• 동아시아식생활학회지
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• 제23권6호
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• pp.789-798
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• 2013

In the present study, optimization on ${\beta}$-glucanase-assisted extraction was made in order to isolate waxy barley starch from domestic cultivar using the D-optimal design suitable for response surface methodology (RSM). The results demonstrated that the amount of enzyme was found to be a major influencing factor on the extraction yield, which was substantially increased by increasing the amount of enzyme. It was also influenced by the reaction time and amount of water addition; however, the two factors were less influential than the amount of enzyme. The optimized condition by RSM for the reaction time was found to be 2.63 hours and amount of enzyme 1.7%, and amount of water addition 4.38 times the weight of raw material. With the enzyme treatment, the starch content in residues (R), particularly in R1 and R5, was reduced considerably, resulting in an increase in the extraction yield and therefore primarily and effectively releasing B-type starch small granule confirmed by scanning electronic microscopy. In addition, the study determined the physicochemical properties of isolated waxy starch (i.e., purity, water adsorption capacity, thermal properties, rheology and starch morphology) and compared them with those from the enzyme-not treated sample. It was found that they were almost similar to each other, except for the purity of starch, which was lower in the enzyme-treated sample than in the enzyme-not treated one.

• 아시안잔디학회지
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• 제25권1호
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• pp.106-111
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• 2011

본 연구는 아메리카동애등애 사육과정에서 발생한 분변토(SFC)가 골프장의 토양개량제로서 사용가능성을 평가하기 위해 모래와 혼합비율별 물리화학성을 조사하고자 한다. 토양개량제의 혼합비율에 따라 상토의 물리화학성을 조사한 결과는 다음과 같다. SFC, compost 및 cocopeat는 pH와 EC에서 고도의 정의 상관성 (P<0.01)을 나타내어 토양개량제의 특성에 따라 상토의 토양화학성에 영향을 주었다. SFC와 compost의 혼합에 따른 토양물리성 변화에서 가장 중요한 요인은 모세관공극으로 총공극이나 수리전도도의 변화에 영향을 미쳤다. 토양개량제의 혼합비율에 따른 토양개선효과를 비교할 때, SFC는 모세관공극, 총공극 및 수리전도도에서, compost는 모세관공극, 비모세관공극, 총공극 및 수리전도도에서, cocopeat는 모세관공극과 비모세관공극에서 고도의 상판성을 나타내었다(P<0.05). 이들 결과를 통해 토양개량제의 종류와 특성 및 혼합비율이 USGA 상토의 근권층 개량과 토양 이화학성에 영향을 미치고 있음을 알 수 있으며, 본 실험조건에서는 SFC는 상토의 공극과 수리전도도의 개선효과를 보였다.

• 한국축산식품학회지
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• 제37권6호
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• pp.940-947
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• 2017

Goat milk has a protein composition similar to that of breast milk and contains abundant nutrients, but its use in functional foods is rather limited in comparison to milk from other sources. The aim of this study was to prepare a goat A2 ${\beta}$-casein fraction with improved digestibility and hypoallergenic properties. We investigated the optimal conditions for the separation of A2 ${\beta}$-casein fraction from goat milk by pH adjustment to pH 4.4 and treating the casein suspension with calcium chloride (0.05 M for 1 h at $25^{\circ}C$). Selective reduction of ${\beta}$- lactoglobulin and ${\alpha}_s$-casein was confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. The hypoallergenic property of A2 ${\beta}$-casein fraction was examined by measuring the release of histamine and tumor necrosis factor alpha from HMC-1 human mast cells exposed to different proteins, including A2 ${\beta}$-casein fraction. There was no significant difference in levels of both indicators between A2 ${\beta}$-casein treatment and the control (no protein treatment). The A2 ${\beta}$-casein fraction is abundant in essential amino acids, especially, branched-chain amino acids (leucine, valine, and isoleucine). The physicochemical properties of A2 ${\beta}$-casein fraction, including protein solubility and viscosity, are similar to those of bovine whole casein which is widely used as a protein source in various foods. Therefore, the goat A2 ${\beta}$-casein fraction may be useful as a food material with good digestibility and hypoallergenic properties for infants, the elderly, and people with metabolic disorders.

