Increase in biomass and bioactive compounds in lettuce under various ratios of red to far-red LED light supplemented with blue LED light

2016 ◽  
Vol 57 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Myung-Jin Lee ◽  
Ki-Ho Son ◽  
Myung-Min Oh
2020 ◽  
Vol 49 (12) ◽  
pp. 2891-2900
Author(s):  
H.S. Chua ◽  
Siew Wei Lai ◽  
Sivajothi Paramasivam ◽  
T.T. Goh ◽  
Gee Chia Chen

Supplemental LEDs lighting technology has been used as the promising lighting source in hydroponic cultures for sustainable production in urban agriculture. It could be the solution to address the growing concern about food safety, environmental impacts, bad weather, and efficient energy usage in agricultural production. In this study, the response of loose head lettuce toward the irradiance of the supplemental red-blue LED light with different power (Watt [W]) was investigated by comparing the treated lettuce with the lettuce cultured under only natural light. The lettuce plants were treated with red LED (640-660 nm) + blue LED (440-450 nm). The power output of the LEDs was specified to 3, 6, 9, 15, and 20 W. The lettuce plants were hydroponically cultured with 8 h red-blue LEDs light exposure (from 12 to 8 am) and 16 h without the red-blue LEDs light exposure (from 8 pm to 12 am) at average air temperatures of 31/28 ºC (day/night) for 50 days (7 weeks). On the harvesting day, the average shoot heights of the lettuce that was treated with 3, 6, 9, 15, 20 LEDs and natural light were 25.00, 24.75, 20.75, 19.88, 17.63, and 12.63 cm, respectively. The lettuce that was exposed to the 3 W LEDs had the highest shoot height compared to those that were exposed to LEDs with other power outputs. The average fresh weights of the lettuce that was treated with 3, 6, 9, 15, 20 W LEDs and natural light were 27.25, 24.75, 21.25, 19.88, 18.38, and 15.75 g, respectively. The results showed that the fresh weight of the lettuce that was irradiated with 3 W LED light was significantly higher compared to the lettuce that was exposed to LEDs with other power outputs. Hence, it can be concluded that supplementary LEDs lighting technology can be used as an alternative lighting source to improve the growth of lettuce in hydroponic systems. Moreover, the use of 3 W LEDs in hydroponic systems could yield a higher shoot weight and fresh weight.


Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 359 ◽  
Author(s):  
Gludia M. Maroga ◽  
Puffy Soundy ◽  
Dharini Sivakumar

The influence of emitting diode (LED) treatments for 8 h per day on functional quality of three types of fresh-cut sweet peppers (yellow, red, and green) were investigated after 3, 7, 11, and 14 days postharvest storage on the market shelf at 7 °C. Red LED light (660 nm, 150 μmol m−2 s−1) reduced weight loss to commercially acceptable level levels (≤2.0%) in fresh-cuts of yellow and green sweet peppers at 7 and 11 d, respectively. Blue LED light (450 nm, 100 μmol m−2 s−1) maintained weight loss acceptable for marketing in red fresh-cut sweet peppers up to 11 d. Highest marketability with minimum changes in color difference (∆E) and functional compounds (total phenols, ascorbic acid content, and antioxidant activity) were obtained in yellow and green sweet pepper fresh-cuts exposed to red LED light up to 7 and 11 d, respectively, and for red sweet pepper fresh-cuts exposed to blue LED light for 11 d. Red LED light maintained the highest concentrations of β carotene, chlorophyll, and lycopene in yellow, green, and red sweet pepper fresh-cuts up to 7 d. Similarly, blue LED light showed the highest increase in lycopene concentrations for red sweet pepper fresh-cuts up to 7 d. Red LED (yellow and green sweet peppers) and blue LED (red sweet pepper) lights maintained phenolic compounds by increasing phenylalanine ammonia lyase activity. Thus, the results indicate a new approach to improve functional compounds of different types of fresh-cut sweet pepper.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yi-Yen Li ◽  
Feng-Jie Su ◽  
Yi-Jui Hsieh ◽  
Tai-Chun Huang ◽  
Yung-Song Wang

This study aims to evaluate the effect of light-emitting diodes (LEDs) of different wavelengths on the embryonic development, covering behavior, righting behavior, and phototaxis of collector urchins (Tripneustes gratilla). The collector urchins were divided into three groups according to the type of LED illumination they received: full-spectrum (400–750 nm wavelength), red light (630 nm), or blue light (450 nm). The results of the embryonic development experiment indicated that the blue LED group had the highest proportion of embryos reaching the prism stage at the 24th hour and the highest proportion of embryos entering the 4-arm pluteus stage, but it also had the highest death rate at the 48th hour. The full-spectrum and red LED groups exhibited similar speeds of embryonic development. In the experiment on covering behavior performed on adult urchins, our findings indicated that the blue LED group gripped the most acrylic sheets for cover, exhibiting the most covering behavior, followed by the full-spectrum group and then the red LED group. Moreover, behavior varied with coloration, as collector urchins with a lower level of melanin exhibited more covering behavior than those with a higher melanin level. In addition, the righting behavior experiments demonstrated that the blue LED group spent the longest time righting themselves. It is possible that the relatively strong stimulation from the blue LED illumination led to a higher level of stress in the collector urchins and hence slowed their righting. The phototaxis experiment revealed the most significant negative phototactic response in collector urchins when they were under the blue LED light, followed by the full-spectrum light; the red LED light did not induce any positive or negative phototactic response in the collector urchins. This experimental result verified collector urchins’ high sensitivity to and dislike of the blue LED light. The study results confirmed that the blue LED light environment accelerated the embryonic development of collector urchins; however, the relatively strong stimulation from that light also caused them to engage in covering behavior or move away from the light. These results indicate that short-wavelength irradiation significantly affects the embryonic development and behavior pattern of this species.


Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 77
Author(s):  
Chang Ha Park ◽  
Ye Eun Park ◽  
Hyeon Ji Yeo ◽  
Jae Kwang Kim ◽  
Sang Un Park

Recent improvements in light-emitting diode (LED) technology afford an excellent opportunity to investigate the relationship between different light sources and plant metabolites. Accordingly, the goal of the present study was to determine the effect of different LED (white, blue, and red) treatments on the contents of glucosinolates (glucoiberin, gluconapin, sinigrin, gluconasturtiin, 4-methoxyglucobrassicin, 4-hydroxyglucobrassicin, glucobrassicin, and neoglucobrassicin) and phenolic compounds (4-hydroxybenzonate, catechin, chlorogenic acid, caffeate, gallate, sinapate, and quercetin) in Brassica juncea sprouts. The sprouts were grown in a growth chamber at 25 °C under irradiation with white, blue, or red LED with a flux rate of 90 μmol·m−2·s−1 and a long-day photoperiod (16 h light/8 h dark cycle). Marked differences in desulfoglucosinolate contents were observed in response to treatment with different LEDs and different treatment durations. In addition, the highest total desulfoglucosinolate content was observed in response to white LED light treatment, followed by treatment with red LED light, and then blue LED light. Among the individual desulfoglucosinolates identified in the sprouts, sinigrin exhibited the highest content, which was observed after three weeks of white LED light treatment. The highest total phenolic contents were recorded after one week of white and blue LED light treatment, whereas blue LED irradiation increased the production of most of the phenolic compounds identified, including 4-hydroxybenzonate, gallate, sinapate, caffeate, quercetin, and chlorogenic acid. The production of phenolics decreased gradually with increasing duration of LED light treatment, whereas anthocyanin accumulation showed a progressive increase during the treatment. These findings indicate that white LED light is appropriate for glucosinolate accumulation, whereas blue LED light is effective in increasing the production of phenolic compounds in B. juncea sprouts.


2018 ◽  
pp. 73-79
Author(s):  
A.L. Kosakovskyi ◽  
◽  
S.O. Gulyar ◽  
I.A. Kosakivska ◽  
N.P. Grushetska ◽  
...  

2020 ◽  
Vol 11 (47) ◽  
pp. 7497-7505
Author(s):  
Jiannan Cheng ◽  
Kai Tu ◽  
Enjie He ◽  
Jinying Wang ◽  
Lifen Zhang ◽  
...  

A novel strategy for preparing block copolymers with semifluorinated alternating copolymers as macroinitiators was established by photocontrolled iodine-mediated RDRP under irradiation with blue LED light at room temperature.


Metabolites ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 472
Author(s):  
Yeong-Ji Oh ◽  
Ye-Rin Park ◽  
Jungil Hong ◽  
Do-Yup Lee

The light-emitting diode (LED) has been widely used in the food industry, and its application has been focused on microbial sterilization, specifically using blue-LED. The investigation has been recently extended to characterize the biotic and abiotic (photodynamic) effects of different wavelengths. Here, we investigated LED effects on kimchi fermentation. Kimchi broths were treated with three different colored-LEDs (red, green, and blue) or kept in the dark as a control. Multiomics was applied to evaluate the microbial taxonomic composition using 16S rRNA gene amplicon sequencing, and the metabolomic profiles were determined using liquid chromatography–Orbitrap mass spectrometry. Cell viability was tested to determine the potential cytotoxicity of the LED-treated kimchi broths. First, the amplicon sequencing data showed substantial changes in taxonomic composition at the family and genus levels according to incubation (initial condition vs. all other groups). The differences among the treated groups (red-LED (RLED), green-LED (GLED), blue-LED (BLED), and dark condition) were marginal. The relative abundance of Weissella was decreased in all treated groups compared to that of the initial condition, which coincided with the decreased composition of Lactobacillus. Compositional changes were relatively high in the GLED group. Subsequent metabolomic analysis indicated a unique metabolic phenotype instigated by different LED treatments, which led to the identification of the LED treatment-specific and common compounds (e.g., luteolin, 6-methylquinoline, 2-hydroxycinnamic acid, and 9-HODE). These results indicate that different LED wavelengths induce characteristic alterations in the microbial composition and metabolomic content, which may have applications in food processing and storage with the aim of improving nutritional quality and the safety of food.


Author(s):  
Chiaki Tsutsumi-Arai ◽  
Yuki Arai ◽  
Chika Terada-Ito ◽  
Takahiro Imamura ◽  
Seiko Tatehara ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Sarayut Pittarate ◽  
Malee Thungrabeab ◽  
Supamit Mekchay ◽  
Patcharin Krutmuang

Ctenocephalides felis is an ectoparasitic flea species commonly found on dogs and cats. The current study verified the in vitro virulence of conidia of the entomopathogenic fungus Beauveria bassiana produced under different color LED light (red, blue, purple, green, yellow, and white) to adults of C. felis. The fungal isolates were cultivated on malt extract agar (MEA). Bioassay treatments used aerial conidia in test tubes. Adult fleas were obtained from a house cat in Chiang Mai province, Thailand. The experiments were composed of one control and eleven treatment groups. All of the treatments with B. bassiana conidia caused adult mortality after an exposure of 12 h. Among the conditions used in this study, B. bassiana cultured under red LED and fluorescent light were the most effective in causing mortality (100 %) in adult fleas after 36 h. The experimental results indicate that these aerial conidia of B. bassiana have promising potential for use in control of C. felis adult stages.


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