• Culinary science and hospitality research
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• v.14 no.3
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• pp.136-142
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• 2008

This study was conducted to investigate the correlation of the physicochemical quality index(pH, acidity, reducing sugar content and lactic acid bacterial count) and sensory index(sourness) of Kakdugi during the fermentation at 5$^{\circ}C$, 10$^{\circ}C$ and 20$^{\circ}C$ respectively. Also, the relations between physicochemical quality index and overall acceptability were carried out. The pH range, based on the middle sour intensity point of 4.5, was 5.75 at 5$^{\circ}C$ fermentation, whereas that was 4.2 at 10$^{\circ}C$ and 20$^{\circ}C$ fermentation. The pH showing the highest overall acceptability decreased along with increased fermentation temperature. The reduced sugar content decreased rapidly up to 0.9% acidity, but after that, decreased slowly from more than 0.9% acidity at all fermentation temperatures. With increased fermentation temperature, the reduced sugar content showing the highest overall acceptability also showed the decreasing tendency. Change patterns of lactic acid bacterial count and sourness didn't coincided at 5$^{\circ}C$ fermentation, whereas those did at 10$^{\circ}C$ and 20$^{\circ}C$ fermentation. The indexes showing high significant correlations with sourness of Kakdugi fermented at 5$^{\circ}C$ were not pH and lactic acid bacterial count but acidity and reducing sugar content(p<0.05). The sourness of Kakdugi fermented at 10$^{\circ}C$ and 20$^{\circ}C$ showed high significant correlations with all of the physicochemical index(p<0.05).

• Journal of the Korean Society of Food Culture
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• v.38 no.5
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• pp.356-364
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• 2023

This study compared the physicochemical properties of soybean curd residue and black soybean curd residue produced by hot air-drying and freeze-drying. Regardless of drying method, the crude protein, crude ash, crude fiber contents, pH, L, a, b color values and water soluble index were higher in soybean curd residue, whereas total polyphenol contents and antioxidant activity were higher in black soybean curd residue. Significant differences in water absorption index, oil absorption capacity and emulsion activity were observed between soybean curd residue and black soybean curd residue in freeze-drying. On the other hand, the emulsion stability was not significant difference in both hot-air drying and freeze-drying. The crude protein and crude fiber contents of soybean curd residue were not significant difference between hot-air drying and freeze-drying. Freeze-drying resulted in higher crude ash contents, pH, water absorption index, water soluble index, oil absorption capacity, emulsion activity and emulsion stability than hot-air drying. Hot-air drying have caused significantly higher water contents, water activity, total polyphenol contents and antioxidant activity in soybean curd residue than freeze-drying. In conclusion, soybean type and drying methods affect the physicochemical and quality characteristics of soybean curd residue, which could be important factors in the manufacture of processed foods.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.114-117
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• 2010

The effects of isolated soy protein(ISP) content on the physicochemical properties of extrudates from rice flour produced by a single-screw extruder were evaluated. The integrity index(II), nitrogen solubility index(NSI), rehydration ratio(RR), and density were measured as indices of the changes of physicochemical properties of rice extrudates. Increased amounts of ISP resulted in increased II but decreased RR and density. There was no change in the NSI value. It was concluded that the addition of ISP to the raw material could be helpful in texturization of rice extrudate.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.827-832
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• 2013

An attempt is made to predict the shelf life of seasoned anchovies packaged with laminated film, composed of polyethylene terephthalate (PET) and ethylene vinyl alcohol (EVOH). First, a descriptive sensory analysis is carried out to determine the principal sensory quality index in seasoned anchovies. Then, the physicochemical quality index with high correlation to the principal sensory quality index is determined accordingly. Subsequently, with the physicochemical quality index, the shelf-life is estimated by using the Arrhenius equation. As for the sensory quality index, 'color' is determined as a principal sensory quality index. For all samples stored at 3 different temperatures (25, 35, $45^{\circ}C$), it is observed that the sensory score is shown to be over 2.5 until 60 days of storage period, which is the lowest acceptable level. In addition, the b-value, as a physicochemical quality index, is determined to have a high correlation to the sensory quality index. Further, the activation energy and the Q10 value for the b-value by the Arrhenius equation is found to be 11.24 kcal/mol, 1.385~2.011, respectively. Thus, it can be concluded that the shelf life of seasoned anchovies packaged with PET/EVOH film is estimated to be 279.44 days when stored at $20^{\circ}C$.

• Macromolecular Research
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• v.10 no.3
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• pp.168-173
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• 2002

Unstabilized low-density polyethylene (LDPE) films and films formulated with hindered amine light stabilizer (HALS) were exposed to UV-radiation; and the physicochemical changes during photooxidation processes have been investigated using tensile, FTIR spectre-photometric and thermal analytical (DSC) techniques. The dependence of tensile properties (elongation- and stress-at-break), carboxyl index and heat of fusion on UV-irradiation time have been discussed. The use of HALS is found to be effective in maintaining the UV-mechanical properties of the LDPE films. The experimental results showed that there exists no correlation between mechanical properties and carbonyl index, whereas crystallinity correlates well with carbonyl index in unstabilized and stabilized films for irradiation times greater than 100 h. The rate of formation of carbonyl groups is found to be dependent on UV exposure time. Crystallinity of the film samples is strongly influenced by both exposure time and presence of HALS.

