• Title/Summary/Keyword: Physicochemical change

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Change of Physicochemical Characteristics of Persimmon Vinegar by Vacuum Concentration (진공농축에 따른 감식초의 이화학적 특성 변화)

  • Lee, Boo-Yong;Yuk, Jin-Su
    • Korean Journal of Food Science and Technology
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    • v.31 no.4
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    • pp.1132-1136
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    • 1999
  • This study was performed to offer fundamental data for concentration of persimmon vinegar. The $5.4^{\circ}Bx$ raw persimmon vinegar was concentrated to $20^{\circ}Bx$, $30^{\circ}Bx$, $40^{\circ}Bx$, $50^{\circ}Bx$, $60^{\circ}Bx$ and $70^{\circ}Bx$ concentration by vacuum concentration at $55^{\circ}C$ and diluted to $5.4^{\circ}Bx$ solution with distilled water. The physicochemical properties such as color, viscosity, pH, acidity, organic acid content and free sugar content of various persimmon vinegar concentrates were examined. The recovery yield of water soluble solid to concentrates was 55.5% on $20^{\circ}Bx$ vacuum concentration. Color of $5.4^{\circ}Bx$ persimmon vinegar diluents from concentrates became more dark brown by vacuum concentration. Flow behavior of persimmon vinegar concentrates was pseudoplastic. As the concentration of persimmon vinegar concentrates increased, pH of $5.4^{\circ}Bx$ diluents increased and acidity as acetic acid decreased compared to original raw vinegar. Acetic acid, lactic acid and citric acid were detected, malic acid and oxalic acid were not detected in persimmon vinegar concentrate. Fructose and sucrose only were detected in persimmon vinegar concentrate.

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Effects of Gamma Irradiation on Physicochemical Properties of Red Beet and Stability of Betalain in the Red Beet (Beta vulgaris L.) (감마선 조사가 비트(Beta vulgaris L.)의 물리화학적 특성 및 Betalain 색소 안정성에 미치는 영향)

  • Kim, Kyoung-Hee;Lee, Sung-A;Yook, Hong-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.4
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    • pp.453-457
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    • 2007
  • The physicochemical properties of red beets and the stability of betalain pigments irradiated at 2.5, 5, 10 and 30 kGy were evaluated. Betalain extraction yield of irradiated red beets was not significantly different from non-irradiated red beet. The red beet irradiated at 5kGy showed high optical density value in betacyanin and betaxanthin. In Hunter's color value lightness (L), redness (a) and yellowness (b) decreased with increment of irradiation dose. All red beets showed no difference in pH. The red beets irradiated above 10 kGy had poor textural property quality but antioxidant activity of betalain was not significantly changed by gamma irradiation. Considering natural colorant and textural quality, the gamma irradiation above 10kGy was an undesirable technique for red beets.

Changes of Physicochemical Characteristics of Korean Type Hot Sauce during Storage (한국식 핫소스의 저장 중 이화학적 특성 변화)

  • Kwon, Dong-Jin;Lee, Sung;Kim, Yoo-Jin;Yoo, Jin-Yong;Jung, Kun-Sub
    • Korean Journal of Food Science and Technology
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    • v.30 no.3
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    • pp.548-551
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    • 1998
  • Physicochemical characteristics of the Korean type hot sauce during storage were investigated. Chemical analysis of the Korean type hot sauce showed as follows; pH 3.29, titratable acidity 3.88%, capsanthin 0.13% and capsaicin 2.68 mg%. The contents of capsanthin and capsaicin except pH and titratable acidity decreased during storage for 50 days at 20 and $30^{\circ}C$. The results of sensory evaluation showed the decrease of value according to storage time. Especially change of color in sensory evaluation was outstanding. For correlationship between the color of sensory evaluation and capsanthin content was high, capsanthin content was selected as a quality index of the Korean type hot sauce. Shelf-lives of the Korean type hot sauce were predicted to be 232.5 days at $20^{\circ}C$, and 178.0 days at $30^{\circ}C$, respectively.

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Changes of Physicochemical, Sensory and Antioxidant Activity Characteristics in Rice Wine, Yakju Added with Different Ratios of Codonopsis lanceolata (더덕을 첨가하여 제조한 약주의 이화학적, 관능적 및 항산화 특성 변화)

  • Jin, Tie-Yan;Lee, Wan-Gyu;Lee, In-Sook;Wang, Myeong-Hyeon
    • Korean Journal of Food Science and Technology
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    • v.40 no.2
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    • pp.201-206
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    • 2008
  • The physicochemical, sensory and antioxidant activity characteristics of rice wine, yakju added with different ratios of Codonopsis lanceolata (0, 10, 20, and 30%) were investigated. The pH of the rice wine decreased and the total acidity increased with greater additions of C. lanceolata. Furthermore, the total sugar content increased, while the alcohol content decreased with increasing amounts of C. lanceolata. The color L-value had no change, but the color a- and bvalues increased with increasing amounts of C. lanceolata. The DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging activity increased with the addition of C. lanceolata. The highest overall acceptability values in the sensory test for color, flavor, taste, and overall favorite were 5.53, 5.50, 5.63, and 5.65, respectively, with the addition of 20% C. lanceolata.

