• Title, Summary, Keyword: Physicochemical properties

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Physicochemical Properties of Enzymatically Modified Maize Starch Using 4-${\alpha}$-Glucanotransferase

  • Park, Jin-Hee;Park, Kwan-Hwa;Jane, Jay-Iin
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.902-909
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    • 2007
  • Granular maize starch was treated with Thermus scotoductus 4-${\alpha}$-glucanotransferase (${\alpha}$-GTase), and its physicochemical properties were determined. The gelatinization and pasting temperatures of ${\alpha}$-GTase-modified starch were decreased by higher enzyme concentrations. ${\alpha}$-GTase treatment lowered the peak, setback, and [mal viscosity of the starch. At a higher level of enzyme treatment, the melting peak of the amylose-lipid complex was undetectable on the DSC thermogram. Also, ${\alpha}$-GTase-modified starch showed a slower retrogradation rate. The enzyme treatment changed the dynamic rheological properties of the starch, leading to decreases in its elastic (G') and viscous (G") moduli. ${\alpha}$-GTase-modified starch showed more liquid-like characteristics, whereas normal maize starch was more elastic and solid-like. Gel permeation chromatography of modified starch showed that amylose was degraded, and a low molecular-weight fraction with $M_w$ of $1.1{\times}10^5$ was produced. Branch chain-length (BCL) distribution of modified starch showed increases in BCL (DP>20), which could result from the glucans degraded from amylose molecules transferred to the branch chains of amylopectin by inter-/intra-molecular transglycosylation of ${\alpha}$-GTase. These new physicochemical functionalities of the modified starch produced by ${\alpha}$-GTase treatment are applicable to starch-based products in various industries.

Physicochemical Properties of Corn Starch-derived Branched Dextrin Produced by a Branching Enzyme

  • Song, Eun-Bum;Min, Byoung-Cheol;Hwang, Eun-Sun;Lee, Hyong-Joo
    • Food Science and Biotechnology
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    • v.17 no.2
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    • pp.234-240
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    • 2008
  • The optimal conditions for the production of branched dextrin from com starch (CSBD) using branching enzyme (BE) were established by investigating the degree of retrogradation of the gelatinized starch. The physicochemical properties of CSBD prepared using the established process were evaluated. It was found that physicochemical properties of com starch were greatly modified by BE treatment. CSBD had a higher dextrose-equivalent value and water solubility than the corresponding control. On the other hand, the viscosities in gelatinized solution and amylose contents of CSBD were lower than those of the control. A high-performance size-exclusion chromatography/multiangle laser light scattering/retractive index (HPSEC/MALLS/RI) system showed that the average molecular weight of CSBD was lower than that of the control. The pasting viscosities of CSBD were stable during the entire temperature cycle. In general, the BE treatment resulted in the retrogradation during storage being lower for CSBD than for the control.

Determination of Physicochemical Properties and Pharmacokinetic Profiles of Soybean Extracts

  • Jung, Hyun-Chan;You, Sung-Kyun;Kwon, Sun-Kyu;Hwang, Ji-Sook;Cho, Cheong-Weon
    • Journal of Pharmaceutical Investigation
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    • v.40 no.6
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    • pp.347-351
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    • 2010
  • Isoflavones have received much attention because of their health-related and clinical benefits such as estrogenic and anti-oxidative activities as well as triggering of natural killer cell activity. However, there are few publications reporting the pharmacokinetic profiles together with physicochemical properties of main isoflavones. Therefore, the pharmacokinetic parameters of main aglycones, daidzein, glycitein and genistein after oral administration of soybean extracts were investigated and the physicochemical properties of soybean extracts were characterized. It was observed that angle of repose was $46^{\circ}$ and tap density, bulk density and porosity were 10.12, 4.3 and $0.86\;g/cm^3$ and the mean $AUC_{last}$ of daidzein, glycitein and genistein was $11.376\;{\mu}g{\cdot}h/mL$, $3.045\;{\mu}g{\cdot}h/mL$ and $0.825\;{\mu}g{\cdot}h/mL$, respectively. Cell viability was 60% at a concentration of 10 mg/mL. Taken together, it was suggested that isoflavones were contained in the soybean products and had an antioxidant activity and this study would be the basis to control the quality of soybean products and study of the bioequivalence between soybean products in future.

A Comparative Study on the Chemicostructural Characteristics of Ecdysteroids (Ecdysteroid 화합물들의 화학구조 특성에 대한 비교연구)

  • Hwang, Gab-Soo
    • Journal of Environmental Health Sciences
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    • v.38 no.4
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    • pp.351-359
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    • 2012
  • Objectives: This study was conducted in order to investigate the specific correlation between physicochemical properties and bioactivity in ecdysteroids found in living organisms. Methods: The examined steroidal compounds were classified into three groups according to their relevance to ecdysone activity. Each compound molecule was completely drawn to automatically calculate its physicochemical parameters and docked against 20-hydroxyecdysone to calculate the total distance. Electronic charge distribution was also observed for each molecule. All procedures were conducted using a computational chemistry program. Results: Ecdysone agonists showed different ranges of parameter values, such as log P, hydrophilic-lipophilic balance (HLB), solubility parameter (SP), hydrophilic surface (HPS), hydrogen bond (HB) and Kappa 2, when compared with antagonists and steroids without ecdysone activity. They also showed a similar electronic charge distribution that is significantly different from the electron charge distribution of antagonists and steroids without ecdysone activity. The total distance values of agonists, estimated by docking them with 20-hydroxyecdysone, were relatively small but showed no correlation with binding affinity with receptor ligand. Conclusions: These results suggest that physicochemical properties such as steric and electronic effects, hydrophobicity and hydrogen bonding may operate in combination to determine the binding activity of ecdysteroids to the receptor protein.

