• Horticultural Science & Technology
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• v.33 no.5
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• pp.705-711
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• 2015

This study was conducted to maintain the postharvest shelf-life of summer strawberry cultivars 'Goha' and 'Flamengo' through $CO_2$ (90%) and $ClO_2$ gas ($5{\mu}L{\cdot}L^{-1}$) pre-treatment. The respiration rate of 'Goha' and 'Flamengo' treated with $CO_2$ and $CO_2$ + $ClO_2$ was the lowest during storage. The weight loss with $CO_2$ + $ClO_2$ treatment was about 1% lower than the control group and 'Goha' was the lowest during storage. The pre-treatments effect on soluble solids contents was minimized. The firmness with $CO_2$ and $CO_2$ + $ClO_2$ treatments was only about 30% higher than $ClO_2$ and control. The firmness of 'Goha' was about 2.15N and 'Flamengo' was 2.37N, 15 days after storage. Decayed fruit was shown from after 6 days after storage in control. Control group lost quality 10 days after storage due to decayed fruit rate 20% of 'Goha' and 'Flamengo'. $CO_2$ and $CO_2$ + $ClO_2$ treatments showed the lowest decay rate during storage. Especially, 'Goha' showed around 5% decay fruit rate 10 days after storage. As a result, $CO_2$ + $ClO_2$ pre-treatment is recommended to extend the shelf-life of the summer strawberries.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.8 no.2
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• pp.27-31
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• 2002

This study was measured weight loss, total ascorbic acid, titratable acidity, soluble solids content and overall appearances to investigate the effect of corrugated fiberboard box coated with functional materials ; R, G, X box, R, G and X box and Con(double wall corrugated fiberboard) box during storage at $25^{\circ}C$. Weight loss of mandarin of control, corrugated paperboard box coated with functional materials(Y-, R-, G-box) after 8 days were 2.56% to 3.67%. There was not different to weight loss among the four kind of packages. Titratable acidity and soluble solids content of packages was not significant. Total ascorbic acid content(TAA) of mandarin packed with R-box and Y-box was 10% higher than that of control after 8 days. Decay ratio of R-box, Y-box, G-box and control was 4%, 10%, 10% and 8%, respectively. Overall appearance of R-box was the best.

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.197-202
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• 2013

This study was aimed to find the storage potential of low temperature adapted shiitake mushroom under freezing temperature ($-3^{\circ}C$). Fresh shiitake mushroom was harvested at late Feb. and cooled to target temperature, $-3^{\circ}C$ in the cooling room for 24 hr. Cooled mushroom were then placed in plastic boxes, wrapped with plastic film ($30{\mu}m$), and stored at $-3^{\circ}C$ for 2 months. Weight loss of mushroom was ranged from 2.1 to 3.2%. Dry weight per unit fresh weight, however, was slightly increased because of moisture loss. Firmness of fruit body increased from $0.95kg/cm^{-2}$ (before storage) to $1.13kg/cm^{-2}$ (after 2 month storage). About half amount of starch was lost during 2 month storage. The amount of total and reducing sugars remained relatively constant. After storage, freshness of mushroom was recovered by thawing treatment. When recovered mushroom were packaged with styrofoam tray and PVC wrapping, and exposed to ambient and $10^{\circ}C$, respectively, brown spot on the gill of fruit body was found and slight decay symptom was also found at ambient temperature only but not at $10^{\circ}C$. Results indicated that low temperature adapted shiitake mushroom has a storage potential under freezing temperature ($-3^{\circ}C$). Freezing storage technology of fresh shiitake mushroom will contribute the increase of storability up to 2 months.

• Food Science and Preservation
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• v.9 no.1
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• pp.85-91
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• 2002

Quality changes of over-wintering satsuma mandarin (Citrus unshiu Marc. var. miyagawa) during storage by chitosan and calcium treatment and type of storage warehouse were investigated. Citrus were treated with 2000-folds diluted iminoctadime-triacetate solution and 1.5% chitosan with 0.5% CaCl$_2$ solutions and were at 30$\^{C}$ far 24 h before storage. The citrus of about 12 kg/26 L plastic container were stored at room temperature, and at 4$\^{C}$ with 87% relative humidity. Chitosan and CaCl$_2$ solution treated citrus fruits were showed lower in decay ratio than the ones without treatment. Also, these chitosan and calcium treated citrus fruits skewed less in weight loss, that seems it also has restraining effect of fruits' transpiration. Decay ratio of citrus with precise temperature and humidity control were lower than the others during storage. Weight loss, moisture content of peel and flesh were decreased slowly during storage. 0.84 ∼0.90% of acid content were decreased on 120 days' storage. Reducing sugar of citrus was decreased rapidly after 90 days, and vitamin C content were also decreased rapidly after 60 days during storage.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.347-353
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• 2002

This study was conducted to investigate the characteristics of chloramination as a secondary disinfection in a drinking water distribution system. At the range from pH 6 to pH 8, monochloramine was predominant with a trace of dichloramine, and the free chlorine was detected after breakpoint. At $25^{\circ}C$, the breakpoints of pH 6, 7 and 8 appeared when the weight ratios of chlorine to ammonia nitrogen were 11:1, 9:1 and 10:1 respectively, and the peak points on the breakpoint curves at pH 6, 7 and 8 were in the Cl$_2$ / NH$_3$-N ratio of 9:1, 6:1 and 5:1 respectively. As pH increased from 6 to 8, maximum point of monochloramine on the breakpoint curve was moved from 7:1 to 5:1 in the weight ratio of chlorine to ammonia nitrogen. The maximum concentration of monochloramine was formed at the pH values of 7~8 and in the Cl$_2$ / NH$_3$-N ratio below 5:1. As the Cl$_2$/NH$_3$-N ratio increased and the pH lowered, chloramines decay proceeded at an increased rate, and residual chloramines lasted longer than the residual free chlorine. The monochloramine and the dichloramine were formed at pH 6, and then the dichloramine continued increasing with contact time.

