• Food Science and Preservation
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• v.20 no.4
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• pp.451-458
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• 2013

The purpose of this research is to distinguish the quantitative determination of phytochemicals in various agricultural products and to optimize an HPLC method for the determination of lycopene, lutein, ${\alpha}$-carotene, ${\beta}$-carotene, and cryptoxanthin. Among the different conditions studied, the most suitable ones for our samples were the extraction with hexane/acetone/ethanol (50:25:25, v/v/v), dissolution of the dry extract in tetrahydrofuran/acetonitrile/methanol (15:30:55, v/v/v), injection on a $C_{18}$ column with methanol/acetonitrile (90:10, v/v) + triethylamine $9{\mu}M$ as mobile phase, and ${\lambda}_{detection}$=475 nm. The mean percent recovery for the HPLC method were $120.7{\pm}4.1%$ (lycopene), $89.2{\pm}3.5%$ (lutein), $91.2{\pm}2.9%$ (${\alpha}$-carotene), $99.1{\pm}4.4%$ (${\beta}$-carotene), and $100.0{\pm}5.3%$ (cryptoxanthin). The contents of lutein in the agricultural products were spinach, kiwi, tomato, blueberry, melon, respectively. However, the lycopene contents were the highest in the Black tomato ($56.66{\pm}7.48mg/kg$) and Jangseong tomato ($50.28{\pm}5.42mg/kg$). The concentration of ${\beta}$-carotene in all of the agricultural products ranged from 0.07 mg/kg to 65.03 mg/kg. The quercetin content of the agricultural products increased in the order of blueberry (986.57~1,054.06 mg/100 g), kiwi (44.96~55.09 mg/100 g), hallabong (31.92~35.60 mg/100 g), and tomato (26.38~34.94 mg/100 g). The highest kaempferol content was found in the blueberry (47.79~76.15 mg/100 g) with results in all of the tested samples varying between 6.54~48.11 mg/100 g. The total polyphenol contents of the various agricultural products increased in the blueberry (213.60~229.96 mg/100 g), spinach (112.50~141.67 mg/100 g) and kiwi (46.49~70.44 mg/100 g). The total flavonoid content was the highest in both blueberry and spinach. Vitamin C content was detected in kiwi > hallabong > tomato > blueberry, respectively. The total anthocyanin contents (TAC) was detected in the Damyang blueberry and the imported blueberry.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.179-184
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• 1982

In this paper, four species of the anthomyiid flies are reported for the first time in Korea, including two newly recorded genera as: Chirosia cinerosa (Zetterstedt, 1845) gen. et sp. hav. nov., Paraprosalpia billbergi (Zetterstedt, 1838) gen. et sp. hav. nov., Lasiomma octoguttatum (Zetterstedt, 1845) sp. hav. nov., and Pegomya cunicularis (Rondani, 1866) sp. hav. nov. Some male genitalic characters and head structures are figured respectively.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.350-357
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• 2014

BACKGROUND: Deicers such as calcium chloride ($CaCl_2$) and sodium chloride (NaCl) in Korea have been commonly used to reduce traffic accidents as well as injuries. However there have been adverse effects of deciders such as pollution of water and soil, and reduced productivity of agriculture as well as forest. This study aimed to investigate biological effects of the deicers against wheat, barley, and spinach. METHODS AND RESULTS: The germination of tested crop seeds exposed to chloride-deicers, $CaCl_2$ and NaCl was significantly reduced at over 3% concentration of chloride-deicers compared to the control. In spraying deicers to the seedlings of the crops, there was no symptom such as inhibition of growth rate or leaf elongation. However the germination of tested crop seeds was affected at 2% concentration of deicers when they were exposed continuously to deicers in soils. The growth of the shoot against $CaCl_2$ and NaCl treatments was very similar in wheat and barley whereas the shoot of spinach was the most susceptible. Based on these results, the sensitivity of the crops to the tested deicers was as follows: NaCl > $CaCl_2$ > mixture ($CaCl_2$ + NaCl). The length of shoots and roots of the seedlings grown in 1% treated soil was decreased. The biomass of all the seedlings decreased 1.5 to 4 times at 1%. CONCLUSION: These results indicate that the effects of salt deicers by inputting into soil against growing tested crops are more severe in germination and growth inhibition as well as biomass decrease.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.211-222
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• 1995

