|
 Southeastern United States
Greenhouse Vegetable Growers
Conference and Trade Show Proceedings
May 19, 1999
|
Postharvest Quality Evaluation of
Greenhouse-Grown Tomatoes
Steven A. Sargent, Abbie J. Fox and Fernando Maul
Horticultural Sciences Department
University of Florida
PO Box 110690
Gainesville FL 32611-0690
Robert C. Hochmuth
North Florida REC - Suwannee Valley
University of Florida
7580 County Road 136
Live Oak, FL 32060
Keywords: Sensory analysis, Lycopersicon esculentum
Mill., cluster tomatoes
Introduction:
Specialty tomatoes continue to grow in popularity, as
evidenced by the number and availability in supermarkets. In a typical
produce department on can find cluster, roma (plum), cherry, grape, yellow, and
sun-dried, in addition to "vine-ripe" and ripened tomatoes.
Cluster tomatoes, once only imported from Europe, are now grown in North America
both in greenhouses and in the field. Several of the more popular cluster
and beefsteak-type tomatoes have been evaluated for yield and postharvest
quality parameters during the past several season at the North Florida Research
and Education Center - Suwannee Valley in Live Oak, Florida (Hochmuth, et al.,
1997). In addition to production characteristics, several tomato quality
parameters were rated including, freedom from fruit russetting, maintenance of
green calyx, luster and flavor.
Tests were conducted during the winter and
spring seasons of 1998 to assess the postharvest quality of nine cluster tomato
varieties and the widely grown "beefsteak" type, 'Trust'.
Materials and Methods:
Fruit Quality Analyses. The tomatoes were
grown in the greenhouse at the North Florida Research and Education Center -
Suwannee Valley near Live Oak in North Florida. Tomato cluster (4-10
fruits/cluster) were harvested during three distinct growing conditions,
representing the short, cloudy days of winter (January 20), fruit set during
cloudy weather (March 10), ideal growing conditions (April 20) and the hot,
humid conditions of late spring (June 3). At each harvest date tomatoes
were held overnight at about 65-75F (18-24C) and transported the following day
to the Postharvest Horticulture Laboratory in Gainesville for initial
analyses. Upon arrival at the laboratory, individual tomatoes were
evaluated for initial quality (calyx appearance, number of full-red
fruits/cluster and number of table-ripe fruits/cluster). Table-ripe was
defined as the point at which the firmness of individual tomatoes began to
noticeably soften. The clusters were stored for 7 days at 12C (55F) and
about 85% relative humidity to simulate commercial shipping, then transferred to
20C (68F) for 1 day to simulate commercial handling. At this time the clusters
were re-evaluated for the same appearance parameters. For the March and
April harvests, soluble solid content, total titratable acidity and pH were
determined from blended, centrifuged pulp.
Sensory Analyses. Tomato flavor
was determined for each of the varieties at table-ripe stage (full red and
slight softening) at the first three harvest dates using a trained sensory
panel. Over a period of three months, a group of 16 panelists, 10 males
and 6 females between 20 and 65 years old, were trained to describe flavor and
aroma attributes from fresh market tomatoes. During the initial training
sessions, panelists were presented with a variety of tomato samples representing
effects of ripeness stage, storage temperature and cultivar on characteristic
tomato flavor. The panel leader compiled a descriptor list from published
literature on tomato flavor to aid panelists in verbalizing flavor and aroma
characters perceived in the samples. The panel reached a consensus on five
flavor attributes (typical tomato, sweetness, sourness, green/grassy and
off-flavor) and two aroma attributes (ripe tomato and off-odor).
