ArticlePublisher preview available

Effect of postharvest irradiation with red light on epidermal color and carotenoid concentration in different parts of tomatoes

Authors:
Lachinee Panjai at Rajamangala University of Technology Lanna
Lachinee Panjai
Simone Röhlen-Schmittgen at Geisenheim University
Simone Röhlen-Schmittgen
Jan Ellenberger at University of Bonn
Jan Ellenberger
Georg J. Noga at University of Bonn
Georg J. Noga
Show all 6 authorsHide
Read publisher preview
Download citation
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

The aim of this study was to investigate the effect of red light irradiation during postharvest ripening with focus on the outer (epicarp and mesocarp) and inner (endocarp and seed) parts of tomatoes by evaluating concomitant alterations in bioactive compounds, such as lycopene, β-carotene, total phenolic and total flavonoid concentrations, external fruit color and spectral reflectance pattern, and the Simple Chlorophyll Fluorescence ratio. As promising measure, deriving from previous studies, green stage-1 tomatoes were harvested and treated daily with red light for 12 h per day, for 15 days (followed by storage in darkness for additional 6 days) or continuously radiated with red light for 21 days. Control untreated tomatoes were kept in the dark for the same period. Application of continous red light strongly accelerated changes in the outer layer of fruit, for example visible in color parameters. Significant differences between treatments were analyzed for major secondary metabolite compounds such as lycopene, β-carotene, total phenolic and total flavonoid in both outer and inner fruit layers. Continuous red light treatment led to the highest concentration of secondary metabolite compounds in all parameters. Therefore, it can be concluded that continuous red light radiation is the most effective treatment to accelerate the color development and ripening of the outer layer of the epicarp. Furthermore, it plays a role in stimulating the inner layer of the endocarp to provide beneficial secondary metabolite compounds.
A preview of this full-text is provided by Springer Nature.
Learn more
Content available from Journal of Food Measurement and Characterization
This content is subject to copyright. Terms and conditions apply.
Vol.:(0123456789)
1 3
Journal of Food Measurement and Characterization (2021) 15:1737–1746
https://doi.org/10.1007/s11694-020-00770-0
ORIGINAL PAPER
Effect ofpostharvest irradiation withred light onepidermal color
andcarotenoid concentration indifferent parts oftomatoes
LachineePanjai1,2 · SimoneRöhlen‑Schmittgen1· JanEllenberger1· GeorgNoga1· MauricioHunsche1,3·
AntjeFiebig1
Received: 14 June 2020 / Accepted: 29 November 2020 / Published online: 3 January 2021
© The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature 2021
Abstract
The aim of this study was to investigate the effect of red light irradiation during postharvest ripening with focus on the outer
(epicarp and mesocarp) and inner (endocarp and seed) parts of tomatoes by evaluating concomitant alterations in bioactive
compounds, such as lycopene, β-carotene, total phenolic and total flavonoid concentrations, external fruit color and spectral
reflectance pattern, and the Simple Chlorophyll Fluorescence ratio. As promising measure, deriving from previous studies,
green stage-1 tomatoes were harvested and treated daily with red light for 12h per day, for 15days (followed by storage in
darkness for additional 6days) or continuously radiated with red light for 21days. Control untreated tomatoes were kept in
the dark for the same period. Application of continous red light strongly accelerated changes in the outer layer of fruit, for
example visible in color parameters. Significant differences between treatments were analyzed for major secondary metabolite
compounds such as lycopene, β-carotene, total phenolic and total flavonoid in both outer and inner fruit layers. Continuous
red light treatment led to the highest concentration of secondary metabolite compounds in all parameters. Therefore, it can
be concluded that continuous red light radiation is the most effective treatment to accelerate the color development and rip-
ening of the outer layer of the epicarp. Furthermore, it plays a role in stimulating the inner layer of the endocarp to provide
beneficial secondary metabolite compounds.
Keywords Lycopene· β-carotene· Epidermis· Fluorescence· Postharvest irradiation
Introduction
As climacteric fruit, tomatoes continue to ripen even after
harvest. During ripening, the green pigment chlorophyll
breaks down and carotenoids are synthesized [1]. There-
fore, considerable work has been conducted to accelerate or
even increase levels of these compounds in tomatoes through
ripening intervention technologies during post-harvest stor-
age [2].
