• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.192-199
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• 1991

The rheological properties of various flour blends of HRW-WW and DNS-WW having protein contents of $9.12{\sim}9.78%$ in the presence or absence of salt and alkaline reagent (an equal mixture of$Na_2CO_3\;and\;K_2CO_3$) were studied. The farinograph absorptions of HRW-WW and DNS-WW blends was increased by 1% and 0.6%, respectively, with increasing protein content by 0.33%. Salt (0.17%) decreased the absorption by 1% regardless protein contents. Alkaline reagent (0.17%) or a combination of salt and alkaline reagent had no effect on absorption of flours, indicating that the effect of salt on decreasing absorption is masked by alkaline reagent. The protein content of the flour in the presence or absence of salt, alkaline reagent or both showed a highly positive correlation with all reference points of farinograph and extensograph, but the peak viscosity of amylograph was negatively correlated with protein content only in the presence of salt, alkaline reagent or both.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.237-242
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• 2019

The purpose of this study was to investigate the optimal amount of alkaline reagent (0.2 or 0.4%) and rice flour (10-40%) for noodle and supplementation, and compare quality characteristics with those of wheat noodles. Texture properties, pH, tension profiles, and cooking quality of noodles supplemented with rice flour and alkaline reagent were measured. Wheat noodles with 0.4% alkaline reagent added displayed increased b values (Hunter's color), pH, hardness, chewiness, tension profiles, and turbidity, and decreased L, and a values, gumminess, weight, and water absorption compared to wheat noodles with 0.2% alkaline reagent added. Hardness and springiness of wheat noodles with 0.4% alkaline reagent added were 35.2 and 0.0118 N, respectively. These values for rice doodles with 0.4% alkaline reagent and 20% rice flour were similar (36.3, 0.0117 N, respectively). This suggests that addition of 0.4% alkaline reagent and 20% rice flour may be the optimal parameters for producing rice noodle.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.232-237
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• 1993

The rheological properties of hard red winter, western white and Australian standard white wheat flours and of HRW-WW and HRW-ASW wheat flour blends having the same protein content were studied. Cooking properties of dry noodles prepared from HRW-WW and HRW-ASW wheat flour blends were also investigated. The noodles were prepared with salt and alkaline reagent. The salt and alkaline concentrations used were 1.7% and 0.17%. respectively, based on the weight of wheat flour. The alkaline reagent was an equal mixture of sodium carbonate and potassium carbonate. The HRW-ASW wheat flour blend had higher farinograph absorption and slightly stronger curve than HRW-WW wheat flour blend. Salt decreased the absorption of wheat flours by 2 and of wheat flour blends by 1%. However, alkaline reagent essentially had no effort on farinograph absorption. Salt and alkaline reagent strengthened the dough of wheat floors and wheat flour blends, with the former being more effective. No significant differences in pasting properties between HRW-WW and HRW-ASW wheat flour blends by amylograph were observed. There were no significant differences in rate of increase of weight or volume between noodles prepared from HRW-WW and HRW-ASW wheat flour blends. Alkaline reagent did not affect the weight gain of noodles hut lowered the volume gain. Breaking force of dry noodles and cutting force of cooked noodles were similar between the two noodles. Alkaline reagent increased both the breaking and cutting forces of noodles. Sensory evaluation revealed that the noodles prepared from HRW-WW and HRW-ASW wheat flour blends were slightly different. but not different from each other by preference test.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.205-213
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• 2011

