• Composites Research
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• v.27 no.5
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• pp.201-206
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• 2014

Utilizing waste materials in making useful products is a globally increasing trend. This can reduce the cost and environmental issues. In this study, oyster shell powder (OSP) is reinforced as a filler in polypropylene (PP) matrix to make a new composite. The purpose is to improve fire retardant properties of PP as a result of OSP reinforcement. Mechanical, fire retardant and water absorption properties of the new composite have been studied in this research. Concentration of OSP reinforcement in PP has been varied by wt% and its effect on the above mentioned properties has been observed. SEM (scanning electron microscopy) images of tensile and bending fractured surfaces have been taken to observe the failure mechanism during mechanical tests. An increase in the fire retardancy has been observed as a result of the OSP reinforcement while tensile strength decreased. Stiffness also increased with the addition of OSP in PP.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.268-275
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• 1997

High prices of raw materials used as media for the mushroom cultivation increased the cost of commercial production of oyster mushroom (Pleurotus ostreatus). In this study, garlic peels (Allium sativum f. pekinese) as an agricultural by-product were investigated to replace the saw dust for the bottle cultivation of oyster mushroom. Mycelial growth of oyster mushroom were examined by the extracts made from the sawdust, rice bran and garlic peels. The mycelial growth was very poor in the agar media containing the extracts of sawdust or garlic peels, but was good when those of the rice bran were added. In the polypropylene bottle experiment, the sawdust medium which ammended with minerals vitamin was essential for the production of the mushroom fruitbodies. The rice bran was considered to stimulate the mycelial growth, but not the development of basidiocarps. The garlic peel was not a factor to stimulate the production of mushroom fruitbodies, but a raw material ammended with the rice bran produced much amounts of mushroom. In this work, garlic peels ($10{\sim}70%$ v/v) added to the mixture of sawdust and rice bran (4 : 1, v/v) was considered to help the productions of mushroom fruitbodies. Based on the result, the replacement of expensive saw dust with inexpensive garlic peels was a good example to reduce production cost of the bottle cultivation of mushroom.

• The Korean Journal of Ecology
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• v.24 no.1
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• pp.19-26
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• 2001

Tributyltn, triphenyltin and their degradation products were quantitatively determined in sediments, seawater, and oysters (Crassostrea gigas) collected from Okpo Bay, Korea where a huge shipyard was located. The concentrations of TBT in sediment and oyster were in the range of 5∼2,050 ng/g and 387∼1,190 ng/g (astin on a dry weight basis), respectively. In seawater, it ranged from 19 to 84 ng/ℓ The distribution of TBT compound showed negative gradient from inner to outer bay, which indicates that the shipyard is the point source of TBT contamination in the bay. The contribution of TBT to butyltin concentration in sediment was above 57%. The pattern of TBT distribution was influenced by waterbreak transected the bay. TPhT concentration in oyster ranged from nd (not detected) to 52 ng Sn/g dry wt., whereas that in sediment and seawater was below detection limit. The biological concentration factor (BCF) in oyster was 1.1×10⁴.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.919-930
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• 2008

This study was conducted to survey the attitudes of oyster consumers and to analyze their purchase behaviors based on demographic variables. To accomplish this, a questionnaire that was developed based on content analysis and panel discussion was distributed to 467 general consumers. The majority of the respondents ate oysters (90.6%), although the proportion of oyster consumers increased with age. The primary reasons for not-eating oysters were odor (33.3%), flavor (16.7%) and concern for safety (11.9%). Most respondents consumed raw oysters (96.1%) during winter (70.0%) at discount stores (51.3%). Fishery wholesale markets were the most common places to purchase oysters for respondents in their 60 s, while the other groups reported that discount stores were the most common place to purchase oysters. Most respondents ate oysters the day of purchased (53.2%). Furthermore, most respondents (39.2%) reported that they consumed the oysters only after evaluating the appearance and odor and that they avoided oysters during summer for safety. Women were more likely to check the expiration date than men, while housewives were the most likely to check the expiration and usually kept the oysters at refrigerator. Overall, the results of this study suggest that the various types of oyster products must be targeted toward different demographic markets. Moreover, this study will be useful for promoting the safer and more effective consumption of oysters.

• Korean Journal of Human Ecology
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• v.15 no.2
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• pp.327-339
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• 2006

We have investigated the distribution of major local foods cultivated in Gwangju City and Jeollanam-Do in order to understand the food culture of Honam region. The local foods were divided into 4 classes: agricultural, aquatic, animal and other products. 124 species of local foods, including 51 agricultural products, 50 aquatic products, 6 animal products and 17 others, were identified from this region. In Jeollanam-Do area, the agricultural products have a variety of fruits and vegetables, and aquatic products have fishes. In particular, rice, cucumber, pear, anchovy, oyster, laver, oyster mushroom, shiitake mushroom, and honey were determined as major local foods in Jeollanam-Do area. Note that Mudeungsan watermelon is cultivated in Gwangju, and sweet smelt and cat fish caught only in Sumjin river and Tamjin river area. In recent years, pumpkin (Cucurbita maxima Duchesne), paprika, kiwi and melon were determined as major local foods in Jeollanam-Do. Furthermore, branding strategy of agricultural and animal products can be said to improve. Wild types of aquatic productions, mushrooms and wild edible greens have been decreasing, whereas cultivated production increasing. The kinds of special local foods in Gwangju City and Jeollanamdo area were influenced by geographical, religious and social factors.