Several studies have shown that the concentrations of
lycopene and β-carotene in fresh tomatoes depend on diverse
factors such as cultivars [3], soil and climate conditions [4,
5] as well as degree of ripening and postharvest storage con-
ditions [6]. Modification of light intensity and/or quality is
particularly promising because of the pivotal role of light
influencing main metabolic processes in the biosynthesis of
phytochemical compounds [7]. Early studies have indicated
that carotenoid biosynthesis in tomato fruit is induced by
red light radiation applied post-harvest [8]. Alba etal. [9]
reported that red light treatments (six 40W Gro-lux lamps)
increased lycopene accumulation 2.3-fold in tomatoes.
The tomato fruit is composed of several different tissues
and cell layers, fruit skin (or peel) and flesh, which vary in
terms of transcript and metabolic profiles [10]. Mintz-Oron
etal. [11] described a comparative transcriptome and metab-
olome analysis of skin and flesh tissues during five stages
of tomato fruit development. Metabolite profiling revealed
100 metabolites that were enriched in the skin tissue during
development and 45 secondary metabolites were identified
* Lachinee Panjai
lachineep@gmail.com
1 Institute ofCrop Sciences andResource Conservation
(INRES), Horticultural Sciences, University ofBonn, Auf
dem Huegel 6, 53121Bonn, Germany
2 Department ofAgro-industry, Rajamangala University
ofTechnology Lanna Lampang, Lampang, Thailand
3 COMPO EXPERT GmbH, Research andDevelopment,
Kroegerweg 10, 48155Muenster, Germany
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... In avocado fruit, red LED enhanced epicatechin content by upregulation of PAL genes [77]. In tomatoes, red LED treatment improved lycopene and b-carotene content, total phenols and flavonoids during storage after harvest [78]. Moreover, blue LED treatment increased lycopene levels, chlorogenic acid, caffeic acid and rutin content after 7 days of storage [78]). ...
... In tomatoes, red LED treatment improved lycopene and b-carotene content, total phenols and flavonoids during storage after harvest [78]. Moreover, blue LED treatment increased lycopene levels, chlorogenic acid, caffeic acid and rutin content after 7 days of storage [78]). In addition, red or blue LEDs improved the content of antioxidant compounds in fresh tomatoes. ...
... Avocado fruit epicatechin red [77] Tomatoes lycopene, b-carotene, total phenol, flavonoid storage after harvest red [78] Tomatoes lycopene levels, chlorogenic acid, caffeic acid and rutin content after 7 days of storage blue [78] Coriandrum sativum leaves during postharvest storage total phenolic content mass loss reduction in color change increased antioxidant activities quercetin 2-tridecenal, 2-dodecenal, Z-9-19 hexadecenal (volatile compounds) reduced the loss of total chlorophyll constant b-carotene blue blue and red blue (2 h) blue and red red [79] Outer and inner leaves lower Brussels sprouts postharvest conservation respiration keeping the green color + visual quality, antioxidants in outer leaves, antioxidant capacity in outer leaves total flavonoids higher in outer than inner leaves on day 10 of storage white-blue (WB) [80] ...
LED Technology Applied to Plant Development for Promoting the Accumulation of Bioactive Compounds: A Review
Article
Full-text available
  • Feb 2023
Light is an important environmental factor for plants. The quality of light and the wavelength stimulate enzyme activation, regulate enzyme synthesis pathways and promote bioactive compound accumulation. In this respect, the utilization of LED light under controlled conditions in agriculture and horticulture could be the most suitable choice for increasing the nutritional values of various crops. In recent decades, LED lighting has been increasingly used in horticulture and agriculture for commercial-scale breeding of many species of economic interest. Most studies on the influence of LED lighting on the accumulation of bioactive compounds in any type of plants (horticultural, agricultural species or sprouts) and also biomass production, were carried out in growth chambers under controlled conditions, without natural light. Illumination with LED could be a solution for obtaining an important crop with maximum efficiency, with a high nutritional value and minimum effort. To demonstrate the importance of LED lighting in agriculture and horticulture, we carried out a review based on a large number of results cited in the literature. The results were collected from 95 articles and were obtained using the keyword LED combined with plant growth; flavonoids; phenols; carotenoids; terpenes; glucosinolates; food preservation. We found the subject regarding the LED effect on plant growth and development in 11 of the articles analyzed. The treatment of LED on phenol content was registered in 19 articles, while information regarding flavonoid concentrations was revealed by 11 articles. Two articles we reviewed debate the accumulation of glucosinolates and four articles analyzed the synthesis of terpenes under LED illumination and 14 papers analyzed the variation in content of carotenoids. The effect of LED on food preservation was reported in 18 of the works analyzed. Some of the 95 papers contained references which included more keywords.
