• Textile Coloration and Finishing
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• v.6 no.1
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• pp.19-27
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• 1994

Mimosa and Quebracho are, in general, tanned with leather skin, finished silk fabrics according to temperature, treatment time, tannin concetration, pH, and studies that relation between tannin weighting and various factors. This makes fundamental study on characteristic of tannin treated fabrics. and the results are as fallows : 1. λ$_{max}$ was found at 278.5nm for Mimosa. 279.5nm for Quebracho. Also a stability was good in standing time and heating. 2. The higher tannin treatment temprature was, the better tannin weighting effect was. But they were slightly decreased at over 8$0^{\circ}C$, and K/S was slowly increased. 3. As tannin treatment time increased, tannin weighting effect increased but they were decreased at over 8$0^{\circ}C$, 90min. 4. As tannin concentration increased, tannin weighting was increased. 5. In tannin weighting effect according to various pH conditions, the it's best range of pH were 3.5~5.5 of Mimosa, 2.5~3.5 of Quebracho.o.

• Textile Coloration and Finishing
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• v.13 no.5
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• pp.1-1
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• 2001

As the basic study to investigate the mechanism of improvement in the dyeing fastness of natural dyes on silk fabrics the optical behavior of tannin solution, the optimal condition of tannin treatment and the changes of the physical structure of silk fabrics were studied in the treatment of tannin. Results obtained were as follows ; 1.The K/S values of tannin-treated silk fabrics were not changed by tannin content on silk fabrics but yellowing of tannin in treatment condition. 2. As the concentration of tannin was increased in its treating condition, the tannin content and K/S vague of tannin-treated silk fabrics were increased. 3. Because tannin gave rise to yellowing by hydrolysis and oxidation at high temperature, the higher tannin-treating temperature was, the lower the tannin content and K/S values of silk fabrics 4. The tannin content of silk fabric was higher in acidic treating condition and the highest K/S value was showed at pH 5. 5. As the tannin content of silk fabric was increased, the value of ζ -potential of it became negative. 6. As the tannin content of silk fabric was increased, the crystallinity and crystallite size of it were decreased. This meant that the fraction of amorphous region in the fibers increased. And the degree of orientation of it was decreased with the tannin treatment.

• Textile Coloration and Finishing
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• v.13 no.5
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• pp.289-297
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• 2001

As the basic study to investigate the mechanism of improvement in the dyeing fastness of natural dyes on silk fabrics the optical behavior of tannin solution, the optimal condition of tannin treatment and the changes of the physical structure of silk fabrics were studied in the treatment of tannin. Results obtained were as follows ; 1 The K/S values of tannin-treated silk fabrics were not changed by tannin content on silk fabrics but yellowing of tannin in treatment condition. 2. As the concentration of tannin was increased in its treating condition, the tannin content and K/S vague of tannin-treated silk fabrics were increased. 3. Because tannin gave rise to yellowing by hydrolysis and oxidation at high temperature, the higher tannin-treating temperature was, the lower the tannin content and K/S values of silk fabrics 4. The tannin content of silk fabric was higher in acidic treating condition and the highest K/S value was showed at pH 5. 5. As the tannin content of silk fabric was increased, the value of $\xi$ -potential of it became negative. 6. As the tannin content of silk fabric was increased, the crystallinity and crystallite size of it were decreased. This meant that the fraction of amorphous region in the fibers increased. And the degree of orientation of it was decreased with the tannin treatment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.3
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• pp.230-234
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• 1996

This study was conducted to compare the intake, digestibility and utilization of nitrogen by goats consuming high and low tannin diets. Low tannin diets were 100% grass(GS) and 50% grass + SO% alfalfa (GA), and high tannin diets were 50% grass + 50% lespedeza(GL) and 50% grass + 50% oak browse(G0). Dry matter intake did not differ among all diets, but digestibility of dry matter, cellular constituents, NDF and ADF showed slightly lower for high tannin diets(GO) than low tannin diets(GS and GA), but those were not differ between GL and low tannin diets with the exception of ADF digestibility. Total faces and urinary N were lower for high tannin diets than for low tannin diets. Apparently digested N was high in GA diets, but low in GO diets(P

• Microbiology and Biotechnology Letters
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• v.3 no.1
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• pp.17-22
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• 1975

Studies on the elimination of tannin from the acorns containing tannin up to 9%, for the utilization of the acorns in Korea, carried out as follows: 1. The strain of Asp. niger sp. which yield the reasonable enzymatic activity of tannase was isolated from the rotten acorns. 2. The method of hydrolyzing tannin in the water by suspending, and agitatiag the acorn powder: followed by decantation, showed the best result aomng the conventional methods in the efficiency of removal of tannin and in the economy of the process by reducing the tannin content to 0.18％ in 24 hours. 3. It was notable that the acorn'powder from which the tannin was eliminated contains various essential amino acids in relatively ample a mount.

