thesis on physiological basis of extending shelf life of tomato
TRANSCRIPT
A THESIS ONPHYSIOLOGICAL BASIS OF EXTENDING
SHELF LIFE IN TOMATO
BYKaaenaat Tanveer
M Tech(Food Technology)4th Semester
DEPT OF FOOD TECHNOLOGYFACULTY OF ENGG & INTERDISCIPLINARY SCIENCE
JAMIA HAMDARD
Contents
INTRODUCTION LITERATURE RIVIEW AIM & OBJECTIVES METHODOLOGY EXPERIMENTAL RESULTS DISCISSION FUTURE LINE OF WORK
Tomato (Lycopersicum esculentum Mill) It belongs to the family solanaceae Originated in the peru-ecuador bolivia area of South America Earlier, tomatoes were thought to be poisonousGrown only as ornamental plantIt is considered as protective as well as productive food because of its special nutritive value It is used directly as raw vegetables in sandwiches, salads etc. Processed items of tomatoes are paste, puree, syrup, juice, ketchup, drinks etc.
It is rich source of lycopene, ascorbic acid, b-carotene and minerals
It also have two important anticarcinogenic and antioxidant property of lycopene and ascorbic acid
Lycopene have anticarcinogenic property protects against epithelial cancers
It contains a component P3 which prevents platelet clots and reduce heart disease and strokes
The production of tomato is109.44million tonnes from area of 4.04 million hectares
Physiological loss in weight Tomatoes stored at room temperature recorded
a maximum weight loss as compared to those packed in polyethylene bags due to higher rate of transpiration and water loss (Lingaiah, 1982).
Total Soluble solids Total soluble solids increased throughtout the
fruit development in tomato (Boe et al., 1967). Lycopene content Lycopene content of tomato fruit increasos with
the advancement of ripening (Hirota et al., 1982).
Respiration Storing of whole and fresh-cut tomatoes
in MAP at 2ºC significantly reduced the co2 production rates. The respiration rate of whole tomatoes at 2ºC was half as that at 10ºc and no chilling injury disorders were observed (Artes et al., 1999).
Polygalacturonase activity Low oxygen concentrations (2.5-
3.5%)diminished the accumulation of polygalacturonase proteins and depressed their isozymes in avocado fruits (kanellis et al., 1991).
Lycopene content Lycopene content of tomato fruit increasos with the advancement of ripening (Hirota et al., 1982). The
pigment changes during ripening is charactized by a loss of Chlorophyll and rapid accumulations of carotenoids, paticularly lycopene due to conversion of chloroplasts to chromoplasts (Hobson and Davies, 1971).
Ascorbic acid content Ascorbic acid content was higher in firm ripe tomato fruits but varied among the cultivars ranging between 18.44 to 23.28 mg/100 g. in soft ripe fruits, the ascorbic acid content decreased (16.48 to 21.72 mg/100g) in all
the cultivars (Singh et al., 1983).
Effect of packaging in tomato quality
Tomatoes harvested at breaker stage and packed in 300 gauge polyethylene bags with three vents recorded minimum changes in moisture, total soluble solids, acidity and sugars than the control fruits.
The organoleptic score was high in above acceptable limits for these fruits with a shell life of 42 days (Naik et al., 1993).
The best colour retention and firmness was noted in black polyethylene bags (badshah et al., 1997).
Effect of calcium chloride dips on tomato quality
The fruits treated with CaCl2(0.5%) + S(0.5%) showed the highest sugar, TSS and organoleptic ratings after the storage period (Bhartiya et al., 1998).
Calcium chloride treated cucumbers had a storage life of more than 14 days as compared to control (10 days). The fresh weight reductions were lower and inhibited the decrease in ascorbic acid content (known et al., 1999).
Effect of heat treatment on tomato quality.