View
... In fruits, light exposure has been shown to induce significant compositional changes [2,[4][5][6]. For example, UV-B irradiation promotes anthocyanin biosynthesis in apple skins, while red light enhances red color development and increases carotenoid concentrations in post-harvest tomatoes [7,8]. In sweet potato leaves, UV radiation is known to induce peroxidase activity, thereby activating defense mechanisms against oxidative stress [9]. ...
Impacts of Light Exposure and Soil Covering on Sweet Potato Storage Roots in a Novel Soilless Culture System
Article
Full-text available
  • Oct 2024
Soilless culture systems, which promote plant growth and enable the precise control of the root-zone environment, have yet to be fully established for sweet potatoes. In this study, we developed a soilless culture system and examined the effects of soil covering and light exposure on the storage roots of sweet potatoes. Sweet potato seedlings with induced storage roots were transplanted into five systems: a previously developed pot-based hydroponics system (Pot), an improved version with storage roots enclosed in a plastic box and covered with a soil sheet (SS), the SS system without the soil sheet (SD), the SD system with light exposure to storage roots after 54 days (SL), and a deep flow technique (DFT) hydroponics system. Our study enabled the time-course observation of storage root enlargement in the SS, SD, and SL systems. In the SL system, light exposure suppressed the storage root enlargement and reduced epidermal redness. No storage root enlargement was observed in the DFT system, even at 151 days after transplantation. Light exposure in the SL system increased the chlorophyll and total phenolic contents in the cortex beneath the epidermis, while the starch content was the lowest in this system. These findings indicate that the developed system can induce normal storage root enlargement without soil. Additionally, the observed changes in growth and composition due to light exposure suggest that this system is effective for controlling the root-zone environment of sweet potatoes.
View
... Nevertheless, there is no information in the literature about the degradation of pigments during the natural fermentation of green table olives under the effect of the red LED light. However, several authors have reported the effect of light on the accumulation of carotenoids and flavonoids [31,32] and the acceleration of chlorophyll degradation in unripe fruit [33]. Thus, these phenomena need to be studied in more detail in the future. ...
View
... In both the outer and inner parts of tomatoes, the color development of lycopene, β-carotene, total phenolic, and total flavonoid concentration was enhanced by red light (Panjai et al., 2021) Tomatoes (Solanum lycopersicum L. ...
Light emitting diode (LED) lights for the improvement of plant performance and production: A comprehensive review
Article
Full-text available
  • Feb 2024
Light quality (spectral arrangement) and quantity (photoperiod and intensity) influence plant growth and metabolism and also interact with several factors including environmental parameters in defining the plant behavior. The Light Emitting Diode (LED) lights are extensively utilized in the cultivation of several plant species , especially horticultural plants due to their lower power consumption and higher luminous efficiency compared to the conventional fluorescent lights. The aim of this review paper is to examine the potential of LED technology as it relates to plant lighting in greenhouses and other horticultural environments. It also desires to give an in-depth study of the advantages of LED lighting on plant development, yield, the production of secondary metabolites, and defense mechanisms. Horticultural lighting might undergo a revolution because LEDs are used in solid-state lighting, which would be a tremendous advancement after decades of research. LEDs may be used in a variety of horticulture lighting applications, such as tissue culture lighting, controlled environment research lighting, supplementary lighting, and photoperiod lighting for greenhouses. The primary impacts of light colors on plant performance are shown by the spectrum effects of LEDs as an independent source of light, together with the diverse sensitivity of many plant species and alternatives. LED light influences performance of enzyme, gene expression, cell wall formation, plant defense and postharvest quality. The spectrum reactions are mediated by the ambient lighting in a greenhouse, which also indicates a strong relationship between the additional supplementary lighting and changing environmental factors. LEDs are growing further to become cost-effective for even large-scale horticulture lighting applications as light output increases and device expenditures decrease.