• Journal of Mushroom
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• v.15 no.2
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• pp.73-77
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• 2017

In Korea, oyster mushroom is one of the commonly cultivated mushrooms. In 2013, the cultivation areas and products of oyster mushrooms were 60,039 M/T and 201 ha, respectively. Many species of oyster mushrooms are cultivated in various countries. These include Pleurotus ostreatus, P. florida, P. sajor-caju, P. eryngii, P. citrinopileatus, P. salmoneostramineus and P. cystidiosus. P. citrinopileatus is a yellow oyster mushroom famous for its health benefits such as anti-cancer and anti-oxidant effects. Therefore, a cultivar P. citrinopileatus 'Jangdari' was developed to improve yield and the ability to grow well at lower temperatures. Two parent strains 'Gumbit (KMCC02150)' and 'KMCC02145' were selected based on their morphological characteristics. 'Jangdari' was developed by the method of Mon-Mon crossing between monokaryons derived from 'Gumbit' and 'KMCC02145', and finally selected through continuous cultivation tests. The optimum temperature for mycelial growth was $30^{\circ}C$. The cultivar could grow well at high temperatures, especially $16{\sim}24^{\circ}C$. Fruiting body production per bottle (850 mL) was about 90.0 g. Stipe length and thickness of 'Jangdari' were similar to those of 'Gumbit'. 'Jangdari' was more resistant to low temperature than 'Gumbit', and thus it could be cultivated with oyster mushrooms (P. ostreatus). In addition, while cultivating 'Jangdari', it is not required to scrape out the upper side of bottle's sawdust medium; hence, its cultivation is expected to save energy and time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.66-71
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• 1981

In order to study the decomposition process of glycogen and protein of oyster during fermentation with salt, and the relationship between their breakdown products, the amounts of free reducing sugars and lactic acid were determined, and amino acid compositions were analysed. In addition, the amount of the available lysine which may help us to estimate the reaction of the free reducing sugars with the free amino acids was also determined. Glycogen and protein were gradually decomposed to free reducing sugars and lactic acid, and free amino acids, respectively, and the available lysine was slightly decreased during the fermentation process. Glutamic acid, aspartic acid, lysine and proline were relatively rich in the amino acid com-position of raw oyster protein while amino acids such as tryptophan, methionine, histidine and tyrosine were poor. It was noted that the decreased amino acids in the protein from the fermented oyster were valine, histine, isoleucine and lysine. As a respect to the free amino acids, proline, taurine, glycine, glutamic acid and alanine were abundant in the raw oyster and reached up to $69\%$ of the total fret amino acids. In the fermented oyster, proline, glutamic acid, glycine, alanine, aspartic acid and lysine were prevalently contained and marke about $65\%$ of the total free amino acids. The contents of free amino acids such as lysine, arginine, aspartic acid, glutamic acid, cysteine, isoleucine and tyrosine increased during fermentation while those of taurine, proline and leucine decreased.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.219-226
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• 2020

Over the last decades, great efforts have been devoted to reuse industrial wastes and by-products from various industries as supplementary cementitious materials in order to reduce carbon dioxide(CO₂) emission by reducing the use of Portland cement in construction. Oyster shell waste, originating from the fishery industry, is available in huge quantities in certain areas, and is generally discarded or landfilled. In this study, we aimed to reuse oyster shell as an alternative to limestone in limestone calcined clay cement(LC³). The oyster shell calcined clay cement(OC³) paste were produced and were characterized via X-ray diffraction, isothermal calorimetry, compressive strength tests, and thermogravimetry. The results revealed that OC³ pastes exhibited similar strength development and reactivities by pozzolanic reaction with LC³, which implies that oyster shell could be used as a substitute for limestone in LC³.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.93-99
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• 2007

The study was carried out to prepare spaghetti sauce with oyster (SSO) and the food components characteristics of the SSO were also compared to those of commercial spaghetti sauces (CSS). The optimal addition ratio of oyster for preparing SSO was 11% based on 100 g of SSO according to the results of organic acid content, Hunter color value, viscosity, and sensory evaluation. The reasonable $F_0$ value for the keeping storage of SSO was about 4 min. The proximate composition of SSO prepared under the optimal processing condition was 71.2% moisture, 2.8% protein, 6.9% crude lipid, and 3.2% crude ash. The results of sensory evaluation suggested that the quality of SSO was superior to that of CSS. However, there was no significant difference (p<0.05) in sensory evaluation on color between CSS and SSO. The total amino acid content (2,532.2 mg/100 g) of SSO was higher than that of CCS (2,305.7 mg/100 g). The contents of calcium and phosphorus of SSO were 25.7 mg/100 g and 48.7 mg/100 g, respectively. The calcium content/phosphorus content showed a suitable ratio for absorbing calcium. The total free amino content and the taste value were 1,040.2 mg/100 g and 151.26, respectively. The major taste-active amino acids were glutamic acid and aspartic acid.

• Journal of Mushroom
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• v.21 no.3
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• pp.118-125
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• 2023

We conducted an on-site application study at the livestock cooperative fertilizer plant to compare the composting period, temperature change, moisture content, and chemical properties between livestock manure compost using sawdust as a moisture regulator with those using spent oyster mushroom substrate. The composting period, moisture content, and fertilizer composition of compost containing spent oyster mushroom substrate did not differ from that of conventional compost mixed with sawdust after the first and second fermentation and post-maturation stages, it was suitable as a material for manufacturing livestock manure compost. The spent oyster mushroom substrate also lower the production cost of livestock manure compost by replacing the more expensive sawdust. The developed technology is expected to contribute towards the utilization of by-products of the oyster mushroom harvest while simultaneously producing high quality livestock manure compost.