Hot water dips (39 C for 90 min) of mature green cherry tomato fruits and subsequent storage in MAP substantially delayed the color development (Ali et al.,2004)
Avocado fruits heat treated in water at 30 oC for 60 min had reduced chilling injury and maintained best quality (Woolf, 1997)
To extend the of shelf life of tomato hybrid Lakshmi by employing various packaging and storage conditions with the following objective
To find out the effective packaging and storage condition to extend the shelf life in tomato
To investigate the physiological changes as influenced by different storage conditions and packaging material in tomato
To assign specific physiological reasons for deterioration in quality during extended storage in tomato
Experiment consisted of two storage conditions and eight
treatments Treatment details: Storage conditions (S) S1 Ambient storage (36 oC ) S2 Cold storage storage (4 oC) Treatments(T) T1 - Modified atmosphere packaging T2 -Low density polyethylene packaging T3 -High density polyethylene packaging T4 -Paper packaging T5 -Calcium chloride dip T6 -Hot water dpi at 39 oC for 90 min T7 -Hot air treatment at 34 oC for 24 hr T8 -Control
Treatment Imposition Packaging treatments For MAP tretment the bags were sealed and made airtight For LDPE and HDPE treatment the bags were perforated and
fruits were stored in these perforated bags. For paper packaging individual fruits were wrapped in single
layer newspaper Calcium chloride treatment Fruits were dipped inchlorinated water (0.7 mM) for 1 min
followed by dipping inCaCl2 ( 1% for 1 min ) Heat treatments Fruits were dipped in hot water at 39 oC for 90 min Fruits exposed to hot air at 34 oC for 24 hr Control Fruits as harvested from the field stored in ambient
atmosphere (36oC) And cold atmosphere (4 oC)
OBSERVATION Physiological loss in weight (PLW) For determining physiological loss in weight the formula is: = Initial fruit weight - Final fruit weight *100 Initial fruit weight pH The filtrate of tomato was used for measuring the pH using pH meter
Total soluble solids Detemined by Erma hand refractometer (0-32) A drop was used to record the TSS and expressed as degree Brix Titrable acidity Acidity was expressed and computed as percent citric acid % acid = Titre value * N * m.eq. of acid *100 Volume of sample ( Milli-equivalent weight of citric acid= 0.06404 )
Ascorbic acid content Calculation was done by the formula Ascorbic acid content = Titre value * dye value * volume made up *
100 (mg/100g fr. Wt) Aliquot taken* weight of sample
Lycopene content Calculation was done by the formula given by Ranganna(1977) Lycopene content = 3.12206 * OD of sample * volume made up *
Dilution (mg/100 g fr. Wt) Weight of sample * 1000
Respiration rate This was measured with a gas chromatograph (Nucon Series 5700) = Vfree * change in CO2/ 100 mass * time Vfree = V of container- V of fruit change in CO2 = final CO2 concentration - initial CO2
