• Korean Journal of Food Science and Technology
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• v.22 no.4
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• pp.445-450
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• 1990

Changes in weight, volume and density of petiole tissue of Chinese cabbage during salting and blanching were investigated. Rapid changes in mass and volume occurred within 4 hours during salting in 5% salt solution and the changes were nearly completed after 8h. After salting, the reduction of mass and volume ranged between $22{\sim}27%\;and\;22{\sim}35%$, respectively. Average density of the sample was found to be 0.88g/ml, and increased to 1.020g/ml after salting. Air content of the sample ranged from 0.093 to 0.120ml/ml cabbage, and about 70% of the initial content was expelled from the tissue by salting. The changes of physical properties of the cabbage during steam blanching were similar to those during salting, but their relative values were smaller. A linearization model for physical changes during salting and blanching was proposed.

• Food Science and Preservation
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• v.14 no.1
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• pp.42-46
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• 2007

To investigate the effects of hot water treatment and modified atmosphere packaging (MAP), compared with non-packaging, of 'Fuji' apples during 18 weeks of storage at $0^{\circ}C$, apple weight loss, firmness, titratable acidity, total ascorbic acid and sensory characteristics were measured After 18 week of storage, the weight loss of MAP-treated apples was 1%, while untreated controls lost 22% of weight Weight loss reduction film packaging was more effective than that afforded by hot water treatment. The firmness reductions in control apples, those receiving hot water treatment those receiving packaging only, and those receiving both hot water treatment and packaging, were 37%, 22%, 10% and 6%, respectively. The titratable acidity was 40% in control apples and respectively, 37%, 32% and 27% in the three groups mentioned above. The total ascorbic acid contentuntreated control apples decreased by 70% after 18 weeks of storage. The total ascorbic acid contentof apples receiving both hot water use of both packagingand hot water treatment to preserve 'Fuji' apple quality.

• Food Science and Preservation
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• v.10 no.1
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• pp.6-10
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• 2003

The objective of this study was to investigate the effect of browning inhibitor and vacuum packaging on minimally processed sweet pumpkin. The browning inhibitor were lo/e of ascorbic acid, citric acid, NaCl, MgCl$_2$and their combination. For the minimal processing, sweet pumpkin was sliced and strip-cut followed by dipping in the solution of browning inhibitor. Effective browning inhibitors fer slice sweet pumpkin were ascorbic acid, NaCl and MgC1$_2$, and those fer thin strip were combination and ascorbic acid. The hardness of minimally processed sweet-pumpkin repeated increasing and decreasing and decreased in the final of storage. However the change pattern of hardness was different according to cutting method. Magnesium chloride treatment was generally high grade on sensory characteristics. Sweet pumpkin treated with citric acid was distinguished on carbon dioxide generation and oxygen exhaustion.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.295-302
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• 2014

This study investigated the effects of storage temperature and time on the physicochemical properties of eggs, and the corelationship of quality factors with egg freshness and the palatability during storage. As storage temperature and time increased, weight loss significantly increased (p<0.05), while the specific gravity, Haugh unit, yolk index, albumen index, and yolk viscosity decreased significantly (p<0.05). A multiple regression equation of $Y_1$ (freshness)=$106.50286-0.81196X_1$ (weight loss)-$77.51667X_5$ (specific gravity)-$2.27156X_8$ (yolk pH)+$0.00178X_{16}$ (yolk viscosity) with $r^2$=0.89 was obtained for the evaluation of egg freshness. Also, sensorial palatability through the multiple regression equation was determined as $Y_2$ (palatability)=$104.98174-0.81466X_1$ (weight loss)-$76.53434X_5$ (specific gravity)-$2.20338X_8$ (yolk pH)+$0.00178X_{16}$ (yolk viscosity) with $r^2$=0.89 indicating that weight loss, specific gravity, yolk pH and yolk viscosity are major factors that affect the freshness and palatability of eggs during storage.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.180.1-180
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• 2003

