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

• Textile Coloration and Finishing
• /
• v.11 no.4
• /
• pp.16-23
• /
• 1999

This study was made to investigate the effects of mimosa tannin and tannic acid on change of properties and photodegradation of silk fabrics according to tannin concentration and irradiation time. The results were as follows. 1. As concentration of tannin increased, thickness, fabric count and stiffness showed no difference. But tensile strength were increased, and elongation were decreased. 2. When concentration of tannin is high, tannin adhered to surface of fabrics. 3. fR absorption bands of untreated silk fabric appeared at $3400cm^{-1},\; 1640cm^{-1},\;1445cm^{-1},\;1235cm^{-1},\;and\;675cm^{-1}$, but those of silk fabric treated with tannic acid appeared at $1710cm^{-1}\;and\;3400cm^{-1}$ by treatment of mimosa tannin, respectively. IR absorption bands of photoirradiated silk fabrics appeared at $3400cm^{-1},\;3280cm^{-1},\;2960cm^{-1},\;2920cm^{-1},\; 1720cm^{ -1},\;1380cm^{-1},\;1280cm^{-1},\;1120cm^{-1},\;and\;1070cm^{-1}$. But those bands were decreased at the silk fabrics treated with mimosa tannin and tannic acid.

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

• Textile Coloration and Finishing
• /
• v.7 no.3
• /
• pp.60-67
• /
• 1995

This study was made to investigate the effect of silk fabrics treated with mimosa and tannic acid-weighting effect, surface color according to temprature, treatment time, concentration, pH. The results were as follows ; 1. The wavelength of maximum absorption of mimosa and tannic acid solution appeared at 278.5nm and 275.0nm, respectively. By the irradiation, spectra at wavelength of maximum absorption of mimosa solution disappeared, but those of tannic acid solution decreased after 48hr irradiation. 2. The tannin weighting increased with the increase of concentration, treatment temperature at 8$0^{\circ}C$, acidic condition. In case of tannic acid, it was higher than mimosa. 3. Surface color of silk fabric with mimosa changed from 2.8YR to 5.8YR acc-ording to the increase o( tannin concentration but in case of tannic acid itchanged from 4.2Y to 3.9Y. It was more changed acidic or alkaline conditionthan origine solution.

• Textile Coloration and Finishing
• /
• v.18 no.4
• /
• pp.1-10
• /
• 2006

Tannin treatment has been used for improving the color fastness of dyed materials. In natural dyeing, the tannin treatment is highly effective in improving the fastness. The chitosan treatment also improves the fastness and depth of shade in natural dyeing. In this study, the effects of tannin and chitosan pre-treatment on the color and fastness in loess dyeing were investigated. Cotton woven fabric specimens and cotton knit fabric specimens were pre-treated with chitosan solution in acetic acid, and the specimens were then treated with or without tannin. The specimens were finally dyed with loess. The tannin treatment decreased the K/S values, while the chitosan treatment increased the K/S. Both the tannin treatment and the chitosan treatment increased the wash fastness and light fastness. In tannin treatment, tannin component and Fe component of loess may react together to decrease the lightness and develop dark color. For maintaining inherent color of the loess, it is much preferable to employ chitosan treatment rather than tannin treatment.

• Food Quality and Culture
• /
• v.2 no.2
• /
• pp.89-96
• /
• 2008

In order to determine whether green tea tannin ameliorates abnormal arginine metabolism as the result of excessive arginine, we have assessed the effects of the administration of green tea tannin mixture in rats treated 30 days with 2% arginine. In the arginine-treated group, the level of guanidino compounds such as arginine (Arg), guanidinoacetic acid (GAA), creatinine (Cr), methylguanidine (MG) and guanidinosuccinic acid (GSA), nitric oxide, urea, protein and glucose increased significantly in the serum, urine and kidney, whereas the oxygen species-scavenging enzymes of kidney were reduced as compared with the non-arginine-treated group. By way of contrast, the administration of green tea tannin reduced blood urea nitrogen and serum creatinine, and reduced the urinary excretion of guanidinoacetic acid, creatinine, and $NO_2^-+NO_3^-$. The increased levels of urinary urea, protein and glucose in the arginine-treated group were also lowered by the administration of green tea tannin. In these groups, the activities of superoxide dismutase and catalase in the kidney were increased, thereby suggesting the involvement of radicals in the normalizing of kidney function. These results show that the abnormal renal function induced by the adminstration of excessive arginine in rats may be restored by treatment with green tea tannin.

