• Korean journal of food and cookery science
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• v.18 no.6
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• pp.603-612
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• 2002

The study was carried out to compare the relation between the color intensity and antioxidant activity of caramelization products using xylose(XY), glucose(GL). sucrose(SU), glucose＋citric acid(GLCA), glucose＋sodium citrate(GLSC), heated at 80, 120 and 140$\^{C}$ for 24hrs, respectively. The color intensity(absorbance at 490nm) of the browning mixtures increased as the browning temperature and time increased. But the degrees of color intensity of SU and GLCA changed very little. The hydrogen donating ability(HDA) of browning reaction products was generally enhanced as the browning temperature and time increased. When browning mixtures were heated at 80$\^{C}$, the HDA of GLGC was the highest, but the HDA of GLSC was the highest when heated at 120 and 140$\^{C}$. The antioxidant activities for the corn oil substrate containing the anhydrous ethanol extracts from the browning mixtures was inferior to that of SU, but was superior to that of GLCA. The relations among the color intensity, the antioxidant activity, and the hydrogen donating ability(HDA, reducing power) of the browning reaction mixtures were as follows: As the color intensity increased, the antioxidant activity decreased. The correlation coefficient of the color intensity and the antioxidant activity by regression equation was -0.73 ∼ -0.82. As the reducing power increased, the antioxidant activity decreased. The correlation coefficient between the reducing power and the antioxidant activity by regression equation was -0.98 ∼ -0.99. Therefore, the antioxidant activity of browning reaction mixtures seemed not correlated with the color intensity and the reducing power.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.8-23
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• 1981

Color is one of the most important quality factors of red ginseng (Hong-sam) which is processed from fresh ginseng (Panax ginseng C. A. Meyer). Therefore, a study of characteristics of browning mixtures of aqueous fresh ginseng extracts, factors which accelerate the browning of the aqueous extracts, and the antioxidant activity of the browning mixtures may contribute to the improvement of the color and other quality of red ginseng and other ginseng products such as ginseng extracts. In the present study, factors which affect the Maillard-type browning reaction of aqueous extracts of fresh ginseng roots were investigated firstly by adding various concentrations (0.001-0.5M) of arginine or glucose solutions, by varying the browning reaction temperatures and durations. Secondly, some characteristics such as brown color intensity, amounts of water-soluble and ether-soluble extracts, amounts of non-dialyzable materials, pH, viscosity, and reactivity with 2,2'- diphenyl -1 - picrylhydrazyl and antioxidant activity of the browning mixtures of the aqueous fresh ginseng extracts with small amounts of 0.1 M arginine, 0.1 M glucose, and distilled water at various browning temperatures and reaction time were studied. The results of the present study are as follows. 1. Color intensity (absorbance at 470 nm) of the browning mixtures was increased by adding various concentrations of arginine solution to the fresh ginseng extract, but the addition of the same amount of glucose solution did not increase the color intensity. 2 The amounts of water- or ether-soluble extracts, amounts of non-dialyzable materials were slightly greater in case of the browning mixtures of the fresh ginseng extract with 0.1M arginine solution than in case of the browning mixtures of the fresh ginseng extract with the same amount of 0.1 M glucose solution. In the process of the browning reaction, the pH of the browning mixtures of the fresh ginseng extract with 0.1 M arginine solution decreased slightly, while that of the browning mixtures with 0. 1 M glucose solution was almost constant. 3. The color intensity (absorbance at 470 nm) of the browning mixtures of the fresh ginseng extract with 0.1 M arginine or 0.1 M glucose solutions did not correlate well with the reducing power or the antioxidant power of the browning mixtures. The antioxidant activity of 90% ethanol extracts from the earlier stages of the browning mixtures of the fresh ginseng extract with the arginine solution was almost comparable to that of the 90% ethanol extracts from the later stages of the corresponding browning mixtures. The browning mixtures of only the fresh ginseng extract or of the fresh ginseng extract with the glucose solution showed considerable antioxidant activity, although both showed less brown color intensity than the fresh ginseng extract with he arginine solution.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.41-41
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• 2011

The aims of this study were to examine the efficacy of phytochemicals of Rumex crispus as anti-oxidant and anti-browning agent. The bioactive properties of Rumex crispus as natural colorants were studied by total phenolic contents, DPPH radical scavenging, ABTS radical scavenging,lipid peroxidation, cell viability, singlet oxygen quenching and photoprotection effect. Among all of the results ($IC_{50}$: the concentration of various extracts required to exert 50% reducing effect), the higher activity of the extract was found in the ethyl acetate and butanol extracts. Anti-browning activity was evaluated by monitoring the change $L^*$, $a^*$, $b^*$ values and total color differences(${\Delta}E$). It was found that ethyl acetate and butanol extracts effectively inhibited browning in apple juice at a concentration below 0.3 mg/ml. Rumex crispus extracts used natural colorants could be of good resources as anti-oxidant and anti-browning agents. The results suggest that our study may contribute to the development of natural and functional materials with potential application to reduce oxidative damage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.6-13
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• 2001

