• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.593-600
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• 2014

Normal rice starch (NRS) possesses high gelling and retrogradation tendencies, with poor freeze-thaw stability. This study investigated the effects of partial replacement of waxy rice starch (WRS) with gums on the pasting and viscoelastic properties as well as the freeze-thaw stability of the WRS paste. Xanthan gum (XAT), locust bean gum (LBG), and their mixtures were individually mixed with WRS at a ratio of 1:19 (w/w). WRS-gum mixtures were pasted using a rapid visco-analyzer at 5% total solid content, and analyzed with respect to the pasting and viscoelastic characteristics, and freeze-thaw stability. Pasting properties of WRS were retarded in pasting temperature and enhanced in pasting viscosity (although peak viscosity was varied) by partial replacement with gum and gum mixtures. Storage moduli of WRS-XAT:LBG pastes became similar to those of NRS paste with increasing angular frequency from 1 to 10 rad/s. Finally, WRS-XAT and WRS-XAT:LBG possessed more enhanced freeze-thaw stability than NRS.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.659-665
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• 2006

The effects of resistant starches on the quality characteristics of cookies were investigated by the physicochemical, instrumental and sensory properties of RS-added flours and cookies. Retrograded RS3 by autoclaving-cooling cycle and cross-linked RS4 after annealing treatment were used. The protein content of RS-added flour decreased, but the ash content of RS4-added flour increased slightly with increasing RS content. The RS levels of wheat flour, RS3- and RS4-added flours were 7.0%, 9.6-13.4% and 11.5-17.9%, respectively. The swelling powers of RS-added flours at 80$^{\circ}C$ decreased, but the solubility of RS3-added flour increased by 2-3 fold compared to that of control flour. Initial pasting temperature increased, but peak, holding, and final viscosities decreased with increasing RS content. The retrogradation degree of RS-added flours was lowered, because of the decreased consistency and breakdown viscosity. The yellowness of RS3-added flour increased with increasing RS3 content which induced browning reaction during baking. On the sensory test, RS-added cookies were significantly different in shape, color and overall quality (p<0.05), and their texture also affected. Overall quality was higher in peanut cookies than in AACC standard cookies and RS addition (up to 30%, w/w), regardless of the RS type, improved the cookie quality.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.474-483
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• 2015

The textural properties of breads containing midified starches such as pregelatinized waxy corn starch, acetylated potato starch and hydroxypropylated tapioca starch, were investigated to determine the optimum addition level of modified starches. Effects of modified starches on dough properties were investigated through a farinogram and amylogram based on the different additional levels of modified starches (3%, 6%, 9%, 12% and 15% of flour content). Moisture contents and firmness values were measured to investigate the degree of retrogradation at 0 h, 36 h and 72 h after production. The levels of moisture contents were highest upon addition of pregelatinized waxy corn starch followed by acetylated potato starch and lowest upon addition of hydroxypropylated tapioca starch. Overall, higher moisture contents resulted in lower firmness levels. The preference scores by type of modified starch were highest upon addition of 9% hydroxypropylated tapioca starch, 3% pregelatinized waxy corn starch, and 6% acetylated potato starch, respectively. Preference scores were significantly correlated with textural properties such as volume, absorption, stability and weakness (p<0.01).

• Korean journal of food and cookery science
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• v.22 no.2 s.92
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• pp.147-157
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• 2006

To improve the properties of non-waxy rice flours for baking, soaked-wet milled rice flour (SWRF) was adjusted moisture content (MC) to 30 and 50 % and heated at 50 and $70^{\circ}C$ in a shaking water bath for 6 and 18 hrs, respectively. Moisture-heat treated rice flours were investigated with regard to particle size distribution, and morphological, physicochemical and pasting properties for comparing dry and wet milled flours. The particle size of rice flour treated with 30% MC was distributed between $4-20{\mu}m\;and\;100-200{\mu}m$, like SWRF. The particles above $200{\mu}m$ in the flour were produced at higher heating temperature. By SEM, starch granules were found in the rice flours treated with 30% MC, who whereas aggregated starch granules were shown in the flours treated with 50% MC. Moisture-heat treatment using higher MC and heating temperature decreased the lightness and increased the yellowness of non-waxy rice flours. Water binding capacity of 30% moisture treated rice flour was similar to that of SWRF. In the same moisture treated rice flour, swelling power was higher, but solubility was lower at $50^{\circ}C$ than at $70^{\circ}C$. The initial pasting temperature by RVA increased after moisture-heat treatment. The peak viscosity of moisture-heat treated rice flour was higher for 30% moisture than that of the others. The rice flour treated with 30% MC and heated at $50^{\circ}C$ showed low setback and increased stability for retrogradation.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.235-240
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• 1991

Starch phosphates were prepared from the corn starch mixed with 2% sodium tripolyphosphate by twin-screw extruder with a feed rate of 20 kg/hr and an extrusion temperature of $130^{\circ}C$, and the effects of extrusion variables on the physicochemical properties (target parameters) of starch phosphates were investigated. Interrelations of system parameters (specific mechanical energy and extrudate moisture) and rheological properities of starch was analyzed by using the response surface analysis. Degree of substitution (DS) was increased with increasing the feed moisture, and showed the maximum value at the screw of near 250 rpm, Degree of gelatinization was proportionally increased with increasing the screw speed and decreasing the feed moisture. Apparent viscosity of the paste was increased with increasing the feed moisture, but it was not significantly affected by the screw speed. It was found by scanning electron microscopy that the starch microgranules were much more degradaded, and as consequent result, the intrinsic viscosity was decreased, whereas, water solubility index was increased. The rate of retrogradation of the gels was retarded with increasing DS and decreasing viscosity.