Changes in the Physicochemical Properties of Soil According to Soil Remediation Methods (토양 정화 방법에 따른 토양의 물리화학적 특성 변화)

  • Yi, Yong-Min;Oh, Cham-Teut;Kim, Guk-Jin;Lee, Chul-Hyo;Sung, Ki-June
    • Journal of Soil and Groundwater Environment
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    • v.17 no.4
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    • pp.36-43
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    • 2012
  • Various methods are used to remediate soil contaminated with heavy metals or petroleum. In recent years, harsh physical and chemical remediation methods are being used to increase remediation efficiency, however, such processes could affect soil properties and degrade the ecological functions of the soil. Effects of soil washing, thermal desorption, and land farming, which are the most frequently used remediation methods, on the physicochemical properties of remediated soil were investigated in this study. For soils smaller than 2 mm, the soil texture were changed from sandy clay loam to sandy loam because of the decrease in the clay content after soil washing, and from loamy sand to sandy loam because of the decrease in the sand content and increase in silt content during thermal desorption, however, the soil texture remained unchanged after land farming process. The water-holding capacity, organic matter content, and total nitrogen concentration of the tested soil decreased after soil washing. A change in soil color and an increase in the available phosphate concentration were observed after thermal desorption. Exchangeable cations, total nitrogen, and available phosphate concentration were found to decrease after land farming; these components were probably used by microorganisms during as well as after the land farming process because microbial processes remain active even after land farming. A study of these changes can provide information useful for the reuse of remediated soil. However, it is insufficient to assess only soil physicochemical properties from the viewpoint of the reuse of remediated soil. Potential risks and ecological functions of remediated soil should also be considered to realize sustainable soil use.

Physicochemical Properties of Root Zone Soil Based on Sand Blending with Coconut Coir and Peat Moss (코코넛 코이어와 피트모스 혼합 모래 토양의 물리·화학적 특성)

  • Kim, Young-Sun;Bae, Eun-Ji;Choi, Mun-Jin;Kim, Tae-Wooung;Lee, Geung-Joo
    • Korean Journal of Environmental Agriculture
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    • v.41 no.2
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    • pp.101-107
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    • 2022
  • BACKGROUND: Soil amendment was necessary applied for the sand that had been used to root zone of green ground in golf course because of its low water retention power and cation exchangeable capacity. This study was conducted to evaluate the effect of the mixed ratio of peat moss and coconut coir as soil amendment materials on the soil physicochemical properties applied to rootzone based on sand. METHODS AND RESULTS: The soil amendments were blended at 0, 3, 5, 7 and 10% by soil volume. The pH in the peat moss treatment was lower than that of control (0% soil amendment), and pH and electrical conductivity (EC) in the coconut coir were higher. The blending ratio of peat moss was negatively correlated with pH of rootzone soil (p<0.01), and that of coconut coir positively with EC (p<0.01). As compared with control, capillary porosity, the physical factors such as air-filled porosity, total porosity, and hydraulic conductivity of rootzone soil were increased by applying peat moss and coconut coir. For correlation coefficients between percentage of soil amendments and soil physical factors, peat moss and coconut coir were positively correlated with porosity and hydraulic conductivity (p<0.01). CONCLUSION(S): These results indicated that the application of peat moss and coconut coir affected on the change of physicochemical properties of rootzone soil, and improved soil porosity and hydraulic conductivity.

Physicochemical Characteristics of Traditional Doenjang with added Lentinus edodes (표고버섯을 첨가한 전통된장의 이화학적 특성)

  • Choi Sun-Young;Sung Nak-Ju;Kim Haeng-Ja
    • Korean journal of food and cookery science
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    • v.22 no.1 s.91
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    • pp.69-79
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    • 2006
  • Traditional doenjang with Lentinus edodes added at a concentration of 0, 3, 5 and 10% (w/w) was prepared and its physicochemical characteristics were analyzed during fermentation for 6 months. The moisture content, salt level and pH for doenjang were decreased with increasing addition of Lentinus edodes powder, but crude protein content was increased. Among the free sugars, glucose, galactose, arabinose, sucrose and maltose were identified and quantified, with the first two being the major free sugar. Minerals were detected in the order of Na> K> P> Ca> Mg> Fe while the content of Cu, Mn and Zn exhibited little change. The contents of each amino acid of traditional doenjang with added Lentinus edodes, glutamic, leucine and aspartic acids, had a much higher level. In fatty acid compositions, palmitic, stearic, oleic and linoleic acids were analyzed, with oleic acid being the most abundant fatty acid at $56.4{\pm}0.8\sim57.5{\pm}0.5%$ in all the tested samples. GMP and IMP contents of nucleotides and their related compounds were extremely high. It was thought that these substances contributed to the sweet taste of traditional doenjang with added Lentinus edodes. These results showed the applicability and high quality of traditional doenjang with added Lentinus edodes.

