• Title/Summary/Keyword: physicochemical qualities

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Development of Teas from Leaves of Korean Box thorn (Lycium chinense Miller) Leaves (구기엽을 이용한 차류의 개발)

  • Kim, Seung Yeol;Lee, Kyong Haeng;Kim, Seung Kyeom
    • Korean Journal of Agricultural Science
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    • v.24 no.1
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    • pp.29-40
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    • 1997
  • Six different types of teas from box thorn leaves collected on mid May were prepared by using different tea making procedures. The selected physicochemical propentes and the sensory qualities of the 6 different teas were analyzed. The box thorn leaves contained 87.71% moisture, 0.69% crude fat, 4.77% crude protein, 2.13% fibers, 3.11% carbohydrates and 1.59% ash. Based on the sensory analysis, roasted tea(duckum tea) had the highest values in taste, flavor, color and overall preference. Eighteen free amino acids were identified in the roasted tea, showing the specially high levels of proline(170.15mg%) and glutamic acid(112.34mg%). The roasted tea also contained glucose(1.07%), maltose(0.87%), sucrose(0.63%) and fructose(0.55%). The content of citric acid(337.43mg%) in the roasted tea was the highest, followed by malonic acid(54.17mg%), oxalic acid(48.66mg%), malic acid(27.41mg%), succinic acid(4.48mg%), fumaric acid(1.08mg%) and lactic acid(trace amount), in a decreasing order.

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Effects of pre-heat treatments on the quality of cut kimchi cabbages during short-term storage (절단배추의 단기 저장에 대한 예열처리 효과)

  • Kim, Sang-Seop;Ku, Kyung-Hyung;Jeong, Moon-Cheol;Hong, Joo-Heon;Chung, Shin-Kyo
    • Food Science and Preservation
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    • v.21 no.6
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    • pp.776-783
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    • 2014
  • Kimchi cabbages were cut ($3{\times}3cm$), and were pre-heat treated at $40^{\circ}C$, and their physicochemical qualities and browning degrees were investigated during 8 weeks storage at $5^{\circ}C$. The Cut kimchi cabbages were treated at $40^{\circ}C$ (1~8 hrs) and their protein bands profiles were determined by sodium dodecyl sulfate polyacrylamide electrophoresis (SDS-PAGE). The 60, 39, 33, and 12 kDa bands considered heat shock proteins (HSPs) were expressed in the cut kimchi cabbage, and the 4-hr pre-heat treatment (HS 4) exhibited the strongest band ratio. The weight ratios and titratable acidities of the pre-heat treated cut kimchi cabbages were not changed so much after 8 weeks storage at $5^{\circ}C$, and the soluble solid contents of HS 4 decreased less than that of any other treatments. The browning degree of HS 4 after 8 week storage was also shown to be the least among the treatments. The polyphenol oxidase (PPO) activities of all treatments slightly rose during the over all storage period, in contrast with the decrease of total phenolic contents. The expression of HSPs was identified in the pre-heat treated cut kimchi cabbages, and HS 4 exhibited the best quality and appearance after 8 weeks storage at $5^{\circ}C$.

Quality Characteristics of Muffins added with Amaranth Leaf Powder (아마란스잎 분말을 첨가한 머핀의 품질특성)

  • Choi, Sang-ho
    • Culinary science and hospitality research
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    • v.22 no.4
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    • pp.51-64
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    • 2016
  • The purpose of this study was to examine the qualities of muffins with 0, 3, 6, 9, and 12% amaranth leaf powder. The specific gravity of muffins prepared by adding amaranth leaf powder was higher than that of the control group. The pH of batter and muffins were decreased with the addition of amaranth leaf powder. The height, weight, volume, and specific loaf volume of muffins were decreased, while the baking loss rate of muffins was increased by the addition of amaranth leaf powder. The moisture content of the samples with amaranth leaf powder was lower than that of the control group. DPPH radical scavenging activity of the control group was 16.23%, whereas the samples with amaranth leaf powder ranged from 23.06~33.63%. In crumb color, the L and a value were decreased, although b value was increased significantly by the addition of amaranth leaves powder. The hardness, springiness, cohesiveness, chewiness, and brittleness of the textural properties of muffins were significantly decreased by the addition of amaranth leaf powder. Sensory evaluation scores in terms of after swallowing, appearance, odor, taste, texture, and overall preference of groups with 3% and 6% of amaranth leaf powder did not show any significant difference when compared to the control group. Based on the above results, using less than 6% of the amaranth leaf powder appears proper to make muffins.

