultivars through several
years (confidential agreement)
Growers must use recommended cultural practices for cultivation
1. Genotype selection: Disadvantages
3. Agricultural practices
2. Environmental conditions
1. Genotypes
Pre‐harvest factors that affect quality of leafy greens
4. Maturity at harvest
5. Harvest time
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Influence cultivation in different production areas and growing cyclesVariety 52 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
Cervantes X X X X X X X X X X X X X X X X X X X X X X X X
Chiquina X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
Cuore X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
Cuore PM23 X X X X X X X X X X X X X X X X
Spring Summer FallWinter
2. Environmental conditions: Temperature, RH, light and rainfall
Fresh‐cut Romaine lettuce cultivars stored for 11 d at 7ºC in Active MAP + 24h 7ºC after opening the bags
Cut edge bro
wning
Average temperature during cultivation
Eth
anol c
ontent (ppm)
Average temperature during cultivation
Influence diseases and disorders of lettuces
Frost damage Excess of water Pinkrib TipburnBacterial soft rot
2. Environmental conditions: Temperature, RH, light and rainfall
Appearance, location and evolution of spots and alterations observed in lettuce leaves
(Blancard et al., 2005)
Influence differences in the specifications of rawmaterial
‐ Maturity indices: size, weight, compactness
2. Environmental conditions: Temperature, RH, light and rainfall
Fresh weight vs harvest week of baby leaf red lettuces
Red Batavia (B1) Red Batavia (B2) Red oak leaf (R)
Fall/Winter: 50 mmSpring/Summer:70 mm
Specifications of raw material
2. Environmental conditions: Temperature, RH, light and rainfall
Phenolic compounds vs harvest week vs harvest week of baby leaf red lettuces
Harvest week
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Fla
vono
ids
(mg
100
g-1dw
)
0
20
40
60
80
100
120
140
Harvest week
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Phe
noli
c ac
ids
(mg
100
g-1dw
)
0
10
20
30
40
50
B1 Cy-3GML-7GcQ-3Gc+Q-3GQ-3GM
5-CQACMAdCTA
B1
14050
Cy‐3MG: cyanidin‐3‐O‐(6”‐O‐malonyl)‐glucoside5‐CQA: 5‐caffeoylquinic acidCMA: caffeoylmalic aciddCTA: dicaffeoyltartaric acidL‐7Gc: luteolin‐3‐O‐glucuronideQ‐3Gc: quercetin‐3‐O‐glucuronideQ‐3G: quercentin‐3‐O‐glucosideQ‐3MG: quercetin‐3‐O‐(6”‐O‐malonyl)‐glucoside
Red Batavia (B1)
Radiation and temperature showed positive correlations with the content of phenolic acids and flavonoids that increased as the season progressed
2. Environmental conditions: Temperature, RH, light and rainfall
Respiration rate of fresh‐cut Iceberg lettuce harvested in different months stored for 9 d at 7 ºC and 0.5% O2
b
bb
a
Harvest month
Novem
ber
Janu
ary
Febru
ary
May
June
mL
O2 k
g-1 h
-1
0
1
2
3
4
5
b
2. Environmental conditions: Temperature, RH, light and rainfall
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Greenhouse vs field production
Soilless system in greenhouse: lack of lettuce heart and bolting in the case of butterheadand the lack of color in the case of red‐leafed genotypes, as well as the presence of
tipburn in all genotypes.
2. Environmental conditions: Temperature and light intensity
• Protected culture system: increases yield, allows off‐season production,
controls abiotic factors and facilitates pest management.
• Cultivation in open field: more resistant crops because of the adverse
weather conditions and long growing cycle.
Conclusions
2. Environmental conditions
3. Agricultural practices
2. Environmental conditions
1. Genotypes
Pre‐harvest factors that affect quality of leafy greens
4. Maturity at harvest
5. Harvest time Control
Urban D
1
Urban D
2
Sewage 2
D1
Sewag
e 2 D
2
Yie
ld (
g m
-2)
0
200
400
600
800
1000
% W
ater
Con
ten
t
75
80
85
90YieldWater content
c c c
b
a
x
xy
xy
y
z
Urban(45 and 135 T/ha)
Control
Sewage(45 and 135 T/ha)
3. Agricultural practices: Fertilizers
Organic soil amendments
Control
Urban D
1
Urban D
2
Sewage 2
D1
Sewage 2
D2
Ph
enol
ic c
onte
nt
(mg
100
g-1 f
.w.)
