• Korean Journal of Food Science and Technology
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• v.7 no.3
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• pp.109-114
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• 1975

Domestic seaweeds Gracilaria verrucosa collected from coastal areas of Namhae, Wando and Yeosoo, Korea were subjected to the examination of yield and quality of agar prepared according to various pretreatment conditions. In alkali treatment at high temperature, higher alkali concentration for one-hour period at $90^{\circ}C$ gave rise to higher yield of agar. In acid treatment, higher yield was obtained by higher acid concentration and longer treating period. Alkali treatment at room temperature gave rise to a slightly decreased yield at higher alkali concentration and longer treating time. Total nitrogen and crude ash of agar samples were greatly decreased by pretreatments. Jelly strength, gelation ability, gelation point and viscosity of agar samples tended to increase as the alkali-treating condition of seaweed became stronger. It was shown that sulfur content of agar had a high negative correlation with jelly strength of its gel. Various alkali treatments of seaweed at room temperature showed no marked difference in agar quality and did not exhibit any good effect comparable to alkali treatment at high temperature.

• Journal of Conservation Science
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• v.35 no.6
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• pp.701-708
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• 2019

Animal glue is a natural adhesive made from processed skins or bones of animals. It is widely used in wooden crafts, papercrafts, dancheong painting, and pictures. Accurate evaluation of the quality of animal glues during production and use is difficult because there is no formal method for testing the glue's properties during pretreatment and measurement conditions. Thus, in this study, a series of tests were carried out by changing the conditions of swelling, temperature, and concentration of animal glue and gelatin sold on the market. Twelve types of animal glues were evaluated, having a viscosity range of 12.67 cP to 29.43 cP. The results showed that the physical characteristics of the glues were stable when allowed to swell for six h in distilled water(23℃). When 10%(by weight in distilled water) of the animal glue was measured in the reflective mode of a spectrophotometer, the optical characteristics of the glues were stable. Powdered animal glues have a medium brightness and middle-high chroma. Relative to powdered glues, stick animal glues have a low brightness and a medium chroma. Based on the results of this study, it is expected that the data can be assembled into a form so that animal glue workers can use it as a reference for the preparation of evaluation standards for testing the characteristics of animal glues.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.1-5
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• 2015

Lactic acid, the most widely occurring hydroxy-carboxylic acid, has traditionally been used as food, cosmetic, pharmaceutical, and chemical industries. Even though it has tremendous potential for large scale production and use in a wide variety of applications, high cost lactic acid materials are primarily problems. Lactic acid can be obtained on either by fermentation or chemical synthesis. In recent years, the fermentation approach has become more successful because of the increasing market demand for naturally produced lactic acid. Generally, lactic acid was produced from pure starch or from glucose. As an alternative, biomass which is the most abundant renewable resources on earth have been considered for conversion to readily utilizable hydrolysate. In this study, we conducted the fermentation method to produce L(+)-lactic acid production from pretreated hydrolysate was investigated by Lactobacillus rhamnosus ATCC 10863. The hydrolysate was obtained from pretreatment process of biomass using Ammonia percolation process (AP) followed by enzymatic hydrolysis. In order to effectively enhance lactic acid conversion and product yield, controlled medium, temperature, glucose concentration was conducted under pure glucose conditions. The optimum conditions of lactic acid production was investigated and compared with those of hydrolysate.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.43-65
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• 1992

Bonding orthodontic adhesive resins to glazed porcelain surface is not attainable. The aim of this investigation was to examine, in vitro, the effect of three methods of porcelain surface pretreatment on the shear bond strength of orthodontic adhesives, and to compare the shear strength of orthodontic bracket bonding to porcelain surface by the best results that to human enamel. Porcelain disks ($Ceramco^{(TM)}$ and $Vita^{(TM)}$) baked in the laboratory were roughened by sandpapers, #320, #600, #800, #1000 and #1200, and were pretreated with silane and dried at the various temperatures, room temperature, $50^{\circ}C$, $70^{\circ}C$ and $90^{\circ}C$, and were etched by 3% hydrofluoric acid solution for 1, 3, 5, 7, and 9 minutes, orthodontic adhesives (System $1+^{(TM)}$ and $Unite^{(TM)}$) were applied on them, and shear bond strengths were measured by Instron. The best results of pretreatment of each method were determined by the shear bond strengths. Again, porcelain disks were pretreated by the determined best results and human enamel were etched by 37% hydrofluoric acid solution, orthodontic brackets were bonded on them by the orthodontic adhesives, and the shear bond strengths were measured and compared between them. 1. Roughening porcelain surfaces with coarse sandpaper (#300) showed higher shear bond strength than that with finer sandpapers, but it $(22.44Kgf/cm^2)$ was distinguishably low compared to that from etched human enamel $(144.11Kgf/cm^2)$. 2. There were disparities in shear bond strengths upon the orthodontic resins, which was presumably related to the contents of fillers in orthodontic adhesive resins. Also there were disparities in shear bond strength upon the porcelains which had different composition. 3. Silane enhanced the shear bond strength of orthodontic resins to porcelain surfaces ($25.20Kgf/cm^2$ at $50^{\circ}C$), which was markedly low compared to that from etched human enamel. 4. Etched porcelain surface with 3% hydrofluoric acid solution for 1 to 9 minutes showed no difference in shear bonding strength of orthodontic adhesive resins. Shear bond strength from etched porcelain $(97.43-120.72Kgf/cm^2)$ were as high as clinically available, but low compared to that from etched human enamel. 5. Roughening with #300 sandpaper and etching by 3% hydrofluoric acid followed silane application on porcelain surface showed lower shear bond strength than etched human enamel, but were as high as clinically useful. 6. The results suggest that etching porcelain surface by 3% hydrofluoric acid solution might provide comparatively high shear bond strength as much as clinically favorable.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.184-189
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• 2004

