• Korean Journal of Environmental Biology
• /
• v.28 no.4
• /
• pp.202-211
• /
• 2010

The variations of physico-chemical factors and the species compositions of phytoplanktons were investigated to analyze the marine ecosystem at the depths during summer in the coast of Dokdo (stations DOK 1-3). The mean values of conductivity (48.9 mS $cm^{-1}$), salinity (32.9 psu) and total suspended solids (57.9 mg $L^{-1}$) were the highest in DOK 1. The biomass (Chl-a) of phytoplanktons was the highest in the surface of DOK 1 (2.61 ${\mu}gL^{-1}$). By the means of physicochemical factors (salinity, turbidity, Chl-a, TN, TP and Si), the water estimated in the coast of Dokdo was more eutrophicated than that in 2008. The phytoplanktons were a total of 42 species in Dokdo, which were composed of 33 species (78.6%) for Bacillariophyceae and 9 species (21.4%) for Dinophyceae. The standing crops of phytoplanktons were the highest ($18{\times}10^3$ cells $L^{-1}$) in the surface of DOK 2 and in the surface of DOK 3, while they were the lowest ($2{\times}10^3$ cells $L^{-1}$) at depth of 40 m of DOK1 and at depth of 30 m of DOK 3. The dominant species of phytoplanktons were Chaetoceros castracanei ($6{\times}10^3$ cells $L^{-1}$) in the surface, Rhizosolenia alata f. gracillima ($3{\times}10^3$ cells $L^{-1}$) at depth of 20 m and Protocentrum compressum ($4{\times}10^3$ cells $L^{-1}$) at the depth of 30 m of DOK 1. At the surface of DOK 2, the dominant species was Bacillaria paxillifer ($6{\times}10^3$ cells $L^{-1}$), while it was Hemiaulus indicus ($12{\times}10^3$ cells $L^{-1}$) at the surface of DOK 3. The DOK 1, which is affected by upwelling, whirlpool and circulation due to the East Korean Warm Current, was the most eutrophicated water body among three stations. The monitoring of marine ecosystem in the coast of Dokdo should be continued to propose the alternatives for water quality and species conservation and to purify the eutrophicated water body due to artificial pollutants as well as natural effectors by the global warming, the climatic change, etc.

• Korean Journal of Soil Science and Fertilizer
• /
• v.39 no.4
• /
• pp.224-229
• /
• 2006

Utilization of organic by-product fertilizers has many beneficial effects on agricultural activities and in aspects of the disposal of enormous amounts of livestock manure. Most of these beneficial effects are related to the improvement of soil condition, such as fertility status and physicochemical quality of soil. But, appropriate indexes are needed to effectively manage the quality of organic by-product fertilizers amended on soil. To find chemical and physical standard to control the compost quality, the changes in chemical and physical characteristics of organic by-product fertilizers during composting were investigated, and also an appropriate physical method for this end. The results showed chemical properties, such as humic acid content, OM/N ratio, cation exchange capacity and salt content, had significant relationships during the composting. The water content, particle and bulk densities, particle size and color indices, as physical properties, were also applicable factors for the quality control of compost.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.10
• /
• pp.1437-1449
• /
• 2006