0
75
150
225
300
375
a
b
c bc
d
Glu
cosi
nol
ates
(m
g 10
0g-1
)
0
30
60
90
120
150
180
a
bb
b
b
Organic soil amendments
3. Agricultural practices: Fertilizers
Irrigation regime= Irrigation treatment + Rainfall – Crop evapotranspiration (Etc)Harvest date
Mar
ch '0
9
Novem
ber '0
9
Mar
ch '1
0
October
'10
Febru
ary
'11
May
'11
Wa
ter
su
pp
lied
(m
m)
0
100
200
300
400R4
R3
R2
R1
T1: ControlT2:FC ‐50% T3: FC ‐25% T4: FC +25 %T5: FC +50 %
Deficit
Excess
2009
2010
2011
MarchNovemberMarch October February May
• Crop: Romaine and iceberg lettuce
• Total cultivated area: 1080 m2
• Number of treatments: 5
• Number of harvest: 6
3. Agricultural practices: Irrigation
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Visual quality of fresh‐cut Iceberg lettuce stored during 13 days in MAP (3 d at 4 ◦C and 7 ◦C for the rest of the storage) as affected by different irrigation regimes
0 8 10 13
Vis
ual
qu
alit
y
1
3
5
7
9
Days of storage
LSDregime= 0.6
LSDstorage= 0.3
R1 () (0‐100 mm)
R2 () (101‐200 mm)
R3 () (201‐300 mm)
R4 () (301‐400 mm)
3. Agricultural practices: Irrigation
Low irrigation doses are recommended for quality and economic reasons
0 1 2 3 40
2
4
6
8
10
12
PP
O (
µM
min
-1)LSDstorage= 2.4
LSDregime= 2.0B
Days of storage
0 1 2 3 4
Cu
t ed
ge
bro
wn
ing
1
2
3
4
5
Days of storage
A
LSDregime= 0.9
LSDstorage= 0.6
Cut edge browning (left) and PPO (right) of fresh‐cut Iceberg lettuce stored in air 7 ◦C as affected by different irrigation regimes
R1 () (0‐100 mm)
R2 () (101‐200 mm)
R3 () (201‐300 mm)
R4 () (301‐400 mm)
3. Agricultural practices: Irrigation
0
100
200
300
400
SoilSoilless
Ph
enol
ic c
omp
oun
ds
(mg
100
g-1
f.w
.)
a
b
Lollo ro
sso
Butterh
ead
Red oak lea
f
ns
ns
Caffeic acid derivativesFlavonolsAnthocyanins
Content of phenolic compounds in different lettuce types
3. Agricultural practices: Soil and soilless systems
Medium HighLow Medium HighLow Medium HighLow
Lollo Rosso
Fre
sh
we
igh
t (g
)
0
100
200
300
400
500 Red oak leaf Butterhead
0
100
200
300
400
500
Fre
sh
wei
gh
t (g
)
SummerWinter
Macroanions (NO3‐) and macrocations (K+, Ca2+ and NH4
+)
Genotype and season strong influence on quality and shelf
life of fresh‐cut product
3. Agricultural practices: Nutrient solutions
Lettuces cultivated in soilless under different salinity concentrations (mM NaCl)
Clarkson et al. (2003) observed that lettuces exposed to an stress increased the plasticity which conferred higher acceptability and shelf life to the product.
Ct=0 S1=50 S2=100 S3= 150
10 cm
Elasticity (reversible extension) and plasticity (irreversible extension)
Treatment
Ct S1 S2 S3
Ela
sti
cit
y (%
)
0
1
2
3
4
5
aa
b
a
3. Agricultural practices: Salinity
Higher procesability if there is a combination between small cells with a high solute concentration and strong cellular walls
(Clarkson et al. 2003; Zhang et al., 2007; Wagstaff et al., 2010).