Rice wine cake (RWC) is the solid waste obtained after rice wine fermentation. For the mass production of the spores of yeast Saccharomyces from RWC, the optimum pretreatment condition of RWC, the optimum composition of culture medium, and the optimum culture condition were examined. For sporulation, yeast cells were grown in the pre sporulation medium (PSM), transferred into sporulation medium (SM) containing 1 % potassium acetate, and incubated in a rotary shaking incubator at $25^{\circ}C$ for 4 days. The supernatant of the mixture of RWC and water was used as the presporulation medium (PSM). The optimum temperature and time for the pre-incubation of the mixture of RWC and water (1:2) to obtain maximum sporulation yield were $V^{\circ}C$ and 24 hr, respectively, and optimum culture time in PSM was 48 hr. Using these optimum conditions, the asci number obtained was 0.72$ 1.06${\times}$10^{8}$$m\ell$. The addition of wheat coat koji into SM increased the final number of asci to beTEX>$10^{8}$ $m\ell$. Spores were formed in the SM with the initial pH of 7-11, but no spores were formed in the SM with the initial pH of 5. To save the time and effort to pretreat the RWC, 2% and 0.5% RWC without any pretreatment were directly added into PSM containing 1 % brown sugar and SM, respectively, and the maximum asci number of $1.27${\times}$10^{8}$ /$m\ell$ was obtained.

• Korean Journal of Food Science and Technology
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• v.7 no.3
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• pp.115-119
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• 1975

Imported seaweeds Gracilaria sp. and Gelidium sp. from the Philippines and Gracilaria sp. from Brazil were subjected to the examination of yield and quality of agar according to various pretreatment conditions. As pretreatment condition for alkali-treated Gracilaria sp. from the Philippines, $0.05{\sim}0.1%$ concentration of sulfuric acid was proper to obtain the higher yield of agar for which a reverse proportionality was shown between the acid concentration and the strength of extraction condition. Highest yield from Gelidium sp. from the Philippines was obtained by pretreating with 5% sodium hydroxide at $90^{\circ}C$ for one hour, followed by 0.1% sulfuric acid treatment. Gracilaria sp. from Brazil gave the highest yield of agar by pretreatments with 1% sodium hydroxide followed by 0.05% sulfuric acid, both at room temperature for one hour. Acid treatment of alkali-treated Gracilaria sp. from the Philippines brought about the decrease of total nitrogen, total sulfur and crude ash, the increase of jelly strength and no marked change in gelation point and gelation ability. In general, acid-treatment conditions to give rise to high yield of agar improved the quality of product.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.66-71
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• 1986