Approximately 20 minutes before each sensory
session, whole tomato samples from each of the varieties were chopped into a
coarse puree using 8 to 10 pulses of a food processor (M. Einstein, personal
communication). Two tablespoons (40-50 g) of tomato puree were placed in
113-mL plastic cups, sealed with lids and labeled with a two-digit random
number. Evaluations were conducted in individual booths with dim lighting
and samples were presented in random order. Panelist were instructed to
open the lid from each tomato sample cup to rate the aroma descriptors, then to
proceed with the flavor descriptors. The intensity rating for each
attribute was recorded on a 15-cm, unstructured line scale, with "low
intensity" at zero (left side) and "high intensity" at 15 (right
side) as anchor terms. Water and unsalted crackers were provided for
panelists to rinse their palates in between samples.
All compositional and sensory data were
analyzed using multiple analysis of variance (MANOVA), and means of significant
data were separated with Duncan's Multiple Range Test using SAS (v6.12, SAS
Institute, Cary, NC).
Results and Discussion:
Fruit Quality Analyses. The clusters were
harvested with a range of ripeness stages, from as low as 38% full-red to 100%
full-red (Tales 1-4). After 7 days at 12C + 1 day at 20C, all tomatoes had
reached full-red stage, although there was significant variation in number of
tomatoes at table-ripe stage within individual cluster. Varieties that
generally reached table-ripe stage after the storage period were 'Aranca',
'Campari' and 'E20-3000090'. Other varieties required longer periods to
completely ripen. Calyxes of 'Durasol' and 'Aranca' tended to maintain
better appearance during storage; these varieties also had the best ratings in
the 1997 study by Hochmuth, et al.
Tomato composition was analyzed for the March
and April harvests. 'Aranca', 'Batsheba' and Fa593 had highest soluble
solids contents (SSC), while 'Aranca', 'Batsheba' and 'Campari' had highest
total titratable acidity contents (TTA) (Tables 2,3). SSC remained fairly
constant for each variety at the two harvests, however, TTA tended to be lower
for tomatoes harvested in April, resulting in higher SSC/TTA for that
harvest. It was not possible to determine if differences in growing
conditions led to the lower acidity in fruits from the April harvest or these
differences were reflected in tomato aroma and flavor.
Sensory Analyses. Sensory
analyses were performed on ripe tomatoes for the January, March and April
harvests. The varieties were generally rated average in typical tomato
flavor notes, or descriptors (ripe aroma, sweetness and tomato flavor) and lower
in negative notes (off-odor, sourness, green/grassy, off-flavor).
'Campari' was rated significantly higher in tomato flavor (7.17 and 8.36) for
the March and April harvests, respectively (Tables 6 &
7). However,
'Aranca' was consistently rated higher in off-odor, sourness and off-flavor for
all three harvests (Tables 5, 6, 7). The other cluster varieties were
rated intermediate to these two varieties. 'Trust', the most widely grown
beefsteak variety in Florida greenhouses, was rated somewhat lower in sweetness
and higher in sourness and green/grassy notes, but intermediate in other notes
(Tables 5, 7).
Sensory analyses which were performed on
several field-grown, beefsteak-type tomatoes are included for comparison (Table
8; Unpublished data, F. Maul, University of Florida).
These tomatoes were harvested at 60 to 90% red color (light-red stage) and
ripened to table-ripe stage for analysis. Of particular interest is the
'SolarSet' variety which was released from the University of Florida tomato
breeding program by J. W. Scott. This variety was consistently received
high scores from sensory panels form tomato flavor and aroma. From Table
8, 'SolarSet' was rated high in ripe aroma (7.38) and tomato flavor (7.15),
however, it was also rated relatively high for sourness (5.53). These
seemingly conflicting results illustrate the complexity of sensory perception of
tomato which has also been shown to be influenced by harvest maturity and by
postharvest temperature exposure (Maul et. al., 1998). Tomato flavor and
aroma consists of very complex interactions between numerous compounds.
For this reason, we concur with other reports that concluded that properly
trained sensory panels, though time-consuming and costly, describe tomato flavor
with much more accuracy than other methods, such as soluble solids content and
total titratable acidity.
