• Food Science of Animal Resources
• /
• v.37 no.4
• /
• pp.571-578
• /
• 2017

This study aimed to determine the optimal ratio of natural calcium powders (oyster shell and egg shell calcium) as synthetic phosphate replacers in pork products. Ground pork samples were subjected to six treatments, as follows: control (-) (no phosphate added), control (+) (0.3% phosphate blend added), treatment 1 (0.5% oyster shell calcium powder added), treatment 2 (0.3% oyster shell calcium powder and 0.2% egg shell calcium powder added), treatment 3 (0.2% oyster shell calcium powder and 0.3% egg shell calcium powder added), and treatment 4 (0.5% egg shell calcium powder added). The addition of natural calcium powders resulted in an increase in the pH values of meat products, regardless of whether they were used individually or mixed. The highest cooking loss was observed (p<0.05) in the negative control samples, whereas the cooking loss in samples with natural calcium powder added was similar (p>0.05) to that in the positive control samples. CIE $L^*$ values decreased as the amount of added egg shell calcium powder increased. CIE $a^*$ values were higher (p<0.05) in samples containing natural calcium powder (treatments 1, 2, 3, and 4) than in the positive control. The combination of oyster shell calcium powder and egg shell powder (treatment 2 or 3) was effective for the improvement of textural properties of the pork products. The findings show that the combined use of 0.2% oyster shell calcium and 0.3% egg shell calcium should enable the replacement of synthetic phosphate in the production of cooked pork products with desirable qualities.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.42 no.2
• /
• pp.93-98
• /
• 2000

This study is performed to evalute experimentally the nondestructive properties on the concrete that is treated with crushed oyster shell powder of 0.15m or smaller in diameter. The ultrsonic pulse velocity of crushed oyster shell concrete(COSC) is in the range of 4.110-4.267m/s, and the dynamic modulus of elasticity of COSC range from 288$\times$10$^3$ to 318 $\times$10$^3$kgf/$\textrm{cm}^2$. The ultrasonic pulse velocity and dynamic modulus of elasticity are similar to those of normal portland cement concrete. The highest ultrasonic pulse velocity and dynamic modulus of COSC are measured at the 2.5% addition rate by weight of crushed oyster shell powder. The acid-resistance in increased of the content of crushed oyster shell powder. The acid-resistance of COSC with 15% addition rate by weight of crushed oyster shell power is 1.6 times greater than that of normal portland cement concrete. It is concluded that the addition of crushed oyster shell powder to normal portland cement concrete contributed to improve the nondestructive properties of concrete.

• Korean journal of food and cookery science
• /
• v.26 no.2
• /
• pp.188-197
• /
• 2010

In this study, the quality characteristics and storage properties of gat kimchi added with oyster shell powder and Salicornia herbacea powder were investigated during a storage time of 80 days at $5^{\circ}C$. After storage for 80 days, the average calcium contents were significantly higher in the kimchi containing the oyster shell powder and Salicornia herbacea powder than the control. In addition, the average hardness value was significantly higher in the OS4 group(oyster shell powder at 4% and Salicornia herbacea powder at 2%) than the control group, as well as the OS10 group(oyster shell powder at 10% and Salicornia herbacea powder at 2%) during storage for 80 days. The hunter b value of the OS4 group was significantly lower than the control group. During fermentation, gat kimchi containing the oyster shell powder and Salicornia herbacea powder had a higher pH and a lower acidity value than the control group. In terms of sensory evaluation, there were no significant differences between the control and calcium-added kimchi during fermentation. After 40 days of storage, the OS4 group showed a lower total viable count, as well as lower lactic acid bacteria, yeast and E. coli, as compared with the control and OS10 groups. Based on the microbial load, the gat kimchi containing the oyster shell powder showed limitations in terms of shelf life.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.11a
• /
• pp.33-34
• /
• 2022

The purpose of this study was to provide basic data for applying oyster shells and egg shells as fireproof cladding materials by substituting fine aggregates for oyster shell powder and egg shell powder, and comparing strength and fire resistance performance. The reason for the high strength was thought to be that the oyster shell had higher strength than the egg shell itself, and both ESP and OSP were measured at a backside temperature of less than 500℃, so it was judged that it could be used as a fireproof coating for steel structures.