Image captured by the optical microscope (A) and the corresponding
cellular vision in the inner part of the area studied (B)
Analysis of the internal anatomy of the tissue
3. Agricultural practices: Salinity
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Ct=0 S1=50 S2=100 S3= 150
10 cm
Analysis of the internal anatomy of the tissue
Lettuces cultivated in soilless under different salinity concentrations (mM NaCl)
ue
le
pp
spie
100µm
ue
pp
spie
le100µm
ue
le
sp
ie
pp
100µm
ue
sp
le
ie
pp
100µm
Ct (control) S1 (50 mMNaCl) S2 (100 mMNaCl) S3 (150 mMNaCl)
Ue, upper epidermis; le, lower epidermis; pp, palisade parenchyma; sp, spongy parenchyma; ie, intercellular spaces
3. Agricultural practices: Salinity
Ct=0 S1=50 S2=100 S3= 150
10 cm
Histology: Analysis of the internal anatomy of the tissue
Lettuces cultivated in soilless under different salinity concentrations (mM NaCl)
Treatments
Ct S1 S2 S3
Are
a o
f e
pid
erm
al c
ells
(µ
m2)
0
500
1000
1500
2000
2500
Treatments
Ct S1 S2 S3
Are
a o
f p
are
nc
hym
a c
ells
(µ
m2)
0
500
1000
1500
2000
2500
ns
a
b b b
Treatments
Ct S1 S2 S3
Ep
ide
rmis
(%
of
tota
l are
a)
0
20
40
60
80
Treatments
Ct S1 S2 S3
Par
ench
yma
(% o
f to
tal
are
a)
0
20
40
60
80
Treatments
Ct S1 S2 S3
Inte
rcel
ula
r s
pa
ces
(% o
f to
tal a
rea
)
0
20
40
60
80
ns
abb b
aab ab
b
3. Agricultural practices: Salinity
3. Agricultural practices: Drought stress
Content of phenolic compounds with mild and
severe deficit irrigation (DI)
Purple
Days of storage
0 5 7
Phe
nol
ics
com
pou
nds
(mg
/ 100
g f.
w.)
0
1000
2000
3000Control25% DI50% DI
Green
Days of storage
0 5 7
Genovese
Days of storage
0 5 70
1000
2000
3000
Ph
enol
ics
com
poun
ds (
mg
/ 100
g f.
w.)
Phenolic
compounds(m
g/100 g FW)
Phenolic
compounds(m
g/100 g FW
)3. Agricultural practices
• Optimization and control of agricultural practices are of paramount
importance, particularly IRRIGATION, to ensure the quality leafy greens.
• The combination of adequate production systems and suitable cultivars is
considered essential to ensure the shelf life of leafy greens.
Conclusions
3. Agricultural practices
2. Environmental conditions
1. Genotypes
Pre‐harvest factors that affect quality of leafy greens
4. Maturity at harvest
5. Harvest time0 2 4 6 8 10 12
kPa
0
2
4
6
8
10
12
14
16
O2
CO2
Days of storage
Immature
Commercial
Over‐mature
4. Maturity at harvest
Influence of maturity stage on quality of fresh‐cut Iceberg lettuce
Headspace gas composition of fresh‐cut Iceberg
lettuce at different maturity stages
Kader and Cantwell, 2010 with permission
9/22/2015
9
0 9 13
Ace
tald
ehy
de (
µm
ol 1
00 g
-1fw
)
2
4
6
8
10
12
0 9 13
Days of storage
aa
b
a
bb
a
aa
1000
2000
3000
4000
5000
6000
a
bb
a
b
Eta
nol
(µ
L kg
-1fw
)
c
A
B
Immature
Commercial
Over‐mature
Days of storage
4. Maturity at harvest
Kader and Cantwell, 2010 with permission
Ethanol (A) and acetaldehyde (B) of fresh‐cut Iceberg lettuce at different maturity
stages
MS 2 > 40 and ≤ 60 mm
MS 3> 60 and ≤ 80 mm
MS 4 > 80 mm Days of storage
0 2 4 6 8 10 12 14
Vis
ual Q
uali
ty (
Scor
e)
1
2
3
4
5
6
7
8
9
MS 2MS 3MS 4
4. Maturity at harvest
Influence of maturity stage on quality of fresh‐cut Romaine lettuce
Baby Multi Whole
Density of planting(plants/m2)
300 30 7
Cultivation (Days) 66 95 130
Baby Multi Whole heads
4. Maturity at harvest
0
200
400
600
800
1000
1200
1400
0
200
400
600
800
1000
1200
1400
Con
ten
ido
fen
ólic
o (m
g·10
0 g-1
p.f
.)
Con
ten
ido
fen
ólic
o (m
g·10
0 g-1
p.f
.)