concentration 100
Polygalacturonase activity A unit of polygalacturonase activity was defined as the amount
of enzyme that catalyses the formation of one micromole of reducing groups in one hour at 37 oC
Organoleptic evaluation This evaluation was carried for color, texture, aroma and over all
acceptance of fruits Modified score card mentioned by Jagadeesh (1994) is below :
Score
Color Texture Aroma
4 25% characteristics color development
Very firm Excellent
3 50% characteristics color development
Firm Good
2 75% characteristics color development
Fair Fair
1 100% characteristicsColor development
Excessively soft
Poor
Shelf life Lot of fruit which showed symptoms of shrinkage or
spoilage were considered to reach the end of shelf life Fruits of cold storage showed longer shelf life as
compared to the ambient starage
Table 1. Influence of post harvest treatments and storage conditions on physiological loss in weight (%) in tomato hybrid (Lakshmi) at 7, 14 ,21 and 28 days of storage
T
7
Days
14 Days
21
Days
28
Days
Ambient
cold Ambient cold Ambient
cold Ambient
cold
T1 MAP 1.15 0.31 2.67 0.75 3.56 1.62 4.65 1.73
T2-LDPE 6.10 1.84 12.48 3.58 17.26 5.55 19.58 6.76
T3-HDPE 4.65 1.64 10.17 2.85 13.75 4.68 17.39 5.55
T4-PP 7.30 3.10 13.25 6.57 15.60 8.17 19.66 10.36
T5-CaCl2 5.37 1.62 8.64 3.14 12.55 5.90 16.55 7.74
T6-HW 7.77 2.53 14.23 4.47 19.35 7.25 22.24 8.38
T7-HA 8.28 3.15 14.73 5.72 19.68 6.86 22.89 8.43
T8-control
8.69 3.48 15.75 6.87 21.71 9.37 23.93 11.62
Table 2. Influence of post harvest treatments and storage conditions on pH in tomato hybrid (Lakshmi) at 7 , 14 , 21 and 28 days of storage
T
7
Days
14
Days
21
Days
28
Days
Ambient cold Ambient cold Ambient cold Ambient cold
T1-MAP 3.91 3.90 4.02 4.00 4.12 4.10 4.15 4.14
T2-LDPE 3.87 3.91 4.04 4.06 4.14 4.13 4.22 4.19
T3-HDPE 3.88 3.89 4.03 4.04 4.12 4.12 4.20 4.18
T4-PP 3.84 3.86 4.05 4.06 4.16 4.15 4.24 4.21
T5-CaCl2 3.81 3.85 4.03 4.05 4.15 4.14 4.20 4.19
T6-HW 3.97 3.88 4.07 4.06 4.14 4.13 4.23 4.21
T7-HA 3.88 3.90 4.05 4.06 4.15 4.13 4.25 4.22
T8-control 3.86 3.88 4.09 4.05 4.18 4.15 4.20 4.17
Table 3. Influence of post harvest treatments and storage conditions on TSS (o Brix) in tomato hybrid (Lakshmi) at 7 ,14 ,21 and 28 days of storage
T 7
Days
14
Days
21
Days
28
Days
Ambient
cold Ambient cold Ambient cold Ambient
cold
T1-MAP 4.17 4.11 4.41 4.37 5.11 5.01 5.24 5.14
T2-LDPE 4.31 4.24 4.57 4.54 5.17 5.14 5.34 5.31
T3-HDPE 4.24 4.14 4.44 4.47 5.14 5.07 5.31 5.24
T4-PP 4.27 4.21 4.61 4.67 5.24 5.11 5.41 5.34
T5-CaCl2
4.21 4.14 4.54 4.51 5.21 5.11 5.34 5.34
T6-HW 4.21 4.31 4.51 4.61 5.24 5.14 5.37 5.41
T7-HA 4.34 4.17 4.64 4.57 6.27 5.17 5.44 5.44
T8-control
4.37 4.34 4.74 4.71 5.31 5.24 5.54 5.57
Table 4. Influence of post harvest treatments and storage conditions on titratable acidity (%) in tomato hybrid (Lakshmi) at 7, 14 , and 14 days of storage
