• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.51-59
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• 2008

Lettuce, a typical light-induced seed germination type, exhibits different germination responses according to cultivars, light quality, and plant growth regulator (PGR) treatments. Germination rates in most tested cultivars were over 85% under both white and red light, and were slightly decreased by blue light. Although photo-inhibition in germination was observed from most cultivars by far-red light, 'Cheongguangcheongchima', 'Okdol', and 'Manchudaecheongchima' could be classified as photo-insensitive lettuce cultivars by exhibiting the germination rates as 78,63, and 48% under for-red light, respectively. 6-Benzylamino purine (BAP) and kinetin promoted seed germination and normal seedling production under far-red light, but ethephon did not show any positive effects. Cytokinins such as BAP, kinetin, thidiazuron (TDZ), and zeatin overcame photo-inhibition of seed germination even the concentration of below $50\;mg{\cdot}L^{-1}$. However, auxins such as IBA, 2,4-D, and NAA failed to overcome the far-red light-induced photo-inhibition.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.351-359
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• 2010

To establish the optimum artificial light illumination method for baby leaf lettuce in closed plant factory system, the effects of red/blue light quality and short-term light quality conversion on growth and anthocyanin content were investigated. The growth of 'Hongha' lettuce was most favorable under red single wavelength LED light after 23 days of treatment, sequentially followed by the growth under red/blue mixed light, blue light, and fluorescent light. Total anthocyanin content in the mixed red/blue light (R57-B43) was 4.1-fold and 6.9-fold increased compared to the red LED and fluorescent light, respectively. With increasing the blue light ratio to 43%, the growth of lettuce was significantly decreased, while the relative chlorophyll content and Hunter's $a^*$ value was increased, indicating that the red/blue light ratio inversely affects on growth and anthocyanin pigment development. By changing light quality from red to red/blue mixed light source (R57-B43) for 9 days before harvest, the growth rate decreased compared to the continuous red light illumination, while the anthocyanin content dramatically increased compared to either red LED or fluorescent light. Whereas, when the light source was changed to red light, the growth rate was increased but anthocyanin content was reversely decreased. The result demonstrated that both growth and anthocyanin expression could be effectively regulated by shifting of light quality between red and red/blue mixed light source at a specific growth stage of lettuce in a plant factory.

• Agribusiness and Information Management
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• v.3 no.1
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• pp.67-74
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• 2011

This study examines the effects of lightemitting diode (LED) light and temperature on lettuce growth. For plant growth, we used an LED bar composed of red, white and blue LEDs (4:1:2). Six types of cultivation equipment were used to measure the temperature. To compare their effects, the heights of the lettuces and the water temperatures were measured. The results demonstrated that the lettuce growth was optimal at $25^{\circ}C$.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.549-565
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• 2015

This study was conducted to investigate the growth characteristics and functional materials of baby vegetables as affected by different LEDs and luminous intensity at Anseongsi, Gyeonggi Province, in 2014. Test crops were beet, chicory, spinach, red leaf lettuce, crown daisy and red mustard purchased from the seed company of Dongbu Hannong and Jinheung. Growth characteristics were measured and the content of functional materials was analyzed 40 days after seeding at plug plate. Treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity showed the highest number of leaves in five baby vegetables of beet, chicory, red leaf lettuce, crown daisy and red mustard. The highest shoot length of chicory, spinach, red leaf lettuce, crown daisy and red mustard was obtained from the treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Fresh weight and dry weight of all six baby vegetables were the highest in treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Content of chlorophyll a and chlorophyll b of spinach, red leaf lettuce and red mustard showed the highest in Fluorescent lamp at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity whereas other crops did not show definite trend under different LEDs lights and luminous intensity. The highest total content of anthocyanins and polyphenol were obtained from the treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity in all six baby vegetables. Free radical scavenging activity was highest in all six vegetable crops at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity, but it was not different significantly between LEDs. As a result, the growth and the content of functional material of baby vegetables are generally to be increased in Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Mixed light of Red+Blue is thought to give good effect on the growth and the content of functional material in baby vegetable crops. Because there are many differences in regard of LED lights, crop varieties, cultivation and experimental methods in their impact on the growth and functional materials of baby vegetables among researchers, it is considered that a more precise studies are needed for the crop responses to LED light and luminous intensity.