Conclusions:
'Aranca', 'Campari' and 'E20-3000090' tended to soften
faster that the other varieties during simulated shipping, while 'Durasol' and
'Aranca' maintained better calyx appearance. Trained sensory panelists
rated all varieties as average in ripe aroma, sweetness and tomato flavor and
lower in off-odor, sourness, green/grassy, off-flavor. 'Campari' was rated
significantly higher in tomato flavor, while 'Aranca' was consistently perceived
to have stronger off-odor, sourness and off-flavor. For specialty tomatoes
to find acceptance in niche markets, consistent quality is critical.
Tomato flavor, aroma and appearance are important factors which must be
considered in the overall evaluation of tomato varieties.
Literature Cited:
Hochmuth, R. C., L. L. Leon and G. J. Hochmuth.
1997. Evaluation of several greenhouse cluster and beefsteak tomato cultivars in
Florida. Extension Report. Suwannee Valley REC 97-3. University of
Florida. Agr. Exp. Sta. Gainesville. 13 pp.
F. Maul, S. A. Sargent, C. A. Sims, E. A.
Baldwin, M. O. Balaban and D. J. Huber. 1998. Storage temperature affects ripe
tomato fruit flavor. Abstract. 1998 Meeting of the Institute of Food
Technologists. Atlanta, Georgia, USA.
Table 1 Subjective Quality
Measurement Means for Cluster Tomatoes. (January 20, 1998 Harvest)
| |
Full-Red Stage (%) |
Table-Ripe Stage (%) |
Calyx Appearance W |
Avg. Fruits |
| Variety |
Initialz |
After Storagey |
Initial |
After Storage |
Initial |
After Storage |
per cluster |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Fa593
Rougella
Tradiro
Trust
870 |
|
|
100.0
93.8
100.0
100.0
91.7
93.8
90.0
79.1
100.0
100.0 |
ax
a
a
a
ab
a
ab
b
a
a |
|
|
100.0 a
100.0 a
100.0 a
100.0 a
100.0 a
100.0 a
100.0 a
100.0 a
100.0 a
100.0 a |
|
|
45.7
20.8
40.3
75.0
73.3
17.5
16.3
25.0
75.0
12.5 |
abc
bc
abc
ab
a
c
c
bc
ab
c |
|
|
100.0
54.2
100.0
87.5
100.0
47.5
75.0
53.3
100.0
56.7 |
a
bc
a
ab
a
c
abc
bc
a
bc |
|
|
3.1
2.1
2.6
3.4
2.6
2.6
2.1
2.3
-
2.9 |
a
d
bcd
a
bc
bc
cd
cd
-
ab |
|
|
2.1
1.2
1.5
2.5
1.5
1.4
1.0
1.5
-
1.8 |
ab
d
cd
a
cd
cd
d
cd
-
bc |
|
|
4.8
3.3
4.0
5.8
4.0
6.8
3.5
4.3
- -
4.0 |
|
zInitial measurements were
made one day after harvest.
yFruit were stored for 7d@12oC+1d@20oC.
xMean Separation within each column by Duncan's multiple range
test, 5% level.
wScale 5=excellent. 4=calyx starting to curl, but green.
3=calyx curled, but green. 2=calyx curled, tips drying. 1=calyx dried. |
Table 2. Quality Measurement
Means for Cluster Tomatoes After Storage (7d @12oC+1d @20o)
(March 10, 1998 Harvest)
| Variety |
Full-Red Stage (%) |
Table-Ripe Stage (%) |
Calyx Appearancez |
Avg. Fruits per Cluster |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Fa593
Rougella
Tradiro
Trust
870 |
|
|
83 ay
100 a
100 a
100 a
100 a
100 a
100 a
100 a
100 a
100 a |
|
|
67
19
70
0
100
33
6
50
25
33 |
abc
de
ab
e
a
bcde
e
bcd
cde
bcde |
|
|
3.9
1.5
2.3
4.1
1.7
3.3
2.0
3.0
-
3.8 |
ab
e
d
a
e
bc
de
c
-
ab |
|
|
4.5
5.3
5.0
4.0
2.3
3.0
4.5
3.0
- -
4.0
|
|
zScale 5=excellent.