T 7
Days 14
Days 21
Days
28
Days
Ambient cold Ambient cold Ambient cold Ambient cold
T1-MAP 0.587 0.596 0.459 0.480 0.373 0.384 0.309 0.320
T2-LDPE 0.533 0.544 0.437 0.427 0.320 0.320 0.256 0.267
T3-HDPE 0.576 0.576 0.448 0.469 0.331 0.354 0.277 0.288
T4-PP 0.512 0.523 0.416 0.427 0.267 0.267 0.224 0.224
T5-CaCl2
0.576 0.565 0.437 0.448 0.309 0.341 0.256 0.288
T6-HW 0.565 0.544 0.427 0.437 0.309 0.299 0.245 0.267
T7-HA 0.533 0.512 0.416 0.416 0.288 0.299 0.245 0.256
T8-control
0.512 0.512 0.384 0.405 0.256 0.267 0.192 2.024
Mean 0.549 0.547 0.428 0.439 0.307 0.316 0.251 0.267
TABLE 5. INFLUENCE OF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON ASCORBIC ACID CONTENT (MG 100 G. FR. WT) IN TOMATO HYBRID (LAKSHMI) AT 7 AND 14 DAYS OF STORAGE
T 7 14 21 28
Ambient Cold Ambient cold Ambient Cold Ambient cold
T1-MAP 30.94 31.85 26.39 28.21 23.66 26.48 21.84 23.66
T2-LDPE 25.48 27.30 22.75 23.66 19.11 21.84 16.38 17.29
T3-HDPE 30.03 29.12 25.48 26.39 21.84 23.66 19.11 21.84
T4-PP 24.57 25.48 21.84 21.84 16.38 19.11 15.47 16.38
T5-CaCl2 28.39 30.03 24.57 25.48 20.02 21.84 16.38 17.29
T6-HW 28.23 28.21 24.57 24.57 19.11 20.02 14.56 16.38
T7-HA 24.57 25.48 23.66 22.75 18.20 19.11 13.65 15.47
T8-control 23.66 24.57 19.11 21.84 16.38 19.11 13.65 13.6
Mean 26.73 27.76 23.55 24.34 19.34 21.40 16.38 17.74
TABLE 6. INFLUENCE OF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON LYCOPENE CONTENT (MG/100 G. FR. WT.) IN TOMATO HYBRID (LAKSHMI) AT 7 AND 14 DAYS OF STORAGE
T 7
14
21
28
Ambient Cold Ambient cold Ambient Cold Ambient cold
T1-MAP 2.622 2.122 3.448 3.104 4.228 4.259 5.320 5.273
T2-LDPE 2.106 2.293 3.697 3.635 4.587 4.451 5.975 5.866
T3-HDPE 2.075 2.340 3.204 3.791 4.306 4.899 5.804 6.06
T4-PP 2.278 2.153 4.009 3.931 4.727 5.070 6.116 6.194
T5-CaCl2 2.309 2.324 3.526 3.588 5.070 4.337 5.913 6.022
T6-HW 2.246 2.309 3.869 3.339 5.305 4.540 6.053 5.929
T7-HA 2.402 2.231 4.087 3.401 4.415 4.774 6.147 6.085
T8-control
2.137 2.256 3.822 3.775 5.617 5.102 6.225 5.929
TABLE 7. INFLUENCE OF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON RESPIRATION RATE (ML CO2 KG H) IN TOMATO HYBRID (LAKSHMI) AT 7 AND 14 DAYS OF STORAGE
T 7
14 21
28
Ambient Cold Ambient cold Ambient
cold Ambient
cold
T1-MAP 16.54 10.96 13.74 11.73 15.19 10.72 19.89 14.26
T2- LDPE 23.02 16.32 23.83 14.68 29.01 17.33 25.17 20.61
T3-HDPE 24.36 15.84 27.18 13.23 25.66 14.16 20.28 19.18
T4-PP 22.29 16.79 29.05 12.26 23.72 15.64 21.75 16.43
T5-CaCl2(1%)
22.18 14.48 26.46 13.17 22.19 15.91 15.13 14.56
T6-HW 20.64 18.38 25.13 14.94 29.16 13.21 23.56 21.40
T7-HA 23.18 15.12 27.54 15.32 20.86 14.37 17.16 20.96
T8-control 24.93 14.26 31.39 16.75 26.63 15.24 20.94 23.84
TABLE 8. INFLUENCE OF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON POLYGALACTURONASE ACTIVITY (MICROMOL GLUCOSE EQV./G. FR.WT./H) IN TOMATO HYBRID (LAKSHMI) AT 7 AND 14 DAYS OF STORAGE.