• Journal of the Korean Society of Food Culture
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• v.15 no.3
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• pp.195-199
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• 2000

Varied levels of mannitol at 0%, 3%, 6% and 9% were added to the commercial orange juice and physicochemical and sensory characteristics of the juice were investigated. Refractive index of control had $11.3^{\circ}Bx$ and the index was significantly increased to that of the $18.4^{\circ}Bx$ as the addition was increased to the 9% level(p<0.05). The values of pH and the acidity did not show significant differences among varied levels of mannitol added samples. However, sensory characteristics of aroma and sweet flavor were significantly increased as the addition levels were increased showing the values of aroma, from 7.5 to 11.3, and those of sweet flavor from 5.0 to 11.9, respectively (p<0.05). The 9% added level sample had significantly the lowest sour and astringent flavor values of 4.0 and 2.3, respectively.

• Journal of Ginseng Research
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• v.38 no.2
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• pp.146-153
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• 2014

A systematic comparison of the physicochemical properties of white ginseng (WG), extruded white ginseng (EWG), red ginseng (RG), and extruded red ginseng (ERG) was performed. The aim of the present study was to identify the effects of the physicochemical properties of ginseng by extrusion cooking. The highest value of the water absorption index (WAI) was 3.64 g/g obtained from EWG, and the highest value of the water solubility index (WSI) was 45.27% obtained from ERG. The ERG had a better dispersibility compared with other samples. Extrusion cooking led to a significant increase in acidic polysaccharide and total sugar content but resulted in a decrease in crude fat and reducing sugar contents. Enzyme treatment led to a sharp increase in acidic polysaccharide content, especially the cellulose enzyme. Extrusion cooking led to a significant increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power, and the increases in WG and RG were 13.56% (0.038) and 3.56% (0.026), respectively. The data of this study provide valuable information about the effects of extrusion on quality changes of EWG and ERG.

• Preventive Nutrition and Food Science
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• v.17 no.3
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• pp.203-209
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• 2012

The effects of variable moisture content, screw speed and barrel temperature on the physicochemical properties of red ginseng powder extrudates were investigated. The raw red ginseng powders were processed in a co-rotating intermeshing twin-screw extruder. Primary extrusion variables were feed moisture content (20 and 30%), screw speed (200 and 250 rpm) and barrel temperature (115 and $130^{\circ}C$). Extruded red ginseng showed higher crude saponin contents (6.72~7.18%) than raw red ginseng (5.50%). Tested extrusion conditions did not significantly affect the crude saponin content of extrudates. Increased feed moisture content resulted in increased bulk density, specific length, water absorption index (WAI), breaking strength, elastic modulus and crude protein content and decreased water solubility index (WSI) and expansion (p<0.05). Increased barrel temperature resulted in increased total sugar content, but decreased reducing sugar content in the extrudate (p<0.05). Furthermore, increased barrel temperature resulted in increased amino acid content and specific length and decreased expansion and bulk density of extrudates only at a higher feed moisture content. The physicochemical properties of extrudates were mainly dependent on the feed moisture content and barrel temperature, whereas the screw speed showed a lesser effect. These results will be used to help define optimized process conditions for controlling and predicting qualities and characteristics of extruded red ginseng.

• Journal of the Korean Society of Food Culture
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• v.37 no.4
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• pp.345-353
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• 2022

This study compared the physicochemical and gelatinization properties of naked barley, tetrastichum barley, and waxy barley. Compared to tetrastichum barley and waxy barley, naked barley had shorter and rounder grains with a 1.43 length/width ratio. Tetrastichum barley had lower crude protein, crude lipid, and crude ash content and higher amylose content compared to naked barley and waxy barley. The L, a, b color values of waxy barley were significantly higher than those of naked barley and tetrastichum barley. The water absorption index (WAI) and the water soluble index (WSI) were highest in waxy barley. The X-ray diffraction pattern was type A in all samples, and the peak intensity was highest in waxy barley. The maximum viscosity, cooling viscosity, breakdown, and setback of amylogram properties were the highest in tetrastichum barley. The thermal properties through the differential scanning calorimeter showed that the waxy barley had higher values of the onset, peak, conclusion temperature and enthalpy (?H). In conclusion, the variety of barley influenced the physicochemical and gelatinization properties, which could be important factors in the manufacture of processed foods. These results would thus useful inputs for the manufacturing of these foods using barley.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.827-832
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• 1998

Soybeans(Hwangkeum Kong) were stored at 5$^{\circ}C$, $25^{\circ}C$ and 35$^{\circ}C$ for 8 months to investigate the changes of the physicochemical properties. Less physicochemical changes were detected in the soybeans stored at 5$^{\circ}C$ than those stored at $25^{\circ}C$ and 35$^{\circ}C$. High temperature and long term storage caused a decrease in the nitrogen solubility index, whereas increases in acid value and organic acid content were detected. As the storage period was extended at high temperatues, the content of unsaturated fatty acids decreased, but the content of saturated fatty acids increased. Decoloration of soybeans was clearly recognized under high temperatures. The water soluble compoents such as total solids, nitrogen and reducing sugar during water-soaking at 2$0^{\circ}C$ for 16hrs were appreciably eluted from the soybeans stored for 8 months at high temperatures. The pH of the water extract slightly shifted to the acidic range.