4=calyx starting to curl, but green. 3=calyx curled, but green. 2=calyx
curled, tips drying. 1=calyx dried
yMean Separation within each column by Duncan's multiple range
test, 5% level. |
| Variety |
SSC (oBrix) |
% TTAz |
Ratio (SSC/TTA) |
pH |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Fa593
Rougella
Tradiro
Trust
870 |
|
|
5.63
4.97
4.43
3.43
3.83
6.20
3.73
4.23
3.43
4.03 |
ay
b
bc
e
cde
a
de
cd
e
cde |
|
|
1.45
1.23
1.15
0.87
0.87
1.12
1.03
0.96
1.05
0.98 |
a
b
bc
e
e
bcd
cde
de
cd
de |
|
|
3.88
4.04
3.85
3.94
4.40
5.54
3.62
4.41
3.27
4.11 |
|
|
4.19
4.28
4.34
4.23
4.51
4.55
4.31
4.29
4.25
4.25 |
e
bcd
b
de
a
a
bc
bcd
cde
cde |
|
zCalculation based on
citric acid.
yMean Separation within each column by Duncan's multiple range
test, 5% level. |
Table 3. Quality Measurement
Means for Cluster Tomatoes After Storage (7d @12oC=1d @20o)
(April 20, 1998 Harvest)
| |
Full-Red Stage (%) |
Table-Ripe Stage (%) |
Calyx AppearanceW |
Avg. Fruits |
| Variety |
Initialz |
After Storagey |
Initial |
After Storage |
Initial |
After Storage |
per cluster |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Fa593
Rougella
Tradiro
Trust
870 |
|
|
81
91
94
63
71
85
38
0
60
77 |
ax
a
a
ab
ab
a
bc
c
ab
ab |
|
|
100
100
100
100
100
100
100
100
100
100 |
a
a
a
a
a
a
a
a
a
a |
|
|
81
0
63
38
64
23
25
0
7
54 |
a
c
ab
bc
ab
bc
bc
c
c
ab |
|
|
100
64
100
100
100
46
75
100
13
54 |
a
b
a
a
a
b
ab
a
c
b |
|
|
4.6
3.6
4.7
4.6
4.3
4.3
3.7
-
3.2
4.7 |
a
b
a
a
a
a
b
-
b
a |
|
|
3.0
2.3
3.0
3.1
3.2
2.7
3.1
-
2.7
2.5 |
a
b
a
a
a
ab
a
-
ab
ab |
|
|
8.7
3.7
5.3
4.0
4.7
4.3
4.0
- -
5.0
4.3 |
|
zInitial measurements were
made one day after harvest.
yFruit were stored for 7d@12oC+1d@20oC.
xMean Separation within each column by Duncan's multiple range
test, 5% level.
wScale 5=excellent. 4=calyx starting to curl, but green.
