• Food Science and Preservation
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• v.18 no.5
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• pp.651-660
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• 2011

This study was conducted to evaluate the quality characteristics of and chilling injury development in 'Ooishiwase' plum fruits after harvest, according to the ripening stage and storage temperature. The fruits were harvested at three ripening stages (60, 80, and >90% skin color) and were then stored at 1, 4, 5, 6, and $20^{\circ}C$ cold-storage rooms for up to 48 days. The fruit quality parameters, respiration patterns, and chilling injury development were monitored during the storage periods and the three days of subsequent ripening at $20^{\circ}C$. The fruits harvested at the 60%-skin-color stage maintained the flesh firmness, color, weight loss, and TA, and their respiration rates and ethylene production were decreased compared with the 80%-or >90%-skin-color fruits, at a lower storage temperature. The major symptoms of chilling injuries in the Ooishiwase plums were gel breakdown, flesh browning, and flesh translucency. These symptoms appeared at all the low-storage-temperature and ripening treatment stages. When the fruits, however, were harvested at a more immature stage and were stored at a lower storage temperature, the chilling injury development decreased. These results show that the development of chilling injury in Ooishiwase plums is related to the climacteric behavior during cold storage.

• The Korean Journal of Ecology
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• v.19 no.2
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• pp.151-163
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• 1996

To investigate the early symptoms of light-chilling, alterations of chlorophyll fluorescence transients were monitored in cucumber (Cucumis sativus L. cv. Ilmichungjang) leaves. During 24 h chilling, decreases in (Fv)m/Fm, qE and qQ, and an increase in Fo were observed. The chilling effects were not recovered at room temperature, and a significant increase in Fo was observed during the recovery period. After 6 h chilling, ‘dip’(D) level of the transients became obscure, and the negative slope after ‘peak’(P) disappeared. The first derivative (dFv/dt) of the fast fluorescence rise curve was used to obtain more accurate information about the changes in the transients. The maximal rate of the fluorescence increase in the D-p rise curve (Fr) has been the most frequently used chilling stress indicator. However, a correct value of Fr could not be measured when the D level became obscure. This problem was overcome by introducing a new indicator, HFr (dFv/dt at Fv = 1/2 (Fv)m), and HFr gave very similar values to Fr. To monitor the changes in curvature around D level, another new parameter, ${\Delta}S$(D-Fr), was also introduced. These three parameters decreased very sensitively during light-chilling. In addition, increases in these parameters were observed during the first 2 h chilling, but this increase in Fr was also observed in pea leaf discs dark-chilled for 15 min, suggesting that this very early change is a common response to chilling in both pea and cucumber leaves. Quenching coefficients were also very sensitive to chilling, especially qE. Discussion on the usage of these parameters as chilling stress indicators is given in the text.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.11
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• pp.915-922
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• 2006

Considering heat pipe design principles in fabrication and operational performances, water is one of the most recommended working fluids to make mid to low tempera lure heat pipes. But the conventional water heat pipes might encounter the failure in a cold start-up operation when socked at a chilling temperature lower than the freezing point. If they are subjected to a heat supply for start-up at a temperature around $-20^{\circ}C$, the rate of the vapor flow and the corresponding heat transfer from the evaporator to the condenser is so small that the vapor keeps to stick on the surface of the chilling condenser wall, forming an ice layer, resulting in a liquid deficiency in the evaporator. This kind of problems was resolved by Kang et al. in 2004 by adopting a gas loading heat pipe technology to the conventional water heat pipes. This study was conducted to examine a chilling start-up procedure of gas loading heat pipes by investigating the behaviors of heat pipe wall temperatures. And the thermal resistance of the gas loaded heat pipe that depends on the operating temperatures and heat loads was measured and examined. Two water heat pipes were designed and fabricated for the comparison of performances, one conventional and the other loaded with $N_2$ gas. They were put on start-up test at a heat supply of 30 W after having been socked at an initial temperature around $-20^{\circ}C$. It was observed that the gas loaded one had succeeded in chilling start-up operation.