Effect of Rice Flour Sourdough Fermented with Omija (Schizandra chinensis) Extract on Quality Characteristics of Bread (오미자청을 이용한 쌀가루 sourdough 첨가 식빵의 품질 특성)

  • Byun, Jong-Beom;Chang, Jin-Hee;Jeoung, Gey-Yeoun;Lee, Jin-Sil
    • Korean Journal of Food Science and Technology
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    • v.47 no.6
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    • pp.704-710
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    • 2015
  • The objective of this work was to examine the effect of rice flour sourdough fermented with omija (Schizandra chinensis) extract on the quality characteristics of bread. Five rice sourdough concentrations (0, 15, 30, 45, and 60%) were used in order to ascertain the best bread composition. Bread qualities were determined by means of physicochemical analysis and consumer acceptability test. The results showed that the dough prepared with 15% rice flour sourdough fermented with omija extract had a positive impact on the bread quality such as volume, hardness, springiness, and consumer acceptability. This study suggests that the rice flour sourdough fermented with omija extract could be added up to 15% without quality changes for making bread.

Long-term Variation and Characteristics of Water Quality in the Garolim Coastal Areas of Yellow Sea, Korea (가로림연안 수질환경의 특성과 장기변동)

  • Park, Soung-Yun;Kim, Hyung-Chul;Kim, Pyoung-Joong;Park, Gyung-Soo;Ko, Joen-Young;Jeon, Sang-Baek;Lee, Seung-Min;Park, Jong-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.4
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    • pp.315-328
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    • 2009
  • Long-term trends and distribution patterns of water quality were investigated in the Garolim coastal areas of Yellow Sea, Korea from 1998 to 2007. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns were not clear among stations but the seasonal variations were distinct except pH and ammonia. The trend analysis by principal component analysis(PCA) during twenty years revealed the significant variations in water quality in the study area. Annual water qualities were clearly classified into 4 clusters by PCA; year cluster 1997, 1998 and 2000-2002, 1999 and 2003-2006/2008. By this multi-variate analysis the annual trends were summarized as follows; In recent years, salinity increased, whereas dissolved inorganic nitrogen, nitrate nitrogen and COD decreased and water quality generally continued to be in good condition in Gsrolim coastal areas without inflow of freshwater from land. Garolim coastal areas are required to be conserved continuously as important coastal areas for fisheries.

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Physicochemical Properties of Rice Cultivars with Different Amylose Contents (아밀로스 함량이 다른 쌀 품종의 이화학적 특성)

  • Choi, In-Duck
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.9
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    • pp.1313-1319
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    • 2010
  • Rice cultivars of Goami2 (G2), Baegjinju (BJJ), and Sulgaeng (SG) with different amylose contents were developed by mutation breeding via N-methyl-N-nitrosourea (MNU) treatment to Ilpumbyeo (IP), high japonica rice. They were identified by different appearances such as grain size, color, and shape. In this experiment, the compositional and physical qualities of those cultivars were examined. The G2 rice classified as a high-amylose rice cultivar was significantly higher in its non-digestable carbohydrates contents. Linoleic and oleic acid were composed of 70~75% of all fatty acids composition regardless of milled and brown rice, except G2 rice in which palmitic acid was the major fatty acid followed by linoleic acid and oleic acid in order. Major amino acids were aspartic acid, glutamic acid, and hydroxy lysine. It was found that cysteine contents were higher in the cultivars of endosperm mutant rice. The DSC analysis revealed that enthalpy was the highest in BJJ followed by SG, IP, and G2 rice. The lowest enthalpy of G2 might be attributable to the higher amylose content. Ilpumbyeo in its cooked rice form showed the highest in Toyo value and less in hardness, but G2 was vise versa. Results of gelatinization and cooked rice properties suggest that G2 was less suitable for cooked rice, but has a potential for functional ingredients from nutritional point of view. The BJJ and SG could be used for traditional cooking as well as for processed foods.

Optimum Milling Degree for Improving Sensory Quality of Cooked Rice (식미 증진을 위한 최적 도정도 구명)

  • Lee, Jeom-Sig;Park, No-Bong;Lee, Jong-Hee;Cho, Jun-Hyeon;Won, Yong-Jae;Park, Hyang-Mee;Chun, A-Reum;Jang, Jae-Ki;Gwak, Do-Yeon;Song, Yu-Cheon;Hwa, Woon-Gu;Yi, Gi-Hwan;Yeo, Un-Sang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.57 no.4
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    • pp.359-364
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    • 2012
  • We conducted this study to identify the optimal milling degree for improving sensory quality of cooked rice and minimizing yield loss. The samples were analyzed for their physicochemical properties and sensory qualities using five different degree of milling(5.5~13.5%, based on brown rice). With increasing of milling degree, amylose content, breakdown, adhesiveness of cooked rice increased, whereas protein content, Mg/K equivalence ratio, fat content, setback and hardness of cooked rice decreased. In sensory quality test, the preference was significantly higher in the 9.5% and 11.5% milling degree. However, considering the yield of milled rice, the optimal milling degree for improving sensory quality of cooked rice was 9.5%.