3=calyx curled, but green. 2=calyx curled, tips drying. 1=calyx dried. |
| Variety |
SSC (oBrix) |
% TTA |
Ratio (SSC/TTA) |
pH |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Rougella
Tradiro
870 |
|
|
5.13
5.10
4.85
4.23
3.73
3.53
3.50
4.08 |
a
a
ab
ab
ab
b
b
ab |
|
|
1.27
0.99
1.20
0.79
0.89
0.82
0.78
0.82 |
a
bz
a
c
ab
ab
c
bc |
|
|
4.04
5.15
4.04
5.35
4.19
4.31
4.49
4.98 |
|
|
|
4.38
4.45
4.38
4.39
4.33
4.35
4.41
4.63 |
d
b
d
cd
e
e
c
a |
|
| zValues in columns
followed by the same letter are not significantly different at the 0.05%
level. |
Table 4. Subjective
Quality Measurement Means for Cluster Tomatoes. (June 3, 1998 Harvest)
| |
Full-Red Stage (%) |
Table-Ripe Stage (%) |
Calyx Appearance W |
Avg. Fruits |
| Variety |
Initialz |
After Storagey |
Initial |
After Storage |
Initial |
After Storage |
per cluster |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Fa593
Rougella
Tradiro
870 |
|
|
81
50
53
71
100
100
100
63
71 |
abx
b
ab
a
a
a
a
ab
ab |
|
100 a
100 a
100 a
100 a
100 a
100 a
100 a
100 a
100 a |
|
81
20
73
71
100
78
30
63
43 |
ab
d
abc
abc
a
abc
cd
abcd
bcd |
|
|
100
80
100
100
100
100
60
88
71 |
a
ab
a
a
a
a
b
ab
bc |
|
|
4.9
3.7
4.5
4.7
4.7
4.1
2.5
3.6
4.2 |
a
d
abc
ab
ab
cd
e
d
bc |
|
|
2.7
1.7
2.0
4.1
2.6
2.1
1.1
2.1
1.7 |
b
c
c
a
b
bc
d
bc
c |
|
8.0
3.3
5.0
3.5
3.7
4.5
3.3
4.0
2.3 |
zInitial measurements were
made one day after harvest.
yFruit were stored for 7d@12oC+1d@20oC.
xMean Separation within each column by Duncan's multiple range
test, 5% level.
wScale 5=excellent. 4=calyx starting to curl, but green.
3=calyx curled, but green. 2=calyx curled, tips drying. 1=calyx dried. |
Table 5. Sensory
Evaluation Means for Cluster Tomatoes After Storage (7d @12oC=1d @20o)
(January 20, 1998 Harvest)
| |
Sensory Descriptors z |
| Variety |
Ripe Aroma |
Off-Odor |
Sweetness |
Sourness |
Green/ Grassy |
Tomato Flavor |
Off-Flavor |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Rougella
Tradiro
870 |
|
|
5.56
6.51
7.84
6.79
6.71
6.55
5.84
6.67 |
nsy
ns
ns
ns
ns
ns
ns
ns |
|
|
5.69
4.31
3.31
4.29
4.53
2.60
3.54
4.52 |
ax
ab
b
ab
ab
b
b
ab |
|
|
7.69
5.95
6.11
5.22
6.71
5.95
5.19
7.39 |
a
ab
ab
b
ab
ab
b
a |
|
|
4.30
5.35
5.39
6.14
4.32
4.71
5.50
4.64 |
ns
ns
ns
ns
ns
ns
ns
ns |
|
|
3.26
3.09
2.89
3.75
3.38
3.55
4.53
2.61 |
ab
ab
b
ab
ab
ab
a
b |
|
|
6.77
6.84
6.84
6.13
7.06
6.47
5.63
7.00 |
ns
ns
ns
ns
ns
ns
ns
ns |
|
|
6.78
3.42
4.05
4.20
3.96
3.09
4.30
4.85 |
a
b
b
b
b
b
b
b |
|
z Unstructured line scale of
0=lowest intensity, 15=highest intensity
y ns=not significantly different within each column
x Mean Separation within each column by Duncan's multiple range
test, 5% level. |
Table 6. Sensory
Evaluation Means for Cluster Tomatoes After Storage (7d @12oC=1d @20o)
(March 10, 1998 Harvest)
| |
