• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.127-134
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• 2014

This study was performed to evaluate the effects of sesame oil addition to a tuna oil-enriched emulsion during chlorophyll-photosensitized oxidation. The emulsion principally consisted of tocopherol-stripped canola and tuna oil with or without sesame oil, acetic acid, phospholipids, and xanthan gum. Chlorophyll b was added to promote the production of singlet oxygen upon exposure to light. The oxidation of oil in the emulsion was evaluated by determining the peroxide value (POV) and conjugated dienoic acid (CDA) contents. Concentrations of minor compounds in the emulsion were monitored. Increasing POV and CDA contents in the emulsion were paralleled with decreased docosahexaenoic acid during oxidation, and oxidation was inhibited by the addition of sesame oil. Chlorophyll, polyphenols, tocopherol, and phospholipids were degraded during oxidation of the emulsion; however, their degradation was slowed down by the addition of sesame oil. Lignans in the emulsions containing added sesame oil were barely changed, suggesting that they quenched singlet oxygen physically. Polyphenols were the most effective in improving the stability of tuna oil-enriched emulsions during chlorophyll-photosensitized oxidation.

• Korean Journal of Medicinal Crop Science
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• v.28 no.2
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• pp.128-135
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• 2020

Background: Sowing seeds of Adenophora triphylla is known to be difficult owing to their small size and irregular seed shape. Therefore, this study was conducted to develop a seed pelleting technique to save labor during sowing. Methods and Results: To identify the optimal germination temperature for A. triphylla seeds, the temperature range was set from 17℃ to 32℃. Germination surveys were conducted in plastic greenhouse conditions in March, April, and May to determine the appropriate sowing time. The optimal germination temperature for A. triphylla seeds was 29℃ and May was the optimal sowing time in plastic greenhouse conditions. Covering materials for seed pelleting used talc (T), kaolin (K), calcium carbonate (C), and vermiculite (V). The pellet binder used agar (A), pectin, xanthan gum, polyvinyl alcohol (PVA), and sodium alginate (S). The best suited treatment mixture were the best suited in kaolin / calcium carbonate / vermiculite (KCV), talc / calcium carbonate / vermiculite (TCV) mixture treatment for covering material, and sodium alginate (S), agar (A) as pellet binder, respectively. The germination rate was the best in TCV mixed with S. Conclusion: The mixture of TCV (2 : 1 : 3) + 1.5% S (TCVS), was found to be the best pelleting materials for A. triphylla seeds, and seed pelleting can be labor-saving during sowing.

• Food Science and Preservation
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• v.10 no.3
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• pp.308-313
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• 2003

In the present study, we investigated the optimum recipe of the pumpkin drink using old pumpkin extract. Response surface methodology (RSM) was applied to optimize and monitor the drink recipe with pumpkin extract. The polynomial equation for color, flavor, taste, mouth feel, overall palatability, pH, brix and viscometer showed 0.7682, 0.9046, 0.9364, 0.9110, 0.8456, 0.9264, 0.7135 and 0.9906 of R$^2$, respectively and flavor, taste, mouth feel, overall palatability, pH and viscometer showed 5～10％ of significance level. The optimum ranges of recipe on organoleptic properties of pumpkin pouch drink were estimated on 86.5～87.5％ of the old pumpkin extract, 0.36～0.42％ of xanthan gum and 9％ of vinegar.

• Journal of the Korean Society of Food Culture
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• v.19 no.2
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• pp.239-249
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• 2004

To develope a sauce using Gochujang which can give foreigners good overall acceptance such as good flavor, taste, color, viscosity and versatility to many foods, we studied on the rheological properties and color control, recipes with spices, herbs, syrup, salt and flavor ingredients and sensory evaluation by Chinese, American and Japanese including Korean. From the survey, the Americans suggested that the proper fellow food of Gochujang sauce be fried chicken, barbecue, hamburger and pina, and hoped to reflect red color, low viscosity, hot taste, low sweetness, salty and sourness and diet effect. The Chinese suggest pork and fried food as a fellow with Gochujang sauce and showed similar opinion in the sensory attributes like the Americans except sweetness. When 5% of starch and xanthan gum was added to sauce, respectively, the yield stress of Gochujang sauce showed 33.21 Pa similar to tomato ketchup. In fluidity measured by voistic flow meter, Gochujang sauce showed 6.2 cm/30sec more or less faster than tomato ketchup which showed 4.7 cm/30sec. Gochujang sauce tended to show strong red color and lightness as pH decreased. The pH adjustant and Paprica oleoresin(2%) improved a value to 12.11 and L value to 24.24 similar to tomato kechup(a:12.42, L:25.48). The 1st gochujang sauce product show 4.50 to 5.75 pots in the overall acceptance in the consumer test including foreigners and koreans. However, the 2nd Gochujang sauce product showed 5.90 points and 6.30 points in the pina and fried chicken, respectively, in the same consumer test. Therefore, we propose that Gochujang can be used for developing sauce products which is most acceptable for various foreigners.