The Folin-Ciocalteu (F-C) reagent has been extensively used for quantifying total phenolic contents in many different types of food materials. Since several different procedures of the assay methods using the F-C reagent have been applied, we investigated changes in reactivity of various phenolic compounds with the F-C reagent under three different assay conditions and factors affecting reactivity. Among 10 standard compounds tested, compounds with high hydroxyl density (number of -OH/molecular weight) showed a largely different response according to addition sequence of the F-C reagent or $Na_2CO_3$. Preincubation in $Na_2CO_3$ significantly reduced the reactivity of the phenolic compounds bearing galloyl moiety (e.g. gallic acid, tannic acid, and epigallocatechin-3-gallate) with the F-C reagent, while monophenol compounds including ferulic acid and sinapinic acid were more stable as compared to diphenols. There was little change in response to the F-C reagent of all phenolic compounds incubated in acidic pH; their reactivity except ferulic acid was reduced significantly when incubated in neutral or alkaline pH. Changes in reactivity of gallic acid incubated in $Na_2CO_3$ or neutral/alkaline pH conditions were the most prominent. $H_2O_2$ generated from phenolic compounds did not affect the reaction with the F-C reagents. The present results suggest that reactivity of different phenolic compounds with F-C reagent was affected considerably by different procedures of the assay, and the total phenolic contents could be fluctuated according to standard compounds and assay scheme.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.11 no.1
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• pp.32-55
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• 1975

The ammonium salt of N-Nitrosophenylhydroxiamine, namely Cupferron, is a well-known analytical reagent which precipitates a great number of metal ions in acid medium. Various structures of electrode reduction for N-Nitrosophenylhydroxiamine have been suggested in acid and alkaline media by many researchers, but not in neutral medium. So the mechanism of electrode reaction of Cupferron was investigated by both chronopotentiometric and polarographic methods. It was estimated that the reduction of Cupferron occurs in a three-step mechanism through which a chemical step is interposed between two charge transfer, the ECE (charge transfer-chemical reaction-charge transfer) mechanism, over a range of neutral and alkaline media. The chemical reaction of the process was assumed to be acid-base catalyzed from the fact that kapp (over all rate constant) of chemical reaction is pH dependent.

• Analytical Science and Technology
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• v.37 no.1
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• pp.47-62
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• 2024

Abu Gurdi area is located in the South-eastern Desert of Egypt which considered as volcanic massive sulfide deposits (VMS). The present work aims at investigating the ore mineralogy of Abu Gurdi region in addition to the effectiveness of the hydrometallurgical route for processing these ores using alkaline leaching for the extraction of Zn, Cu, and Pb in the presence of hydrogen peroxide, has been investigated. The factors affecting the efficiency of the alkaline leaching of the used ore including the reagent composition, reagent concentration, leaching temperature, leaching time, and Solid /Liquid ratio, have been investigated. It was noted that the sulfide mineralization consists mainly of chalcopyrite, sphalerite, pyrite, galena and bornite. Gold is detected as rare, disseminated crystals within the gangue minerals. Under supergene conditions, secondary copper minerals (covellite, malachite, chrysocolla and atacamite) were formed. The maximum dissolution efficiencies of Cu, Zn, and Pb at the optimum leaching conditions i.e., 250 g/L NaCO₃ - NaHCO₃ alkali concentration, for 3 hr., at 250 ℃, and 1/5 Solid/liquid (S/L) ratio, were 99.48 %, 96.70 % and 99.11 %, respectively. An apparent activation energy for Zn, Cu and Pb dissolution were 21.599, 21.779 and 23.761 kJ.mol^-1, respectively, which were between those of a typical diffusion-controlled process and a chemical reaction-controlled process. Hence, the diffusion of the solid product layer contributed more than the chemical reaction to control the rate of the leaching process. High pure Cu(OH)₂, Pb(OH)₂, and ZnCl₂ were obtained from the finally obtained leach liquor at the optimum leaching conditions by precipitation at different pH. Finally, highly pure Au metal was separated from the mineralized massive sulfide via using adsorption method.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.195-202
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• 2023