The Effect of Temperature and Time on Physicochemical, Microbiological Properties and Sensory Analysis of Dongchimi during Fermentation and Storage (발효와 저장 중 온도와 시간 변화에 따른 동치미 품질 특성)

  • Cho, Mi Sook;Na, Yeseul
    • Journal of the Korean Society of Food Culture
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    • v.35 no.5
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    • pp.450-458
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    • 2020
  • This study examined the optimal temperature and time conditions to maintain high quality Dongchimi during the fermentation and storage period. Dongchimi was fermented at low (5℃), medium (10 and 15℃), and high (20℃) temperatures until the acidity reached 0.2, 0.3, and 0.4%. respectively. From the consumer's preference test enrolling five consumers, Dongchimi fermented at 15℃ until an acidity of 0.3% (for approximately six days) was evaluated to be the optimal status because of its high score of overall acceptance, taste, and odor of consumers. To determine the optimal storage temperature of fermentation, Dongchimi was stored at three different temperatures (-1, 2, 5℃) for four weeks after fermenting at 15℃ for six days. During the storage period, most of the physicochemical properties (pH, acidity, reducing sugar content, and organic acid) and microbiological properties changed significantly in the 2 and 5℃ groups, resulting in a significant change in descriptive sensory analysis of Dongchimi. These results indicate that fermentation at 15℃ and storage at -1℃ for Dongchimi enables it to maintain the best quality for a long time.

The Physicochemical Properties of $\alpha$-Amylase Inhibitors from Black Bean and Naked Barey in Korea (한국산 검정콩 및 쌀보리 $\alpha$-Amylase 저해물질의 이화학적 특성)

  • 심기환;문주석;배영일
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.3
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    • pp.367-375
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    • 1998
  • The physicochemical properties of the $\alpha$-amylase inhibitors from black bean and naked barley is Korea were investigated. Preincubation time for maximum inhibition was 30min and no activity change was seen after that time. Optimum pH of the $\alpha$-amylase inhibitors from the black bean and naked barley was pH 7.0 and the inhibitory activities were stable in the range of pH 6.0~8.0 in both phosphate and Tris-HCI buffer solutions. Both inhibitors maintained more than 50% of activity after incubation for 17 min at 7$0^{\circ}C$. The inhibitors from the black bean and naked barley maintained more than 50% of activities after treatment for 40 min and 30 min with pepsin, and 30 min and 50 min with trypsin, respectively. Both inhibitors functioned via a noncompetitive mechanism and were active against porcine pancreatic and human salivary $\alpha$-amylases. The activities of both inhibitors were linear for the ionic stength ranging from 0 to 0.9. The addition of 70 mM maltose to the reaction mixture caused a maximum increase in the relative activities of both inhibitors, but it did not affect the dissociation of the EI complex. The activities of both inhibitors were significantly enhanced by adding 1mM of K+ or Mg2+.

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Electrochemical Energy Storage of Milled Carbon Nanofiber (탄소나노섬유의 밀링에 따른 전기화학적 에너지 저장 특성)

  • Lee, Hye-Min;Jeon, Hyeon;Choi, Weon-Kyung;Cho, Tae-Hwan
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.4
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    • pp.527-533
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    • 2011
  • CNFs had been well addressed due to numerous promising applications in science and technology. Besides the same physicochemical properties of ordinary carbon materials such as active carbons and carbon black, they exhibit specific, e.g., tubular or fibrous structures, a large surface area, high electrical conductivity stability, as well as extremely high mechanical strengh and modulus, which make them a superior material for electrochemical capacitors. In this study, CNFs were pretreated by mechanical milling with different time in mortar and pestle. The milled CNFs were used as active material of electrode whose electrochemical property was tested to find physicochemical characterization variation. CNF electrode milled for 5 min has the highest electric capacitance. XPS spectrum were employed to explore changes in functional group induced from mechanical milling. Crystal size was calculated to analyze change of peak from different milling time by XRD. The CNF milled for 5 min has the largest crystal size and the highest electric capacitance.