The studies were carried out to screen the optimum conditions for enzymatic degumming of raw silk yarn and silk fabric by use of Alkalase, a protease produced by Bacteria, comparing with Papain and Trypsin representing natural proteolytic enzymes. 1. The optimum temperature and acidity of degumming solution were 70$^{\circ}C$, pH 5-6 for Papain degumming, 40$^{\circ}C$, pH 8 for Trypsin and 50-60$^{\circ}C$ pH 8-9 for Alkalase. 2. By increasing the Alkalase concentration in the range of 0.6 to 1.0 gram per liter, the time for enzymatic degumming of silk yarn could be reduced by 40 minutes. 3. In degumming of silk yarn by Alkalase, the pretreatment of 95$^{\circ}C$, 10 minutes at 0.1% sodium bicarbonate solution or posttreatent of 80$^{\circ}C$, 20 minutes at 2% (o.w.f.) sodium silicate solution improved the efficiency of enzymatic degumming, as compared to that of nontreatment. 4. The breaking strength, elongation and Lousiness results of enzymatically degummed silk yarn were apt to be improved more than those of soap-degummed one. 5. When the pretreatment of alkaline solution was done with over 20% of degumming ratio, the enzymatic degumming efficiency of both Havutae and Crepe de chine could be reached to the same level with those of soap-soda degummed. 6. As the pretreated silk fabric with 20% of degumming ratio was under action of three proteases, respectively, the deumming efficiency of Havutae and Crepe de chine were completed by Alkalase more than by Papain or Trpysin. 7. The stiffness of enzymatically degummed Crepe de chine was not only reduced by 17% more than that of soap-soda degummed one but also the Drape coefficient was decreased in enzymatically degummed fabrics, which was closely related with the soft touch of degummed fabrics.

• Journal of Food Hygiene and Safety
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• v.36 no.6
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• pp.474-480
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• 2021

Sodium alginate is the sodium salt of alginic acid, commonly used as a food additive for stabilizing, thickening, and emulsifying properties. A relatively simple and universal analysis method is used to study sodium alginate due to the complex pretreatment process and extended analysis time required during the quantitative method. As for the equipment, HPLC-UVD and Unison US-Phenyl column were used for analysis. For the pretreatment condition, a shaking apparatus was used for extraction at 150 rpm for 180 minutes at room temperature. The calibration curve made from the standard sodium alginate solution in 5 concentration ranges showed that the linearity (R²) is 0.9999 on average. LOD and LOQ showed 3.96 mg/kg and 12.0 mg/kg, respectively. Furthermore, the average intraday and inter-day accuracy (%) and precision (RSD%) were 98.47-103.74% and 1.69-3.08% for seaweed jelly noodle samples and 99.95-105.76% and 0.59-3.63% for sherbet samples, respectively. The relative uncertainty value was appropriate for the CODEX standard with 1.5-7.9%. To evaluate the applicability of the method developed in this study, the sodium alginate concentrations of 103 products were quantified. The result showed that the detection rate is highest from starch vermicelli and instant fried noodles to sugar processed products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.221-226
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• 1977

The quality changes of yellow sea bream, Branchiostegus japonicus japonicus, during frozen storage were mentioned from the view point of commercial value. The experiments were conducted to find out the effective storing method by varying the storage temperatures $(-5^{\circ}C,\;-35^{\circ}C)$ and pretreatment with chemicals $(0.l\%\;BHA,\;1\%\;sodium\;Polyphosphate)$. The samples were stored for 6 months at $-5^{\circ}C$ and $-35^{\circ}C$ after dipping in the chemical solutions and packing with polyethylens film. The extractibility of salt soluble protein of sample stored at $-35^{\circ}C$ was higher than that of samples stored at $-5^{\circ}C$, while the chemical treatments were not so much effective. Difference in the amount of free water released from samples was obvious between $-5^{\circ}C$ and $-35^{\circ}C$ storage, and that of samples treated with sodium Polyphosphate was much less than the BHA-treated ones. VBN content was differed by varying the storage temperature whereas no effect by the chemical treatments. TBA value of the sample storage at $-35^{\circ}C$ was lower than $-5^{\circ}C$ and the effect of chemicals on the development of oxidation was in order of sodium polyphosphate, BHA and control. Carotenoid content also changed by varying the storage temperature and the color was completely faded out with quality deterioration after 3 months storage at $-5^{\circ}C$.

• Food Science and Preservation
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• v.13 no.3
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• pp.344-350
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• 2006

Soaking and drying were studied for seven grains and legumes including glutinous rice, brown rice, glutinous brown rice, glutinous barley, Seoritae, Heuktae and red bean to improve taste of cooked mixed grams and make easy to cook then Seoritae and Heuktae showed the highest water absorption and the rest were in the order of glutinous barley, glutinous rice, milled rice, brown glutinous rice, brown rice, and red bean. In regards with water absorption index by soaking temperature, the higher the temperature showed, the more water absorption and the shorter time to reach the water absorption balance, the more grinding legumes. showed the more water absorption and the shorter time to reach to the water absorption balance. The soaked samples were dried at mom temperature $30^{\circ}\C,\;50^{\circ}\C$, and microwave 300 W, 700 W and 1000 W power. As a result 700 W drying method br microwave can dry samples in the shortest time without damage to the samples. Therefore, it was considered as the best pretreatment conditions for mixed stains to dry with 700 W microwave after one-hour soaking at $30^{\circ}C$.