• Horticultural Science & Technology
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• v.34 no.2
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• pp.257-268
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• 2016

Physiological characteristics of five new apple cultivars from the Korean apple breeding program were evaluated as a function of harvest time and storage after harvest. Internal ethylene concentration (IEC), flesh firmness, soluble solids concentration (SSC), and titratable acidity (TA) were measured in 'Summer Dream', 'Summer King', 'Green Ball', 'Picnic', and 'Hwangok' apples at harvest, during shelf life at $20^{\circ}C$, and one day after cold storage at $0.5^{\circ}C$ in air. IEC increased during shelf life in 'Summer Dream', 'Summer King', and 'Green Ball' but not in 'Picnic' or 'Hwangok', regardless of harvest time. Flesh firmness decreased towards harvest time and decreased gradually with time in cold storage only in the former three cultivars. In turn, IEC increased during cold storage in the first three cultivars but not for the last two cultivars, irrespective of harvest time. Changes in SSC and TA did not consistently relate to harvest time or storage period but TA tended to decrease as IEC increased. Furthermore, IEC was negatively correlated with flesh firmness except in the 'Green Ball' cultivar but the significance level was much greater in 'Summer Dream' and 'Summer King' (p < 0.0001) than in 'Picnic' (p < 0.01) or 'Hwangok' (p < 0.05) cultivars. Flesh firmness was positively correlated with TA in the first three cultivars but not in the last two cultivars. Overall, the results indicate that cultivars for which IEC increased after harvest had reduced flesh firmness and TA after storage.

• Journal of Bio-Environment Control
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• v.7 no.3
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• pp.253-258
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• 1998

Lettuce plants(Lactuca sativa var. capitata L.) were subjected to nitrogen starvation for 18, 14, 11, 7, and 0 days before harvest. The nitrate content of lettuce was decreased greatly by nitrogen starvation and also its fresh weight. The nitrate content of the middle part of leaves was lowest at the treatment of 18 days before harvest. In the inner part it was lowest at the treatment of 11 and 14 days before harvest. The longer the period of nitrogen starvation was, the more were decreased the absorption rates of cations at harvest. During the experiment, the pH was decreased except the treatment of 7 days before harvest. The EC was continuously increased regardless of treatments.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.8-12
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• 1998

The study aimed at development of a riding-type mulberry harvester for mechanical harvest. A riding-type mulberry harvester has been developed to harvest on sloped land with a higher efficiency. It has been implemented over a period of 2 years from 1996 to 1997. The result is as follows. It moves on carterpillar with a level adjusting system. It reduced only from 14.6 hrs to 0.9hrs/10a for cutting in a range of 25 to 80 cm high and possibly used for both spring and autumn. It reduced only the labor requirements of mulberry harvesting by 94 percent, as compared to that of the manual harvest. All related processes, cutting, binding and loading are simultaneously done by this harvester and totally it can reduce 96 percent of the labor requirements, as compared to 20.4 hrs/10a of the manual harvest. The machine compared to improved mulberry harvest efficiency with 11.11a per hour by about 23 times as compared to 0.49a per hour manpower. Cost analysis indicated that the riding-type mulberry harvester saved overall cost by 66 percent from 980,000 won per ha manpower to 330,000 won per ha.

• Journal of Biosystems Engineering
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• v.33 no.5
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• pp.309-316
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• 2008

The goal of this study was to develop prediction models to estimate the storage days of tomato. The transmittance spectral data measured on tomato were preprocessed through normalization, SNV, Savitzky-Golay, and Norris Gap and then were used to build the prediction models using partial least square (PLS) method. For the experiments, the tomato samples of different varieties were collected at different harvest time. The samples were taken right after harvest from the field and then were stored in a low-temperature storage room in which room temperature was maintained at $10^{\circ}C$. The transmittance spectral data of the tomato samples were measured at three-day intervals for 16 days. The performance of the prediction models was affected by the preprocessing techniques as well as the varieties and harvest time of the tomato. The best model was found when SNV was applied. The accuracy of the best model was 90.2%. It can be concluded that the transmittance spectra are useful information for predicting the period of storage of tomato.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.460-463
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• 2008

The change of glutelin contents in rice grain during the maturity period was investigated to determine optimum rice harvesting time. The glutelin content was increased with increasing time after heading. In this study, eight of glutelin subunits were found. Among the glutelin subunits, 7208-subunit (MW, 35 kD) contents was significantly increased at 65 days after heading compared with 55 and 60 days after heading. 7405-subunit (MW, 50 kD) contents was steadily increased with time after heading. The results showed that at 55th day after heading would be optimum time for harvest to get the low glutelin content of rice grain.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.47-51
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• 2004

In order to know the residual pattern of pesticides and predict to the degradation period until below MRL we experimented procymidone and chlorothalonil for grape which were the most detected pesticide in grape by NAQS(National Agricultural product Quality management Service) survey. In this experiment we sprayed those pesticides 10 days before harvest and analyzed 0, 1, 2, 3, 5, 7, 10 day sample to establish logical equation and to calculate $DT_{50}$. Also the same day samples stored at $4^{\circ}C$ and $20^{\circ}C$, which were compared their degradation patterns. During the cultivating period, the residue amount of procymidone was changed from 1.85 mg/kg (0 day) to 0.33 mg/kg (10 day), $DT_{50}$ was 3.5 days, and chlorothalonil was changed from 5.5 mg/kg (0 day) to 3.49 mg/kg (10 day), $DT_{50}$ was 4.4 days. During the storage period, $DT_{50}$ of procymidone and chlorothalonil at $4^{\circ}C$ were 10.5 and 7.6 days, and 6.3 and 6.1 days at $20^{\circ}C$, respectively.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.125-135
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• 2019