• Journal of Ginseng Research
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• v.25 no.4
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• pp.167-170
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• 2001

Experiments were conducted to study the optimum chilling period for breaking physiological dormancy of dehisced ginseng(Panax ginseng C. A. Meyer) seed. Embryo of ginseng seed is too small to be noticed with naked eyed on harvesting time. Embryo grew to half size of endosperm after seeds were stratified for 3 months. It takes 6 months for this embryo to reach the size enough for germination. And it grew faster indoors than outdoors. Dehisced ginseng seed with full-size embryo did not germinate at room temperature and required chilling treatment for 75days in outdoors and 90 days in cold chamber. While seed receiving sufficient chilling treatment were left to be in room temperature, the chilling effect decreased remarkably.

• BMB Reports
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• v.29 no.5
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• pp.398-404
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• 1996

Light-chilling effects were investigated in chilling-sensitive cucumber (Cucumis sativus L. cv. Ilmichungjang) and chilling-resistant pea (Pisum sativum L. cv. Giant) leaf discs in relation to possible damage in D1 protein. In both plants, dark-chilling did not cause any noticeable changes in (Fv)m/Fm and lincomycin did not affect the decrease in (Fv)m/Fm caused by light-chilling. This result suggests that the de novo synthesis of D1 protein did not occur actively during light-chilling. In pea light-chilled for 6 h. the decreased (Fv)m/Fm was partly recovered in the dark, and almost complete recovery was observed in the light. In cucumber light-chilled for 3 h. the reduced (Fv)m/Fm decreased further for the initial 2 h recovery process in the light regardless of the treatment of lincomycin and recovered very slowly. In both plant species, the treatment of lincomycin inhibited the recovery process in the light, but did not significantly inhibit the process in the dark. In cucumber leaves pulse-labeled with $[^{35}S]Met$, the labeled band intensities of isolated pigment-protein complexes were almost the same during the 6 h light-chilling, but significant decreases in band intensities were observed during the 3 h recovery period. This result suggests that the irreversibly damaged D1 protein was degraded during the recovery period. However, no noticeable changes were observed in the pea leaves during the 12 h chilling and 3 h recovery period. The polyacrylamide gel electrophoresis of the pigment-protein complexes showed that the principal lesion sites of light-chilling were different from those of room temperature photoinhibition.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.119-126
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• 2019

For rockets using cryogenic liquid hydrogen or liquid oxygen, chilling is required to avoid cavitation and surge problems. Chilling is categorized by the initial chilling/filling stage and the low-temperature maintenance stage. In addition, to improve satellite insertion capability, a multi-ignition capability is required and accordingly chilling to prepare for the next ignition during low-gravity coasting is also required. This paper describes the overall aspects of filling and low temperature maintain marinating for the booster and the upper stage engine including chilling for multi-ignition.

• Korean Journal of Veterinary Service
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• v.23 no.4
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• pp.361-366
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• 2000

The growth of bacteria on the surface of the meat was monitored to investigate the relationships between microbiological quality and some environmental factors such as the chilling temperature, alcohol spraying, and transport in slaughter process of pigs. The temperature changes of the surface and inner part of pork carcass were monitored with GreenTrack$\textregistered$ system during the process of chilling and transport Of the 100pigs tested, the prevalence of level on number of standard plate count (SPC) less than $10^4$ CFU/$\textrm{cm}^2$ and Escherichia coli less than $10^2$ CFU/$\textrm{cm}^2$ in pig were 82% and 80%, respectively. Suface bacterial numbers are decreased in the course of chilling process of the carcass. Alcohol spray process before packing meat also could decrease the surface bacterial count. In conclusion, this study could be overemphasized the importance of relationship between microbiological quality and refrigerating temperature in the process of refrigeration and cutting.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.273-279
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• 2020