Hoja verde Hoja roja Lollo rosso
Derivados de ácidos cafeicos Flavonoides Antocianos
Baby Multi Cabezas Baby MultiBaby Multi Cabezas CabezasBaby Multi Whole Baby Multi Whole Baby Multi Whole
Cafeic acid derivativesFlavonoidsAnthocyanins
Green Leaf Red Leaf Lollo Rosso
Content of polyphenols(m
g 100 g
‐1FW
) Content o
f polyp
henols(m
g 100 g ‐1
FW)
4. Maturity at harvest
Content of individual and total polyphenols
4. Maturity at harvest
Influence of maturity stage on quality of fresh‐cut Iceberg lettuce
Days of storage
-2 0 2 4 6 8 10 12 14 16
0
Days of storage
-2 0 2 4 6 8 10 12 14 16
0
Days of storage
-2 0 2 4 6 8 10 12 14 16
Unwashed
Wash
ed
Unwashed
Wash
ed
Unwashed
Wash
ed
kPa
Lactic acid bacteria
0
1
2
3
4
5
6
7
8
Lac
tic
acid
bac
teri
a
0
1
2
3
4
5
6
7
8
Red LeafGreen Leaf Lollo RossoBaby-leafMulti-leafWhole-head
3. Agricultural practices
2. Environmental conditions
1. Genotypes
Pre‐harvest factors that affect quality of leafy greens
4. Maturity at harvest
5. Harvest time
9/22/2015
10
Harvest Processing Storage
8:00 h
H1
24 h
13:00 h
H2
24 h
17:30 h
H3
24 h
3d 40C+ 6d 70C
5. Harvest time: Time of the day for harvest
Growing cycle: 54 dSun radiation: 7 h/dayTª : 10 0CRain: 0.1 mm
Growing cycle: 36 d Sun radiation: 9 h/dayTª : 13 0CRain: 1.1 mm
January
April
Leaf water content and environmental Vapor Pressure Deficit (VPD)
1:004:00
7:0010:00
13:0016:00
19:0022:00
H1
H2
H3
0
0.0
0.3
0.5
0.8
1.0
1.3
1.5
020
40
60
80H1 H2 H3
Wat
er c
onte
nt
(%)
At harvest
020
40
60
80H1 H2 H3
Wat
er c
onte
nt (
%)
At harvest
Winter Spring
0
0.0
0.3
0.5
0.8
1.0
1.3
1.5
22:001:00
4:007:00
10:0013:00
16:0019:00
H1
H2 H3
VP
D (
KP
a)
VP
D (
KP
a)
(VPD: Vapor Pressure Deficit)
5. Harvest time: Time of the day for harvest
Dehydration of the leaves in the middle ofthe day but it recovers in the afternoon.
Dehydration as the day progresses.
Respiration rate of minimally processed baby spinach cultivated in spring, harvested at different times and stored for 9 d at 7 ºC
H1: 8:00h
H2: 13:00h
H3: 17:30h
0 2 in
take
(m
l Kg-1
h-1
)
0
5
10
15
20
25
H1 H2 H3
5. Harvest time: Time of the day for harvestVisual quality of minimally processed baby spinach harvested at different times
and stored for 3 d at 4 ºC and 6 d at 4 ºC
Vis
ual
qu
ality
1
2
3
4
5
6
7
8
9
0 days
of storage9 days
of storage
0 days
of storage9 days
of storage
Vis
ual
qu
ality
1
2
3
4
5
6
7
8
9
Winter Spring
H1 H2 H3
H1: 8:00hH2: 13:00hH3: 17:30h
5. Harvest time: Time of the day for harvest
9 5 18 7 6 4 3 2
InedibleInedibleLimit of marketabilityLimit of marketabilityExcellentExcellent
• In winter, the differences observed among harvest times were reduced after
processing during storage, while in spring these differences remained.
• Baby spinach could be harvested at any time of the day in winter and early morning in
spring.
• Baby spinach harvested early in the morning had a higher water content, firm
texture, lower respiration rate and better visual quality.
Conclusions
5. Harvest time: Time of the day for harvest
A greater understanding of the mechanisms, including the metabolites
involved in browning, off‐odor development and texture loss will led to the
identification of the key preharvest factors for each species or cultivar.
Preharvest Factors and Fresh‐cut Quality of Leafy Vegetables
Future steps
9/22/2015
11
1 : Genotypes
2 : Environmental conditions
Marin, A., Ferreres, F. Barberá, G.G., Gil, M.I.2015. Weather variability influences color and phenolic content of pigmented baby leaflettuces throughout the season. J. Agric. Food Chem., 63, 1673‐1681.