• Korean journal of food and cookery science
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• v.26 no.6
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• pp.677-684
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• 2010

The purpose of this study was to investigate the effects of black foods (black rice and black garlic) and the ratio of black garlic on the quality of Sulgiddeok. Pasting properties as measured by a rapid visco analyzer (RVA) were lower for black rice flour than white rice flour. Colorimetric analysis revealed that L, a, b values were dependent on the type of rice. For texture profiles, texture was associated with RVA profiles. During storage, hardness of black rice Sulgiddeok increased to a lesser degree than that of control. After observation via scanning electron microscopy (SEM), black rice Sulgiddeok showed a honeycomb-like network structure. In sensory analysis, black rice Sulgiddeok showed a tendency to prefer the control. The addition of appropriate black garlic (BG1) helped to improve the quality. In accordance with the aforementioned results, decreased retrogradation related to black rice Sulgiddeok and black foods (black rice and black garlic) could result in quality products with high nutritional value.

• Korean journal of food and cookery science
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• v.24 no.1
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• pp.99-105
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• 2008

Laver-wrapped rice and laver-wrapped rice containing a vinegar blend (vinegar:sugar:water:salt = 5:2:2:1) were prepared and their degrees of aging from 10 to $30^{\circ}C$, total cell numbers, and total coliforms were examined and compared. The total cell numbers of the laver-wrapped rice increased to 1 log cfu/g at 36 hours, and the total cell numbers of the laver-wrapped rice with vinegar had increased to within 48 hours. At $20^{\circ}C$ for 24 hrs, the total cell numbers for the laver-wrapped rice had increased to 5 log cfu/g: whereas trhe total cell numbers of the laver-wrapped rice with vinegar(5ml of vinegar marinade mixed into 100g of steamed rice), stored at the same conditions had not increased. In the vinegar-marinated rice (2ml/100g rice), microorganisms appeared at 18 hours. However, at the concentration of 5ml/l00g of rice, microorganisms were not observed at 24 hours. Coliforms did not appear in the laver-wrapped rice nor in the laver-wrapped rice with vinegar(prepared at 10ml/100g) until 48 hours. When stored at 10 and $20^{\circ}C$, no microorganisms were found in the laver-wrapped rice with vinegar until 48 hours, respectively. However, at $30^{\circ}C$, microorganisms were observed in the laver-wrapped rice from 24 hours, and from 48 hours in the laver-wrapped rice with vinegar. These results suggest that laver-wrapped rice should be consumed within one day. The number of microorganisms inside the laver-wrapped rice reached 6 log cfu/g by 24 hours, but the increase in the laver-wrapped rice with vinegar was slower. The aging(% damaged starch) of the laver-wrapped rice with vinegar(5ml/100g the rice) stored at $20^{\circ}C$ was reduced, with 3% damaged starch at 24 hours. Consumer evaluations revealed that the laver-wrapped rice prepared with 5ml of the vinegar blend received higher scores for flavor, taste, texture, and overall acceptance as compared to the control. In particular, significantly higher scores were given for taste, texture, and overall acceptability. In summary, the laver-wrapped rice with vinegar had an extended shelf-life(more than 1 day) at storage temperatures of $20-30^{\circ}C$, as well as reduced retrogradation. In addition, based on consumer evaluations, adding vinegar to laver-wrapped rice laver is effective for increasing overall acceptability.

• Korean journal of food and cookery science
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• v.29 no.2
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• pp.137-146
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• 2013

Premature-green wheat is typically obtained by early harvest when culms of wheat still appear green in color, and the wheat and its food products have been considered as wellbeing foods. The pasting properties of prematured whole green wheat powder (WGWP), were analyzed with a rapid viscosity analyzer (RVA), and compared with commercial flours. The RVA values of lower peak viscosity and time, holding strength, final viscosity, as well as breakdown and setback viscosity showed that the WGWP could retard a gelatination of starch and also delay retrogradation in bakery products. WGWP with different levels of 10, 20, 30 or 50% was added into flours for preparing bakery product (bread, muffin and cookie), and their quality properties were evaluated. The addition of WGWP lead to a reduction in loaf volume of bread and muffin, and bakery products containing different levels of WGWP showed the changed internal surface structure (e.g. pore size) observed with a scanning electron microscope when compared with the control (0% WGWP). The hardness, gumminess, chewiness of bread and muffins were increased, and cohesiveness was decreased as the WGWP content increased, but the hardness of cookies was decreased. The bakery products added WGWP showed darker and more greenish and yellowish color than control (p<0.05). The sensory evaluation showed that bakeries with WGWP were scored to have more greenish taste and green color (p<0.05), and muffins and cookies with WGWP were evaluated to have more nutty and less oily taste (p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.616-621
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• 2017

The objective of this study was to investigate the physicochemical properties of domestic strong wheat flour (DSWF). Three commercial DSWFs (D1, D2, and D3) were compared with imported strong wheat flour (ISWF). DSWFs had higher moisture content, crude protein content, lightness, and whiteness than ISWF. DSWFs showed lower solvent retention capacity and water absorption index than ISWF. DSWFs also showed significantly higher water solubility index than ISWF (P<0.05). Setback values by rapid visco analysis were significantly higher in D1 and D2 than in ISWF and D3, which means ISWF and D3 were better in retarding retrogradation. Differential scanning calorimetry results showed that ISWF required 6.2 J/g of energy for phase transition, whereas DSWFs needed 6.67~7.13 J/g. The farinograph results showed that ISWF had higher water absorption, longer dough stability time, and significantly higher softening of dough at 20 min than DSWF (P<0.05). Dough resistance and extensibility were higher in ISWF than in DSWFs.

• 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 $4^{\circ}C$.