Physicochemical and Sensory Properties of Baikseolgi Incorporated with Strawberry Powders

  • Lee, Jun Ho;Kim, Ji-Hye
    • Food Engineering Progress
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    • v.14 no.3
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    • pp.271-276
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    • 2010
  • Strawberry powder was incorporated into Baikseolgi by substituting the non-glutinous rice flour in the range of 0-8% based on the total weight of the non-glutinous rice flour and the effects on physicochemical and sensory properties were investigated. pH decreased significantly with the higher amount of strawberry powder in the formulation whereas titratable acidity showed a reverse trend (p<0.05). Moisture content also decreased significantly with the increasing amount of strawberry. Lightness ($L^{*}$-value) decreased significantly with higher strawberry powder concentration, indicating that the color of Baikseolgi became dark as also indicated by the visual observation. Redness ($a^{*}$-value) and yellowness ($b^{*}$-value), on the other hand, increased significantly with the substitution of strawberry powders up to 8% (p<0.05). Increases in strawberry powder concentration up to 8% in the Baikseolgi formulation significantly increased the intensities of sensory color, flavor, and taste attributes; on the other hand, the intensities of sensory moistness and chewiness decreased significantly (p<0.05). Results from the consumer test revealed that control received the highest acceptability scores in all attributes but 4% sample also obtained the competitive scores. Finally, Pearson correlation analysis revealed several very highly significant linear correlation between the means used to access physicochemical, sensory properties, and consumer preferences.

Physicochemical Properties and Antioxidative Activities of White Radish Tea by Different Preparation Methods (가공 방법을 달리한 무차의 이화학적 품질 특성과 항산화 활성)

  • Kim, Min-Ji;Park, Jong-Dae;Sung, Jung-Min
    • Culinary science and hospitality research
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    • v.24 no.1
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    • pp.73-81
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    • 2018
  • The objective of this study was to investigate their physicochemical properties and antioxidant activities of white radish teas such as pH, color value, total polyphenol contents, total flavonoids, DPPH radical scavenging activity, reducing power and sensory evaluation. They were processed by drying(AD), drying and roasting(ADR), steaming and drying(SAD), and steaming, drying, and roasting(SADR). As a result, the pH of ADR, and SADR tended to be significantly lowered and SADR was the lowest at $5.48{\pm}0.14$(p<0.001). Additionally, ADR and SADR were significantly different in color and browning value, compared to AD and SAD. There was no significant difference in reducing sugar content depending on processing methods. The total polyphenol content and total flavonoid content of the teas were significantly increase after roasting. DPPH radical scavenging activity was significantly higher in ADR and SDAR than in AD or SAD by 1.1~1.5 times(p<0.05). Compared with ADR and SADR after roasting, the sensory characteristics of AD and SAD were significantly lower than those of roasted ADAD and SAD, respectively. From the above results, it was concluded that the roasting process is a major process that affects the physicochemical quality characteristics and antioxidant activities.

Improvement of Physicochemical Properties of Waterborne Polyurethane/Poly(3,4-ethylenedioxythiophene) Hybrid Thin Films (수분산 Polyurethane/Poly(3,4-ethylenedioxythiophene) 혼성 필름의 물리화학적 특성 향상)

  • Ko, Young Soo;Yim, Jin-Heong
    • Polymer(Korea)
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    • v.37 no.5
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    • pp.587-591
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    • 2013
  • Poly(3,4-ethylenedioxythiophene) (PEDOT) has good properties such as high conductivity, optical transmittance, and chemical stability, while offering relatively weak physicochemical properties. The main purpose of this paper is the improvement of physicochemical properties such as solvent resistance and pencil hardness of PEDOT. Carboxyl groups in the anionic type waterborne polyurethane (WPU) chains can effectively crosslink each other in the presence of aziridine, resulting in physicochemically robust PEDOT/WPU organic-organic hybrid conductive thin films. The electrical conductivity, optical properties, and physicochemical properties of the hybrid conductive film were compared by varying the solid content and WPU portion in the coating precursor solution. From the results, the transparency and surface resistance of the hybrid film show a decreasing tendency with increasing solid content in the coating precursor. Moreover, solvent resistance and hardness were dramatically enhanced by hybridization of PEDOT and crosslinked WPU due to curing reactions between carboxyl groups.