• Economic and Environmental Geology
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• v.52 no.2
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• pp.129-139
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• 2019

This study investigates the spectral response of red lettuce (Lactuca sativa var crispa L.) to Zn concentration. The control group and the experimental groups treated with 1 mM(ZnT1), 5 mM(ZnT2), 10 mM(ZnT3), 50 mM(ZnT4), and 100 mM(ZnT5) were prepared for a pot experiment. Then, Zn concentration and spectral reflectance were measured for the different levels of Zn concentration in red lettuce. The Zn concentration of the control group had the range of 134-181 mg/kg, which was within the normal range of Zn concentration in uncontaminated crops. However, Zn concentration in the experimental group gradually increased with an increase in concentration of Zn injection. The spectral reflectance of red lettuce showed high peak in the red band due to anthocyanin, high reflectance in the infrared band due to the scattering effect of the cell structure, and absorption features associated with water. As Zn concentration in red lettuce leaves increased, the reflectance increased in the green and red bands and the reflectance decreased in the infrared band. The correlation analysis between Zn concentration and spectral reflectance showed that the reflectance of 700-1300 nm had a significant negative correlation with Zn concentration. The spectral band is a wavelength region closely related to the cell structure in the leaf, indicating possible cell destruction of leaf structure due to increased Zn concentration. In particular, 700-800 nm reflectance of the infrared band showed the strongest correlation with the Zn concentration. This study could be used to investigate the heavy metal contamination in soil around mining and agriculture area by spectroscopically recognizing heavy metal pollution of plant.

• Journal of the East Asian Society of Dietary Life
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• v.5 no.2
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• pp.27-38
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• 1995

This study was conducted to standardize ingredient ratio and preparation method of mafor traditional special kimchies in kyungsang province, korea. There were about 35 varieties of special kimchi in Kyungsang province. Six varieties of them such as burdock kimchi, wild leek kimchi, green thread onion kimchi, perilla leaf kimchi, Godulbaegi(Korean wild lettuce) kimchi, and red pepper leaf kimchi were selected, because they tasted good and the physiological functions of their main ingredients were excellent. The ingredient ratios of the selected special kimchi were standardized through surveying hereditary preparation of some families in kyungsang province and using the literatures including cooking books. The standardized ingredient ratio of the burdock kimchi was 15.1 pickled anchovy juice, 6.8 red pepper powder, 5.7 garlic, 2.2 ginger, 18.0 rice flour paste, 13.5 green thread onion, and 1.2 sesame seed in proportion to 100 of burdock. The standardized preparation step of the selected special kimchies was similar except some preprocessing methods of main ingredients. The diagonally cut-up burdock ws usually parboiled or soaked in salted water, then it was mixed with the other ingredients. Wild leek and green thread onion were usually pickled with salt or pickled anchovy juice. Sometimes the green thread onion pickled was dried in the sun. General preprocessing of perilla leaf, Korean wild lettuce, and red pepper leaf was soaking them in salted water for about 5-10 days. Sometimes red pepper leaf was heated with steam and dried in the sun, then it was mixed with the other ingredients.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.259-264
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• 1993

Allelopathic chemicals exudated from plants stimulate or inhibit crops directly or indirectly. To prove the effects of allelochemics, we isolated and identified the compounds by bioassays on the monoculture and crosscropping cultre systems. p-Coumaric acid were exudated on all of the test crops such as tomato, red pepper, lettuce, chinese cabbage and sesame, but pyrogallol and phenylacetic acid on tomato. hydroquinone on red pepper and egg plant, pyrogallol on lettuce, and vanillic acid on chinese cabbage. The highest total concentration of allelochemics was $5,883{\mu}g$ on tomato, lowest was $220{\mu}g/g$ dry plant weight on sesame. On the cross-cropping culture of tomato-egg plant, tomato-red pepper, chinese cabbage-egg plant, chinese cabbage-red pepper and chinese cabbage-sasame, the plant height, aerial dry weight and total dry weight of the tomato and the chinese cabbage were inereased contrast with monoculture, but decreased greatly on red pepper and sesame. Growth rate of both crops on the cross-cropping culture of tomato-chinese cabbage declined, while that of chinese cabbage was increased but lettuce decreased on the chinese cabbage-lettuce cross-cropping culture contrast with monoculture.

