• Food Science of Animal Resources
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• v.25 no.2
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• pp.127-133
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• 2005

Aging effect of vacuum-packaged beef loins was investigated at $0\pm1^{\circ}C$ for 8 weeks. Hardness, chewiness, and shear force value of beef loins decreased steadily for the first 5 weeks of chilling period, but thereafter they did not changed significantly. Myofibrillar protein extractability, Mg-ATPase activity, and myofibrill fragmentation index of beef loins were increased for the first 6 weeks, and did not change for the rest period The Hunter's value in $L^{\ast},\;a^{\ast}\;and\;b^{\ast}$ of beef loin showed that no significant changes had occurred over the whole storage time. The palatability of beef loin was improved progressively for the first 5 weeks, but it became inferior thereafter. It can be concluded that the storage time to obtain optimum aging effect for the vacuum-packaged beef loin would be 5 weeks at $0^{\circ}C$ at the longest.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.384-391
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• 1997

In the cultivation of Bupleurum falcatum, one of the problems to surmount is long-term germination period and unstable germination. This experiment was done to examine the effect of $GA_3$ concentration [0(water), 0.01, 0.lmM], chilling, their treatment period [2, 4, 8 days ($GA_3$) : 0, 2, 4 weeks (chilling)] and light quality (red, white, dark) given during the period as pretreatment before sowing on the seed germination of its two cultivars (cv. Jaerae, cv. Jangsu). Light treatment was given during all the periods of $GA_3$ treatment or for 0, 2, 4 days at the end of the chilling treatment. There was no difference in the mean germination rate between the levels of all the treatments except the $GA_3$ concentration meaning that water imbibition and $GA_3$ treatment had the same effect. As light quality treatment during the water imbibition was forced, the mean germination rate of Jaerae, 2 to 4 days imbibition period or red light was more increased or accelerated compared to the other levels of the same treatment, respectively. The rate of Jaerae not affected by the light quality was the greatest in the 2 days water imbibition while the rate of Jangsu was the greatest when water-imbibed for 4 days or treated by red light. No chilling before sowing showed the highest rate due to the light quality and white light forced after sowing had greater rate than the dark treatment. Although there was no difference between the rates of light quality treatment levels in the condition of no chilling before sowing and white light treatment after sowing, the rate of Jangsu was enhanced or accelerated only under illumination during 2 days water imbibition before sowing.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.427-431
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• 2013

Paprika fruits should be stored and distributed at above $7^{\circ}C$ to prevent chilling injury but the small amount of paprika that transports with other horticultural products in refrigerated container by ship usually stored less than $5^{\circ}C$ for other products. In this case, paprika fruits cannot help exposing chilling temperature, so that the paprika must be lost marketable value during a long period of transfer. This study was conducted to compare the alleviated effects of high $CO_2$ treatment (passive MAP), heat (hot water dipping), and UVc treatment on chilling injury of paprika fruits due to low temperature storage, and also to decide if these treatments can be used for transporting under $5^{\circ}C$. After each treatment the paprika were put in the low temperature storage ($4^{\circ}C$) for 20 days and afterwards change the in room temperature ($20^{\circ}C$) for 5 days. The fresh weight loss of all the treatments except the high $CO_2$ treatment showed around 7~12% after 25 days of storage and the ethylene concentration showed periodical increases and decreases as around 3 ${\mu}l/l$. The $CO_2$ concentration was rapidly increased 33% carbon dioxide in high $CO_2$ treatment during room temperature storage after cold storage for 20 days. The firmness which is key quality characteristics during storage and is decreasing caused by chilling injury was not significantly different among all treatments. However, the firmness of stored paprika was maintained highest in the treated with hot water dipping. Therefore, HWD and UVc treatment that showed 60% of electrolyte leakage in the $4^{\circ}C$ control (chilling injury control) and similar level with the $7^{\circ}C$ control (non-chilling injury control) would be effective to alleviate chilling injury in the stored paprika.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.137-143
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• 2005

