• Food Science and Preservation
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• v.24 no.2
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• pp.230-236
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• 2017

This study was carried out to investigate the effects of ultrasonic thawing on physicochemical characteristics of frozen pork sirloin. To determine the velocity of an ultrasonic thawing machine, $-80^{\circ}C$ frozen pork sirloins were thawed using 132, 580, and 1,000 kHz ultrasonic thawing machines, and the physicochemical properties of pork sirloin thawed with $15^{\circ}C$ tap water and those using the ultrasonic thawing machines were compared. As a result, thawing speed by ultrasonic thawing was three times faster than that of tap water, but drip weight loss rate is increased by about 5% during ultrasonic thawing compared to that during thawing in tap water. However, biochemical properties, such as pH, volatile basic nitrogen, thiobarbituric acid, and total aerobic bacteria, were not improved by ultrasonic thawing. Hunter values, such as total color change and redness, improved slightly after 580 kHz ultrasonic thawing. The hardness and chewiness of the pork sirloin decreased significantly after 580 kHz ultrasonic thawing; however, springiness was not changed. These results indicate that ultrasonic thawing is faster than thawing in tap water, but the physicochemical characteristics of frozen pork sirloin was not significantly improve by ultrasonic sound.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.90-98
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• 2009

Every spring, Korea is always plagued by sandy dust from the western region of China and Mongolia. Yellow sand is causing an environmental problem to Japan and far into the American continent, let alone Korea. At present, the western region of China is going under desertification at a great speed due to climatic change and humans' damaging activities. To cope with this, each country including China is considering ecological restoration of deserts through planting. Accordingly, this research conducted a vegetation survey on Baicheng district which is a representative dry land of western China to obtain a basic data for ecological restoration of a desert. The survey revealed that Setaria viridis which invaded an arid land made a succession into Setaria viridis-Cannabis sativa var. fruderalis community together with Artemisia mongolica-Setaria viridis community due to the increase in salt concentration and alkalization subsequent to dryness. It was also found out that there finally formed Artemisia mongolica community on a flat intense in harsh wind and dryness with the continuous worsening of environmental conditions. There appeared a different type of vegetation on hilly districts where sporadic shade could come into being because the air humidity could be available relatively there. Frequently, typically appearing at the whole survey area, the Tributlus terrestris community was found to make succession into Tribulus terrestris-Cleisrogenes squarrosa community due to the aggravation of soil environment. In addition, with the worsening of the environment at hilly districts, there formed Clesirogenes squarrosa community resistant to dryness, salinity in soil and strong alkalinity. Further, there appeared higher plant life totalling to 62 taxa comprising 58 species and 4 varieties with 27 families and 49 genuses at the whole survey area. Among these, Compositae plants excellent in resistance to environment was surveyed the most, accounting for 27%.

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.62-68
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• 2010

This study was conducted to find out how the germination, phenology and leaf morphology of Phytolacca insularis(endemic species of Korea) and P. americana(alien species) react to the global warming situation. Seed and seedlings of two species were sampled and placed under two separate conditions for the experiment. One of the seed and seedlings was treated in the glass house with control(ambient $CO_2$+ambient temperature, (AC-AT), and the other with control(elevated $CO_2$+ elevated temperature, EC-ET), over the period of one year, 2008-2009. The germination rate of two species was fast, and the time of their germination started early, when they were treated at EC-ET than at AC-AT. Furthermore, the germination rate of Phytolacca insularis(endemic species of Korea) was found to be comparatively lower than that of P. americana(alien species). The former showed only vegetative growth whereas the latter showed both vegetative growth and reproductive growth in one year period. The more $CO_2$ degree and temperature increased, phenological responses of two species, including leaf growth, the formation of flower stems, flowering, and fruit maturing, became much faster, and the time of their leaf-yellowing was delayed. The lamina length of P. insularis was not significantly affected by elevated $CO_2$ and temperature. The lamina length of P. americana, on the other hand, became longer at EC-ET than at AC-AT, but the leaf width of both species increased at EC-ET. As for the number of leaves, both species showed no difference. Finally, the ratio of the leaf area of P. insularis was high at AC-AT, but P. americana was high at EC-ET. These results indicate that P. americana, aliens species, reacts more sensitively to global warming than P. insularis, endemic species, does.