References: Preharvest Factors and Fresh‐cut Quality of Leafy Vegetables
Martínez‐Sánchez, A., Gil‐Izquierdo, A., Gil, M.I., Ferreres, F. 2008. A comparative study of flavonoid compounds, vitamin C and
antioxidant properties of baby leaf Brassicaceae species. J. Agric. Food Chem., 56, 2330‐2340.
Tudela, J.A., Marín, A., Martínez‐Sánchez, A., Luna, M.C., Gil, M.I. 2013. Preharvest and postharvest factors related to off‐odours offresh‐cut iceberg lettuce. Postharvest Biol. Technol., 75, 75‐85.
3 : Agricultural practices
Selma, M.V., Luna, C., Martínez‐Sánchez, A., Tudela, J.A., Beltrán, D., Baixauli, C., Gil, M.I. 2012. Sensory quality, bioactive constituentsand microbiological quality of green and red fresh‐cut lettuces (Lactuca sativa L.) are influenced by soil and soilless agriculturalproduction systems. Postharvest Biol. Technol., 63, 16‐24
Luna, C., Tudela, J.A., Martínez‐Sánchez, A., Allende, A., Marín, A., Gil, M.I. 2012. Long term deficit and excess of irrigation influencesquality and browning related enzymes and phenolic metabolism of fresh‐cut iceberg lettuce (Lactuca sativa L.). Postharvest Biol.Technol., 73, 37‐45.
3 : Agricultural practices
Luna, C., Tudela, J.A., Martínez‐Sánchez, A., Allende, A., Gil, M.I. 2013. Optimizing water management to control respiration rate andreduce browning and microbial load of fresh‐cut romaine lettuce, Postharvest Biol. Technol., 80, 9–17.
Luna, M.C., Martínez‐Sánchez, A., Selma, M.V., Tudela, J.A., Baixaulib, C., Gil, M.I. 2013. Influence of nutrient solutions in open fieldsoilless system on the quality characteristics and shelf life of fresh‐cut red and green lettuces (Lactuca sativa L.) in differentseasons, J. Sci. Food Agric., 93, 415‐421.
Gil, M.I., Tudela, J.A., Luna, M.C. 2013. Water management and its effect on the postharvest quality of fresh‐cut vegetables. StewardPostharvest Review, September 1:2
Garrido, Y., Tudela, J.A. Marín, A., Mestre, T., Martínez, V., Gil, M.I. 2014. Physiological, phytochemical and structural changes of multi‐leaf lettuce caused by salt stress. J. Sci. Food Agric., 94, 1592‐1599
Bekhradi, F., Luna, M.C., Delshad, M., Jordan, M.J., Sotomayor, J.A., Martínez‐Conesa, C., Gil, M.I. 2015. Effect of deficit irrigation on the postharvest quality of different genotypes of basil including purple and green Iranian cultivars and a Genovese variety. Postharvest Biol. Technol., 100, 127‐135.
Bekhradi, F., Delshad, M., Marín, A., Luna, M.C., Garrido, Y., Kashi, A., Babalar, M., Gil, M.I. 2015. Salt stress on physiological andpostharvest quality characteristics of different Iranian genotypes of basil. Horticulture Environment and Biotechnology, in press.
References: Preharvest Factors and Fresh‐cut Quality of Leafy Vegetables
4 : Maturity at harvest
Gil, M.I., Tudela, J.A., Martínez‐Sánchez, A., Luna, M.C. 2012. Harvest maturity indicators of leafy vegetables. Steward PostharvestReview, June 1:2
5 : Harvest time and postha<rvest handling
Medina, M.S., Tudela, J.A., Mar<<<<<<<ín, A., Allende, A., Gil, M.I. 2012. Short postharvest storage under low relative humidityimproves quality and shelf life of minimally processed baby spinach (Spinacia oleracea L.). Postharvest Biol. Technol., 67, 1‐9.
Martínez‐Sánchez, A., Luna, C., Selma, M.V., Tudela, J.A., Abad, J., Gil, M.I. 2012. Baby‐leaf and multi‐leaf of green and red lettuces aresuitable raw materials for the fresh‐cut industry. Postharvest Biol. Technol., 63, 1‐10.
Garrido, Y., Tudela, J.A., Gil, M.I. 2015. Time of day for harvest and delay to processing affect the quality of minimally processed babyspinach. Postharvest Biol. Technol., 110, 9‐17.
References: Preharvest Factors and Fresh‐cut Quality of Leafy Vegetables
Preharvest Factors and Fresh‐cut Quality of Leafy Vegetables
Thank you for your attention!