• Food Science and Preservation
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• v.6 no.1
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• pp.66-70
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• 1999

The mechanism of natural removal of astringency and seasonal changes of tannin substance in sweet persimmon(Fuyu) and astrigent persimmon(Chungdo Bansi)were investigated. Tannin productivity of astringent persimmon fruit was higher than that of sweet perimmon fruit during growth. In the reactivity of tannin to acetaldehyde, it was observed that tannin from sweet persimmon have a milder chemical properties than that from astrigent persimmon. The threshold value of astringency on sweet persimmon tannin was higher than that of astrigent persimmon tannin. Tannin substances from sweet persimmon distributed mainly in lower molecular weight range at harvest stage, but those from astrigent persimmon distributed mainly in higher molecular weight range. Therefore, the natural removal of astringency was related to difference of tannin productivity, threshold value of astringency, reactivity and qualitative difference of tanni.

• Textile Coloration and Finishing
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• v.14 no.2
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• pp.85-85
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• 2002

The interaction between berberine and tannin in aqueous solution was investigated spectrophotometerically. The dyeing mechanism of silk fabrics (control and tannin treated silk fabrics) with berberine was based on thermodynamic parameters obtained from equilibrium adsorption experiments. In adsorption spectra of aqueous solution of berberine and tannin mixture two isosbestic points (328nm, 357nm) were found and the mole fraction of reaction of components was 1:1. Initial dyeing rates were increased and the diffusion of dye was more effective by tannin treatment. Without regard to tannin treatment the adsorption isotherm of berberine was the langmuir type except high temperature, 80℃. By tannin treatment the saturation dye uptake was increased, the increase of dye uptake appeared to be a result of entropy change rather than enthalpy change. All these results can be interpreted by the hydrophobic interaction between berberine and silk treated with tannin and it is reasonable to conclude that not only the ionic force, but also the hydrophobic interaction contributes to the binding of berberine and tannin treated silk treated with tannin.

• Textile Coloration and Finishing
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• v.14 no.2
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• pp.9-17
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• 2002

The interaction between berberine and tannin in aqueous solution was investigated spectrophotometerically. The dyeing mechanism of silk fabrics (control and tannin treated silk fabrics) with berberine was based on thermodynamic parameters obtained from equilibrium adsorption experiments. In adsorption spectra of aqueous solution of berberine and tannin mixture two isosbestic points (328nm, 357nm) were found and the mole fraction of reaction of components was 1:1. Initial dyeing rates were increased and the diffusion of dye was more effective by tannin treatment. Without regard to tannin treatment the adsorption isotherm of berberine was the langmuir type except high temperature, $80^\circ{C}$. By tannin treatment the saturation dye uptake was increased, the increase of dye uptake appeared to be a result of entropy change rather than enthalpy change. All these results can be interpreted by the hydrophobic interaction between berberine and silk treated with tannin and it is reasonable to conclude that not only the ionic force, but also the hydrophobic interaction contributes to the binding of berberine and tannin treated silk treated with tannin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.921-926
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• 2008

Wild grapes contain lots of organic acids, vitamins and inorganic salts compared to other fruits. Also, it has known to have excellent effects on preventing cancer and heart disease. Wild grapes are supposed to be superior material for fermentation of wine. Tannin contents of wine, which is an important functional factor in flavor of wine, were enhanced to develop quality of Korean wild grape wine. In this study, we investigated tannin extraction conditions and analyzed quality properties of tannin-enhanced wild grape wine. The most suitable tannin extraction condition for enhancing tannin of wild grape wine was extraction of tannin from green tea using spirits at 4oC. For producing high quality wild grape wine, added concentration and time of tannin extract were 6.5 mg/mL before wild grape wine fermentation. Tannin contents of tannin-enhanced wild grape wine was $7.4{\pm}0.05\;mg/mL$. Quality properties of tannin-enhanced wild grape wine fermented under optimized fermentation conditions were analyzed. pH, acidity and alcohol contents were $3.69{\pm}0.01$, $0.95{\pm}0.01%$ and $12.2{\pm}0.03%$, respectively. Total sugar, tannin, polyphenol and resveratrol contents of tannin-enhanced wild grape wine were $60.00{\pm}1.15\;mg/mL$, $79.50{\pm}0.55\;mg/mL$, $7.40{\pm}0.05\;mg/mL$ and $5.00{\pm}0.11\;mg/mL$, respectively showing significantly higher value than that of commercial wine. Production of high quality wild grape wine is expected with the establishment of optimum fermentation condition and tannin-enhancing process of wild grape wine.

• Journal of Nutrition and Health
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• v.17 no.1
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• pp.41-49
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• 1984

Tannin from acorn was identified by TLC and gallic acid in the tannin was determined by HPLC. The tannin extracted with methanol-butanol was not dissolved in ethanol, methanol for HPLC and water, while the tannin extracted with acetone-ethylacetate was so pure that it could be used for HPLC-running. The gallic acid showed a Rf -value of 0.39, the digallic acid of 0.21, the trigallic acid of 0.09, and the gallotannin of 0.00 respectively. The content of gallic acid in the tannin from acorn powder was 3.04%, from acorn starch, 0.90%, and from acorn starch gels, 0.64-0.86% respectively. The effect of tannin contents on the viscosity of acorn atarch was also studied. The maximum and cooling viscosity of the starch were decreased as the contents of tannin increased.