• Korean Journal of Agricultural Science
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• v.35 no.1
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• pp.101-118
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• 2008

This paper reviews the present situation of Triticale cultivation and examines the potentiality of contribution to livestock as well as poultry sector in Bangladesh Agriculture. Triticale is a human-made cross between rye and durum wheat that has the ability to produce quality green fodder, and then re-grow after first and second cutting to produce grain. In Bangladesh, it is a non-traditional cereal that grows well during the cool and dry Rabi season (November-March) when fodder and feed scarcity is a major limiting factor for ruminant livestock. In Bangladesh Triticale was started to grow in the late Ninety's. The scientists of Bangladesh Agricultural Research Institute (BARI) were first introduced triticale in Bangladesh. Still now the situation of Triticale is grown as fooder and feed in Bangladesh within the scientists under trial. High quality grass fodder was obtained by cutting green triticale plants twice, at 35 and 50 days after seeding, while later the ratooning tillers produced grain to a yield of 1.1-2.4 t/ha of grain for poultry feed or human food. Triticale straw was twice as nutritious as rice or wheat straw and its grain contained more protein than other cereals. Researchers and farmers have also successfully made triticale hay and silage from a mixture of triticale green cuttings, rice straw and molasses. A feeding trial at Bangladesh Livestock Research Institute(BLRI), Savar station showed a large(46%) increase in cow live weight gain and a 36% increase in milk yield (but no change in milk quality or dry matter intake) in cows fed triticale silage compared with those fed rice straw over a period of nine weeks. In another feeding trial, it was found that triticale grain was a good replacement for wheat in the feed blend for chickens in Bangladesh. So it will be a good chance to alive our livestock as well as poultry sector if triticale enters to our existing cropping system as fodder cum grain. The challenge in Bangladesh is to identify fodder technologies that match existing small-scale farmer cropping patterns without needing major inputs or increasing risks. Preliminary field experiments revealed that triticale is a crop with good potential to produce quality fodder and grain for small scale farmers in Bangladesh.

• Food Science and Preservation
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• v.21 no.5
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• pp.627-635
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• 2014

We investigated the changes in the quality characteristics of Doenjang with low salt contents (6, 8, 10, and 12%) and 10% garlic. The Doenjang was analyzed at an interval of a week during its fermentation for six weeks, at room temperature. Its L color gradually decreased, but its a and b colors did not change significantly. Its salinity increased by about 1% after six weeks. In contrast, immediately after its preparation, its pH was gradually decreased and its acidity was increased for the fermentation. The reducing sugar was significantly increased from 1.34~1.88 g/100 g immediately after its preparation to 7.25~9.13 g/100 g after six weeks, which was higher as the salt concentration decreased. The amino-type nitrogen doubled from 100~130 mg% at 0 week to 210~290 mg% at six weeks, which were lower with the higher salt concentrations. The growth curve of the Bacillus fermentation strains of Doenjang increased to two weeks but gradually decreased since, and the growth of the Bacillus was favorable for up to two weeks in the Doenjang with 10% and 12% salt added. Otherwise, the yeast was reduced rapidly during the early fermentation of the Doenjang, and slightly changed after three weeks of fermentation. The results of this study showed that the reducing sugar and amino-type nitrogen contents of the low-salt garlic Doenjang were higher with the lower salt dose, and the physicochemical quality of the 6%-salt Doenjang was not significantly affected. Thus, we suggest that low-salt Doenjang can be manufactured with the addition of 6% salt and 10% garlic.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.390-399
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• 2016

Purpose: The objective of this study was to examine the effect of plant scale and cooking conditions on the quality characteristics of sausages during refrigerated storage. Methods: Sausages used in this study were classified into two groups: those submitted to $1^{st}$ cooked treatments and those submitted to $2^{nd}$ cooked treatments. The pH, volatile basic nitrogen (VBN), gas production ratio, and microorganisms were measured in triplicate. Results: The change of quality in the products was assessed every 7 days by measuring pH, VBN levels, total microbes, coliform bacteria, Escherichia coli, and pathogenic bacteria in the products. Pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens, and E. coli were not detected in the sausages with $1^{st}$ cooked treatments. The results showed that the pH of the sausages decline as storage time increased. The pH value of the sausages with $2^{nd}$ cooked treatments changed gradually. VBN levels were generally lower in products with $2^{nd}$ cooked treatments than in those with $1^{st}$ cooked treatments, but they varied with the type of products. On the $35^{th}$ day, the number of total microbes ranged between 6.13-7.12 log CFU/g in products with $1^{st}$ cooked treatments and 3.44-6.92 log CFU/g in products with $2^{nd}$ cooked treatments, showing fewer bacteria in the latter products. Conclusions: $1^{st}$ cooked treatments were effective in microbial control, but $2^{nd}$ cooked treatments could prolong the shelf life of the sausages, indicating a need for differential management of each product.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.482-491
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• 1992