BACKGROUND: After transplanting, the recent abnormal low temperature caused physiological disorders of pepper seedlings. This study was conducted to evaluate the effects of UV-A LED, a physical elicitor, on the chilling tolerance of pepper seedlings. METHODS AND RESULTS: Seedlings were continuously irradiated with 370 and 385 nm UV-A LEDs with 30 W·m^-2 for 6 d. After that, seedlings were exposed to 4℃ for 6 h and then recovered under the normal growing condition for 2 d. There were no significant differences in growth characteristics of UV-A treatments compared to the control. Fv/Fm values of two UV-A treatments were below 0.8. Electrolyte leakage in the control was increased by chilling stress, while 385 nm UV-A had the significantly lowest value. Total phenolic content and antioxidant capacity of two UV-A treatments significantly increased due to UV-A radiation. However, total phenolic content and antioxidant capacity of the control increased due to chilling stress and tended to decrease again during the recovery time. CONCLUSION: We confirmed that UV-A light was effective to induce the chilling tolerance of pepper seedling, and the supplemental radiation of 385 nm UV-A LED before transplanting could be used as a cultivation technique to produce high quality pepper seedlings.

• Plant Biotechnology Reports
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• v.3 no.1
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• pp.75-85
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• 2009

We report here a first evaluation of chilling-responsive gene regulation in the sweetpotato. The growth of sweetpotato plants was severely retarded at $12^{\circ}C$; the lengths of the leaf, petiole, and root were markedly reduced and microscopic observation revealed that the elongation growth of the epidermal cells in each of these organs was significantly reduced. We examined the transcriptional regulation of three sweetpotato expansin genes (IbEXP1, IbEXP2 and IbEXPL1) in response to various chilling temperatures (12, 16, 22, and $28^{\circ}C$). In the leaf and petiole, the highest transcript levels were those of IbEXP1 at $28^{\circ}C$, whereas IbEXPL1 transcript levels were highest in the root. IbEXP1 mRNA levels in the $12^{\circ}C-treated$ petiole showed a fluctuating pattern (transient decrease-recovery-stable decrease) for 48 h. In the leaf and petiole, IbEXP1 and IbEXPL1 exhibited a similar response to chilling in that their mRNA levels decreased at $22^{\circ}C$, increased at $16^{\circ}C$, and decreased dramatically at $12^{\circ}C$. In contrast, mRNA levels of IbEXP2 in the leaf fell gradually as the temperature fell from 28 to $12^{\circ}C$, while they remained unaltered in the petiole. In the root, mRNA levels of IbEXPL1 and IbEXP1 reached maximum levels at $16^{\circ}C$, and decreased significantly at $12^{\circ}C$. These data demonstrated that expression of these three expansin genes was ultimately down-regulated at $12^{\circ}C$; however, transcriptional regulation of each expansin gene exhibited its own distinctive pattern in response to various chilling temperatures.

• Korean Journal of Environmental Agriculture
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• v.20 no.5
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• pp.310-316
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• 2001

To find out the effect of low temperature on the regulation of tomato chloroplast genes, the optimization of the system in chloroplast protein synthesis and the identification of the changes in chloroplast protein synthesis induced by chilling were studied. Incorporation reaction occurred rapidly at the first 30 minutes and was constantly maintained after 60 minutes. A broad optimal temperature on protein synthesis was found around 20 to $30^{\circ}C$. No difference was shown in the chloroplast protein synthesis under high light intensity (1600 ${\mu}E/m^2/s$) as well as under low light intensity (400 ${\mu}E/m^2/s$) even darkness. $K^+$, $Mg^{++}$ and ATP at an optimal concentration act as an activator, while DTT, chloramphenicol, cycloheximide, $Ca^{++}$ and inorganic phosphate act as an inhibitor in the chloroplast protein synthesis. Synthesis of 15, 55 and 60 kd chloroplast encoded stromal proteins and 18, 24, 33 and 55 kd chloroplast encoded thylakoid membrane proteins were reduced by chilling, while 17 kd chloroplast encoded stromal protein and 16 kd chloroplast encoded thylakoid membrane protein was induced by chilling. It was expected that the 55 kd stromal protein would be the large subunit of rubisco and the 33 kd thylakoid membrane protein would be the D1 protein which was drastically reduced by chilling.