T 7
14
21
28
Ambient Cold Ambient cold Ambient
Cold Ambient
cold
T1-MAP 0.984 0.875 2.299 2.080 3.613 2.682 4.525 3.942
T2- LDPE 1.313 1.258 3.066 2.353 5.037 4.215 6.296 5.584
T3-HDPE 1.149 0.930 2.408 2.189 4.544 3.778 6.022 5.092
T4-PP 1.861 1.697 3.504 3.120 5.201 4.982 6.625 6.077
T5-CaCl2 1.533 1.040 3.284 2.656 4.928 4.379 6.132 5.365
T6-HW 1.422 1.368 2.792 3.230 5.310 4.653 6.406 5.912
T7-HA 1.587 1.477 3.448 3.394 5.420 4.763 6.515 6.241
T8-control 1.915 1.806 3.723 3.558 5.968 5.256 7.172 6.898
Mean 1.471 1.306 3.065 2.823 5.003 4.338 6.187 5.639
TABLE 9. INFLUENCE OF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON COLOUR (SCORE OUT OF 4.0) IN TOMATO HYBRID (LAKSHMI) AT 7 AND 14 DAYS OF STORAGE.
T 7
14 21
28
Ambient Cold Ambient
cold Ambient
Cold Ambient
cold
T1-MAP 3.0 3.2 2.7 2.8 2.3 2.3 2.0 2.0
T2- LDPE
2.7 3.0 2.3 2.7 2.0 2.2 1.8 1.8
T3-HDPE 3.0 3.0 2.3 2.8 2.2 2.3 2.0 2.0
T4-PP 2.2 2.2 2.0 2.0 1.8 1.7 1.3 1.3
T5-CaCl2
2.3 2.7 2.0 2.3 1.7 1.8 1.3 1.7
T6-HW 2.3 2.5 2.2 2.3 2.0 2.0 1.7 1.8
T7-HA 2.2 2.3 2.2 2.2 1.8 2.0 1.7 1.7
T8-control
2.0 2.0 1.8 1.8 1.3 1.7 1.0 1.2
TABLE 10. INFLUENCE OF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON TEXTURE (SCORE OUT OF 4.0) IN TOMATO HYBRID (LAKSHMI) AT 7 AND 14 DAYS OF STORAGE
T 7
Days 14
Days 21
Days
28
Days
Ambient Cold Ambient
cold Ambient
cold Ambient
cold
T1-MAP 3.3 3.3 3.2 3.2 2.8 3.0 2.7 2.5
T2- LDPE 3.0 3.0 2.8 2.8 2.5 2.7 2.2 2.0
T3-HDPE 3.2 3.0 3.0 3.2 2.7 2.8 2.3 2.3
T4-PP 3.2 3.2 2.8 3.0 2.3 2.5 2.2 2.0
T5-CaCl2 3.3 3.3 3.0 3.2 2.8 2.8 2.5 2.3
T6-HW 3.2 3.3 3.0 3.0 2.5 2.7 2.2 2.2
T7-HA 3.0 3.2 2.8 2.8 2.3 2.5 2.0 2.0
T8-control 3.0 3.0 2.5 2.7 2.2 2.2 1.3 1.2
Mean 3.1 3.2 2.9 3.0 2.5 2.6 2.2 2.1
TABLE 11. INFLUENCE OF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON AROMA (SCORE OUT OF 4.0) IN TOMATO HYBRID (LAKSHMI) AT 7 AND 14 DAYS OF STORAGE
7 Days 14 Days
21 28
TAmbient
cold Ambient cold Ambient
cold Ambient
cold
T1-MAP 3.0 3.2 2.5 2.7 2.3 2.3 2.2 2.0
T2- LDPE 2.8 3.0 2.2 2.5 1.8 2.0 1.7 1.7
T3-HDPE 2.8 3.2 2.3 2.7 2.0 2.3 2.0 1.8
T4-PP 2.5 2.5 2.2 2.3 1.7 2.0 1.5 1.5
T5-CaCl2 2.7 2.8 2.3 2.5 1.8 2.2 1.7 1.7
T6-HW 2.8 3.0 2.5 2.7 2.2 2.2 1.8 1.8
T7-HA 2.7 2.8 2.2 2.3 1.8 1.8 1.7 1.5
T8-control 2.5 2.7 2.0 2.2 1.5 1.5 1.0 1.0
Mean 2.7 2.9 2.3 2.5 1.9 2.0 1.7 1.6
TABLE 12. INFLUENCE NONF POST HARVEST TREATMENTS AND STORAGE CONDITIONS ON SHELF LIFE (DAYS) IN TOMATO HYBRID (LAKSHMI)
TShelf Life (days)
Ambient cold Mean
T1-MAP 42.0 45.0 43.5
T2- LDPE 37.7 40.2 38.9
T3-HDPE 39.0 42.7 40.8
T4-PP 30.3 31.2 30.7
T5-CaCl2 37.2 34.0 35.6
T6-HW 34.3 33.2 33.9
T7-HA 34.3 31.3 32.8
T8-control 32.2 30.0 31.1
Mean 35.9 35.9 35.9
Major problem with the storage and marketing of tomato is fast deterioration , hence post harvest technologies are employed to reduce it
TEMPERATURE is a effective environmental factor involved in fruit ripening. This has effect on respiration rate . So temperature management reduces respiration rate and extends shelf life.