Protease is a widely used enzyme particularly in the detergent industry. In this research, we aimed to isolate alkaline protease-producing bacteria for characterization as a laundry detergent additive. The screening of alkaline protease production was investigated on basal medium agar plus 1% skim milk at pH 11, with incubation at 30℃. The highest alkaline protease-producing bacterium was 6BS15-4 strain, identified as Bacillus gibsonii by 16S rRNA gene sequencing. While the optimum pH was 12.0, the strain was stable at pH range 7.0-12.0 when incubated at 45℃ for 60 min. The alkaline protease produced by B. gibsonii 6BS15-4 using dairy effluent was characterized. The optimum temperature was 60℃ and the enzyme was stable at 55℃ when incubated at pH 11.0 for 60 min. Metal ions K⁺, Mg²⁺, Cu²⁺, Na⁺, and Zn²⁺ exhibited a slightly stimulatory effect on enzyme activity. The enzyme retained over 80% of its activity in the presence of Ca²⁺, Ba²⁺, and Mn²⁺. Thiol reagent and ethylenediaminetetraacetic acid did not inhibit the enzyme activity, whereas phenylmethylsulfonyl fluoride significantly inhibited the protease activity. The alkaline protease from B. gibsonii 6BS15-4 demonstrated efficiency in blood stain removal and could therefore be used as a detergent additive, with potential for various other industrial applications.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.221-226
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• 2019

This study investigated the optimal amount of shell powder (0.1, 0.2, 0.3, and 0.4%) to add to rice noodles containing 20% rice flour and compared their quality characteristics to those of wheat noodles containing a commercial alkaline reagent (added at 0.4%). As the amount of shell powder was increased, the L and b values (Hunter's color) increased. The pH, turbidity, and water absorption also increased as the amount of shell powder was increased. However, when the shell powder content exceeded 0.3%, the hardness, chewiness, springiness, and tension tended to decrease below acceptable levels. This might be because the shell powder inhibited network formation. The textural properties and pH value of rice noodles containing 0.2% shell powder were similar to those of the wheat noodles. This suggests that 0.2% shell powder may be the optimal amount to add to rice noodles when used as the alkaline reagent.

• Journal of environmental and Sanitary engineering
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• v.9 no.1
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• pp.89-96
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• 1994

This report was investigate the biological characteristic of $\delta$-endotoxin of product by TH109 strain, one strain TH109 which has toxicity on Cockroach is isolate and identification. Generally the $\delta$-endotoxin of product by 3. thuringiensis strain was easily soluble in acid, alkaline and organic solvents but $\delta$-endotoxin of product by TH109 strain are insoluble in HCI, NaOH Thiol- reagent(25mM Dithiotheritol, 25mM Dithioeryritol, 25mM Nathioglycolate, 0.2M ESCN, 2% v/v $\beta$-mecaptethanol), organic solvents( acetone, $CCI_{4}$, ether, dioxin MeOH chloroforrh xylene ), Protease. Through this study of $\delta$-endotoxin produced by TH109 strain is insoluble in acid, alkaline, organic solvents and pretense etc. In the point of view, it is greater possibility that $\delta$-endotoxin will be transform into toxin by the reducible materials instead of the reaction of protease in the intestine.

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.18-25
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• 2004

In this study, the effect of microwave which can increase temperature rapidly on polyester alkaline dyeing was investigated. The final K/S values of polyester fabrics dyed by microwave lower than those of atmospheric dyeing because of the evaporation loss of dyeing solution. If the dyeing time makes longer as much as that in atmospheric dyeing, the K/S values of polyester fabrics dyed under microwave were similar to those of atmospheric dyeing. The K/S values of polyester fabrics dyed in pH 9.5 were higher than those in pH 5.5 in case of aliphatic carriers. The K/S values of organic reagent pretreated polyester fabrics dyed by use of aromatic carriers were not higher than those of non-treated polyester fabrics. But the K/S values of polyester fabrics dyed by use of aliphatic carriers were higher than those of non-treated polyester fabrics. The tensile strength were decreased with increasing of dyebath pH because the polyester fabrics were easily decomposed by high alkali.