• Journal of Powder Materials
• /
• v.23 no.3
• /
• pp.221-227
• /
• 2016

Waste oyster shells create several serious problems; however, only some parts of them are being utilized currently. The ideal solution would be to convert the waste shells into a product that is both environmentally beneficial and economically viable. An experimental study is carried out to investigate the recycling possibilities for oyster shell waste. Bulk ceramic bodies are produced from the oyster shell powder in three sequential processes. First, the shell powder is calcined to form calcium oxide CaO, which is then slaked by a slaking reaction with water to produce calcium hydroxide $Ca(OH)_2$. Then, calcium hydroxide powder is formed by uniaxial pressing. Finally, the calcium hydroxide compact is reconverted to calcium carbonate via a carbonation reaction with carbon dioxide released from the shell powder bed during firing at $550^{\circ}C$. The bulk body obtained from waste oyster shells could be utilized as a marine structural porous material.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.11a
• /
• pp.94-95
• /
• 2020

Oyster shells are characterized by coarse and coarse grains, but similar in strength to sand, and egg shells are fine grains but weak in strength. In terms of supply and demand of raw materials, oyster shells can be supplied only in limited periods and regions in winter and south coast of the year, but egg shells have the advantage of being able to supply and supply nationwide 365 days. This study aims to study the change in strength characteristics by mixing oyster shell powder and egg shell powder with the same particle size and mixing up to 150%. The conclusions of the flexural and compressive strength tests of mortar mixed with oyster shell powder and egg shell powder are as follows. The 7-day flexural and compressive strength with ESP added and the 3-day flexural and compressive strength with OSP added were similar, which is thought to be because the strength of OSP is higher than that of ESP.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.6
• /
• pp.383-387
• /
• 2004

Effects of oyster shell powder as a liming material were investigated in an apple orchard. Soil texture of the apple orchard was silty clay loam (Upyeong series with 7% of slope) and topsoil pH was 5.6. Treatments of 1,590 kg oyster shell powder $ha^{-1}$ and calcium-magnesium carbonate as much as oyster shell powder were included in the experiment. With treatments of oyster shell powder and calcium-magnesium carbonate, the length, number and diameter of new branches and the diameter of main, secondary and side branches increased in comparison with control. With oyster shell powder application, soil pH increased from 5.6 to 6.8 at the harvest. In addition, it increased exchangeable Ca from 2.6 to $4.2cmol_c\;kg^{-1}$. But it didn't make any difference in chlorophyll, sugar and malic acid contents. The apple weight per fruit of oyster shell powder application was 9 g more than that of control. Apple yield was highest ($37,000kg\;ha^{-1}$) in the oyster shell powder treatment, and the yield increase was significantly different at 5% level LSD. We concluded that the oyster shell powder can be an alternative of lime and effective to restore soil nutrient balance in apple orchard soil.

• Journal of Environmental Health Sciences
• /
• v.26 no.2
• /
• pp.30-33
• /
• 2000

The objective of this study is to examine the subsitiution effect of the waste oyster shell powder as the conditioning agent in municipal wasterwater sludge dewatering process. Beacuse the oyster shells have a large amount(about 38% by weight) of alkaline minerals, such as calcium and magnesium, they are thought to have the potential as a good conditioning agent. In this study, the physico-chemical properties of powdered oyster shells (75${\mu}{\textrm}{m}$ or 200 mesh) and the dewatering characteristics of municipal waste water sludge using powdered oyster shells and CaCO3 are investigated. The conclusions are as follows, 1. Oyster shell could produce calcium ions up to 14ppm at pH-7.0, and this represents that oyster shell is a potential properties as a good conditioner. 2. 100ml of wastewater sludges, conditioned with pretreated oyster shell, are dewatered to the level of 25% solid concentration. 3. Wasterwater sludges, conditioned with oyster shell and CaCO3 are dewatered to the level of 32% solid concentration. And this shows that two-stage combined conditioning process is desirable than the one-stage conditioning process.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.135-136
• /
• 2017

Oyster shell is produce by shucking process in oyster farming in southern coast of Korea. In average, about 6.7kg of oyster shell is produced as an industrial waste for 1kg of oyster flesh, and even only in last year, it is estimated that about 150,000 ton of oyster shell is produced. Oyster shell is light weighted and the strength characteristic of it is similar to send. So we produced mortar test piece using grounded oyster shell powder according to Filler and reviewed Fireproof Performance.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.10a
• /
• pp.58-59
• /
• 2016

Oyster shell is produced by shucking process in oyster farming in southern coast of Korea. In average, about 6.7kg of oyster shell is produced as an industrial waste for 1kg of oyster flesh, and even only in last year, it is estimated that about 150,000 ton of oyster shell is produced. Oyster shell is light weighted and its strength characteristic is similar to sand. So we produced mortar test piece using grounded oyster shell powder under 0.6mm, 0.6~1.2mm, 1.2~2.5mm, 2.5~5.0mm of its particle size according to fine aggregate standard and reviewed strength Properties.