• Korean journal of food and cookery science
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• v.29 no.1
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• pp.53-62
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• 2013

Lipid oxidation and antioxidants changes in perilla oil emulsion added with chlorophyll were studied during storage in the dark or under 1,700 lux light at $25^{\circ}C$ for 48 h. The emulsion was consisted of perilla oil (33.12 g), 5% acetic acid (66.23 g), egg yolk powder (0.5 g), and xanthan gum (0.15 g), and Chlorophyll b was added to the emulsion at 0, 2.5 and 4 mg/kg. The lipid oxidation was evaluated by headspace oxygen consumption and hydroperoxide formation, and tocopherols and polyphenols were monitored by HPLC and spectrophotometry at 725 nm, respectively. The lipid oxidation of the perilla oil emulsion in the dark was not significant regardless of the addition of chlorophyll. Light increased and accelerated the lipid oxidation of the emulsion, and increased addition level of chlorophyll under light increased it further. However, there was no significant change in fatty acid composition in any case. Contents of tocopherols and polyphenols in the emulsion were not significantly changed during storage in the dark regardless of chlorophyll addition, indicating their little degradation. Tocopherols and polyphenols in the emulsion were significantly degraded during storage of the emulsion under light, and the degradation rate of polyphenols was increased with addition level of chlorophyll. The lipid oxidation of the perilla oil emulsion was inversely related with the residual amounts of tocopherols and polyphenols, with more dependent on the retention of polyphenols than that of tocopherols.

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.15-21
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• 2021

In this study, we investigated the dynamics of a droplet impacting rough hydrophobic surfaces through high-speed imaging. Micrometer-sized structures with grooves and pillars were fabricated on smooth Polydimethylsiloxane (PDMS) surfaces by laser ablation. We used Newtonian and non-Newtonian liquid droplets to study the drop impact dynamics. De-ionized water and aqueous glycerin solutions were used for the Newtonian liquid droplet. The solutions of xanthan gum in water were prepared to provide elastic property to the Newtonian droplet. We found that the orientation of the surface structures affected the maximal spreading diameter of the droplet due to the degree of slippage. During the droplet retraction, the dynamic receding contact angles were measured to be around 90° or less. It resulted in the formation of the micro-capillary bridges between the receding droplet and the surface structures. Then, the rupture of the capillary bridge led to the formation of micrometer-sized droplets on top of the surface structures. The size of the microdroplets was found to increase with increasing the impacting velocity and viscosity of the Newtonian liquid droplets. However, the size of the isolated microdroplets decreased with enhancing the elasticity of the droplets, and the size of the non-Newtonian microdroplets was not affected by the impacting velocity.

• Geomechanics and Engineering
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• v.33 no.1
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• pp.29-40
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• 2023

Xanthan gum and starch compound biopolymer (XS), an environmentally friendly soil-binding material produced from natural resources, has been suggested as a slope protection material to enhance soil strength and erosion resistance. Insufficient wet strength and the consequent durability concerns remain, despite XS biopolymer-soil treatment showing high strength and erosion resistance in the dried state, even with a small dosage of soil mass. These concerns need to be solved to improve the field applicability and post-stability of this treatment. This study explored the utilization of an alkaline-based cation crosslinking method using calcium hydroxide and sodium hydroxide to induce non-thermal gelation, resulting in the enhancement of the wet strength and durability of biopolymer-treated soil. Laboratory experiments were conducted to assess the unconfined compressive strength and cyclic wetting-drying durability performance of the treated soil using a selected recipe based on a preliminary gel formation test. The results demonstrated that the uniformity of the gel structure and gelling time varied depending on the ratio of crosslinkers to biopolymer; consequently, the strength of the soil was affected. Subsequently, site soil treated with the recipe, which showed the best performance in indoor assessment, was implemented on the field slope at the bridge abutment via compaction and pressurized spraying methods to assess feasibility in field implementation. Moreover, the variation in surface soil hardness was monitored periodically for one year. Both slopes implemented by the two construction methods showed sufficient stability against detachment and scouring, with a higher soil hardness index than the natural slope for a year.

