What drives the eating Outline experience in...
Transcript of What drives the eating Outline experience in...
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Factors influencing mandarin fruit quality
David Obenland, USDA-ARS, Parlier, CAMary Lu Arpaia, UCR
OutlineWhat drives the eating experience in mandarins?
Exterior appearance is important for the initial purchase and can have some impact on the perception of taste
Flavor quality is even more critical. Consumer acceptance……and whether they will buy again….is strongly linked with flavor quality
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Outline of talk
Impact of sugar and acid balance
Influence of aroma compounds
Off-flavor formation during storage
Sensory properties of food related to flavor
Odor/smell/aroma
Taste
Texture/mouthfeel
Temperature
Irritation/pain
Flavor
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TasteTaste is a sensation that is perceived inthe mouth by the tongue
• Sweet
• Salty
• Bitter
• Sour (acidic)
• Umami (protein – savory)
Very important in mandarins
Outline
Analysis: Mark LoeffenDelytics Ltd, New Zealand
CA Standard = (SSC – (TA * 4)) * 16.5
California Standard
In navel oranges sweetness and acidity are described by the California standard
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California Standard
California Standard
Data from Australia suggests that if a California standard for mandarins is developed the value may need to be higher than that currently set for navels
Navels – California data
Mandarins – Australian data
Analysis: Mark LoeffenDelytics Ltd, New Zealand
50% liking
35% liking
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Brim A
He
do
nic
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ale
2003-2004
2004-2005
2005-2006
Dislike Extremely
Like Extremely
The scatter in the individual points (fruit)below indicates that sugar and acid doesnot entirely determine flavor
Navel orange data
SSC-(4*TA)
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Flavor is not just Sugar:Acid….aromacompounds are very important
80-90% of taste isaroma 2% of the human genome is involved in olfactory perception
Elizabeth BaldwinUSDA/ARS
Aroma (or smell or odor) is the sensation perceived when volatile compounds are drawn into the nose.
These compounds are also perceived by the brain when
they travel up the back of the
throat.
Aroma compounds (Volatiles)
Florence Negre-Zakharov, UC Davis
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GCMS for aroma volatile analysisRobotic solid phase microextraction system
Aroma Analysis and Product Quality
• Odor thresholds (minimum concentration of a substance at which a majority of test subjects can detect and identify the substance characteristic odor) Florence Negre-Zakharov, UC Davis
• Odor descriptors
Hexyl acetate apple, cherry,
floral, pear, wine
2-Ethyl hexanolcitrus, fresh, floral,
oily, sweet2-Methyl
butyl acetate banana, candy,
citrus5 ppb
270,000 ppb
2 ppb
?…
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Many aroma volatiles are present in mandarins and help determine flavor. These below were found to change as a result of storage.
Sweet, fruity
Storage time (wks)
Compound (µg/L) Gold Nugget (low) Pixie (high)
Alcohols 0 3 0 3
Ethanol (mg/L) 359 554* 930 3445*
3‐Methylbutanol tr tr tr 75*
2‐Methyl‐1‐butanol tr tr tr 44*
Linalool 254 34* 122 60*4‐Terpineol 104 22* 41 24*Esters
Ethyl acetate 1753 2922* 487 5812*
Ethyl propanoate 92 201* 36 320*
Ethyl isobutyrate tr 8* tr 73*
Ethyl butanoate 18 37* tr 466*
Ethyl 2‐methylbutanoate tr 6* tr 209*
3‐Methylbutyl acetate tr tr tr 9*
2‐Methylbutyl acetate tr tr tr 8*
Octyl acetate 256 60* 185 106
Decyl acetate 102 19* 64 34
Ketones
1‐Penten‐3‐one 7 7 6 8*
Carvone tr 12* 15 8
Aldehydes
Pentanal 9 11* 9 15*
Hexanal 20 24 28 19
E‐2‐Hexenal 27 21 18 47*
Heptanal 17 16 15 19
Octanal 179 48* 386 66*
E‐2‐Octenal tr tr 8 6
Nonanal 83 44* 106 47
E‐2‐Nonenal tr tr tr tr
Decanal 529 38* 223 54*
Malty, woody, earthy
Spearmint, caraway
Fatty, grassy, green
Mandarins often develop off-flavorduring storage
SpoiledSpoiled Really oldReally oldStrange aftertasteStrange aftertaste
Over ripeOver ripeNot freshNot fresh
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Weeks
0 1 4 7
Acc
epta
bili
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-fla
vor/
Tar
tnes
s
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Likeability Off-flavor Tartness
Typical mandarin response to cold storage + 1 week at 68F
W. Murcott
Some factors influencing off-flavorin mandarins
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He
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sc
ore
Weeks after packing
41F 0 weeks 2 weeks 4 weeks
Warm temps enhance
Time in cold storageinfluences response
Some varieties moreproblematic than others
68 F storage
W. Murcott
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Warm temperature response of other mandarin types
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0 1 3 @ 5 °C + 1
Hed
onic S
core
Weeks following packing
China S-9
5 °C
20 °C
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0 1 3 @ 5 °C + 1
Hed
onic S
core
Weeks following packing
Okitsu Wasi
5 °C
20 °C
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0 1 3 @ 5 °C + 1
Hed
onic S
core
Weeks following packing
Fairchild
5 °C
20 °C
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0 1 3 @ 5 °C + 1Hed
onic S
core
Weeks following packing
Nova
5 °C
20 °C
Harvest date can affect the negative impact of storage on mandarin flavor
OjaiLindcove
Early in the seasonthere was less of aflavor difference
When the flavor lossoccurred it was mainlydue to off-flavor
Data from Owari satsumas
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Coatings provide a formidable barrier to gas exchange
Waxed Unwaxed
Bailey-Serres et al., 2012
O2ethanol
We assayed for ethanol asan attempt to screen foroff-flavor susceptibility
• Ethanol easy to measure
• Substrate for volatile synthesis
• Major product of low oxygen and fermentation
Is there variability out there?
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Large varietal differences exist in the amount ofethanol accumulated after waxing and storage
Harvest Coating + 68F 1 week
Pix
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Gol
d N
ugg
et
0.00
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15.00
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25.00
0 50 100
Time after waxing (h)
GN
P
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EtO
H (
mg
/L)
Time after waxing (h)
GN
P
Response of a high ethanol producer (Pixie) vs. a low ethanol producer
(Gold Nugget)to waxing
After waxing Gold Nugget maintains a higher internal oxygen level and produces less ethanol than does Pixie
% I
nte
rna
l O2
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EthanolCO2 O2
Passage of gases through the peel occurs more slowly in Pixie than Gold Nugget
0.00
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% I
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rnal
O2
Time (h)
GN
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Time (h)
GN
P
Ethanol production similar forboth varieties in nitrogen gas and suggests an important role for the peel
Lowering internal oxygen in the fruit with nitrogen gas leads to a very similar ethanol response for Pixie and Gold Nugget
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ConclusionsThe sugar:acid balance is a very important
component of mandarin taste
Aroma compounds also play a critical role in determining mandarin flavor
Loss in flavor quality as a result of storage is common
• Waxing• Temperatures following waxing• Time of season• Variety
Our joint lab groupUC and USDA-ARS
Our research has been funded by the California
Citrus Research Board and the US-IS BARD Program
Our research has been funded by the California
Citrus Research Board and the US-IS BARD Program
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Questions?