Thirty six pre-weaned Barbari kids at 4 months age were reared on four rations computed using coarse cereal grains and by-products of pulses and oil seeds with Crude Protein (CP) and Total Digestible Nutrients (TDN) of 12 and 55% (Low protein Low energy); 12 and 60% (Low protein High energy); 14 and 55% (High protein Low energy); and 14 and 60% (High protein High energy), respectively. After 180 days on feed, male animals ($4{\times}5=20$) were slaughtered to study the effect of diet on carcass characteristics and meat quality. To asses the effect, if any, of such diet on product quality, meat balls were prepared and evaluated for quality changes when fresh as well as during storage ($-20{\pm}1^{\circ}C$). Feeding a ration with CP12 and TDN 60% (LH) to kids produced animals with highest slaughter weight (20.3 kg) yielding higher carcass weight and dressing percentage, lean (65.6%) and fat (6.6%) contents with low bone and trim losses. Although total variety meat yield was markedly higher in HL, the non-carcass fat deposition was relatively higher in LH carcasses. The water activity ($a_w$) of fresh goat meat ranged from 0.994-0.995 and total cholesterol 72.8-90.5 mg/100 g meat. The pH was high in HL and HH meat resulting in decreased ($p{\leq}0.05$) extract release volume (ERV). Meat balls were prepared using meat obtained from goats fed different rations (treatments) and stored at $-20{\pm}1^{\circ}C$. They were evaluated on day 0 and months 1, 2, 3, 4 for physicochemical, microbiological and organoleptic changes. Overall moisture (%), $a_w$, TBA number and pH value were 67.9, 0.987, 0.17, 6.6 respectively and were not affected by treatments except pH that was significantly ($p{\leq}0.01$) lower on LH. As the storage period advanced moisture, pH, $a_w$ and TBA number increased irrespective of treatments. Feeding various diets had no marked effect on microbial load of meat balls but with increasing storage period Standard Plate Count (SPC) and psychrotrophs declined ($p{\leq}0.01$). Treatment LL and LH produced meat balls with better flavour.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.1
• /
• pp.157-165
• /
• 2020

Objective: The objective of this study was to compare the quality of dry-aged beef from cull Hanwoo cows slaughtered at 60 or 80 months old. Methods: A total of eight cull Hanwoo carcasses with a quality grade of 3 (low-grade) were selected and divided into two age groups: 63.5±2.5 months old (n = 4) and 87.8±4.5 months old (n = 4). Whole longissimus thoracis et lumborum from the 11th rib to the last lumbar vertebrae, including the back fat, was removed from the carcass at 24 h postmortem and aged for 50 days in darkness at a temperature of 2℃±1℃, a relative humidity of 85% and an air flow of 2 m/s. The sampling was performed aseptically after 0, 20, 24, 40, and 50 days of aging. Results: Regardless of the aging period, aging increased the lightness (p<0.05), redness (p<0.05) and yellowness (p<0.05) at initial blooming (90 min after slicing) and the overall acceptance (p<0.05). No further tenderization effect was found after 20 days of aging, but aging for 50 days significantly increased the lipid oxidation (p<0.05). The generation of aroma volatiles in the roast steak from aged samples was higher (p<0.05) than that of non-aged samples. No significant effect of age at slaughter was found on the color, pH, water-holding capacity, cooking loss, shear force value, bacterial counts, volatile basic nitrogen, consumer acceptance, lipid oxidation, fatty acid composition or aroma volatiles. Conclusion: The quality of dry-aged beef obtained from cull Hanwoo cows slaughtered at either 60 or 80 months old with similar quality grade was comparable and extending dry aging for more than 40 days is not recommended considering the costs and further lipid oxidation.

• Food Science of Animal Resources
• /
• v.34 no.3
• /
• pp.395-402
• /
• 2014

The current study was conducted to identify technology for the production of high quality pork, based on the meat consumption habits of consumers. Macsumsuk, a type of kaolinite (a clay mineral), and/or a mixture of herbs (Mori Folium, Sophorae Radix, Glycyrrhizae Radix, Citri Leiocarpae Exocarpium, and Pogostemi Herba) were added to the diets of fattening pigs. Sixty barrow pigs (4 kinds of treatment ${\times}5$ pigs/treatment ${\times}3$ replicates) were randomly assigned to either the Control (no additives), T1 (3% Macsumsuk), T2 (3% Herb mixtures), or T3 (3% Macsumsuk + 3% Herb mixtures) groups, and were fed the diets for 60 d. Dressed weights were in the order of T1 ($93.40{\pm}4.68kg$) > T2 ($91.40{\pm}6.52kg$) > Control ($88.80{\pm}1.57kg$) > T3 ($86.80{\pm}2.01kg$). Back-fat thickness of the Control animals ($23.2{\pm}1.03mm$) was significantly greater than that of the various treatment groups (p<0.01). Numeric values representing the carcass yield and quality grade were higher for all the treated groups than the Control group, thought the difference was not statistically significant. Crude fat content was significantly higher in the Control group ($2.23{\pm}0.34%$) than in the treated groups (p<0.05). The addition of both Macsumsuk and herb mixtures into the diets of the pigs significantly reduced cooking loss of the pork compared to the Control (p<0.05). No statistically significant changes were observed in the shear force (average $5.87{\pm}0.54kg/cm^2$), water holding capacity (average $54.59{\pm}3.16%$), or CIE values of the pork, whereas cholesterol levels significantly decreased (p<0.01) in those fed Macsumsuk and/or the herb mixtures. No significant changes in fatty acid composition, total saturated fatty acid (SFA), total unsaturated fatty acid (UFA), or UFA/SFA ratios were observed by any of the treatments. In conclusion, the results obtained from this study suggest that the addition of Macsumsuk and/or herb mixtures into the diets of growing and fattening pigs improves the pork quality by reducing cooking loss, decreasing cholesterol content, and enhancing sensory characteristics.