• Journal of Animal Science and Technology
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• 제58권6호
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• pp.23.1-23.17
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• 2016

Background: The functionality of myofibrillar proteins is a major factor influencing the quality attributes of muscle foods. Nonetheless, the relationships between muscle type and oxidative changes in chevon during ageing are meagrely elucidated. Postmortem changes in antioxidant status and physicochemical properties of glycolytic gluteus medius (GM) and oxidative infraspinatus (IS) muscles in goats were compared. Methods: Twenty Boer bucks (9-10 months old, body weight of $36.9{\pm}0.725kg$) were slaughtered and the carcasses were subjected to chill storage ($4{\pm}0.5^{\circ}C$). Analyses were conducted on GM and IS muscles sampled on 0, 1, 4 and 7 d postmortem. Results: Chill storage did not affect the antioxidant enzyme activities in both muscles. The IS had greater (P < 0.05) superoxide dismutase and catalase activities than GM. Carotenoid and tocopherol contents did not differ between muscles but decreased (P < 0.05) over storage. The IS had higher (P < 0.05) glycogen and ultimate pH and lower (P < 0.05) shear force and cooking loss than GM. The carbonyl content, % metmyoglobin, drip loss and TBARS increased (P <0.05) while free thiol, metmyoglobin reducing activity (MRA), shear force and myoglobin decreased (P < 0.05) over storage. Muscle type had no effect (P > 0.05) on free thiol, MRA and TBARS. The GM had lower (P < 0.05) redness on d 0 and 1 than IS while the IS had greater carbonyl, % metmyoglobin and drip loss than GM on d 7. The reflective density of slow myosin heavy chain (MHC) was higher (P < 0.05) while the density of fast MHC and actin was lower (P < 0.05) in IS than GM. Regardless of muscle type, the density of MHC decreased (P < 0.05) while that of actin was stable over storage. Nonetheless, the degradation of fast and slow MHC was greater (P < 0.05) in IS than GM. Muscle type had no effect (P > 0.05) on consumer preference for flavour, juiciness and overall acceptability. However, IS had higher (P < 0.05) tenderness score than GM on d 1 and 4 postmortem. Intramuscular fat was higher (P< 0.05) in IS compared with GM. Fatty acid composition did not differ between the muscles. However, GM had lower (P < 0.05) n-6/n-3 ratio than IS. The n-3 and n-6 PUFA declined (P < 0.05) while the SFA increased (P < 0.05) over storage. Conclusion: The changes in myofibrillar proteins and physicochemical properties of goat meat during postmortem chill storage are muscle-dependent.

• 한국식품저장유통학회지
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• 제13권6호
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• pp.740-748
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• 2006

천마를 채취한 그대로 이용하는 데에는 생체 보존에 따른 불편, 독성 그리고 자극성 등의 부작용으로 간단한 전처리 과정이 필요하다. 따라서 본 연구에서는 천마를 이용한 가공제품의 개발을 위한 전처리 과정 중 건조 조건별로 천마의 이화학적 특성을 반응표면 분석법으로 모니터링하여 최적 건조조건을 설정하였다. 천마 건조물의 수분활성도는 건조온도 $79.56^{\circ}C$, 건조시간 7.17 hr에서 가장 높은 간을 나타내었고, 총 페놀성 화합물 함량은 $79.64^{\circ}C$, 8.74hr에서, 전자공여능은 $79.79^{\circ}C$, 8.57 hr에서 최대값을 나타내었으며, 아질산염 소거능(pH 1.2)은 건조온도 $79.99^{\circ}C$, 건조시간 8.07hr에서 각각 최고의 이화학적 특성을 나타내는 것으로 예측되었다. 천마 건조물의 이화학적 특성을 고려한 최적 건조조건 범위는 건조온도 $75{\sim}80^{\circ}C$와 건조시간 $8{\sim}9 hr$으로 각각 나타났다.

