Antioxidant and Polyphenolic Changes in Tomato during storage under different conditions
Loading...
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Biochemistry and Biochemical Engineering, Jacob Institute of Biotechnology and Bio-Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, U.P. (India)
Abstract
Tomato, Lycopersicum esculentum, corresponds to the Solanaceae family of vegetables.
L. esculentum belongs to a class of climacteric fruit which has a very short shelf life of
usually 1-2 weeks. The present study was carried out to determine the optimum storage
temperature and treatments by taking a record of various kinds of biochemical changes
during the post-harvest storage for ensuring better quality for consumption and its shelf-life.
Treatment of Calcium Chloride (1%, 2% and 5%), Hydrogen Peroxide (1%, 2% and 4%),
Controlled atmosphere storage (1% CO2 & 0.5% O2; 2%CO2 & 1% O2; and 3% CO2 & 1 %
O2) and 1-MCP (0.5 μL/L, 1.0 μL/L and 1.5 μL/L) were given to the tomato fruit of the
Hisar Arun and Kashi Vishesh cultivar, harvested at three stages of ripening (Mature Green,
Breaker, and Mature Red) and stored under three different temperatures (5°C, 10°C and
15°C). Changes in non-enzymatic and enzymatic activity as well as nutritive substances
were evaluated after every 7 days up to a total of 21 days of the storage period.
When treated with CaCl2 or H2O2, the non-enzymatic antioxidants (except lycopene) in both
the cultivars of tomato and for all the treating conditions provided, showed an increasing
trend until 14 days of storage after which, it started declining. On the other hand, the same
exhibited a gradual, yet increasing trend all the way up to 21 days of the storage when treated
with 1-MCP or provided Controlled Atmospheric Storage (CAS) condition. Particularly,
corresponding to the mature green stage of Kashi Vishesh, the maximum (39%; 233.184)
change in antioxidant activity was seen for 5% CaCl2 treated fruits after 14 days while
minimum (16%; 181.824) change was perceived by the fruits treated with 0.5 μL/L 1-MCP
after 21 days stored at 15°C.
Nutritionally, ascorbic acid is very important for the human diet; and tomatoes are a rich
source of ascorbic acid. The trend of change in ascorbic acid on the basis of maturity stages
was different as compared to the other studied parameter. Highest changes were seen in
mature green, followed by mature red. However, the breaker stages displayed least changes
in due course of the storage at all conditions. The quality of fruits is decided by the phenolics,
thus maintenance of phenolics during storage is crucial. Changes in total phenol content
during storage was found to be temperature dependent, notably at 5°C storage temperature,
the increase in the total phenol content was minimum, followed by that corresponding to
10°C, and 15°C. Initially, phenolic content was the highest in mature green fruits, but the
rate of change was higher in mature red stages, followed by the breaker, and then in the
mature green stage.
The contents of carotenoids, as well as other chemoprotective substances, are highly
conditioned by the genotype and environmental conditions. Percentage change in
carotenoids increased up to 14 days in CaCl2 and H2O2 treated fruits; while the same
increased consistently up to 21 days in CAS and 1-MCP treatment. Lowest carotenoid
content was recorded in 5% CaCl2 (51.831 mg/100gm) in the mature red Hisar Arun cultivar
corresponding to the storage temperature of 15°C. Lycopene is a natural plant nutrient with
antioxidative properties and great health benefits. In general, a continuous rise in lycopene
content was found up to 21 days of storage. A higher amount of change was recorded
corresponding to the mature green fruit when treated with CaCl2 or H2O2. Whereas for the
CAS and 1-MCP treated fruits, mature red fruits showed the maximum changes. Changes in
Lycopene content of tomato fruits is found to vary in the range of 1.5-58% in the mature
green of Hisar Arun.
The enzymatic antioxidants assessed in the present study viz. Superoxide Dismutase (SOD),
Glutathione reductase (GR), Ascorbate Peroxidase (APX) and Catalase (CAT) shown an
increasing trend up to 21 days of storage. Specific activity of SOD (78.633 unit/mg/protein
FW); APX (212.819 unit/mg/protein FW); GR (125.506 unit/mg/protein FW) and CAT
(203.486 unit/mg/protein FW) were found to be maximum in the mature green fruits of Kashi
Vishesh cultivar when treated with 5% CaCl2 stored at lower temperature (5°C) after 21 days
of storage among all the studied conditions.
In contrast to the aforementioned biochemical activities in tomatoes, which, in general,
increased during the storage, Protein showed a totally different trend i.e. decreased from day
one. Fruits of Kashi Vishesh harvested at the mature red stage when treated with 5% CaCl2
displayed the highest decrement while 1.5 μL/L 1-MCP showed the lowest change after 21
days of storage when stored under 15°C temperature. Sugars constitute an important
component of tomato fruit as they determine sweetness and influence the overall tomato
flavor. Reducing sugar in all the treated fruits samples were increased up to 21 days and the
rate of change was highly dependent on the provided treatment. Reducing sugar content of
local cultivar varied in the range of 2.245-3.201 mg/100gm FW; 3.146- 4.619 mg/100gm
FW and 4.733-6.088 mg/100gm FW in the mature green, breaker and mature red fruits,
respectively.
Summarily, we found tomato fruits, harvested at the breaker stage, retained a significantly
higher amount of non-enzymatic antioxidants after 14 days of storage compared to fruit
harvested at the mature green and red stage. In addition, our investigations suggest the 0.5
μL/L 1-MCP treatment to be the most effective in terms of offering a definitive control in
the rate of evolution of non-enzymatic antioxidants of the tomatoes such as lycopene and
carotenoids. Further, although Hisar Arun (Local) variety is found to retain more nutritional
content than Kashi Vishesh (hybrid) variety, the latter showed a higher shelf life.
Description
Ph. D. Thesis
Keywords
null