This experiments were carried out to investigate the growth responses of spinach to temperature controlling by shading treatments at different times during the summer, and the effects of environmental parameters on the growth and yield were evaluated. The fourth cultivation was showed maximum temperature at air temperature of 33.1$^{\circ}C$ and soil temperature of 28.6$^{\circ}C$, followed by third, second, fifth and first cultivation. Among the tested temperature decreasing by shading, shading with silver - coated PE film strips was the most effective in lowering greenhouse air temperatures by showing 1.1$^{\circ}C$ decrease as compared to the outside air temperature and 3.1$^{\circ}C$ decrease as compared to the air temperatures inside the non-shaded PE house and 2.3$^{\circ}C$ decrease as compared to the air temperaturese shading with black- coated PE film strips, the soil temperature was showing 2$^{\circ}C$ decrease in both shading treatments than non-shaded PE and outdoor. In first cultivation, difficult cultivated as compared to others period owing to bolting of spinach. This first period was cultivated used two domestic cultivars and six imported cultivars, significantly better growth and higher yield of spinach were recorded in glory, manchuparuk and sunlighr cultivars. The effectiveness of shading on spinach, as expressed by the crop yield increase, was the highest in the planting from July 1 to August 24.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.35-39
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• 2002

This study was conducted to investigate the effect of early $CO_2$ enrichment during seedling stage on long-term $CO_2$ enrichment after transplanting in the culture of pat-choi (Brassica campesris L), spinach (Spinacia oeracea L.), and leaf lettuce (Lactuca saliva L). During seedling stage, $CO_2$enrichment had significantly higher fresh and dry weight and leaf area of the top parts (above ground) of all three plant species than the control (no $CO_2$ enrichment). About 53%, 70% , and 40% increase in fresh weight of the top parts of pak-choi, spinach, and leaf lettuce were observed, respectively. Also, in seedling stage, dry weights of roots of spinach and leaf lettuce were significantly increased by early $CO_2$ enrichment. Relative fresh weight increment, compared with fresh weight of the control, in the top parts of roll three plants showed the highest values in 10 days after $CO_2$ enrichment treatment. In the long-term $CO_2$ enrichment experiment, early $CO_2$ enrichmented plants had 20% greater leaf area than the control in all three leafy vegetables. Fresh and dry weights of top parts of early $CO_2$-treated plants were also increased from 10 to 20%, as compared with the control plants. However, these increasement rates in the long-term $CO_2$ enrichment were lower than those seedling stage, which had 30-60% increment-rates. After transplanting, photosynthetic rate of each leafy vegetable in the control treatment slowly decreased, but those rates of early $CO_2$ enriched plants rapidly decreased.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.97-102
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• 2003

Raw and washed spinaches were tested to evaluate the incidences of Aeromonas hydrophila, Escherichia coli O157:H7, Plesiomonas shigelloides, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Yersinia enterocolitica, Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Listeria monocytogenes, and Staphylococcus aureus. Four pathogenic bacteria were isolated from spinach samples, and identified by morphological and biochemical methods, including API and ATB identification systems. Isolates from MacConkey, Cereus Selective, Clostridium Perfringens, and Baird-Parker agar media were in 99.9, 99.8, 99.9, and 97.8% agreements with A. hydrophila, B. cereus, C. perfringens, and S. aureus at the species level, respectively. SET-RPLA revealed, among the five strains of S. aureus isolates, two produced type A enterotoxin. All five strains of B. cereus isolates produced enterotoxin as revealed with CRET-RPLA.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.187-191
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• 2004

For the production of $2-O-{\alpha}-D-glucopyranosyl-L-ascorbic$ acid (ascorbic acid-2-g1ucoside, AA-2G) from ascorbic acid, the usability of spinach seed as the source of ${\alpha}-glucosidase$ having transglucosylation activity was studied. The optimum conditions for the production of AA-2G from ascorbic acid and glucose donor were investigated by using crude extract of Spinachia oleracea L. Woosung, the selected source of enzyme. The production of AA-2G was the highest with 1.053 mM when spinach seeds were grown for 2 days after germination. Maltose was the most effective glucose donor, and the optimum concentration of ascorbic acid and maltose were 175 mM and 225 mM, respectively. The optimum concentration of ${\alpha}-glucosidase$ was 60 units. The most effective buffer was sodium acetate and its optimum concentration was 175 mM. The optimum pH and temperature were 5.0 and $65^{\circ}C$, respectively. Under the optimum condition, 2.14 mM of AA-2G was produced from ascorbic acid after 50 minutes of reaction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.117-123
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• 2007

