• Journal of the Korea Furniture Society
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• v.14 no.2
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• pp.1-12
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• 2003

This study was carried out to determine the mechanical and physical properties of particle boards glued with condensed tannin (Wattle Tannin) powder that was single-molecule phenolic compounds like powdered phenolic resin. Our findings are; 1) It is necessary to spray water on the chip surfaces for effective application of powdered -form tannin resin. It shows that the best and optimum mat moisture increase is 14% of water spray on the surface of chips for developing PB properties. 2) In general, for both liquid and powdered tannin adhesives, their physical and mechanical properties has been proportional to the increase of resin level. But, the most efficient addition ratio is 16% of resin on dry basis. Specially, it is found that the resin level influences on the amount of free formaldehyde emission. The higher the resin level is, the lower the emission is. These phenomena seem to result from the increase of hexamine or formaline in the adhesives used as a hardener, that reduce the free-formaldehyde amount by reaction of tannin of poly-molecule and water. 3) The optimum condition for manufacturing PBs is the condition of hexamine of 5% and formaline of 6% in mechanical and physical properties. Hexamine is superior to formaline in mechanical and physical properties along with the control of the free formaldehyde emission amount. The result of NaOH's addition is insignificant in all experiments of both mechanical and physical properties.

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

• Elastomers and Composites
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• v.45 no.3
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• pp.199-205
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• 2010

Medium-density fiberboard (MDF) is widely used as an indoor building materials. However, formaldehyde resins, commonly used to bind MDF together, emit formaldehyde and other volatile organic compounds that cause health risk at sufficient concentration. In this study, condensed tannin having formaldehyde absorption ability was used to solve the problem of formaldehyde emission generated from surface material. The synthesis of melamine-formaldehyde resin and reaction of melamine-formaldehyde and condensed tannin were analyzed by FT-IR spectrum. Also surface properties, such as shear force, impact strength, tape adhesion, pencil hardness and gloss retention were measured. Free formaldehyde analysis was performed to analyze remaining unreacted formaldehyde. According to the results, the optimum shear force and impact strength could be obtained by 10 wt.% usage of condensed tannin. In cases of pencil hardness and gloss retention, the optimum properties could be obtained at 20 wt.% of condensed tannin. The amounts of formaldehyde emission of surface material containing 20 wt.% of condensed tannin was 59 ${\mu}g/m^2{\cdot}h$. The amounts of formaldehyde emission could be reduced 3 times by using 20 wt.% of condensed tannin.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1134-1138
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• 2006

Forest tree leaves (12 different species) of semi hilly arid region of Punjab State were collected at 30-day interval throughout the year to assess the seasonal variations in tannin profile. Tannins were extracted and fractionated from fat free samples and data were analyzed statistically by $12{\times}12$ factorial design. The leaves of Anogeissus latifolia had the highest (p<0.05) concentration of total phenols (17.4%), net (15.9%) and hydrolysable (16.9%) tannins, followed by leaves of Acacia nilotica. Majority of the tree leaves selected had moderate levels (2-5%) of net tannins. Leaves of Carrisa had the highest (p<0.05) concentration of condensed tannins (CT), whereas the leaves of Anogeissus had the lowest (p<0.05) concentration of condensed tannins. The protein precipitable phenols (PPP) corresponded well with the net tannin content present in different tree leaves. Seasonal variation data revealed that in summer, net tannins and PPP decline in leaves of Bauhinia and Zizyphus whereas the net tannin content of Anogeissus and that of Carrisa increased during summer. The CT and PPP content in the leaves of Pheonix, Leucaena, Zizyphus and Ougenia increased in winter till spring season. Tree leaves generally had higher concentration of HT during summer months. It was concluded that leaves of leaves of A. nilotica, A. latifolia and L. leucocephala could serve as an excellent alternate feed stuffs for ruminants. However, leaves of Phoenix, Carrisa, Bauhinia and Dodonea should be avoided.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.158-163
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• 1995

This study was surveyed and compiled the contribution about acorn in korea .the physico-chemical properties of acorn and acorn starch. preparation of acorn starch and elimination of the acorn tannin, the rheological properties of acorn starch gel. Nutrition of acorn and antioxidative activity of tannin in acorn extract. The result obtained were as follow. 1. The chemical compositions of acorn were water 6.5∼13.7%, crude ash 1.9∼3.4%, crude fat 1.1∼5.0%, crude protein 5.8∼7.8%, crude fiber 2.1∼3.6%, N-free extract 71∼77.5%, total tannin 4.6∼9.3%, Ca 92.7∼460.9mg%, p 80.0∼740.9mg%, Na 66.2∼93.9 mg%, and K 867.9∼983.1mg%. 2. The acorn tannin was extracted with water, acetone, and ethanol. The generation method was wash SE settling method with water. 3. The shape of acorn starch granule was rounded triangular and some elliptical, rasing power 12.4∼12.5, Blue value 0.43∼0.47, Alkali number 10.8∼11.3, Amount of Arnylose 28.8∼30.50% Tannin contents on the initial go tim-zation temperature of acorn starch were not influenced but maximum and cooling viscosity o the acorn starch were decreased. 4. Nutritional effect and diet absorption rate were not influence, by rice and 20% T-A(elimination of tannin from the acorn) mixed diet, and the content of lipid in s rum were not influenced by rice 40% and T-A (elimination of tannin from the acorn) mixed diet. 5. jallic acid, digallic acid, gallotannin were contained in acorn powder extract. The main antioxidative : stlvity was speculated due to the gallic acid.