Sensory Descriptors z |
| Variety |
Ripe Aroma |
Off-Odor |
Sweetness |
Sourness |
Green/ Grassy |
Tomato Flavor |
Off-Flavor |
Aranca
Batsheba
Campari
Durasol
Rougella
Tradiro
Trust
870 |
|
|
5.91
5.97
7.24
6.47
6.67
6.11
6.01
6.18 |
nsy
ns
ns
ns
ns
ns
ns
ns |
|
|
3.18
2.98
2.66
2.73
2.42
2.44
2.51
2.52 |
ns
ns
ns
ns
ns
ns
ns
ns |
|
|
6.80
7.39
6.79
5.39
5.75
7.70
4.05
6.12 |
abx
ab
ab
bc
abc
a
c
abc |
|
|
6.36
4.27
6.63
4.06
4.08
3.95
6.29
4.78 |
ab
bc
a
c
c
c
ab
abc |
|
|
4.71
3.11
2.88
2.93
3.54
3.72
4.61
3.03 |
ns
ns
ns
ns
ns
ns
ns
ns |
|
|
5.86
5.88
7.17
4.55
5.25
6.29
5.25
6.00 |
ab
ab
a
b
ab
ab
ab
ab |
|
|
4.61
3.21
2.85
3.93
3.70
3.21
4.09
2.99 |
ns
ns
ns
ns
ns
ns
ns
ns |
|
z Unstructured line scale of
0=lowest intensity, 15=highest intensity
y ns=not significantly different within each column
x Mean Separation within each column by Duncan's multiple range
test, 5% level. |
Table 7. Sensory Evaluation
Means for Cluster Tomatoes After Storage (7d @12oC=1d @20o)
(April 20, 1998 Harvest)
| |
Sensory Descriptors z |
| Variety |
Ripe Aroma |
Off-Odor |
Sweetness |
Sourness |
Green/ Grassy |
Tomato Flavor |
Off-Flavor |
Aranca
Batsheba
Campari
Durasol
E20-3000090
Rougella
Tradiro
870 |
|
|
5.46
6.14
6.15
7.10
5.73
6.58
6.10
5.78 |
nsy
ns
ns
ns
ns
ns
ns
ns |
|
|
5.77
3.08
4.30
3.04
3.85
3.06
2.91
2.90 |
ax
b
ab
b
ab
b
b
b |
|
|
6.81
6.98
7.50
6.47
5.71
5.64
6.16
6.06 |
ns
ns
ns
ns
ns
ns
ns
ns |
|
|
6.56
5.14
4.94
4.51
5.83
4.85
4.63
6.25 |
a
ab
ab
b
ab
ab
b
ab |
|
|
3.78
3.51
2.51
3.62
3.49
3.74
4.39
3.13 |
ab
ab
b
ab
ab
ab
a
ab |
|
|
6.25
8.06
8.36
6.40
6.61
6.71
5.39
6.98 |
bc
ab
a
abc
abc
abc
c
abc |
|
|
7.03
3.30
2.92
3.33
4.33
3.65
3.61
3.20 |
a
b
b
b
b
b
b
b |
|
z Unstructured line scale of
0=lowest intensity, 15=highest intensity
y ns=not significantly different within each column
x Mean Separation within each column by Duncan's multiple range
test, 5% level. |
Table 8. Descriptive sensory analysis of
selected commercial tomato varieties harvested at light red stage and ripened to
table-ripe stage. (Unpublished data, Fernando Maul)
| |
Sensory Descriptors z |
| Variety |
Ripe Aroma |
Off-Odor |
Sweetness |
Sourness |
Green/ Grassy |
Tomato Flavor |
Off-Flavor |
SolarSet
|
7.38 ay |
2.54 a |
5.56 a |
5.53 a |
3.86 a |
7.15 a |
4.41 a |
Solimar
|
5.49 b |
3.41 a |
6.03 a |
4.09 b |
3.44 a |
5.72 b |
5.02 a |
| Mountain Spring |
6.53 ab |
3.58 a |
6.72 a |
2.73 b |
3.28 a |
6.85 ab |
4.05 a |
| Mountain Supreme |
6.62 ab |
3.10 a |
6.01 a |
4.44 ab |
4.01 a |
6.11 ab |
4.97 a |
z Unstructured line scale of
0=lowest intensity, 15=highest intensity
y Sensory descriptor rating with different letters were
significantly different at the 5% level according to Duncan's Multiple
Range test. |
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