• Composites Research
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• v.22 no.2
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• pp.18-23
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• 2009

Failure of Kevlar29/Phenolic composite plate under high velocity impact of FSP(Fragment Simulation Projectile) is investigated using a non-linear explicit finite element code, LS-DYNA. Composite laminate and impactor are idealized by solid element and interface between laminas are modeled by tied-break element in LS-DYNA. Interaction between impactor and laminate is simulated face-to-face eroding contact algorithm. When the stress level meets a failure criteria, the layer in the element is eroded. Numerical results are verified by existing test results.

• Journal of People, Plants, and Environment
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• v.22 no.2
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• pp.199-207
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• 2019

The purpose of this study was to investigate the mood states and concentration of students when they see the natural scenery indoors throughout the Free Semester Program (FSP) of middle school. The subjects were total 180 students comprised of 60 students in the group viewing natural scenery, 60 students in the group viewing urban scenery and 60 students in the control group from the first year of middle school located in Daejeon, and the experiment was carried out from September 3 to October 30, in 2018. The results showed that tension, depression, anger, fatigue and confusion were decreased and vigor was increased significantly in group viewing natural scenery compared to group viewing urban scenery and the control group. Ratings of 'pleasant,' 'natural,' and 'calm' were increased and concentration was also improved significantly in the group viewing natural scenery compared to the group viewing urban scenery and the control group. This indicates that positive effects can be anticipated on the improvement of mood states and concentration by developing indoor program viewing natural scenery for people who have difficulties in outdoor activities.

• Food Science and Preservation
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• v.31 no.1
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• pp.64-79
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• 2024

The rise in popularity of vegetarian and plant-based diets has led to extensive research into plant-based whipped creams. Whipped cream is an oil-in-water emulsion that creates foam through whipping, stabilizing the foam with proteins and fats. Pea protein is an excellent emulsifier and foaming agent among plant-based proteins, but its application in whipped cream is currently limited. The objective of this study was to investigate the quality characteristics of plant-based whipped cream made with ultrasonicated pea protein. The whipped creams were evaluated based on their quality characteristics. A commercially available dairy whipped cream (CON) was used as a control. Plant-based creams were evaluated using pea protein solution, cocoa butter, and canola oil to produce un-ultrasonicated pea protein whipped cream (PP) and ultrasonicated pea protein whipped cream (UPP) at 360 W for 6 min. UPP significantly reduced whipping time and foam drainage compared with CON and PP, resulting in significantly increased overrun, fat destabilization, and hardness. Optical microscopy showed that UPP had smaller fat globules and bubble size than PP. The fat globules of UPP and CON were mostly below 5 ㎛, whereas those of PP were distributed at 5-20 ㎛. Finally, ultrasonication significantly improved the overrun, foam drainage, fat destabilization, and hardness of UPP, which are significant quality characteristics of whipped creams. Therefore, ultrasonicated plant-based pea protein whipped cream is believed to be a viable alternative to dairy whipped cream.

• Food Science and Preservation
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• v.31 no.1
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• pp.46-63
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• 2024

This study evaluated the impact of storage temperature on the quality characteristics of texturized vegetable protein (TVP). TVP was prepared by mixing defatted Daewon soybean flour at 80℃, gluten, and corn starch in a 5:3:2 ratio, which was then extruded at a screw speed of 250 rpm and a barrel temperature of 190℃ with moisture addition at 9 rpm. Subsequently, the extruded TVP was vacuum-sealed in polyethylene packaging and stored at -20℃, 0℃, and 4℃ for 9 days. Texture analysis revealed that the curing rate followed 4℃ > 0℃ > -20℃ sequence. No significant color variation was observed across the storage conditions, although water content increased at all temperatures. Notable changes were detected in moisture absorption capacity (%) and solid leaching (%), following the order of -20℃ > 0℃ > 4℃. The turbidity of the solution released during cooking varied, with the highest to the lowest sequence being -20℃ > 4℃ > 0℃, while pH levels remained neutral. Regarding free amino acids, sweetness and textural quality improved with storage across all temperatures, whereas bitterness components diminished at 4℃. The study suggests that refrigerated storage at 4℃ is a viable method for distributing TVP, which was previously distributed only in a frozen and dry state.

• Food Science and Preservation
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• v.31 no.1
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• pp.33-45
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• 2024

Three spring potato varieties (Atlantic, Chubaek, and Superior) were cultivated for 80, 90, and 100 days and compared in terms of their total and marketable yields and specific gravities. Subsequently, changes in the quality parameters (weight loss, sprouting rate, disease incidence, dry weight, and specific gravity) of potatoes cultivated for 100 days were monitored during two-month storage in improved and semi-underground warehouses at 4℃ and room temterature. The productivities of Atlantic, Superior, and Chubaek were maximized at cultivation periods of 100, 100, and >90 days, respectively. In all cases, cold storage resulted in <5.3% weight loss and no marketability loss. However, two-month room temperature storage resulted in pronounced marketability loss due to weight loss (6.2, 7.3% and 10.9% for Atlantic, Superior, and Chubaek, respectively) and sprouting (in ~13%, >75%, and 99% of Atlantic, Superior, and Chubaek tubers, respectively). The marketability of Atlantic, Superior, and Chubaek during cold storage was maintained for >2, ~2, and <2 months, respectively. All varieties were characterized by rapid sprouting, low dry weight and specific gravity, and rapid marketability loss during storage.

