• Food Engineering Progress
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• v.15 no.3
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• pp.250-256
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• 2011

This study was performed to analyze the quality characteristics of Sulgidduk added with different ratio 0, 10 and 15% (w/w) of apple pomace dietary fiber powder (DFP). Increasing DFP from 0% to 15% was decreased in color L* value from 87.9 to 65.9, while a* and b* values were increased from -1.9 to 5.9 and from 5.0 to 20.5, respectively. Scanning Electron Microscopy (SEM; ${\times}500$) showed that air cell size in the Sulgidduk surface increased as the DEP increased. On the other hand, control without DFP had a compact structure without air cell. Enthalpy by DSC showed that control without DFP, 10 and 20% DEP Sulgidduk after 3 days of storage were 4.83, 3.80 and 3.18 J/g at $4^{\circ}C$ and those of $25^{\circ}C$ were 1.14, 0.60 and 0.60 J/g, respectively. DEP had more effective on retarded retrogradation of Sulgidduk at $4^{\circ}C$ than that at $25^{\circ}C$. Hardness of 15% DEP Sulgidduk was around 42% compared to that of control without DFP after 3 days of storage at $4^{\circ}C$. In hedonic test, 15% DEP Sulgidduk showed the highest overall quality score among samples after making and storage 3 days at $4^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.486-494
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• 2021

A rice (Oryza sativa L.) cultivar of the SPP (stakeholder participatory program) and ordinary rice were characterized based on water-absorption properties and cooked rice texture. During rice soaking, the rice grain transformed from transparent to opaque (white), indicating that water molecules diffused into the rice grain during soaking. In addition, cracks in the internal structure of soaked rice gradually increased with an increase in soaking time. Water absorption increased rapidly up to 20 min, but no increment was observed after 30 min of soaking. At this point, the entire areas of the soaked rice grain turned white, indicating that water absorption had reached saturation. SPP rice showed lower hardness and higher stickiness in its cooked form than ordinary rice, suggesting that SPP rice could be a more preferable choice than ordinary rice. Furthermore, cooked SPP rice was more edible in terms of hardness and stickiness after being kept warm for 12 h than ordinary rice. These results indicated that cooked SPP rice exhibited slow retrogradation and improved taste.

• Resources Recycling
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• v.23 no.2
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• pp.17-25
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• 2014

The thermal effect on the compositional change of the $SO_2$ absorption process product was investigated compared with the composition of raw material when dolomite is employed in place of lime in the scrubbing process based on thermodynamic estimation. It was considered that the equilibrium reactions which directly related with the formation of $CaSO_4$ and $MgSO_4$, the absorption process products, are those between $Ca^{2+}$ and $Ca(OH)_2$, $Mg^{2+}$ and $Mg(OH)_2$, and the secondary dissociation reaction of $H_2SO_4$. It was thought to be necessary to examine the enthalpy change for the formation reactions of $CaSO_4$ and $MgSO_4$ along with the thermal feature of the relative reactions to figure out the influence of temperature on the compositional change of absorption process products. The stable regions for $Ca(OH)_2$ and $Mg(OH)_2$ in Pourbaix diagram were found to be increased as temperature rises and the equilibrium reaction between $Ca^{2+}$ and $Ca(OH)_2$ was investigated to be more strongly influence by temperature change compared with the equilibrium reaction between $Mg^{2+}$ and $Mg(OH)_2$. The amounts of $CaSO_4$ and $MgSO_4$ were anticipated to be decreased with temperature considering the thermal characteristics for the equilibrium reactions regarding calcium, magnesium, and $H_2SO_4$. It was understood that the formation ratio between $CaSO_4$ and $MgSO_4$ is greater than the composition ratio between calcium and magnesium contained in dolomite at specific temperature and the decrease of the formation ratio of $CaSO_4$ and $MgSO_4$ with temperature was estimated to be diminished as the content of calcium in dolomite is increased. In addition, the extent of the change in the compositional ratio between absorption process products was examined to be reduced compared with the composition of raw material as the calcium content in dolomite is raised.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.905-913
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• 2003

The physicochemical properties of rice flour roasted at various temperatures and times were analyzed, and the quality characteristics of tarakjuk made from these roasted rice flours were investigated. As roasting temperature and time increased, rice flour showed decreasing moisture, protein content, and glucose the major reducing sugar of rice flour. Total amino acid content did not show any significant changes, but the amount of free amino acids and individual amino acids, such as lysine, tryptophane, and tyrosine, decreased. A decrease in L value and increases in a and b values from both roasted rice flour and tarakjuk was observed. Reduced crystallinity and gelatinization temperatures of roasted rice flour were investigated with X-ray diffractogram and DSC, respectively. The thermal transitions between $100.6{\sim}127.6^{\circ}C$ of tarakjuk by DSC are considered to be due to the melting of amylose-lipid complex. As the roasting temperature and time of rice flours increased, tarakjuk showed lower viscosity and higher spreadability. Sensory characteristics, such as nutty flavor, color intensity, and gritty texture increased significantly. Tarakjuk made from rice flour roasted at $185^{\circ}C$ for 25min showed the highest score on overall preference. From the above results, roasted rice flour produced more preferable tarakjuk than nonroasted flour in terms of sensory quality.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.765-772
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• 2004

Cooking condition of Tarakjuk (milk-rice porridge) was established based on gelatinization temperature using differential scanning calorimetry (DSC) of roasted Ilpum rice flour, which has highest enzyme-resistant starch (RS) content. Effect of cooking temperature and time on DSC characteristics, crystallity with X ray diffractogram, RS content, in vitro starch digestibility (IVSD), amino acid composition, and in vitro protein digestibility (IVPD) of Tarakjuk were determined. Tarakjuk was cooked at 50, 56.5, 64, and $69^{\circ}C$ for various durations. Rice flour ingredient used was Ilpum, previously roasted at $185^{\circ}C$ for 25 min. Tarakjuk cooked at 50 and $56.5^{\circ}C$ showed two thermal transitions between $63.7-125.2^{\circ}C$ as determined by DSC, corresponding to endotherms of starch gelatinization $(63.7-73.8^{\circ}C)$ and melting of amylose-lipid complex (AM-lipid complex, $97.7-125.2^{\circ}C$), whereas that cooked at 64 and $69^{\circ}C$ showed only AM-lipid complex melting transition between $96.9-127.6^{\circ}C$. As cooking temperature increased, RS content of Tarakjuk decreased, whereas IVSD increased. Total amino acid content was between 11,558-15,601mg/100g, depending on cooking condition used. Compared with conventionally made control, contents of essential amino acids, such as lysine and tryptophane, were higher at 50 and $56.5^{\circ}C$, and IVPD showed higher increase. Results reveal degree of gelatinization in Tarakjuk with high RS content as well as low IVSD and high IVPD, which are important from physiological and nutritional point of view, can be produced by controlling cooking condition.