View
... As mentioned above, due to their peculiar, distinctive properties, LEDs have gained popularity in the postharvest handling of horticultural crops. Even though the effect of various wavelengths, irradiation intensity, and exposure time of these LEDs on fresh fruit and vegetables has proved to be beneficial in enhancing color, bioactive compounds, antioxidants, shelf life, and overall quality [7,11,[18][19][20][21], the mechanism(s) involved in LED irradiation technology is (are) still not clear. It is, however, known that the photosynthesis period of postharvest horticultural produce may be extended by illumination with LEDs. ...
An Overview of the Recent Developments in the Postharvest Application of Light-Emitting Diodes (LEDs) in Horticulture
Chapter
Full-text available
  • Mar 2023
The majority of losses in horticultural produce occur during postharvest storage, particularly due to poor handling. Most fruit, especially climacteric fruit, have a short postharvest life due to an increase in ethylene synthesis which signals ripening and, subsequently, senescence. Traditional practices for preserving the postharvest quality of horticultural crops are chemical-based, a practice which has lately received enormous criticism. Recently, the use of postharvest illumination with LEDs as a nonchemical and environmentally friendly technique to preserve fruit and vegetables has been reported by various authors. Unique properties of LEDs such as low radiant heat, monochromatic nature and low cost have made this lighting gain popularity in the food industry. This paper, therefore, reviews the recent development in the postharvest applications of LEDs in horticultural crops, while focusing particularly on physical characteristics, nutritional value, and overall quality alterations of fruit and vegetables. According to the recently published research, red and blue LED lights are most valuable in terms of usage, while other wavelengths such as purple and yellow are slowly gaining attention. Furthermore, LEDs have been shown to affect fruit ripening and senescence, enhance bioactive compounds and antioxidants in produce, and prevent disease occurrence; however, there are some limitations associated with the use of this novel technology.
View
... The increase in vitamin C meditated by ABA has been proven to also occur in other fruit, such as blueberries or strawberries [19,25]. Other metabolites with a great antioxidant capacity in fruit are carotenoids [18,41,42]. The mechanism controlling the carotenoid metabolism during postharvest is complex; however, it has been proven that ABA also affects its synthesis and accumulation in tomato fruit [43]. ...
Postharvest Treatment with Abscisic Acid Alleviates Chilling Injury in Zucchini Fruit by Regulating Phenolic Metabolism and Non-Enzymatic Antioxidant System
Article
Full-text available
  • Jan 2023
Reports show that phytohormone abscisic acid (ABA) is involved in reducing zucchini postharvest chilling injury. During the storage of harvested fruit at low temperatures, chilling injury symptoms were associated with cell damage through the production of reactive oxygen species. In this work, we have studied the importance of different non-enzymatic antioxidants on tolerance to cold stress in zucchini fruit treated with ABA. The application of ABA increases the antioxidant capacity of zucchini fruit during storage through the accumulation of ascorbate, carotenoids and polyphenolic compounds. The quantification of specific phenols was performed by UPLC/MS-MS, observing that exogenous ABA mainly activated the production of flavonoids. The rise in all these non-enzymatic antioxidants due to ABA correlates with a reduction in oxidative stress in treated fruit during cold stress. The results showed that the ABA mainly induces antioxidant metabolism during the first day of exposure to low temperatures, and this response is key to avoiding the occurrence of chilling injury. This work suggests an important protective role of non-enzymatic antioxidants and polyphenolic metabolism in the prevention of chilling injury in zucchini fruit.
View
... At present, part of the mechanism of red light-regulated carotenoids biosynthesis has been reported in tomato fruit (Li et al., 2020b;Zhang et al., 2020;Panjai et al., 2021). This study found that the hue angle value (Supporting Information, Figure 1) and chlorophyll level gradually decreased with fruit ripening, while the carotenoid content gradually increased. ...