• Ecology and Resilient Infrastructure
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• v.5 no.3
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• pp.163-173
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• 2018

The biopolymer (BP) used in this study is mainly composed of xanthan gum and ${\beta}$-glucan derived from microorganism and has been introduced as a novel material for soil stabilization. However, the broad applicability of BP has been suggested in the field of geotechnical engineering while little information is available about the effects of BP on the vegetation. The goal of this study is to find the BP effects on the growth of Camelina sativa L. (Camelina) under drought condition. For more thorough evaluation of BP effects on the plant growth, we examined not only morphological but also physiological traits and gene expression patterns. After 25 days of drought treatment from germination in the soil amended with 0, 0.25, 0.5, and 1% BP, we observed that the BP concentration was strongly correlated the growth of Camelina. When plants were grown under drought stress, Camelina in 0.5% BP mixture showed better physiological parameters of the leaf stomatal conductance, electrolyte leakage and relative water content compared to those in control soil without BP. Plant recovery rate after re-watering was higher and the development of lateral root was lower in BP amended soil. RNA expression of Camelina leaf treated with/without drought for 7 and 10 days showed that aquaporin genes transporting solutes at bio-membrane, CsPIP1;4, 2;1, 2;6 and TIP1;2, 2;1, were induced more in the plants with BP amendment and drought treatment. These results suggest that the soil amended with BP has a positive effect on the transport of nutrients and waters into Camelina by improving water retention in soil under drought condition.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.208-217
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• 2020

A biopolymer based on microorganism-derived β-glucan and xanthan gum is being studied as a new eco-friendly material that stabilizes the riverbank slope, and also promotes vegetation growth. However, it is still inconclusive whether biopolymers have a positive effect on plant performance in the riverbanks which are subjected to various climatic factors and plant competitions. For a practical ecological evaluation of the biopolymers, their effect on plant growth promotion was studied in a natural environment. Considering the relationship between competition and plant community formation, the effects of biopolymers on competition were also investigated. For four plant species (Echinochloa crus-galli, Pennisetum alopecuroides, Leonurus japonicus, and Coreopsis lanceolata), the biopolymer effects under intra/interspecific competition were tested at the riverbank (20 m × 10 m) near Samjigyo Bridge in Damyang-gun, Jeollanam-do. A biopolymer powder was mixed with water and commercial soil following the manufacturer's recommendations. The soil mixed with the biopolymer was filled in a pot or applied to the surface of the commercial soil with a thickness of 3 cm. Across the competition treatments, the biopolymer treatment promoted root growth of the target plant species and decreased the specific leaf area. The total biomass and shoot dry weight of P. alopecuroides increased in response to the biopolymer treatment. The competition treatment decreased the total biomass and shoot dry weight compared to the case without competition. Notably, such a competitive effect was similar in all the biopolymer treatments. Thus, biopolymers, when mixed with soil, promote the growth of some plant species, but do not appear to affect the competitive ability of plants.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.83-92
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• 2016

New tree wound-treatment formulations (WTF) were developed in this study. Stimulating effects of plant growth regulating substance on callus formation were evaluated in vivo twig disc culture of Zelkova serrata, Ziziphus jujuba, Pinus densiflora, Ginkgo biloba. and Aesculus turbinata. Based on the evaluation, WTF were prepared with 2,4-D, NAA, and IBA using xanthan gum as an extending agent. WTF were pasted on $2{\times}10cm$ artificial wound on the stem and the effects were evaluated 12 weeks later with the thickness of new callus-tissues. The effects varied with tree species and the growth regulators. In Z. serrata and A. turbinata, 2 mg/L of 2,4-D was the best WTF. In P. koraiensis and G. biloba, 8 mg/L of NAA and 1 mg/L of IBA were the best, respectively. Callus formation was quite lower in G. biloba compared to other species. Stimulating effect of thiophanate-methyl paste was excellent only in Z. serrata and lower than certain WTF in other species. Vaseline, which was used generally as an WTF, remained longer on the wound and causing decay. From the results, it could be recommended that 2,4-D, NAA and IBA were the best WTF for Z. serrata/A. turbinata, P. koraiensis and G. biloba, respectively.