• 한국식품저장유통학회지
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• 제24권8호
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• pp.1053-1059
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• 2017

우엉 분말(BP)은 여러 기능적 활성을 나타내고 있고, 쿠키와 같은 간편식품에 활용하면 소비진작에 도움이 될 것으로 판단되어, 우엉 분말의 첨가량을 0-8%로 달리하여 제조한 쿠키의 물리 화학적 품질, 항산화 활성 및 소비자 기호도를 비교하였다. 쿠키반죽의 pH와 밀도는 BP의 첨가량에 현저한 영향을 받지 않는 것으로 나타났다. 쿠키의 수분함량과 퍼짐성 지수는 BP의 첨가량이 증가함에 따라 유의적 차이 없는 증가경향을 보였다(p>0.05). 쿠키표면의 명도($L^*$), 적색도($a^*$) 및 황색도($b^*$) 그리고 경도는 BP의 첨가량이 증가할수록 유의적으로 감소하였다(p<0.05). 항산화 활성을 나타내는 전자공여능과 ABTS 라디칼 소거능 활성은 BP를 첨가할수록 유의적으로 증가하는 경향이 나타났다(p<0.05). 소비자 기호도 결과 2% 첨가군이 전체적 기호도를 포함한 모든 평가항목에서 유의적으로 높게 평가되어, 관능품질과 건강기능성 효과 등을 고려할 때 소비자의 기호를 충족시키기 위한 최적 첨가비율은 2%가 가장 적합한 것으로 판단된다.

• 한국식품과학회지
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• 제31권6호
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• pp.1503-1510
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• 1999

영귤을 이용한 다양한 가공제품의 개발을 위한 기초자료로 영귤의 과피와 과즙을 분리하여 수확시기별 (9월 3일부터 11월 8일까지 약 20일 간격) 및 산지별(서귀포, 제주시)에 따른 물리화학적 성분특성을 조사하였다. 영귤의 평균중량은 서귀포산이 제주시산보다 2배 이상이었으며, 평균직경도 10mm 이상 큰 것으로 나타났다. 과피의 수분함량은 $74.0{\sim}78.7%$로 성숙함에 따라 높아지는 경향을 보였으나 과즙에서는 $90.1{\sim}91.9%$ 수준으로 차이를 보이지 않았다. 환원당은 과피와 과즙에서 모두 9월 3일에서 11월 8일 사이에 약 2배 가량 증가하였고, 조섬유는 과피와 과즙에서 모두 감소하는 경향을 나타냈으며 조단백질과 회분의 경우, 과피에서는 감소하는 경향을 나타냈으나 과즙에서는 뚜렷한 차이를 나타내지 않았다. pH와 비타민C는 성숙이 진행됨에 따라 과피 및 과즙에서 다소 감소하는 경향을 나타내었다. 또한 과즙의 경우 중요한 품질인자가 되는 transmittance는 9월 20일에서 10월 13일 사이에 급격히 증가하였다. 그리고 유리당의 함량은 과피의 경우 9월 3일에서 11월 8일까지 2배 가량 증가한 반면에 과즙은 4배까지 증가하였다. 무기질의 경우 과피에는 Ca과 K이 다량 함유되어 있었고 과즙에는 K이 가장 큰 비율로 함유되어 있었으며 각 무기질의 함량은 과실이 성숙함에 따라 감소하는 것으로 나타났다.