• Food Science and Preservation
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• v.31 no.2
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• pp.324-331
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• 2024

This study examined the nutrient composition and taste properties of Sargassum fusiforme (SF) from two locations in the Wando region (Wando-eup: WD-A, Sinji-myeon: WD-B) and control region in Korea. The protein content of the SF in Wando regions was higher than that of the control, while the carbohydrate content was lower. The WD-A region had the lowest calorie content and the highest ash level when compared to the other regions. The potassium, iron, and zinc contents of the in WD-A were significantly higher than the other groups, but the sodium, phosphorus, and magnesium contents were lower. Free and constitutive amino acids, as well as the total and essential amino acid content, were higher in Wando regions than in the control. When analyzing using an electronic tongue, the SF from the WD-A region had the highest umami and sourness and the lowest bitterness and sweetness. Therefore, the results of this study can serve as fundamental data for seaweed research in the Wando region.

• Food Science and Preservation
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• v.31 no.2
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• pp.199-209
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• 2024

This study explored how temperature, time, and moisture content affect the rheological properties (apparent viscosity, flow behavior index, and consistency coefficient) of stored tomato and pepper purees. These purees were prepared with moisture contents of 85%, 90%, and 95% (w/v) using the hot-break method and tested over 6 days at 2-day intervals and temperatures of 5℃, 10℃, and 15℃. Results displayed distinct ranges for apparent viscosity, consistency coefficient, and flow behavior indices: tomato puree (2,519.9-4,324.6 mPa·s, 258.0-550.6 mPa·Sn, 1.80-0.48) and pepper puree (2,105.6-4,562.0 mPa·s, 268.4-580.4 mPa·Sn, 0.22-0.48). The temperature and storage time had significant (p≤0.05) effects, but moisture content did not affect these properties. Flow behavior and consistency coefficients demonstrated relative variation with apparent viscosity, indicating pseudoplastic behavior. Optimal processing and storage conditions were identified within specific ranges: 13.21-14.42℃ for 2 days with 92.22-94.23% (w/v) moisture content for pepper, and 8.42-11.77℃ for 2-6 days with 85% (w/v) moisture for tomato.

• Food Science and Preservation
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• v.31 no.2
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• pp.245-255
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• 2024

The proximate composition, quality characteristics, antioxidant activity, and sensory evaluation scores of yakgwa added with mealworm powder (MP) were examined. MP contained 5.83 wt% moisture, 55.70 wt% crude protein, 35.96 wt% crude fat, 3.70 wt% crude ash, and 2.43 wt% carbohydrate and feature total polyphenol and flavonoid contents of 406.52 mg GAE/100 g and 21.18 mg NE/100 g, respectively. The DPPH and ABTS^•+ radical scavenging activities and the reducing power of MP were determined as 90.25%, 44.06%, and 1.74, respectively. Except for moisture and carbohydrate content, the proximate composition of mealworm yakgwa (MY) increased with the amount of MP increased. The pH of the dough increased with the addition of MP, whereas the expansion degree tended to decrease. Sugar content was highest at MP contents of 0 wt% and 12 wt% (FM4 group), and hardness was lowest in the FM4 group. With the increasing MP content, the L, b values and antioxidant activity increased, whereas a value decreased. The sensory evaluation scores for the overall preference, appearance, color, and taste were lowest in the FM4 group. These results suggested that MP contents of 6-9 wt% were optimal for mealworm-based yakgwa.

• Food Science and Preservation
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• v.31 no.2
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• pp.256-266
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• 2024

This study examined the effects of chestnut powder content (2.5%, 5%, 7.5%, and 10%) on the antioxidant activity and quality characteristics of rice muffins. With the increasing chestnut powder content, the total polyphenol content, flavonoid content, antioxidant activity (determined by radical scavenging activity and reducing power), hardness, gumminess, chewiness, and overall acceptability (determined by sensory evaluation) increased, whereas the moisture content, pH, specific volume, and cooking loss decreased. Regarding color, chestnut powder content was negatively correlated with L and b and positively correlated with a. Notably, overall acceptability abruptly decreased to its minimum at 10%. Thus, adding powder at loadings of <7.5% improved the antioxidant activity and acceptability of rice muffins. Our results can be used as preparatory data for developing a rice muffin model.

• Food Science and Preservation
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• v.31 no.3
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• pp.499-505
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• 2024

Patulin has been reported as a risk factor in various foods, especially apple juice. This study monitored residual patulin and polyphenolic content in apple juice during post-irradiation storage conditions. Response surface methodology (RSM) was applied to monitor the changes in dependent variables (Yn, patulin, and polyphenolics) as affected by independent variables, such as storage temperature (Xi, -20℃ to 20℃), irradiation dose (Xii, 0-2 kGy), and storage period (Xiii, 0-20 days), which were based on a central composite design. The predicted peak point resulted in the lowest residual patulin content of 58.42 ppb with the corresponding independent parameter conditions, such as 18.19℃ of storage temperature, 1.24 kGy of irradiation dose, and 13.42 days of storage period. The residual patulin content of 58.42 ppb is the minimum desirable level, representing a 91% reduction compared to the non-irradiated control (675.00 ppb). A maximum polyphenolics content (11.98 mg/g) was obtained under the predicted maximum conditions of 14.40℃, 0.78 kGy, and 3.4 days. The most influential parameter in reducing residual patulin content while maintaining polyphenolic content in apple juice was irradiation dose (p<0.01), which showed potential to be applied in controlling the patulin levels in apple juice.