• Korean journal of food and cookery science
• /
• v.7 no.1
• /
• pp.27-34
• /
• 1991

This study attempted to set up reasonable extraction time of Omija that was put in water for the various components to soak out. Changes of free sugars, organic acids, reducing sugar, total acid and tannin in Omija with various extraction times were investigated (together with the analysis of each components in Omija fruit). 1. High Performance Liquid Chromatography showed fructose, glucose, and sucrose to be the major free sugars of the Omija fruit. Free sugars and reducing sugar value in Omija beverage increased gradually in according with the extraction time, and marked 75.6% per total free sugars and 82.1% per total reducing sugar at 12 hours. 2. Gas Chromatography showed lactic acid, oxalic acid, fumaric acid, levulinic acid, succinic acid, malic acid, citric acid and pyroglutamic acid to be the major organic acids of the Omija fruit. Organic acids and total acids value in Omija beverage increased gradually on proportion to extraction time, and marked 97.0% per total organic acids at 9 hours and 79.0% per total acids at 12 hours. 3. Tannin content in Omija beverage was increased when extraction time was longer but it showed a low percentage as compared with the reducing sugar and total acid. Tannin content marked 48.8% per total tannin at 12 hours. 4. Sensory evaluation revealed that !1 hours of extraction produced the best quality products based in taste, flavor, color and over-all acceptability, considering the data, it seems possible to conclude that the optimum of time for extraction of Omija to water is 9 hours.

• Korean Journal of Environmental Biology
• /
• v.19 no.4
• /
• pp.248-253
• /
• 2001

These studies were carried out to examine the developmental process of galls caused by aphids in Rhus gavanica and the effects of indole-3-acetic acid (IAA) and ${\alpha}$-naphthalene acetic acid (NAA) on the tannin accumulation in the callus induced from that galls. The results are follows. The development of fist-shaped galls has begun at the beginning of June earlier than the case of finger-shaped galls, and also, the growth of fist-shaped galls has last to September longer than the period of finger-shaped galls. These results indicate that the life cycle and feeding activity of the aphids inhabited in fist-shaped galls were longer and mire active than the case of the aphids inhabited in finger-shaped galls. Tannin contents of fist-shaped galls revealed about 60${\sim}70%$ of total dry weights during the whole growth periods, however, the contents in finger-shaped galls were under 10% at the maximum value. These facts mean that finger-shaped galls seem to be as a habitat of aphids rather than as a major source of tannin such as fist-shaped galls. The growth of callus induced from fist-shaped galls was the most effective in the plot of $10^{-5}$ mole IAA, but the tannin accumulation in callus growth was not even caused in any plots of IAA treatments as wells as in any NAA plots. These results considered that the tannin accumulation in fist-shaped galls may be caused only in specific relation between host plant and life cycle of aphids.

• Fashion & Textile Research Journal
• /
• v.8 no.3
• /
• pp.343-348
• /
• 2006

This study aims to attain gray tone dyed goods by using tannin that is contained in green tea. Tannin is given general name of polyphenol, which has a characteristic that bonds with protein and it is used for food preservative that protects against bacteria, as well as its purpose of black tone dye for silk treatment that has been processed since its early ages. In particular, as tannin reacts with all kinds of metallic mordant and changes to various colors, when tannin acid is combined with iron, it becomes tannin steel and produces gray tone color. Tannin that is contained in green tea is condensed tannins and its structure does not hydrolyze, thus having flavan type structure. In order to find the suitable condition for processing tannin, UV-Vis part absorption spectrum of green tea tannin, dye ability based on temperature and time, reflection rate based on concentration, color changes based on acid treatment and alkali treatment, changes on surface based on concentration or metal mordant condition, and lightfastness were measured. Maximum absorption wavelength (${\lambda}_{max}$) of green tea tannin was at around 273nm, while strong absorption was also observed at below 350 nm. Dye ability of green tea tannin is done more easily on silk rather than cellulose fibers such as cotton, while the optimum condition for dyeing was observed to be at $60^{\circ}C$, for 20 minutes. As a result of acid treatment, the color of dye material consisted highly of gray tones and showed overall gray tone with the combined color of yellow and red after the alkali treatment. While it was observed that as dye concentration and metal mordant concentration increased, the color changed at counter-clockwise direction on the Y-scale of Munsell's scale of colors. Additionally, lightfastness was more on a normal fading.

• Journal of the Korean Applied Science and Technology
• /
• v.8 no.1
• /
• pp.79-83
• /
• 1991

The extracts of Quercisemen(Quereus acutissima Carruthers seed) powder was obtained by the extraction with distilled water, water : acetonet(1:1, v/v), ethanol and ethyl ether, respectively. As a result this experiment, the antioxidative activity of each solvent extracts on linoleic acid were examined as follows: 1. Each fraction extracted by the acetone : water(1:1, v/v), water and ethanol respectively showed high antioxidative activity. 2. A fraction of the tannin extracted from the solvent, acetone, water(1:1, v/v) showed even more antioxidative activity than that of the ${\alpha}$-tocopherol or BHT. 3. Acceleration of peroxide reaction by $Fe^{++}$ and $Cu^{++}$ on the linoleic acid was strongly inhibited by adding the tannin, 4. Organic acid, such as malic acid, citiric acid and tartaric acid with the tannin were showed the synergistic effect fo the antioxidation reaction.