• Ocean and Polar Research
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• 제29권4호
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• pp.349-366
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• 2007

Seasonal variations of various physicochemical components (temperature, salinity, pH, DO, COD, DOC, nutrients-silicate, DIN, DIP) and potential limiting factor for phytoplankton primary production were studied in the surface water of semi-enclosed Masan Bay. Seasonal variations of nutrient concentrations, with lower values in summer and winter, and higher in fall, are probably controlled by freshwater loadings to the bay, benthic flux and magnitude of occurrence of phytoplankton communities. Their spatial distributional patterns are primarily dependent on physical mixing process between freshwater and coastal seawater, which result in a decreasing spatial gradient from inner to outer part of the bay. In the fall season of strong wave action, the major part of nutrient inputs (silicate, ammonium, dissolved inorganic phosphorus) comes from regeneration (benthic flux) at sediment-water interface. During the summer period, high Si:DIN and Si:DIP and low DIN:DIP relative to Redfield ratios suggest a N- and secondarily P-deficiency. During other seasons, however, silicate is the potential limiting factor for primary production, although the Si-deficiency is less pronounced in the outer region of the bay. Indeed, phytoplankton communities in Masan Bay are largely affected by the seasonal variability of limiting nutrients. On the other hand, the severe depletion of DIN (relatively higher silicate level) during summer with high freshwater discharge probably can be explained by N-uptake of temporary nanoflagellate blooms, which responds rapidly to pulsed nutrient loading events. In Masan Bay, this rapid nutrient consumption is considerably important as it can modify the phytoplankton community structures.

• 수산해양교육연구
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• 제28권6호
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• pp.1662-1672
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• 2016

To address physicochemical factors of yellow clay for removing Cochlodinium polykrikoides blooms, the correlation of removal efficiency with mineralogical characteristics of yellow clay collected from various areas was surveyed. Yellow clay from different localities showed the wide range of chemical compositions $SiO_2$ : 43~71%, $Al_2O_3$ : 13~26%, $Fe_2O_3$ : 5~14%, MgO : 0.4~1.8%, $K_2O$ : 0.6~3.3%, L.O.I.(Loss of Ignition) : 4.5~15%. The mineral compositions of yellow clay were mainly consisted of quartz and feldspar including small amounts of kaolinite, chlorite, and Fe-oxides. The result of size analysis showed that $6{\Phi}(31{\sim}16{\mu}m)$ and $7{\Phi}(16{\sim}8{\mu}m)$ were dominated sizes. The zeta-potential were in the range of -4.1~-20.7mV(average -13.7). As increasing removal efficiency of C. polykrikoides, contents of $Al_2O_3$, $Fe_2O_3$ and L.O.I. in yellow clay increased, whereas $SiO_2$ content decreased. Furthermore, the amounts of silt mineral and small particle were high when the removal efficiency was high. According to factor analysis using principle component analysis, two components of factor 1 and factor 2 showed 79% of the total variance, which is related to cohesion and adsorption. Inducing cell lysis of C. polykrikoides by cohension and adsorption between C. polykrikoides and yellow clay.

• 상하수도학회지
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• 제36권5호
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• pp.261-273
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• 2022

In this study, we collect water control valves that have had accidents due to existing cracks, etc. are collected, and propose investigation items for strengthening the valve structural safety evaluation through a series of analyzes from valve specifications to physicochemical properties are proposed. The results of this study are as follows. First, there was a large variation in the thickness of the body or flange of the valves to be investigated, which is considered to be very important factor, because it may affect the safety of the valve body against internal pressure and the flange connected with the bolt nut. Second, 60% of the valves under investigation had many voids in the valve body and flange, etc. and the decrease in thickness due to corrosion was relatively large on the inner surface in contact with water rather than the outer surface. It is judged that the investigation of depth included voids is very important factor. Third, all valves to be investigated are made of gray cast iron foam, and therefore it is judged that there is no major problem in chemical composition. It is judged that the chemical composition should be investigated. Fourth, as a physical investigation item, the analysis of metal morphology structure seems to be a very important factor for nodular cast iron from rather than a gray cast iron foam water valve with a flake structure. As it was found to be 46.7~68.8% of the standard recommended by KS, it could have a direct effect on damage such as cracks, and therefore it is judged that the evaluation of tensile strength is very important in evaluating the safety of the valve.