Late-maturing Dark Horse, and early-maturing High Speed oat varieties were seeded on March 3, 2016 and harvested on three periods: May 31, June 10, and June 20 coded as early, mid, and late-harvest, respectively. Dried and ground samples were subjected to chemical analysis to determine nutritional values such as crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), organic matter (OM), and total digestible nutrient (TDN). Effective degradability (ED) of nutrients and fermentation characteristics including volatile fatty acid (VFA) composition, pH, gas production, and ammonia-N concentration were evaluated through an in vitro digestion method. Varieties of oat hays showed significant difference in terms of nutritional value, ED, and fermentation characteristics. Dark Horse showed higher CP and OM, and lower EE contents than High Speed. Dark Horse also showed higher EDDM (dry matter), NDF, ADF, and OM than High Speed, and although High Speed showed higher pH and ammonia-N, it had lower gas and total VFA production than Dark Horse. However, in terms of harvest period, significant difference was only observed in Dark Horse where early-harvest increased the CP, and late-harvest increased the NDF and OM contents. In addition, early-harvest of Dark Horse increased the EDDM and EDNDF of the forage. Therefore, early-harvest of late-maturing Dark Horse would give better nutrient efficiency than High Speed. Allowing Dark Horse to advance in maturity would decrease its nutrient productivity and efficiency.

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.107-112
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• 2004

Many studies have showen that Letinus edodes have a reducing effects on blood pressure and lipid levels in animals with high blood pressure and hyperlipidemia. But the only cap has been on the market as goods and the stipe has been wasted. The price is very variable and is based on harvest time and the part of the plant currenty, there is not much information about the nutritional composition and bio-fuctional effects of Letinus edodes based on harvest time and part. Some farmers have been selling the powder seasoning by drying and pulverizing Letinus edodes including stipe to develop value added, late harvested Letinus edodes and its stipe these days. This study was conducted to investigate and compare the nutritional composition of Letinus edodes harvested at different times (early: E, late: L) and separated by part (cap: C, stipe: S). The 4 kinds of materials were named as early harvested cap (EC) and stipe (ES), and late harvested cap (LC) and stipe (LS) samples were obtained from Mungyeong City Agricultural Technology & Extension Center. The composition analysis of the nutrients in the 4 materials was conducted by using the AOAC method. The proximate components (moisture, protein, fat, fiber, ash, and carbohydrates), minerals and vitamin content were measured. Nutritional composition of Lentinus edodes did not show any significant difference between early and late harvested mushrooms. Nutritional compositions were different according to part. The results demonstrate that the late harvested stipe can also be used as a quality food material.

• Food Science and Preservation
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• v.30 no.6
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• pp.929-943
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• 2023

This study analyzed the variation in vitamin K content in conger eel (Conger myriaster) caught off Tongyeong, Gyeongsangnam-do, Korea, focusing on the influence of size (large and small) and harvest period (monthly throughout 2021). We applied enzymatic extraction and HPLC-fluorescence methods for the analysis of vitamin K₁ (phylloquinone) and K₂ (menaquinone). The vitamin K content in conger eel varied significantly with size and harvest season (p<0.05). In large-sized samples, the phylloquinone content peaked in July (0.80±0.09 ㎍/100 g), while the highest menaquinone content was in May (0.79±0.11 ㎍/100 g). Conversely, in small-sized conger eels, the highest phylloquinone was found in December (1.94±0.15 ㎍/100 g), and the peak menaquinone level was in January (0.66±0.02 ㎍/100 g). The fat content was highest in July for large samples and in January for smaller ones. There was a positive correlation between fat and total vitamin K contents in conger eel (r=0.631, 0.667). Method validation and quality control measures ensured data reliability for vitamin K₁ and K₂ analyses. This study provides reliable information on the size and seasonal variations of vitamin K in conger eels, a staple in the Korean diet. This information is valuable for inclusion in Korea's national food nutrition database and for formulating future national health and nutrition policies.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.136-141
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• 2013

BACKGROUND: This study was performed to establishment the PHRLs of peach during cultivation period, and also to estimate biological half-lives for residues of fenarimol and flufenoxuron. METHODS AND RESULTS: The extracted samples of fenarimol were analyzed by GC-ECD and the flufenoxuron extracted samples were analyzed by HPLC-DAD. Recoveries of fenarimol at two fortification levels of 0.1 mg/kg, 0.5 mg/kg were $93.69{\pm}6.56$(%) and $94.45{\pm}1.60$ (%), respectively. And recoveries of flufenoxuron at two fortification levels of 0.1 mg/kg, 0.5 mg/kg were $106.73{\pm}5.90$(%) and $96.37{\pm}6.66$(%), respectively. CONCLUSION(S): The biological half-lives of fenarimol in single treatment and triple treatment were 3.5day and 3.8day. that of Flufenoxuron was also 7.1day and 4.9day, respectively. The PHRL of fenarimol were recommended as 1.5 mg/kg for 10day before harvest and the PHRL of flufenoxuron were recommended as 1.4 mg/kg for 10day before harvest.