Integrated transcriptomics and metabolomics analyses reveal the molecular mechanisms of red-light on carotenoids biosynthesis in tomato fruit
Article
Full-text available
  • Feb 2022
Carotenoids are the main pigments responsible for the coloration and account for the major antioxidant activity of tomato (Solanum lycopersicum L.) fruit. Significant increments in total carotenoids and lycopene levels were observed in tomato fruit illuminated by red light relative to white light in previous studies, but the mechanism of carotenoid biosynthesis regulated by red light is still unclear. In the present study, the influence of red light on carotenoid biosynthesis in postharvest tomato fruit was conducted using targeted metabolomics and transcriptomic methods. A total of 25 differentially accumulated carotenoids and 1939 differentially expressed genes were isolated and identified. The results illustrated that the contents of phytoene and lycopene were considerably higher in fruit treated with red light than those with white light at 12 h. These differentially expressed genes are mainly enriched in plant hormone signal transduction, photosynthesis, secondary metabolite biosynthesis, and plant circadian rhythm. Moreover, from the results of coexpression network analysis, 15 transcription factors from red light-treated fruit were screened; among these, transcription factors of SlERF4, SlbHLH93 and SlIAA29, which are involved in signal transduction of light and hormones, respectively, may also play important roles in carotenoid biosynthesis regulated by red light in tomato fruit. It is concluded that red light enhanced carotenoid biosynthesis in postharvest tomato fruit and the mechanisms of enhanced carotenoid biosynthesis were not only associated with the direct regulation by red light signalling, but also with the indirect regulation by hormonal signalling.
View
View
Role of LED (Light Emitting Diode) Light Illumination on the Growth of Plants in Greenhouse Farming-Hydroponics: IOT Technology
Article
Full-text available
  • Nov 2024
This review paper of literature highlights role of Light Emitting Diode (LED) on the growth of plants under controlled conditions of greenhouse farming particularly hydroponics. "Internet of Things (IOT)" is a system of interconnected computing devices, sensors, objects, microcontrollers, and cloud servers that can transmit data across a network and control other devices remotely without human intervention. Light Emitting Diode (LED) is a more efficient, versatile, lasts longer, highly energy-efficient, directional, narrow light spectrum, low power consumption, and little heat production. Common LED colors include amber, red, green, and blue. Hydroponic grow lights are designed to mimic the natural light that plants need for photosynthesis. Plants can only use the spectrum of visible light to produce photosynthesis, and this narrow spectrum (400 to 700 nanometer) is recognized as the Photosynthetically Active Radiation (PAR). The development and growth of diverse plant species can be influenced differently by a variety of colored LED lights. LED illumination provides an efficient way to improve yield and modify plant properties. Therefore, LED systems plays an important role in controlling morphological, genetic, physiological, chemical properties, increasing the synthesis of a variety of beneficial secondary metabolites, and optobiological interactions of plants in greenhouse farming. In general, red and blue light is essential for maximizing the photosynthesis process due to their strong absorption by the plant chlorophyll molecules. LED illumination sources are increasingly being utilized to enhance the growth rate of vegetables and herbs cultivated in greenhouses worldwide. LED illumination spectrum manipulation could enable significant morphological adaptations, and identification of the wavelength ranges is required to increase the plant photosynthesis process.
View
Application of Red and Blue LED Light on Cultivation and Postharvest of Tomatoes (Solanum lycopersicum L.)
Article
Full-text available
  • Sep 2024
Currently, light-emitting diode (LED) technology has produced a more energy-efficient and versatile technology as an artificial lighting system that can be applied in the agricultural sector. Artificial lighting technology has been proven to be effective in increasing the production of agricultural products, especially horticultural commodities. As one of the primary horticulture commodities, tomatoes are the most common crop produced in controlled environments with LED artificial lighting. The focus of this study is to describe the application of LED lights in tomato cultivation and postharvest. We provide an amalgamation of the recent research achievements on the impact of LED lighting on photosynthesis, vegetative growth, flowering, production, and postharvest of tomatoes. Red-blue (RB) lighting induces photosynthesis; increases the content of chlorophyll a, chlorophyll b, and carotenoids in tomato leaves; regulates vegetative growth in tomatoes; and increases the production of tomatoes. In postharvest tomatoes, blue LED lighting treatment can slowly change the color of the tomato skin to red, maintain hardness, and increase shelf life. Future research may be carried out on the effect of LED artificial lighting on tomatoes’ phytochemical, antioxidant and other crucial nutritional content. Different LED wavelengths can be explored to enhance various bioactive compounds and health-promoting components.
