Articles
Enhancement of accumulation of bioactive compounds in red leaf lettuce by manipulation of UV light before harvest
Article number
1271_11
Pages
79 – 84
Language
English
Abstract
In a plant factory with artificial light, accumulation of bioactive compounds can be enhanced via precise environmental control.
Light is essential for growth and development, and for the production of bioactive compounds in plants.
Ultraviolet (UV) light stimulates bioactive compound biosynthesis in plants including antioxidants.
We developed a new and economical UV-rich fluorescent lamp (UV-FL), with the ability to adjust the ratio of UV-A and UV-B. The objective of this study was to determine the effect of UV light on the accumulation of bioactive compounds in red leaf lettuce.
Red leaf lettuce plants were grown in a plant factory with normal growing conditions under white light as light source (23/20°C, 70% RH, 16 h light period, PPFD 150 μmol m‑2 s‑1, 1,000 ppm CO2) for 23 days.
The plants were subjected to UV light under white light (low, middle, and high; 0.3, 0.6, and 0.9 W m‑2) for 3 days before harvest.
Fresh and dry weights of shoot, leaf area, total chlorophyll, total phenolic concentration, and ORAC for antioxidant activity were measured before and after the UV treatments.
Middle and high UV treatments resulted in negative effects on the growth characteristics such as shoot fresh and dry weight, and leaf area.
However, low UV treatment was not significantly different from the control for shoot dry weight.
Total chlorophyll was higher in low and middle UV treatments than the high UV treatment and the control.
In contrast, total phenolic concentration and ORAC value of lettuce plants grown under UV treatments were significantly higher than that of the control.
This study suggests that short-term UV irradiation using economical UV-FL lamp before harvest was effective in improving the vegetable quality.
Light is essential for growth and development, and for the production of bioactive compounds in plants.
Ultraviolet (UV) light stimulates bioactive compound biosynthesis in plants including antioxidants.
We developed a new and economical UV-rich fluorescent lamp (UV-FL), with the ability to adjust the ratio of UV-A and UV-B. The objective of this study was to determine the effect of UV light on the accumulation of bioactive compounds in red leaf lettuce.
Red leaf lettuce plants were grown in a plant factory with normal growing conditions under white light as light source (23/20°C, 70% RH, 16 h light period, PPFD 150 μmol m‑2 s‑1, 1,000 ppm CO2) for 23 days.
The plants were subjected to UV light under white light (low, middle, and high; 0.3, 0.6, and 0.9 W m‑2) for 3 days before harvest.
Fresh and dry weights of shoot, leaf area, total chlorophyll, total phenolic concentration, and ORAC for antioxidant activity were measured before and after the UV treatments.
Middle and high UV treatments resulted in negative effects on the growth characteristics such as shoot fresh and dry weight, and leaf area.
However, low UV treatment was not significantly different from the control for shoot dry weight.
Total chlorophyll was higher in low and middle UV treatments than the high UV treatment and the control.
In contrast, total phenolic concentration and ORAC value of lettuce plants grown under UV treatments were significantly higher than that of the control.
This study suggests that short-term UV irradiation using economical UV-FL lamp before harvest was effective in improving the vegetable quality.
Authors
K.-H. Son, S. Furuyama, K. Hayashi, Y. Ishigami, S. Hikosaka, E. Goto
Keywords
abiotic stress, antioxidant capacity, phenolics, plant factory, phytochemical
Groups involved
- Division Greenhouse and Indoor Production Horticulture
- Division Precision Horticulture and Engineering
- Division Plant-Environment Interactions in Field Systems
- Working Group Nettings in Horticulture (subgroup of Protected Cultivation in Mild Winter Climates)
- Working Group Light in Horticulture
- Working Group Organic Greenhouse Horticulture
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- Working Group Vegetable Grafting
- Working Group Computational Fluid Dynamics in Agriculture
- Working Group Design and Automation in Integrated Indoor Production Systems
- Working Group Mechanization, Digitization, Sensing and Robotics
- Working Group Greenhouse Environment and Climate Control
- Commission Agroecology and Organic Farming Systems
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