• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.366-370
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• 1996

Fruits of Rubus coreanum (Korean name: Bog-bun-ja) have been used in oriental traditional medicine as the remedies for impotence, pollution, premature ejaculation and frequency of urination etc. It is known to have phenolic compounds as an astringent. By means of chromatographic methods, four hydrolyzable tannins were isolated from the fruits of R. coreanum. The structures of these compounds were established as gallic acid, 2,3(S)-HHDP-D-glucopyranose, sanguiin H-4 and sanguiin H-6 on the basis of physicochemical and spectroscopic evidences.

• Textile Coloration and Finishing
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• v.7 no.1
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• pp.72-79
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• 1995

The effect of copper sulfate/thiourea on the diffusion and the dye exhaustion of two dyes, C. I. Acid Orange 7 and C. I. Food Yellow 3 in nylon 6 fiber has been studied. The results obtained from the experimetal are as follows : 1) Copper sulfate reacted with thiourea at constant temperature and then generated the colorless trasparent coordination compound, and then combinated end group of carboxyl of nylon 6 fiber. 2) The coordination compound [$Cu_{2}$($TU_{6}$)] ($(SO_{4})_2$) is conducted at pH 5-6 in solution intensity and repulsed the sulfonic acid group of dyes, and therefore the diffusion of dyes is restraint. 3) Dye uptake and diffusion coefficient were decreased in the order of untreated > copper sulfate/thiourea-treated > tannin-treated.

• Korean Journal of Pharmacognosy
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• v.26 no.4
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• pp.327-336
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• 1995

Twelve phenolic components were isolated from the aqueous acetone extract of the leaf of Cornus controversa H. (Cornaceae). On the basis of chemical and spectroscopic evidence, the structures of these components were established as gallic acid, $1-O-galloyl-{\beta}-{_D}-glucose$, $1,6-di-O-galloyl-{\beta}-{_D}-glucose$, $1,2,3-tri-O-galloyl-{\beta}-{_D}-glucose$, $1,2,6-tri-O-galloyl-{\beta}-{_D}-glucose$, 3,4,6-tri-O-galloyl ${_D}-glucose$, eugeniin, gemine D, quercetin, quercitrin, hyperoside and rutin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.283-287
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• 2001

Persimmon vinegar was clarified with 400mg/L chitosans of two different molecular weights (MW 150 and 37 kDa), and its quality changes were investigated during storage at room temperature for 6 months. No significant changes in pH, acidity, and tannin content were observed. However, turbidity and browning slightly increased while protein content slightly decreased. Soluble solids content slightly decreased when treated with high MW chitosan. Color L* value decreased while a* and b* values increased with storage periods. The major organic acid in the persimmon vinegar after 6 months storage was acetic acid with minor lactic, malic, tartaric, galacturonic, and succinic acids. Overall, the quality of persimmon vinegar clarified by chitosan treatment, irrespective of molecular weight, was more stable without noticeable changes during storage than that of control group without chitosan treatment.

• Food Science and Preservation
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• v.23 no.3
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• pp.301-309
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• 2016

The objective of this study was to investigate physicochemical and antioxidant characteristics of immature flat persimmon during 7 heat treatment aging steps. The pH decreased, and hence, acidity increased with aging. Hunter L value decreased with aging. The a value rapidly increased until step 3, whereas the b value decreased. Fructose content decreased while glucose contents slightly increased during aging. Hardness, chewiness and gumminess rapidly decreased, indicating softening in texture, but it was negligible after aging step 3. Phenolic compounds including gallic acid and homogentisic acid were detected at step 3 and then gradually increased with aging. However, contents of flavonoid and tannin were much higher in step 1 sample than others. The antioxidant activities observed by DPPH, ABTS, and FRAP assay were the highest at step 1 possibly due to the higher levels of flavonoids and tannin acid in the step 1 sample.

• Food Science and Preservation
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• v.20 no.5
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• pp.720-726
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• 2013

This study was carried out to optimize the filtration, clarification, anti-browning processing conditions of clear pear juice and to investigate changes in antioxidant activity of pear juice produced through different heating treatment. For the filtration with cheese cloth, filter paper, or centrifugation (10 min at 3,000 rpm), the pear juice was most efficiently filtered with centrifugation because it showed the highest lightness (L value) and lowest yellowness (a value). Among various clarifying agents, 1% of gelatin or bentonite clarified effectively pear juice but tannin or egg albumin did not. Among anti-browning agents (0.1%) like L-ascorbic acid, NaCl or citric acid, L-ascorbic acid prevented the browning of pear juice with the lowest browning index value (2.62), compared to that of NaCl (2.74), or citric acid (2.87). Fructose, sucrose, glucose and sorbitol were present in the pear juice, the fructose and glucose contents increased but that of sucrose decreased in the heated pear juice. The total polyphenol content of the heated pear juice significantly increase, and did the total flavonoid contents in the clear and heated pear juice. The DPPH radical scavenging activity and nitrate scavenging activity were higher in the clear and heated pear juice than in the fruit crush.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.315-319
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• 1992

Korean green tea leaves which were harvested three times(May, June, August) were treated with anaerobic conditions and were measured changes of ${\gamma}-aminobutyric$ acid(GABA) and other constituents. In anaerobically treated green tea leaves, the content of ${\gamma}-aminobutyric$ acid(GABA) and alanine increased while glutamic acid decreased. Whereas theanine, arginine, caffeine and tannin showed little change and the content of vitamine C slightly decreased with the passing of the anaerobic treatment time. Formation of GABA, a hypotensive constituents, was proportioned to the content of glutamic acid and the optimum time of the anaerobic treatment was about 12 hours. In the anaerobic treatment of green tea leaves, effect of nitrogen gas and vacuum condition was no difference between two.