View
Potential of hyperspectral imaging to detect and identify the impact of chemical warfare compounds on plant tissue
Article
Full-text available
  • Jun 2018
The OPCW Member states cover 98% of the global population and landmass. Regrettably, unanticipated chemical warfare agent assaults are reported during the last decades. In addition to the frequent threat situation, the sampling of bio-medical samples from these areas is critical and mainly depends on investigation opportunities of victims. Non-contact sensor technologies are desirable to enable a fast and secure estimation of a situation. Plants react on pollution because of their direct interaction with gases and it is assumed that chemical warfare agents influence plants, respectively. This impact can be analyzed for the detection and characterization of chemical warfare assaults. Nowadays technological progress in digital technologies provides new innovations in detectors, data analysis approaches and software availability which could improve the screening, monitoring and analysis of chemical warfare. Within this context hyperspectral imaging (HSI) is a promising method. Different applications from remote to close range sensing in medicine, food production, military, geography and agriculture do exist already. During the last years HSI showed high potential to determine and assess different plant parameters, e.g. abiotic and biotic stresses by recording the spectral reflectance of plants. Within the present manuscript, the basics principle of HSI as an innovative technique, aspects of recording and analyzing HSI data is presented using wild growing apple leaves which are treated with sulfuric acid, fire or heat. Resulting spectral signatures showed significant changes among the treatments. Especially the shortwave infrared was sensitive to changes due to the different treatments. Furthermore, the calculation of common spectral indices revealed differences due to the treatments which are not visible to the human eye. The results support HSI applications for the detection of chemical warfare agents and elucidate the impact of chemical warfare on plants.
View
Optimal red light irradiation time to increase health-promoting compounds in tomato fruit postharvest
Article
  • Mar 2019
  • SCI HORTIC-AMSTERDAM
The impact of postharvest red light irradiation via LED modules on the content of health promoting compounds was evaluated on green tomatoes stage 1 exposed to intermittent or continuous irradiation. The first experiment studied the overall effects of different duration periods of red light radiation (darkness, continuous red light for 10 d, continuous red light for 15 d and continuous red light for 20 d) while the second experiment focused on effects of intermittent red light (darkness, red light for 30 min per day, red light for 6 h per day, red light for 12 h per day and continuous red light). In both experiments, tomatoes exposed to darkness served as control. Continuous red light irradiation accelerated ripening of green tomatoes. In addition, continuous red light also significantly increased lycopene, β-carotene, total phenolic content, total flavonoid concentration and antioxidant activity compared to all other treatments, suggesting that continuous red light exposure positively influences metabolic processes and contributes to a higher content of health promoting compounds in tomatoes.
View
Suitability of fluorescence indices for the estimation of fruit maturity compounds in tomato fruits
Article
  • May 2018
Background We examined the suitability of chlorophyll fluorescence‐based indices to monitor and predict concentrations of fruit maturity compounds during tomato ripening under different growing conditions in the greenhouse. The aim of this study was to evaluate the effects of chlorophyll concentration changes on fluorescence‐based indices and to exploit the relation between fluorescence and reflectance indices with the corresponding maturity compounds determined analytically. Results Fruits grown under water deficit matured faster than control fruits as recorded with fluorescence‐based indices. The SFR_R index correlated well with the analytical determination of chlorophyll content, whereas the single signal FRF_G correlated with lycopene content even if the sensor was unable to differentiate precisely between maturity stages two to four. Neither the FLAV index nor the FLAV_UV index was suitable for flavonoid prediction in tomato fruits. Compared to fluorescence indices, the relation between the reflection index and pigment concentrations was lower for chlorophyll and higher for lycopene. Conclusion Chlorophyll and lycopene content in tomato fruits can be estimated by means of fluorescence indices during the pre‐harvest phase. Since the chlorophyll decrease during tomato ripening is the driving force affecting all fluorescence signals, the methods are not reliable for estimation of other maturity compounds in tomato fruits.