• Korean journal of food and cookery science
• /
• v.17 no.5
• /
• pp.490-496
• /
• 2001

The purpose of this study was to investigate the effects of ingredients(spices and medicinal plants) on the physicochemical properties of Pyunyuk a Korean style-cooked pork. Pyunyuk samples were prepared by the following 5 cooking conditions: Control(pork, water), A(pork, water, soy sauce), B(pork, water, soy sauce, onion, ginger), C(pork, water, soy sauce, onion, ginger, licorice, cinnamon) and D(pork, water, soy sauce, onion, ginger, licorice, cinnamon, clove and chestunt inner skin(CIS). The contents of ash, crude protein in loin and shank Pyunyuk were not significantly different among Pyunyuk samples, but crude fat content of C, D were significantly lower than control, A and B(p＜0.05). In Hunter’s color values of Pyunyuk, the lightness(L) was decreased by the addition of multiple ingredients, whereas the redness was increased. In mechanical characteristics, the hardness of control was the highest among the samples(p ＜0.05). In sensory evaluation, sample D obtained the highest score in flavor, taste, hardness, cohesiveness, springiness, gumminess and overall acceptability(p<0.05), and it was most preferred by the panels. There were higher negative-correlations between mechanical hardness and sensory characteristics of flavor, taste, cohesiveness, gumminess, brittleness and overall acceptability. From these results, it could be concluded that Pyunyuk ingredients(herbs and medicinal plants) reduce the content of crude fat, increase the tenderness and improve the flavor and taste of pork during cooking.

• Food Science of Animal Resources
• /
• v.27 no.4
• /
• pp.432-439
• /
• 2007

This study was performed to investigate the physicochemical properties and antioxidative activities of water or methanol extracts of Bokbunja (Rubus coreanus), and pork patties containing bokbunja extract at various levels. The total phenolic content of methanol extract (6.76 g/100 g, dry base) was higher than that of water extract (3.38 g/100 g, dry base). In addition, methanol extract had higher 1,1'-diphenyl-2-picrylhdrazyl (DPPH) radical scavenging activity than water extract at low concentrations (0.025-0.1%). However, no significant differences were found at high concentrations (0.2% or higher) (p>0.05). The DPPH radical scavenging activities of methanol and water extracts were 76.97% and 74.87% at 0.2% level, respectively. The lightness and yellowness values of pork patties containing Bokbunja extract decreased with increasing concentrations. The thiobarbituric acid reactive substances (TBARS) in pork patties with Bokbunja extract were lower than that of the control (p<0.05). The antioxidative activities increased with increasing concentrations of Bokbunja extract. In conclusion, Bokbunja extract might be used as a natural antioxidant in meat products, however levels lower than 3% will be required to prevent quality defects in pork patties.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.4
• /
• pp.463-470
• /
• 1998