• The Korean Journal of Food And Nutrition
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• v.32 no.6
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• pp.717-729
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• 2019

The chemical informs about 70 individual phenolic compounds were constructed from various lettuce samples based on literature sources and analytical data. A total of 30 phenolic compounds including quercetin 3-O-glucuronide, quercetin 3-O-(6''-O- malonyl) glucoside, cyanidin 3-O-(6''-O-malonyl)glucoside, chlorogenic acid and chicoric acid as major components were identified in 6 lettuce samples from Korea using UPLC-DAD-QToF/MS on the basis of constructed library. Among these, quercetin 3,7-di-O-glucoside(m/z 627 [M+H]⁺), quercetin 3-O-(2''-O-malonyl)glucoside(morkotin C, m/z 551 [M+H]⁺), quercetin 3-O-(6''- O-malonyl)glucoside methyl ester(m/z 565 [M+H]⁺), 5-O-cis-p-coumaroylquinic acid(m/z 339 [M+H]⁺) and 5-O-caffeoylquinic acid methyl ester(m/z 369 [M+H]⁺) were newly confirmed from the lettuce samples. In total content of phenolic compounds, 4 red lettuce samples(2,947.7~7,535.6 mg/100 g, dry weight) showed higher than green lettuce(2,687.3 mg) and head lettuce(320.1 mg).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.142-147
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• 2015

The artificial light sources for growth of plant are usually high-pressure sodium lamp, metal haloids lamp, and fluorescent light; however, these light sources have relatively weaker Red and Blue lights that are necessary for growth of plants. Especially the effect of Photosynthetic Photon Flux Density (PPFD) is pointed out as the weakness. Meanwhile, LED light source can be selected by specific wavelength to greatly improve the effect of PPFD. In this regard, this paper aims to investigate the promotion of plant growth by measuring photosynthetic photon flux density (hereafter referred to as PPFD) according to changes in light quality of the LED light sources. Towards this end, LED light sources for plant growth were produced with 4 kinds of mono-chromatic lights and 6 kinds of combined lights by mixing red, blue, green and white lights. A comparative analysis was conducted to investigate the effects of optical properties and PPFD on plants (green leaf lettuce) using the produced light sources. The results monochromatic light has fastest growth rate, but plant growth conditions have poor. This being so, mixed light is suitable for the green leaf lettuce.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1358-1365
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• 2018

Objective: The effect of pre-converted nitrites from natural sources (spinach, lettuce, celery, and red beet) on color development in raw and cooked pork sausage was investigated in this study. Methods: The pork sausage was manufactured with six treatments: NC (negative control, nitrite free), PC (positive control, 150 ppm sodium nitrite), FS (3.0% fermented spinach extracts), FL (3.0% fermented lettuce extracts), FC (3.0% fermented celery extracts), and FR (3.0% fermented red beet extracts). Results: The pH value of the pre-converted nitrites groups was lower than those treated with 150 ppm sodium nitrite (p<0.05). The color values of raw and cooked pork sausage added with pre-converted nitrite showed slightly lower and/or similar lightness, lower redness, and higher yellowness values than PC. Color development (redness values) of cooked samples added with FS was higher than those of the NC and other treatments (FL, FC, and FR). Additionally, treatments with FS and FL were most effective for reducing thiobarbituric acid reactive substances and volatile basic nitrogen than the NC. Conclusion: Effects of natural nitrites from fermented vegetables on shelf stability of raw and cooked pork sausages were investigated. Fermented spinach extract was much more useful for maintaining the color development, but also inhibiting lipid and protein oxidation of cooked pork sausage. Therefore, pre-converted nitrite from spinach as a natural nitrite could be used as another natural nitrite source for making processed meat products.