• Journal of Ginseng Research
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• v.19 no.3
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• pp.244-248
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• 1995

Water-soluble browning pigments were artily purified from Korean red ginseng through the several procedures such as fractionation by n-butanol, precipitation by ethanol, dialysis and gel filtration. At least four kinds of water-soluble browning pigment were separated from each other, two kinds of low-molecular-weight and two kinds of high-molecular-weight pigments.

• Journal of Ginseng Research
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• v.19 no.3
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• pp.249-253
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• 1995

In the browning reaction of Korean ginseng, it appears that enzymatic and non-enzymatic browning reaction occurred in the initial stage of heating fresh ginseng at low temperature, and then non-enzymatic browning reaction followed in the drying period after heating. Activation energy of the browning reaction for red ginseng was about 9.0 kcal/mol. Browning reaction of red ginseng was accede- rated with an increase in steaming time, and a great extent of browning reaction occurred between 60-90 min of steaming at 10$0^{\circ}C$. Browning pigments of red ginseng were mostly water soluble subset.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.37-43
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• 1973

In this paper, non-enzymatic browning reactions as a factor of self stability of boiled and dried anchovy were studied to discuss the effect of water activity to the discoloring reaction and the preservative moisture content. The development of rancidity of the fish meat was also mentioned since the fish is fatty and the lipid oxidation is a functional deteriorative reaction. Fresh anchovies were boiled in $10\%$ salt solution immediately after the catch, sun dried, and stored at room temperature ($20^{\circ}C$) for two months in humidistat chambers maintaining different levels of water activity as described in Table 1. The pigments formed by non-enzymatic browning reations were extracted in two fractions, those were chloroform-methanol soluble and water dialyzed fraction, and analyzed spectrophotometrically at the wavelength of 460 nm. These two fractions were considered, respectively to be the brown pigments formed by lipid oxidation reactions for the formler and for the latter, to be the pigments developed by sugar-amino or Maillard reaction. The oxidation of lipid in anchovy meat during the storage was measured as the changes in Peroxide value and the color development of thiobarbituric acid reaction. It is summarized from the results that the rate of both reactions, lipid oxidation and browning, was affected by water activity levels. In regard to the changes in peroxide and TBA value during the storage, the propagation of lipid oxidation was obviously accelerated at lower humidities whereas the development of browning progressed at the higher. These two reactions occurring simultaneously and contrary in activity resulted in that the rate of deterioration occurring oxidatively or by browning, was the minimum at the water activity of 0.32-0.45 which were $7-9\%$ as moisture content and slightly higher value than that of monolayer (Aw=0.21, $5.11\%$ as moisture content). It is also noted that the lipid oxidative browning was presumed to dominate sugar-amino reactions so that the rate of browning of the meat was ultimately depended on the development of rancidity although sugar-amino reactions initiated earlier than the other at the first ten days of storage, particulary at higher humidity. At the lower humidity sugar-amino reactions were occurred gradually but lower levels in color development in contrast to the consistent increase in lipid oxidative browning.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.273-281
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• 1987

In this work the antioxidant effects of browning reaction products prepared by xylose-tryrtophan reaction system were discussed. The antioxygenic brown pigments were separated by solvent extraction, and column chromatography and isolated by gel filteration. The functional groups of the brown pigments which had antioxidant activity were examined. The brown pigments extracted with methanol showed antioxidant effect and were fractionated in 5portions on DEAE-cellulose column. The elutes with methanol: acetic acid(10:30 v/v sol n(A), methanol: chloroform(95:5 v/v) sol n(C), and chloroform: acetic acid(10:30 v/v) sol n(E) only showed antioxidant activity and their compositions were 22.43, 21.51 and $34.43\%$ respectively. When each fraction on DEAE-cellulose column was reseparated on Sephadex LH-20 column, 2 fractions were obtained from portion A and C respectively. Molecular weights of A, C and E fraction of brown pigments were from 2,600 to 3,700. By elucidation of IR spectra, the pigment fractions which showed a strong antioxidant activity were tearing the indole group. It is suggested that the antioxidant function of the brown pigment is due to hydroxy and amino group. A higher activity of the brown pigment fraction E might be attributed to carboxylic acid or carboxylic ester compounds.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.682-688
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• 2009