• Food Science and Preservation
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• v.10 no.4
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• pp.435-440
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• 2003

Such fruits as nut persimmons, mandarin oranges and apples stored in the far-infrared radiated chamber at 5$^{\circ}C$ under 90% of relative humidity had been maintained in the fresh state for longer times than the control stored only in the cold chamber. Fruits stored in the far-infrared radiated chamber showed lower values in weight loss rate, microbial colony count and decay ratio and higher ascorbic acid content than the control stored only in the told room through the storage period. We confirmed that fruits stored in the far-infrared radiated chamber under low temperature and high humidity showed least changes in quality properties through the storage period and the far-infrared radiated facilities could be a good storage system.

• Korean Journal of Plant Resources
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• v.25 no.5
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• pp.591-595
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• 2012

This study was conducted to investigate the possibility of changes in onion (cv. 'Turbo' and 'Changnyongdaego') bulb quality during storage at room and cold temperature. Increased weight loss was found in the onion bulb stored at both cold and room temperature conditions. 4% weight loss was found in bulbs stored at room temperature and 2% at cold storage as compared to fresh cultivated onion bulb; after three months. Initially, there was no significant difference in the firmness of bulbs between cultivars and storage conditions. Hunter a value of bulb stored at room temperature was higher than the value of bulb stored at cold temperature. 27% and 7.9% decay was found after three months in 'Changnyongdaego' and 'Turbo' cultivars stored under room temperature condition respectively. In contrast, only 2% decay was noticed in both cultivars stored at cold storage condition. Hunter L value of onion bulb gradually decreased in both room and cold temperature storage conditions. In conclusion, quality of onion bulb can be maintained until three months. For long term storage and quality maintenance, under room temperature conditions a resistance cultivar should be selected.

• Food Science and Preservation
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• v.17 no.5
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• pp.581-585
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• 2010

The effects of plastic container vent ratio on fruit quality during strawberry precooling and storage were analyzed. Plastic containers ($520mm{\times}355mm{\times}182mm$) were manufactured with bottom and side vents at areal ratios of 5%, 10%, 15% and 20%. Fruit was loaded at a volume ratio of 80% prior to pressure cooling and storage at $5^{\circ}C$. The internal fruit temperature was $18^{\circ}C$ and the times taken to attain $2^{\circ}C$ after precooling were 1 hour 9 minutes, 1 hour 13 minutes, 2 hours 2 minutes, and 2 hours 51 minutes at vent ratios of 20%, 15%, 10%, and 5%, respectively. To mimic the current distribution system, precooled strawberries were packaged in tray wrapping and stored at $5^{\circ}C$. Changes in weight, bruising, extent of decay, and firmness, were measured. Weight loss, bruising, and decay were highest at a vent ratio of 20%, lowest at a vent ratio of 15%, and moderate at vent ratios of 5% and 10%. No significant among-treatment difference in fruit firmness was evident.

• Food Engineering Progress
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• v.23 no.1
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• pp.55-61
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• 2019

For the vessel export of strawberries, modified atmosphere package (MAP) using polyamide (PA) film and linear low density polyethylene (LLDPE) film was investigated to extend the shelf life of strawberries. Because the temperature and relative humidity changes of the MAP were lower than the changes of the control, the weight loss of the MAP were lower than that of the control. The low oxygen level and high carbon dioxide level were effective to decrease the fungal decay rate and to increase the hardness of strawberries. The Hunter's color differences before and after storage showed no distinct difference between the MAP and the control. The lightness had a tendency to decrease while the redness increased. There were no significant changes of the soluble solids during the storage. The shelf life of strawberries could be extended to 16 days using the MAP considering the weight loss and the fungal decay rate. Thus, this MAP method using PA film and LLDPE film was effective to extend the shelf life of strawberries.

• Journal of Bio-Environment Control
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• v.33 no.2
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• pp.114-119
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• 2024

Rockwool substrate has superior physicochemical characteristics and is often used in crop cultivation. However, rockwool substrate has the disadvantages of high purchase cost and difficulty in disposal. Reuse of substrate can compensate for these disadvantages. Substrate must be disinfected and rehydrated during reuse, and various physicochemical changes during this process must also be considered. This study was to compare the physical properties of two types of rockwool substrates (reused and unused) and to evaluate the reuse potential of rockwool substrate by analyzing the chemical properties of the reused rockwool substrate during the rehydration process. The experiment on substrate physicochemical properties comparison was conducted from March to August 2023 using used rockwool substrates in tomato cultivation and unused rockwool substrates. Drainage time, drainage volume, and substrate weight were measured using load cells installed at the top and bottom of the irrigation monitoring system. The reused rockwool substrate weight and density were higher than those of the unused rockwool substrate, while the average drainage time after irrigation was 1.5 times longer for the reused rockwool than for the unused rockwool. The salinity concentration in different parts of the reused rockwool substrate was found to be lower in the reused rockwool substrate compared to the unused rockwool substrate. The electrical conductivity of the drainage was at its peak at the beginning of the drainage and decreased exponentially as the drainage volume increased. Change in electrical conductivity of the drainage over the irrigation time showed an exponential decay pattern. Through the experiments, the potential reusability of the rock wool substrate was assessed by conducting a comparative analysis of its physicochemical properties.