Water Quality Characteristics Along Mid-western Coastal Area of Korea (한국 서해 중부 연안역의 수질환경 특성)

  • Lim, Dhong-Il;Kang, Mi-Ran;Jang, Pung-Guk;Kim, So-Young;Jung, Hoi-Soo;Kang, Yang-Soon;Kang, Young-Shil
    • Ocean and Polar Research
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    • v.30 no.4
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    • pp.379-399
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    • 2008
  • Spatial-temporal variations in physiochemical water qualities (temperature, salinity, DO, SPM, POC and nutrients) of surface and bottom waters were investigated along the mid-western coastal area (Taean Peninsula to Gomso Bay) of Korea. Spatial distribution patterns of temperature and salinity were mostly controlled by the physical mixing process of freshwater from Geum River and/or Gyunggi Bay with nearby coastal water. A strong tidal front is formed off Taean Peninsula during spring and summer. Seasonal variations in nutrient concentrations, lower in spring and summer and higher in fall and winter, are primarily regulated by magnitude of phytoplankton occurrence rather than freshwater loadings into the bay. Based on seasonal and spatial variability of physicochemical parameters, water quality of the study area can be divided into four water masses; Gyunggi Bay-influenced Water Mass (GBWM), Geum River-influenced Water Mass (GRWM), Yellow Sea Bottom Cold Water Mass (YSBCWM) and Cheonsu Bay Water Mass (CBWM). Water quality of the GBWM (Taean Peninsula coastal area), which has relatively low salinity and high concentrations of nutrients, is strongly controlled by the Gyunggi Bay coastal water, which is under influence of the Han River freshwater. In this water mass, the mixed layer is always developed by strong tidal mixing. As a result, a tidal front is formed along the offshore boundary of the mixed layer. Such tidal fronts probably play an important role in the distribution of phytoplankton communities, SPM and nutrients. The GRWM, with low salinity and high nutrients, especially during the flood summer season, is closely related to physiochemical properties of the Geum River. During the flood season, nutrient-enriched Geum River water mass extends up to 60 km away from the river mouth, potentially causing serious environmental problems such as eutrophication and unusual and/or noxious algal blooms. Offshore (<$30{\sim}40m$ in water depth) of the study area, YSBCWM coupled with a strong thermocline can be identified in spring-summer periods, exhibiting abundant nutrients in association with low temperature and limited biological activity. During spring and summer, a tidal front is formed in a transition zone between the coastal water mass and bottom cold water mass in the Yellow Sea, resulting in intensified upwelling and thereby supplying abundant nutrients to the GBWM and GRWM. Such cold bottom water mass and tidal front formation seems to play an important role in controlling water quality and further regulating physical ecosystem processes along mid-western Korean coastal area.

Effect of Different koji and Irradiation on the Quality of Traditional Kochujang (우수 균주접종과 감마선 조사에 따른 전통고추장의 품질 비교)

  • Kim, Moon-Sook;Kim, In-Won;Oh, Jin-A;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.31 no.1
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    • pp.196-205
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    • 1999
  • Kochujang prepared by liquid and solid koji using isolated bacteria(Sunchang 1 and Park 2) showing excellent enzyme activities were gamma irradiated at $15{\pm}1.5\;kGy$ to investigate their qualities from the physicochemical, microbiological and enzymatic points of view during fermentaion at $25^{\circ}C$ for 90 days. The amino type nitrogen contents were $0.6{\sim}0.7%$ after 30 days of fermentation. Irradiation completly stopped gas production which is one of biggest problem of kochujang distribution. Enzyme activities were some different according to koji and irradiation treatment. Amino type nitrogen content as one the most important quality indice was higher in kochujang fermented by isolated bacteria (Park 2) than non inoculated traditional kochujang. But sensory quality was not significantly different.

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Changes of Biogenic Amine Level during Storage and Development of New Quality Index on Silkworm Pupa (식용 번데기의 저장 중 Biogenic Amine 함량 변화와 품질지표 개발)

  • Cho, Tae-Yong;Han, Gyu-Hong;Kang, Byung-Sun;Kim, Seon-Bong
    • Journal of Food Hygiene and Safety
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    • v.22 no.4
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    • pp.268-272
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    • 2007
  • A study on the evolution of acid value, peroxide value and biogenic amines in silkworm pupa during 7 days at different temperature of storage (-18, 25 and $35^{\circ}C$) was performed. Seven biogenic amines (putrescine, cadaverine, histamine, tyramine, spermidine, spermine and 2-phenylethylamine) were determined. Acid value in Silkworm pupa increased both during normal temperature $(25^{\circ}C)$ and room temperature $(35^{\circ}C)$ and thebiogenic amine (histamine, tyramine) content generally increased in $25^{\circ}C\;and\;35^{\circ}C$ with storage time. Significant differences were found (P<0.05) in the levels of tyramine and histamine among Silkworm pupa. The relationship of storage time and acid value of Silkworm pupa were resolved a simple linear equation, and histamine and tyramine could be predicted using this equation. Quality indices related to the contents of the major biogenic amines were calculated and they correlated well with physicochemical characteristics qualities such as acid value.