Changes in lipophillic pigments concentration and its relation to color of fresh green tea liquor during heat treatment were studied. The results showed liquor greenness decreased markedly with extension of incubation time at $55^{\circ}C$, while the brightness and yellowness changed a little. Significant increase in 'a' and 'b' values of tea liquor was observed at $95^{\circ}C$. Color change of liquor at $55^{\circ}C$ was accompanied by a decrease in the level of chlorophylls, lutein and neoxanthin, and an increase in the pheophytins and ${\beta}-carotene$ levels. However, all pigments except ${\beta}-carotene$ decreased with time extension at $95^{\circ}C$. Significant correlation was found between pigments and color difference index. The browning of fresh green tea liquor was attributed to vicissitudes of lipophillic pigments during heat treatment, especially to the change of chlorophylls/pheophytins ratio. Result also showed addition of $Zn^{2+}$ at 1.6 ${\mu}mol/L$ could partially alleviate the decrease in greenness during heat treatment.

• Journal of Ginseng Research
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• v.5 no.2
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• pp.122-131
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• 1981

An aqueous extract s of fresh ginseng roots was heated at loot for 64 hrs. and the changes of color intensity, pH and the amount of free sugars and amino acids during the various intervals of the heating time were investigated. Color intensity and absorbance of the solution at 490nm were increased in proportion to the length of the heating time. Most of brown pigments produced during the treatment were water soluble, and pH 5.1 at initial stage of the solution, was slightly decreased at the final stages of the reaction. Sucrose, glucose and fructose were major free sugars in ginseng roots, and the amounts of sucrose was over 90 % of total free sugars. Sucrose. was largely decreased approximately 50%, by 64 hrs of the treatment, whereas sharp increase in the amount of glucose and fructose was observed during the reaction in the solution. The observed increase in reducing sugars, glucose and fructose was presumed due to hydrolysis of sucrose. Evidently, glucose and fructose were not important factor to control the browning reaction of the solution. Most of free amino acids and peptides except alanine and isoleucine especially arginine, serine and threonine, were sharply decreased up to 40 : 50% of the original concentration within 2 hrs. Accordingly, the content of free amino acids and peptides seems to be extremely important factor to control the browning reaction in ginseng. A free amino acid, presumed to be nor-leucine, was found in fresh ginseng root on the basis of re mention on liquid chromatography. Kinetic analysis of the browning reaction indicated a pseudo second order with respect to amino acid concentration at the initial stage.

• ALGAE
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• v.36 no.3
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• pp.195-206
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• 2021

Increasing inputs of dissolved organic matter (DOM) to northern lakes is resulting in 'lake browning.' Lake browning profoundly affects phytoplankton community composition by modifying two important environmental drivers-light and nutrients. The impact of increased DOM on native isolates of red and green-pigmented cyanobacteria identified as Pseudanabaena, which emerged from a Dolichospermum bloom (Dickson Lake, Algonquin Provincial Park, Ontario, Canada) in 2015, were examined under controlled laboratory conditions. The genomes were sequenced to identify phylogenetic relatedness and physiological similarities, and the physical and chemical effects of increased DOM on cellular performance and competitiveness were assessed. Our study findings were that the isolated red and green phenotypes are two distinct species belonging to the genus Pseudanabaena; that both isolates remained physiologically unaffected when grown independently under defined DOM regimes; and that neither red nor green phenotype achieved a competitive advantage when grown together under defined DOM regimes. While photosynthetic pigment diversity among phytoplankton offers niche-differentiation opportunities, the results of this study illustrate the coexistence of two distinct photosynthetic pigment phenotypes under increasing DOM conditions.