FILM PACKAGING is another technique which slows downthe biochemical changes and reduces the moisture loss
MODIFIED ATMOSPHERE PACKAGING (MAP)is the recent advance in packaging technology. It reduces respiration rate, retards softening and slows all biochemical changes associated wiyh the ripening.And it also prevents the chilling injury
POST HATVEST HEAT TREATMENTS delays the ripening process and reduces chilling injury and controls activity of pathogens
CALCIUM addition rigidifies cell wall and obstructs the enzyme polygalacturonase from reaching the active sites. It also maintains the firmness and reduces the respiration rate.
The output of these post harvest treatments and storage conditions were undertaken to find out the effective post hervest method for extention of shelf life in tomato
PHYSIOLOGICAL LOSS IN WEIGHT (PLW) Weight loss was significanty lower in MAP under both
ambient and cold storage Cold storage fruits had a low weight loss due to
temperature effects
pH No significant changes were observed in general The MAP delayed the change in pH over storage period
TOTAL SOLUBLE SOLIDS (TSS) MAP significantly delayed the change in total soluble
solids
TITRATABLE ACIDITY This differed significantly over the storage period A gradual decline in titratable acidity was noticed by the
end of the storage period among the tomato fruitsMAP maintained the titratable acidity and had a significantly
higher acidity over other treatments
ASCORBIC ACID CONTENT MAP significantly maintained higher ascorbic acid content over the
storage period. Loss of ascorbic acid in cold storage was significantly lower than the
ambient stored tomatoes
LYCOPENE CONTENT Investigation shows significant increase in lycopene content during
the storage period Storing the tomatoes in MAP significantly delayed the lycopene
biosynthesis RESPIRATION RATE Modified atmosphere packaging (MAP) significantly delayed the
rise in climacteric respiration both in ambient and cold storage POLYGALACTURONASE ACTIVITY Tomatoes stored in MAP had a significantly low
polygalacturonase activity Cold storage of fruits had significantly redyced
polygalacturonase activity
ORGANOLEPTIC EVALUATION Organoleptic scoring was high for fruits stored in MAP Fruits kept in cold storage suffered chilling injury at the
end of storage period But fruits packed and kept in cold storage has a reduced
chilling injury A better avoidance of chilling injury was observed in cold
stored MAP fruits
SHELF LIFE Shelf life of tomato fruits was extended by 4 weeks in
MAP
FUTURE LINE OF WORK
We included tomoto hybrid in our investigation which has better shelf life , the local tomato variety can also be compared with them
Studies on the storage and packaging practices are limited in local varities hence studies on the local tomato varities should be carried out
Exact mechanism of exchange of gases between various packaging material and its impact on tomato ripening can be estimated