To improve muscle quality and prolong freshness of sashimi, the effects of freezing-thawing condition on physicochemical and rheological properties of plaice muscle were investigated. Muscle tested were frozen with quick freezing (liquid nitrogen gas) or slow freezing ($-15^{\circ}C$ air). Transition time of zone of ice crystal formation was within 10 minute for quick freezing and 110 minute for slow freezing. Time required for thawing to $0^{\circ}C$ in muscle temperature by various thawing methods was shortest with $25^{\circ}C$ tap water, followed by $15^{\circ}C$ tap water, $10^{\circ}C$ tap water, $25^{\circ}C$ air, $5^{\circ}C$ tap water and $0^{\circ}C$ cold water. Breaking strength of muscle was higher in quickly frozen sample than in slowly frozen sample. According to sashimi term, changes in breaking strength of muscle did not show any difference in quickly frozen sample, while showed significant difference in slowly frozen sample. The remaining content of ATP was not effected by freezing speed, and ATP content was apt to higher in quickly thawed sample than in slowly thawed sample. IMP was the majority of ATP and it's related compounds of sample after freezing and thawing. Collagen matrix was weakened markedly in slowly frozen sample than in quickly frozen sample.

• The Korean Journal of Food And Nutrition
• /
• v.17 no.2
• /
• pp.111-119
• /
• 2004

A new type of drinkable yoghurt was prepared to develop a functional yoghurt. Skim milk containing 0.4-1.0％(w/v) water extract of omija(Schizandra chinensis Baillon) was fermented by the mixed strains of Lactobacillus acidophilus and Streptococcus thermophilus. Quality characteristics of the drinkable yoghurts were evaluated in terms of compositions, keeping-quality(pH, titratable acidity, number of viable cells) and sensory properties. The drinkable yoghurts added with water extract of Schizandra chinensis were composed of 2.92-3.03％ protein, 9.98-10.23％ lactose, 0.81-1.08％ fat, 16.21-16.64％ total solid, and 14.57-15.17％ solid-not-fat. The L values(brightness) were significantly lower in the yoghurts containing water extract of Schizandra chinensis than that of the control which had no water extract of Schizandra chinensis, while the a values(redness) and b values(yellowness) were significantly higher than those of the control. The pH, titratable acidity and number of viable cells of the lactic acid bacteria of all yoghurts were not changed during the storage at 4$^{\circ}C$ for 15 days, while the pH and titratable acidity were remarkedly changed during the yoghurts stored at 20$^{\circ}C$ for 15 days. The drinkable yoghurts containing 0.4％(w/v) water extract of Schizandra chinensis added 15％(w/v) oligosaccharide, or 0.6％(w/v) water extract of Schizandra chinensis added 20％(w/v) oligosaccharide had the highest sensory score in taste and overall acceptability among the treatments. From the results, Schizandra chinensis was a useful natural additive with the bioactive effect by provision of a acceptable physicochemical and sensory properties in the drinkable yoghurt.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.2
• /
• pp.269-276
• /
• 2016

This study was conducted to determine the inactivation effects of slightly acidic electrolyzed water (SAEW) on microorganisms attached to salted Chinese cabbage and food materials of kimchi, such as slice radish and green onion. In addition, changes in microbial and physicochemical quality of manufactured kimchi during storage at $4^{\circ}C$ for 4 weeks were investigated. Compared to the untreated control with tap water, total bacterial counts (TBC) of Chinese cabbage, slice radish, and green onion were reduced by 1.75, 1.68, and 1.03 log CFU/g at dipping times of 20 min, 5 min, and 10 min, respectively, upon treatment with 30 ppm SAEW at $40^{\circ}C$. Effect of microbial inhibition was higher in salted Chinese cabbage brined in 10% salt (w/v) of 30 pm SAEW at $40^{\circ}C$ than in untreated control with tap water, as indicated by 1.00 log CFU/g reduction. TBC of kimchi manufactured with materials treated with 30 ppm SAEW at $40^{\circ}C$ was not significantly affected compared to untreated control, although coliforms were remarkably reduced compared to the untreated control. At the beginning of storage (1 weeks), TBC and lactic acid bacteria (LAB) counts increased by approximately 9 and 7.66~8.18 log CFU/g, respectively, and coliforms were completely eliminated. The pH and acidity of kimchi at 2 weeks were 4.34~4.49 and 0.55~0.66%, respectively, and then slowly decreased. The texture (firmness) of kimchi decreased with storage time, but the difference was not significant. This combined treatment might be considered as a potentially beneficial sanitizing method for improving the quality and safety of kimchi.