Physicochemical and Gel Properties of Starch Purified from Mealy Sweet Potato, Daeyumi (분질고구마 대유미 전분의 이화학적 및 겔 특성)

  • Jeong, Onbit;Yoon, Huina;No, Junhee;Kim, Wook;Shin, Malshick
    • Korean journal of food and cookery science
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    • v.32 no.4
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    • pp.524-530
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    • 2016
  • Purpose: The properties of starch and starch gel prepared from a newly inbred sweet potato, Daeyumi were compared to the properties of starch and starch gel prepared from Sinyulmi which is a well known mealy type sweet potato. Methods: The starch was isolated by using the alkaline steeping method. Physicochemical, pasting, and thermal properties, and crystallinity were measured. The texture properties of starch gel (10%, w/w) were examined. Results: The amylose contents of Daeyumi and Sinyulmi starches were 25.57% and 22.59%, respectively. The initial pasting temperature of Daeyumi starch was significantly higher than that of Sinyulmi starch (p<0.05), but other paste viscosities were not different. The peak and conclusion temperatures of Daeyumi starch were higher than those of Sinyulmi starch by differential scanning calorimetry. The shape of Daeyumi starch gel was more clear and rigid than the shape of Sinyulmi starch gel. The surface and the upper side of Daeyumi starch gel were smoother than the surface and the upper side of Sinyulmi starch gel. Hardness and gumminess were higher in Daeyumi starch gel than in Sinyulmi starch gel. The crystallinity types of Daeyumi and Sinyulmi starches were $C_b$ and A types, respectively, but starch gels showed an amorphous type. Conclusion: Therefore, it is suggested that Daeyumi starch would have better physicochemical properties and higher quality of starch gel than Sinyulmi starch.

Efficacy of Alkali-treated Sugarcane Fiber for Improving Physicochemical and Textural Properties of Meat Emulsions with Different Fat Levels

  • Kim, Hyun-Wook;Setyabrata, Derico;Lee, Yong-Jae;Kim, Yuan H. Brad
    • Food Science of Animal Resources
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    • v.38 no.2
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    • pp.315-324
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    • 2018
  • The objective of this study was to evaluate the efficacy of alkaline-treated sugarcane bagasse fiber on physicochemical and textural properties of meat emulsion with different fat levels. Crude sugarcane bagasse fiber (CSF) was treated with calcium hydroxide ($Ca(OH_2)$) to obtain alkaline-treated sugarcane bagasse fiber (ASF). The two types of sugarcane bagasse fiber (CSF and ASF) were incorporated at 2% levels in pork meat emulsions prepared with 5%, 10% and 20% fat levels. Alkaline-treatment markedly increased acid detergent fiber content (p=0.002), but significantly decreased protein, fat, ash and other carbohydrate contents. ASF exhibited significantly higher water-binding capacity, but lower oil-binding and emulsifying capacities than CSF. Meat emulsions formulated with 10% fat and 2% sugarcane bagasse fiber had equivalent cooking loss and textural properties to control meat emulsion (20% fat without sugarcane bagasse fiber). The two types of sugarcane bagasse fiber had similar impacts on proximate composition, cooking yield and texture of meat emulsion at the same fat level, respectively (p>0.05). Our results confirm that sugarcane bagasse fiber could be a functional food ingredient for improving physicochemical and textural properties of meat emulsion, at 2% addition level. Further, the altered functional properties of alkaline-treated sugarcane bagasse fiber had no impacts on physicochemical and textural properties of meat emulsions, regardless of fat level at 5%, 10% and 20%.

The Study of Acceptance and Physicochemical Characteristics of Beef Consomme by Boiling Time (가열시간에 따른 Beef Consomme의 기호도 및 이화학적 특성에 관한 연구)

  • 김용식;장명숙
    • Korean journal of food and cookery science
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    • v.19 no.3
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    • pp.271-279
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    • 2003
  • This study was conducted to investigate the sensory and physicochemical properties of beef consomme made with different boiling times (1, 2, 3 and 4hrs). The sensory properties were evaluated with respect to both the acceptability (color, smell, mouth feel, taste, overall acceptability) and intensity characteristics (color, smell, clarify, taste). From the results, the 3hr treatment was most favored for color, smell, mouth feel, taste and overall acceptability, from the sensory evaluation tests. According to a quantitative descriptive analysis of the sensory evaluation for the product, the color, smell and taste gave higher scores with increases in the boiling time. As for the physicochemical characteristics, the pH was increased with increasing boiling time. The reducing sugars, turbidity and viscosity increased with increasing boiling time. The colorimetric lightness values (L) decreased, and redness (a), yellowness(b) and color difference values (ΔE) increased with increasing boiling time. There were 18 free amino acids identified; the alanine, glutamic acid, arginine and leucine contents were high in the free amino acids of the consomme made with different boiling times. There were 3 free sugars identified, glucose, fructose and sucrose. The free sugar contents increased with increasing boiling time. There were changes in the mineral contents of the consomme made with different boiling time; with high K, Na and P contents. The mineral contents increased with increasing, boiling time. The results showed the consomme made by boiling for 3hrs was superior in both its sensory and physicochemical qualities.