• Journal of the Korean Society of Food Culture
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• v.4 no.4
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• pp.411-416
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• 1989

Optimum leaching conditions of Korean green tea were determined by examining the relationship between sensory evaluation and tasting constituents of green tea infusion at various leaching conditions. Total nitrogen, total reducing sugar and tannin contents of green tea were $4.70{\sim}5.02%$, $16.5{\sim}18.0%$ and $10.3{\sim}12.7%$, respectively. They increased with the increased of leaching temperature and time. The sensory score was significantly correlated with the tannin contents of green tea in fusion in the range of $15{\sim}30\;mg/g$.(r=-0.9061). Optimum leaching conditions of green tea were $0.5{\sim}1.0$ min at $55^{\circ}C$, 0.5 min at $70{\sim}85^{\circ}C$ in high grade parched green tea, $1.0{\sim}2.0$ min at $55^{\circ}C$ and $0.5{\sim}1.0$ min at $70^{\circ}C$ in medium one.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.99-104
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• 1985

This research was carried out study the effect of several relative humidities on the cracking of kernels of chestnuts. The moisture contents of total kernel increased at the higher humidity over 88% relative humidity. but the moisture contents of inner layer was decreased at low relative humidity below 76 %. The starch contents of kernel decreased, but free stgars increased during the total period of storage. The tannin contents increased during total of storage, and the tannin contents of out layer was higher than inner layer because of tannin transfer from astringent shell. As we considered the sprouting ratio, the rotting ratio and the cracking ratio, the optimal relative humidity of chestnut storage was proved 88% relative humidity.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.80-87
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• 2004

This study was carried out to improve the properties of powdered tannin adhesive(PT) by adding liquid tannin resin(LT) to PT in the manufacture of particleboard. Mixing the LT to PT from 50% to 100% by weight did not show any difference in particleboard properties, but the higher the powdered tannin resin ratio, the lower the properties of the board. The proper ratio of PT to LT was 30:70 for the improvement of PT-particleboard, unless LT lower than 70%. Internal bonding strength was in proportional to the amount of LT. Mixing amino adhesives and PT did not show any improvements in mechanical and physical properties of the board but they only acted as scavenger for the free formaldehyde.Manufacturing particle board with the adhesive of 30:70 (PT:LT) and by using double blender resulted in high-performance products of E₀ level of formaldehyde emission with high water resistance (U type; below 12%, M type; below 25%), as well as saving chip drying energy.

• The Korean Journal of Food And Nutrition
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• v.12 no.6
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• pp.575-581
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• 1999

In result of chemical properties of bamboo shoots and changes of chemical components of salted bamboo shoots during 120 days salting, the contents of moisture crude fat tannin and ascorbic acid were decreased but those of crude protein curde ash and salt concentration were increased. The main free amino acids of bamboo shoots were serine arginine alanine leucine and tyrosine. The content of total free amino acid was rapidly decreased in 80days-past of salting and after that slowly decresed. Wang bamboo shoots was the highest as 1060.18mg/100g in content of total free amino acid. The main mineral elements were K, P, Na and Mg. The contents of Fe and K were the hihest among them. The contents of P, Fe, Zn. Mn. Ge and Cu were decreased but K, Mg, Na and Ca were increased during salting. When fresh bamboo shoots were compared with salted bamboo shoots fresh bamboo shoots contained the contents of moisture crude protein crude fat tannin and ascorbic acid more than salted bamboo shoots did but the less the contents of ash fiber and salt concentration.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.217-221
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• 1983

$\beta$-Galactosidase($\beta$-D-galactoside galactohydrolase, E.C. 3. 2. 1. 23) from E. coli K-12 CSH 36 was immobilized on porous cellulose beads which were previously activated with tannin and p-benzoquinone. Their general properties and applicational possibities were investigated. The most effective, enzyme immobilization was obtained when tannin and p-benzoquinone, pH 11.0, were used together as activation reagents and a period of 6 hours of activation. The optimum pH of $\beta$-galactosidase was 5.5 for free enzyme and 6. 0 for the immobilized enzyme, the optimum temperatures for native and immobilized enzyme were both $50^{\circ}C$. Kms of native $\beta$-galactosidase and immobilized enzyme for ONPG(o-nitrophenyl galactopyranoside) were about $4.0{\times}10^(-4)M$ and $7.5{\times}10^(-4)M$, respectively. In the case of tannin : p-benzoquinone activated cellulose beads, the immobilized enzyme retained over 80% of the initial enzyme activity after 20 runs, which is very promising result far a possible industrial application.