• Analytical Science and Technology
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• v.11 no.1
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• pp.54-61
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• 1998

Chemical components of domestic Ligusticum chuanxiong HORT and Cnidium officinale MAKINO were analyzed. Proximate analysis of each species showed crude protein 18.5% and 11.1%, crude lipid 5.9% and 6.2%, crude fiber 6.4% and 6.5%, crude ash 5.4% and 6.0%, and carbohydrate 63.7% and 70.2%, respectively. Contents of potassium which was found to be the most abundant mineral in both species were 1.8% and 3.0%, and those of sucrose were 0.4% and 0.3% respectively while neither fructose nor glucose were detected in each species. Major fatty acids in Ligusticum chuanxiong HORT and Cnidium officinale MAKINO were linoleic acid (60.7% and 61.2%), oleic acid (19.9% and 21.3%), palmitic acid (11.4% and 11.3%)(respectively) but there was no significant difference between two species. Glutamic acid was revealed as the most abandant amino acid in both species with 2.5% in Ligusticum chuanxiong HORT and 1.6% in Cnidium officinale MAKINO. Ligusticum chuanxiong HORT and Cnidium officinale MAKINO also were shown to be contained 0.0009% and 0.0005% vitamin $B_1$, and 0.6% and 0.7% tannin, respectively.

• Journal of the Korean Society of Food Culture
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• v.11 no.5
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• pp.635-641
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• 1996

As a basic study for preparing pine sprout tea, chemical components in pine sprouts and pine needles were analyzed as follows: In proximate composition the contents of most components except for crude fat were different between in pine sprouts and pine needles. Moisture content in pine sprouts was higher than that in pine needles. Calcium and potassium were major minerals contained in pine sprouts and needles, and their contents in pine needles picked in December were higher than those picked in June. Soluble tannin and vitamin C contents in leaf part of pine sprouts were much higher than those in stem part and their contents in pine needles were increased according to their growth. Free sugars like fructose, glucose and sucrose were contained in both pine sprouts and needles, and their contents in pine sprouts were higher in stem part as compared that in leaf part. Although fourteen kinds of amino acids were detected in pine sprouts and pine needles, their contents were extremely low. Amino acid composition between pine sprouts and pine needles was different each other, but major amino acids contained in them were same, those are acidic amino acids such as aspartic acid and glutamic acid. Amino acid contents in pine needles were increased according to the growth. In fatty acid composition in leaf part of pine sprouts, saturated fatty acid contents were higher than unsaturated fatty acid contents, but in stem part unsaturated fatty acid contents were higher. In pine needles the amount of saturated fatty acid was increased with the growth, but the amount of unsaturated fatty acid was rather decreased.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1462-1467
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• 2007

This study investigated the effect of chemical treatments on tannins (condensed and hydrolysable) and on the trypsin inhibitor (TI) activity in salseed meal. Triplicate samples of ground salseed meal (1 kg) were mixed with 820 ml of either distilled water (pH 5.3), 0.67 M acetic acid (pH 2.4), 0.67 M sodium bicarbonate (pH 8.2) or 2% polyvinyl-pyrrolidone (PVP) solution. The material was placed in airtight plastic containers and incubated at $37^{\circ}C$ for 0, 3, 6, 12, 24, 48 and 72 h. Samples of untreated salseed meal which had not been subjected to soaking or incubation were run through the analysis to serve as control. Addition of water, acetic acid, sodium bicarbonate and PVP solutions to salseed meal and subsequent anaerobic incubation at $37^{\circ}C$ significantly reduced chemically detectable tannins. At each incubation time, alkali solution was more effective than its counterparts. The effect of acidic solution on hydrolysable tannin was least among the treatments. All the treatments reduced TI activity of salseed meal. The reduction in TI activity by these treatments was similar and ranged between 80-84%. Treatment time effected a decrease in the contents of antinutritional substances. However, the effect of the treatment with the reagents, even for zero incubation time, was quite pronounced. It may be concluded from the present results that the treatment of salseed meal with sodium bicarbonate (0.67 M) is more effective in reducing hydrolysable and condensed tannin contents than PVP, water and acid solutions. Treatment with sodium bicarbonate solution is more economical and easier to handle than acid and PVP treatments. Incubation of the treated material for 12 h is reasonably effective, economical and safe from any mould growth.