양파건조분말 제조에 있어 품질고급화를 목적으로 건조방법을 달리하여 건조과정 중 양파의 이화학적 품질특성 변화를 조사하였다. 수분함량변화는 50'E 열풍건조의 경우 건조 5일에 수분함량 10% 이하로 건조가 되었으며 건조1일에 수분함량 5.30%로 분말화상태가 가능했다. 또한, 4$0^{\circ}C$ 진공건조의 경우는 건조기간 3일째에 수분함량이 6.05%로 거의 건조가 완료된 상태였으며 건조 5일째는 수분함량 5.23%를 나타내어 분말화하였다. -7$0^{\circ}C$ 동결건조의 경우 건조 7일째에 수분함량 5.10%를 유지하여 분말화가 가능하였다. 건조과정 중 양파의 중량감소율 변화는 5$0^{\circ}C$ 열풍건조의 경우 건조 3일째 중량 감소율이 89.6%로 매우 급격한 감소현상을 보였으며, 4$0^{\circ}C$ 진공건조의 경우는 건조 2일째 중량감소율이 84.4%까지 급격한 감소현상을 나타내었고, 또한, -7$0^{\circ}C$ 동결건조의 경우는 건조 최종일인 7일째 중량감소율은 94.9%를 나타내었다. 건조과정 중 갈색도변화는 5$0^{\circ}C$ 열풍건조와 4$0^{\circ}C$ 진공건조의 경우 건조 3일째까지 각각 흡광도(420nm)값을 2.119와 1.941로 급격한 증가현상을 나타낸 후 감소하는 경향을 나타내었고, -7$0^{\circ}C$ 동결건조의 경우는 건조 최종일인 7일째 흡광도가 1.173으로 가장 낮은 갈색도변화를 보였다. 건조과정 중 색도변화에 있어‘L’값의 변화는 5$0^{\circ}C$ 열풍건조의 경우가 양파의 내부와 외부면의 초기 L값이 77.40과 74.82에서 최종 L값이 63.72와 65.07로 4$0^{\circ}C$ 진공건조와 -7$0^{\circ}C$ 동결건조의 L값 변화보다 큰 변화를 보였고, 또한‘a’값과 ‘b’값의 경우도 마찬가지로 5$0^{\circ}C$ 열풍건조의 경우가 양파의 내부와 외부면의 적색도 및 황색도 변화가 크게 일어나는 경향을 나타내었다. 건조과정 중 vitamin C의 함량변화는 건조에 의한 수분함량의 감소로 vitamin C의 함량은 상대적으로 증가하였고, -7$0^{\circ}C$ 동결건조의 경우가 가장 높은 vitamin C의 증가량을 나타내었고, 그와 반대로 5$0^{\circ}C$ 열풍건조의 경우는 열에 의한 vitamin C의 변화로 인한 상대적 증가량은 감소하는 경향을 나타내었다.

• Korean Journal of Agricultural Science
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• v.30 no.2
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• pp.154-163
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• 2003

This study was performed to examine the freezing and thawing properties of the high strength concrete using recycled coarse aggregate. The recycled coarse aggregate was replaced by 0%, 25%, 50%, 75% and 100% of natural crushed aggregate. The compressive strength of the concrete used recycled coarse aggregate was shown in more than $400kgf/cm^2$ at the curing age 28 days. The weight loss ratio by freezing and thawing was shown in less than 1% at all mix type. The pulse velocity and relative dynamic modulus were decreased with increasing the freezing and thawing cycles. Also, durability factor for the freezing and thawing were decreased with increasing the content of recycled coarse aggregate. But, recycled concrete replaced with recycled coarse aggregate 100% was shown in more than 60 by durability factor in freezing and thawing of 300cycles Accordingly, these recycled coarse aggregate can be used for high strength concrete.

• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.45-52
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• 2007

The anatomical characteristics of Quercus variabilis woods carbonized at 310 to $350^{\circ}C$ were examined with an optical and scanning electron microscopy, and an X-ray diffraction analysis. Dimensional change and weight loss were also investigated. Volume of wood samples decreased with increasing the carbonization temperature, and checks were developed along with radial direction. Vessel diameter in tangential direction showed higher shrinkage than that in radial direction. Weight loss of samples increased with increasing carbonization temperature. Especially, the weight loss rapidly increased at the temperature ranging from 330 to $340^{\circ}C$. SEM study presented that the cell walls of samples carbonized at below $320^{\circ}C$ showed the layering structure. However, it was revealed that the layering structure was disappeared at $330^{\circ}C$ and over and showed an amorphous-like structure without cell wall layering. Interestingly, the existence of cellulose crystalline substance at $340^{\circ}C$ was confirmed by X-ray diffraction analysis and it was not detected at $350^{\circ}C$. Consequently, it is considered that the critical temperature for carbonization of wood was around $350^{\circ}C$.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.117-122
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• 1997

The conditions of cold storage of Citrus unshiu Marc. var. miyagawa produced in Cheju were investigated. Compared to the citrus fruits stored at room temperature, the content of soluble solids, total sugar, vitamin C and specific gravity decreased slightly on the fruits stored at $4^{\circ}C$ and 87% relative humidity. Decay ratio and weight loss were below 10% on keeping freshness relatively till late of March during cold storage. Weight loss, decrease of firmness and soluble solids occured gradually during cold storage. Nevertheless seal-packaging with 0.02 mm LDPE film or wax-coating of citrus fruits were effective on weight loss and appearance, decay ratio increased for long-term storage. It was needed to control humidity in cold chamber for preventing from decay and weight loss. Edible part ratio was decreased gradually by respiration, and peel and tissue of fruits were softened slightly by 60 days of cold storage. Decay ratio and weight loss of full-ripened citrus fruits were little during the storage for 100 days, compared to the fruits harvested early. Appearance and taste of citrus fruits stored for 4 month were good relatively, but decay occured rapidly on seal-packaging fruits putting out of cold room for a few days. Because of the difficulty of long-term storage for early variety of Citrus unshiu, the conditions and periods of cold storage would be determined after considering the physicochemical properties of fruits.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.1-7
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• 2008

Quality attributes of welsh onion (Allium fistulosum L.) as affected by harvest timing (November, December 2006 and January 2007) and storage temperature (5, 10 and $20^{\circ}C$) were investigated in terms of respiration rate, weight loss, decay rate, color, hardness, sensory quality. A higher respiration rate was found when welsh onions were harvested later and storage temperature was higher. A smaller weight loss was observed in welsh onions that were harvested in November and stored at temperature of $5^{\circ}C$, demonstrating a 9.35% reduction. In other words, there were a minimum difference of 2.15% and a maximum difference of 9.92% between the weight loss in test samples harvested in November and those of test samples harvested in other months. The decay rate was higher in welsh onions harvested in January. The degree of color was more stable in test samples kept at temperature of $5^{\circ}C$ than those kept at higher temperature (10 and $20^{\circ}C$). There were, however, no significant differences in color changes among test samples harvested at different times of the year. Thus color change is closely associated with temperature. Also, welsh onions were harvested in November and stored at temperature of $5^{\circ}C$ showed a good sensory quality.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.205.1-205
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• 2003

본 연구는 국내 유통쌀의 포장재로 널리 이용되고 있는 지대포장재와 합성수지계열의 PE 및 AL 포장재의 저장기간에 따른 품질특성을 구명하고, 포장재의 투습도 5~700g/$m^2$범위의 4수준에 대하여 함수율, 중량 및 지방산가의 변화를 측정하여 포장재의 적정 투습도를 결정하는데 목적이 있다. 지대, PE 및 AL포장재의 저장 4주 후의 중량은 7.8, 0.1 및 1.5%감소하였으며, 함수율은 지대포장의 경우 3.7%(w.b.)감소하였다. 지방산가는 저장 4주 후에 지대포장은 9.4, PE포장재는 42.0, AL포장재는 16.8(mg KOH/100g)로 나타났다. 저장온도 20 및 3$0^{\circ}C$에서의 포장재 투습도에 따른 중량, 함수율 및 지방산가의 변화를 고려했을 때 130~210g/$m^2$이 적정한 것으로 나타났다.