• Journal of Ginseng Research
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• v.30 no.1
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• pp.41-48
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• 2006

In the browning reaction of Korean ginseng, it appears that enzymatic and non-enzymatic browning reaction occurred In initial stage of steaming fresh ginseng at low temperature, and then non-enzymatic browning reaction followed in the drying period after steaming. Browning reaction of red ginseng occurred between $60{\sim}90$ min of steaming at $100^{\circ}C$, and browning pigments of red ginseng were mostly water soluble substances. The structural characteristics of water soluble browning reaction products(WS-BRPs) isolated from Korean red ginseng were showed the presence of hydroxyl, amide carbonyl and aliphatic methane groups. From sugar analysis it was identified that L and S-1, melanoidins isolated from red ginseng, contained two kinds of sugars, glucose and xylose, and the other melanoidin S-2 contained the previous and fructose. In order to find out pertinent methods for the acceleration of browning during ginseng processing, various treatment were made on fresh ginseng with sugars, amino acids and inorganic nitrogenous compounds and the extent of browning was measured. Among sugar tested, maltose resulted in the greatest acceleration of browning followed in decreasing order by glucose and lactose, whereas pentoses, fructose, sucrose and raffinose had negligible effect. A marked browning occurred in ginseng treated with basic amino acids, while the extent of browning was not greatly increased when ginseng was treated with aliphatic amino acids, hydroxyl amino acids, or acidic amino acids. The brown color intensity gradually increased with an increase of glucose concentration far up to 0.5M. L, S-1, and S-2 were found to have an ability to donate hydrogen to DPPH, and also they had anti-oxidative activity in the experiments of hydrogen peroxide scavenging, inhibitory activity in the formation of MDA from linoleic acid, auto oxidation of ok-brain homogenates, lipid peroxidation by the enzymatic and non-enzymatic system in liver microsome fraction, and mitochondrial fraction etc. The amounts of acidic polysaccharide(AP) in red ginseng were higher than those of wild and cultured Panax quinquefolius, Panax notoginseng as well as white ginseng (Panax ginseng). In white ginseng, the AP amount is no difference in root ages or sizes, also, the AP amount of ginseng body was similar to that of rhizome, but was higher than that of leaf and epidermis. Addition of red ginseng acidic polysaccharide(RGAP) increased production of nitric oxide(NO) and tumor necrosis factor (TNF)-$\alpha$ in the rodent macrophage cultures, and treatment of RGAP in vivo stimulated tumoricidal activities of natural killer (NK) cells.

• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.287-294
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• 1983

Change of color, browning index, soluble protein, reducing sugar content, and available lysine were monitored for raw and extruded barely powders during four months of ambient and accelerated storage temperatures with $A_w$ of 0.31 and 0.71, respectively. Loss of whiteness and soluble browning pigments increased with increased $A_w$ and temperature. The raw sample had an increased rate of browning intensity than the extruded samples. Among the extruded samples, the added sucrose sample had the lowest rate of browning during storage. Loss of reducing sugar content in all samples increased with increased $A_w$ and temperature. The loss of soluble protein and of the available lysine also increased with increased $A_w$ and temperature. The loss of reducing sugar and of the available lysine was at least partly due to the Maillard browning reaction. These results have important implications in teh processing and storage of raw and extruded burleys.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.2
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• pp.143-152
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• 1989

Some sugars and proteins were mixed with yellow corvenia lipids, soybean lipids or see yolk lipids to study the influence of the sugars or proteins on lipid oxidation and browning in dry and wet system during kept at $40^{\circ}C$. In the yellow corvenia lipids mixed with various food components, peroxide value(POV), carbonyl value(COV) and brown pigments were much higher than the case that soybean lipids or egg folk lipids were mixed. In terms of the food components, they appealed high in glucose, sucrose and starch but low in albumin and casein. When the soybean lipids were mixed, POV appeared low in all these maxture. COV and brown pigments appeared high in glucose, sucrose and starch but low in albumin and casein. In the case of egg york lipids, POV appeared lower than that of soybean lipids but COV and brown pigments were similar. In the starch mixture of three lipids in wet system, POV and COV in yellow corvenia lipids appealed lower, but appeared higher in soybean lipids and egg yolk lipids than those in dry system. Brown pigments appeared similarly with the case in dry system. And the all mixtures of casein in wet system, POV and COV appealed lower thanthose of the dry system, but brown pigments appeared high.