HPLC quantifications of fresh and cooked (steamed/microwaved) spinach, one of the most frequently consumed vegetables in foodservice operations, were carried out to determine carotenoids compositions. An S-3 $\mu$m C30 stationary phase for reversed-phase columns with diode-array detection was used to separate and quantify geometric isomers of provitamin A carotenoids in the fresh and cooked spinach. The carotenoids in fresh spinach were identified and quantified: Lutein (63.0%), $\beta$-carotene isomers (all-trans 29.6%, 9-cis 3.2%, 13-cis 1.8%, $\alpha$-carotene 0.4%, zeaxanthin 2.1%) and cryptoxanthin. Cryptoxanthin, detected in a trace amount in HPLC, was not quantified in this study. Lutein was little affected by cooking methods and frozen conditions. 9-cis and 13-cis-$\beta$-carotene isomers were major types formed during cooking. Cooking (steam/microwave) did not alter carotenoid profiles of the samples, but the amounts of carotenoids quantified were greater than those in the fresh samples. Heat treatment such as steaming increased total carotenoids contents, especially trans-$\beta$-carotene (p<0.05). The carotenoid contents of the frozen spinach increased even after the microwaved treatment (p<0.05). These increases were likely to result from the increased extraction efficiency and inactivation of enzymes capable of carotenoids degrading during the heat treatments.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.529-537
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• 2022

The susceptibilities of five insecticides to the larvae of Spoladea recurvalis, a major pest of spinach, were evaluated. Lufenuron EC, chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed 90% or more insecticidal activity at dilution concentrations of 2 (12.5 ppm), 4 (12.5 ppm), 8 (2.5 ppm), 4 (20.0 ppm), and 8 (12.5 ppm), respectively. At their recommended concentrations, Chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed very high insecticidal activity of 98.3%, 100%, 95.0%, and 100%, respectively, after 72 h on S. recurvalis larvae exposed after 7 days of treatment. Field tests at two spinach greenhouses in Hwaseong and Yeoncheon showed a high control effect of over 90% after 7 days of treatment in both areas. In addition, the insecticides can be used as exclusive agents for S. recurvalis that occurs in spinach, as there is no phytotoxicity even at double doses.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.45-54
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• 2024

A proper level of UV-A light treatment in terms of intensity, spectrum, and exposure duration is known to have a positive impact on plant growth, photosynthesis, and the biosynthesis of secondary metabolites. However, there are few studies investigating the physiological responses of spinach (Spinacia oleracea L.) to UV radiation. Hence, this study aimed to assess the effects of short-term UV-A radiation on the growth and bioactive compounds of spinach. Spinach seedlings were cultivated in a vertical farm module under the following environmental conditions: photosynthetic photon flux density 200 µmol·m^-2·s^-1, white LED, 12 h on/off, 20℃ air temperature, 70% relative humidity, and 500 µmol·mol^-1 CO₂ concentration. After 5 weeks of sowing, the seedlings were subjected to continuous UV-A (peak wavelength; 385 nm) irradiation at two different energy levels: 20 W·m^-2 and 40 W·m^-2 for 7 days. As a result, the UV-A_20W treatment increased the shoot fresh and dry weights of spinach. However, there were no significant differences observed in photosynthetic parameters between the UV-A treatments and the control. The maximum quantum efficiency of photosystem II (Fv/Fm) consistently decreased across all UV-A treatments for 7 days in UV-A treatments. Additionally, the total phenolic content and antioxidant capacity increased in the UV-A_20W treatment at 7 days of treatment as well as the total flavonoid content significantly increased at 5 and 7 days of treatment. These findings suggest that supplemental UV-A LED radiation can enhance the growth and quality of spinach cultivated in closed type plant production systems such as vertical farms.