View
Effects of continuous red light and short daily UV exposure during postharvest on carotenoid concentration and antioxidant capacity in stored tomatoes
Article
  • Dec 2017
  • SCI HORTIC-AMSTERDAM
Due to their health benefits, high concentrations of antioxidative compounds in vegetables and fruit are important for end-consumers. The aim of this research was to investigate the effects of continuous red light and short periods of daily ultraviolet (UV) radiation on the postharvest quality of green tomatoes. Green tomatoes were exposed for 30 min to UV radiation, continuous red light or a combination of both for up to 20 d. Non-treated (control) fruit ripened within 15 d while fruit exposed to red light and a combination of red light with UV radiation required five days less to reach the same maturity level. In addition, the exposure to red light alone or in combination with UV raised concentrations of lycopene, ß-carotene, total flavonoids and phenolics. This possibility to steer the concentrations of health-promoting antioxidants through light treatments is a safe method to increase fruit quality according to customer wishes and demands.
View
Data Analysis
Chapter
  • Jun 2016
So far, every example in this book has started with a nice dataset that’s easy to plot. That’s great for learning (because you don’t want to struggle with data handling while you’re learning visualisation), but in real life, datasets hardly ever come in exactly the right structure. To use ggplot2 in practice, you’ll need to learn some data wrangling skills. Indeed, in my experience, visualisation is often the easiest part of the data analysis process: once you have the right data, in the right format, aggregated in the right way, the right visualisation is often obvious.
View
View
Total phenolic, flavonoid and antioxidant activity of 23 edible flowers subjected to in vitro digestion
Article
  • Aug 2015
In order to provide new information on the antioxidant activities before and after in vitro digestion of the selected flowers for consumers, nutritionists, and food policy makers, total phenolic and flavonoid contents and antioxidant capacities of 23 edible flowers were evaluated. In addition, some bioactive components in the flowers were also identified and quantified by ultra performance liquid chromatography (UPLC). The correlations between 2, 2-diphenyl-1-picrylhydrazylradical scavenging activity assay (DPPH), Ferric reducing antioxidant power assay (FRAP), and ABTS•+ radical cation scavenging activity assay (ABTS) values and total flavonoid contents and total phenolic contents were also evaluated. Three flowers, Osmanthus fragrans (Thunb.) Lour, Paeonia lactiflora Pall, and Rosa rugosa Thunb (purple) showed the strongest antioxidant activities before or after the digestion, which implied that these flowers are important natural sources for the prevention of oxidative stress diseases.
View
View
Fruit-Localized Phytochromes Regulate Lycopene Accumulation Independently of Ethylene Production in Tomato
Article
  • May 2000
We show that phytochromes modulate differentially various facets of light-induced ripening of tomato fruit (Solanum lycopersicum L.). Northern analysis demonstrated that phytochrome A mRNA in fruit accumulates 11.4-fold during ripening. Spectroradiometric measurement of pericarp tissues revealed that the red to far-red ratio increases 4-fold in pericarp tissues during ripening from the immature-green to the red-ripe stage. Brief red-light treatment of harvested mature-green fruit stimulated lycopene accumulation 2.3-fold during fruit development. This red-light-induced lycopene accumulation was reversed by subsequent treatment with far-red light, establishing that light-induced accumulation of lycopene in tomato is regulated by fruit-localized phytochromes. Red-light and red-light/far-red-light treatments during ripening did not influence ethylene production, indicating that the biosynthesis of this ripening hormone in these tissues is not regulated by fruit-localized phytochromes. Compression analysis of fruit treated with red light or red/far-red light indicated that phytochromes do not regulate the rate or extent of pericarp softening during ripening. Moreover, treatments with red or red/far-red light did not alter the concentrations of citrate, malate, fructose, glucose, or sucrose in fruit. These results are consistent with two conclusions: (a) fruit-localized phytochromes regulate light-induced lycopene accumulation independently of ethylene biosynthesis; and (b) fruit-localized phytochromes are not global regulators of ripening, but instead regulate one or more specific components of this developmental process.
View
View