Oriental melons hold at $38^{\circ}C$ for 48 hours before storage increased their soluble solid, titratable acidity, vitamin C contents and ${\alpha}$-tocopherol activity. These heat treated oriental melons maintained lower production of carbon dioxide, ethylene and acetaldehyde and loss of fresh weight than untreated them, called control, during $3^{\circ}C$ MA storage. After 39 days in storage, the last day of storage, visual quality and internal quality, such as firmness, soluble solid, titratable acidity, vitamin C and ${\alpha}$-tocopherol activity, showed higher in heat treated oriental melons. Especially, Ion leakage of flesh, index of chilling injury, increased remarkably in control, so that heat treatment had to alleviate chilling injury in oriental melon. Moreover, while Alternaria rot was shown in control plot after 25 days in $3^{\circ}C$ MA storage, oriental melons treated heat were not appeared any decomposition after 39 days in $3^{\circ}C$ MA storage. As storage life of oriental melon was calculated by regression equation between visual quality and days in storage, that was longer 8 days in heat treated than control. Consequently, heat treatment that was mild, $38^{\circ}C$ and long period, 48 hours, executed before storage, sterilized surface alleviated chilling injury and lengthened storage life in oriental melons.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.1
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• pp.40-49
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• 2013

Current service system of the Korea Meteorological Administration (KMA) for blooming date forecasting in spring depends on regression equations derived from long term observations in both temperature and phenology at a given station. This regression based system does not allow a timely correction or update of forecasts that are highly sensitive to fluctuating weather conditions. Furthermore, the system cannot afford plant responses to climate extremes which were not observed before. Most of all, this method may not be applicable to locations other than that which the regression equations were derived from. This note suggests a way to replace the location restricted regression equations with a thermal time based phenology model to complement the KMA blooming forecast system. Necessary parameters such as reference temperature, chilling requirement and heating requirement were derived from phenology data for forsythia, azaleas and Japanese cherry at 29 KMA stations for the 1951-1980 period to optimize spring phenology prediction model for each species. Best fit models for each species were used to predict blooming dates and the results were compared with the observed dates to produce a correction grid across the whole nation. The models were driven by the KMA's daily temperature data at a 5km grid spacing and subsequently adjusted by the correction grid to produce the blooming date maps. Validation with the 1971-2012 period data showed the RMSE of 2-3 days for Japanese cherry, showing a feasibility of operational service; whereas higher RMSE values were observed with forsythia and azaleas.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.116-124
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• 2006

Remarkable winter season warming has been observed in East Asian countries during the last century. Accordingly, significant effects on dormancy and the resulting budburst of deciduous trees are expected. However phenological observations are rare and insufficient compared with the long-time climate records in the same region. A chill-day accumulation, which can be estimated from daily maximum and minimum temperature, is expected to make a reasonable proxy for dormancy depth of temperate zone fruit trees. To simulate dormancy depth during 1921-2004, a chill-day model parameterized for 'Campbell Early' grapevine, which is the major cultivar grown virtually anywhere in South Korea, was applied to daily temperature data at 8 locations in South Korea. The calculations showed that the chilling requirement for breaking endo-dormancy of this grapevine cultivar can be satisfied by mid-January to late February in South Korea, and the date was delayed going either northward or southward from the 'Daegu-Jeonju' line crossing the middle of South Korea in the east-west direction. Maximum length of the cold tolerant period (the number of days between endo-dormancy release and forced dormancy release) showed the same spatial pattern. When we divide the 83 years into 3 periods (I: 1921-1950, II: 1951-1980, and III: 1981-2004) and get the average of each period, dormancy release date of period III was accelerated by as much as 15 days compared with that of period I at all locations except Jeju (located in the southernmost island with subtropical climate) where an average15-day delay was predicted. The cold- tolerant period was also shortened at 6 out of 8 locations. As a result, budburst of 'Campbell Early' in spring was accelerated by 6 to 10 days at most locations, while inter-annual variation in budburst dates was increased at all locations. The earlier budburst after the 1970s was due to (1) warming in winter resulting in earlier dormancy release (Incheon, Mokpo, Gangneung, and Jeonju), (2) warming in early spring accelerating regrowth after breaking dormancy (Busan and Jeju), and (3) both of them (Seoul and Daegu).