Experiments were conducted to elucidate the effects of pH change and sodium alginate, gum karaya and gum arabic on the foaming properties of soy protein isolate (SPI). The surface tensions of SPI solution (5%) adding to gums at pH 4.0 and 5.0, near the isoelectric point (pH 4.5) were higher than those at pH 7.0 and 8.0. Specific viscosity of the solutions adding to gums (0.1, 0.2 and 0.3%) at pH 7.0 and 8.0 were $3.6{\sim}51.8$ and $4.0{\sim}51.2$, respectively. In cases of addition of sodium alginates specific viscosity were predominantly increased, while those of gum arabic did not almost increase. Addition of gums reduced the overrun, but it stabilized the foams, especially those of sodium alginates (0.2%) increased the foam stability at pH 5.0, 7.0 and 8.0 by 57, 413 and 315%, respectively. Foaming ability, foam stability and heat stability of the foam were significantly (p<0.05) affected by changing pH. There was a tendency to increase the foaming ability according to the decrease of surface tension. Specific viscosity was also important in foam stability and heat stability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.361-367
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• 1984

In previous paper(Lee et al., 1984), preparation formula and processing conditions of the fish meat (mackerel) paste using dielectric heating were described, that included the proper shape and size of product and the conditions of dielectric heating, hot air dehydration, and heating with electric heater to yield the minimum expansion and case hardening during heating and to controll the final rater activity of 0.86 to 0.83 accompanying with a complete reduction of viable cells and good texture. In present study, changes in VBN, pH, total plate count, water activity, texture, the loss of available lysine, color indexes, TBA value, and the content of TI were determined to assess the quality stability and shelf-life of the product during the storage for 35 days at $5^{\circ}C\;and\;25^{\circ}C$, respectively. And the effect of vacuum sealing and hot water treatment before storage on the storage stability of product was also mentioned. As the product was vacuum packed in K-flex film bag, heat treated in boiling water for 6 minutes, and stored, water activity was maintained 0.86 to 0.84 for 35 days regardless of storage temperature, and the increase of total plate count was negligible in case of $5^{\circ}C$ storage while tended to gain slightly after 25 days at $25^{\circ}C$ storage. Changes in VBN was also minimum with an increase of 1.5 mg/100g at $5^{\circ}C$ and 7.0mg/100g at $25^{\circ}C$, but in case of unpacked sample, it was 24.5mg/100g at $5^{\circ}C$ and 42.4 mg/100g at $25^{\circ}C$ even after 7 days. In textural property hardness tended to increase after 28 days and folding test score was down to A or B from AA grade. The loss of available lysine was $7.5\%\;at\;5^{\circ}C$ and $17.0\%\;at\;25^{\circ}C$ but brown color was not deeply developed as the color index score indicated. TBA value was not increased at $5^{\circ}C$ while it tended to increase rapidly after 30 days at $25^{\circ}C$. Changes in TI content was not obvious except that it showed a tendency of increase at the end of storage as well as in the change of lysine and TBA value. It is concluded from the results that the quality of the product, pasteurized and water activity controlled by dielectric heating, and vacuum packed in K-flex film would be stable for more than 35 days at $5^{\circ}C$ and at least 25 days even at room temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.335-342
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• 2011

The purpose of this study was to investigate the effects of mugwort powder on the quality characteristics and antioxidant activity of Maejakgwa. Maejakgwa were prepared with mugwort powder at levels 0%, 1%, 3% and 5% ($60{\pm}1^{\circ}C$, 14 days). The lightness, redness, and yellowness values of Maejakgwa significantly reduced depending on mugwort powder. The hardness of Maejakgwa was decreased with the increase of storage period and increased with the increase of mugwort powder. In the sensory evaluations, the Maejakgwa prepared with 3% added mugwort powder received higher acceptance scores for the properties of color, taste, hardness, crispiness, adhesiveness and overall acceptability. As the mugwort powder content increased, acid value and peroxide value were decreased. With the increase of storage period, acid value and peroxide value of all sample increased but growth rate of these values decreased with the addition of the mugwort powder. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity was improved significantly via the addition of mugwort powder and decreased as storage period increased. During storage period, Maejakgwa with mugwort powder showed a stronger antimicrobial effect in yeasts and molds than in total aerobic bacteria. Coliform bacteria were not detected in all samples. Also the antimicrobial activity was increased with the addition of the mugwort powder and decreased as storage period increased. The results show that addition of the mugwort powder to foods with fat such as Maejakgwa would be a useful way to enhance the antioxidant quality, sensory characteristics and shelf life.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.12
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• pp.715-732
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• 2009

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.