The study was conducted to investigate the effect of the browning inhibitors such as PVPP(polyvinylpoly-pyrrolidone), A.A.(ascorbic acid) on nonezymatic browning factors [free sugar, total amino acid, organic acid, A.A., HMF (hydroxymethylfurfural)] and enzymatic browning factors [PRO (polyphenoloxidase) activity, polyphenol compounds] in concentrated apple juice during 90 days storage. Considering color value (L value, $\Delta$E), absorbance at 420 nm, concentrated apple juice during 90 days storage. Considering color the effect of browning inhibition. According to the storage period, the changes of nonenzymatic factors in concentrated apple juice added with browning inhibitors were similar to those in control (concentrated apple juice without browning inhibitors), which were the decreased of sucrose(0.24~0.35% at 90 days), the slight increase of glucose and fructose, the decrease of total amino acid (530.4~573.1 mg/10g at 90 days), same value of A.A. at 90 days (38.5~78.6 mg/100g), and the increase of HMF (27.8~30.6 mg/100g at 90 days). On the contrary, enzymatic browning factors were significantly inhibited in concentrated apple juice added with PVPP, judging from the slow increase of PRO activity and the significant decrease of initial value in polyphenol compounds (especially chlorogenic acid). These results suggest that PVPP plays an important role as enzymatic browning inhibitor, that is, a scavenger of polyphenol compounds by adsorption in concentrated apple juice.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.108-114
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• 1996

The study was carried out to compare the reaction rate of Maillard browning reaction of 2 dipeptides (Leucylglycine, Tryptophylglycine) and 4 amino acids (Lysine, Glycine, Leucine, Tryptophan) with xylose heated for 0∼24 hours at 60∼100$^{\circ}C$. 1. The color intensity of the browning mixture heated at 100$^{\circ}C$ for 24 hours was the highest in tryptophanxylose, and in order to tryptophylglycine-xylose > lysine-xylose > leucylglycine-ylose > leucine-xylose > glycine-xylose. 2. The reaction rate constants (k) determined from the browning pigment concentrate with time were similar to the result of the color intensity, that is, the k were the highest in the tryptophan-xylose. 3. The residual amounts of dipeptides, amino acids and xylose in the browning mixture diminished as the browning temperature increase. 4. The activation energies (Ea) calculated from k were the highest in leucine-xylose (143.72 J/mol) and the lowest in tryptophan-xylose (117.45 J/mol). The range of Q$\sub$10/ values were 2.84∼3.58.

• Journal of Mushroom
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• v.7 no.3
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• pp.110-114
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• 2009

Sawdust bag cultivation of Shiitake mushroom (Lentinula edodes) is getting increase. The mycelia browning on the substrate surface is important for the stable production. The development of methods for the rapid mycelia browning is quite required. In this study changes in intracellular enzyme during the mycelial browning were investigated to find the rapid mycelia browning. Mycelia of L. edodes was changed into brown color while it grew in agar and liquid media like sawdust substrates. Mycelia of L. edodes was started to change color at 25 days after inoculation and browning was occurred in whole mycelia colony at 30 days and browning was completed at 40 days. The activities of enzymes was evaluated in these periodically color changing mycelia. Laccase activity was highest at 15 days after inoculation on PDB, but it gradually decreased from 15 days. Tyrosinase activity drastically increased in period between 30 days and 40 days while mycelia browning was progressed. The kinds of phosphotase identified by electrophoresis were esterase, acid phosphotase, and alkaline phosphotase. Activities of phosphotase were increased before the initiation of mycelial browning but they were decreased after browning.

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.161-165
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• 1994

It was aimed to investigate the effects of caffeic acid on the rates of Maillard reaction. The rates of browning reaction increased as the browning temperature increased. The color intensity of the browning mixtures indicated to depend on the amino acid rather than reducing sugar. Also, the color intensity of the browning mixtures increased more rapidly in the presence of caffeic acid. The increase in color intensity seemed to depend mainly to the polymerization of o-quinones formed from caffeic acid. The caffeic acid, furthermore, appeared to enhance the color intensity of the browning mixtures through the interaction with amino acid, especially methionine and phenylalanine. The activation ener-gies of the browning reaction without caffeic acid were 108∼130 J/mol, and Q10 values were 2.6∼3.2. The activation energies and Q10 values of browning mixtures decreased in the presence of CA. The activation energies of the browning mixtures with caffeic acid were 90∼101J/mol, and Q$\_$10/ values were 2.0∼2.6.

• Korean journal of food and cookery science
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• v.15 no.4
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• pp.363-369
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• 1999

The study was carried out to compare the reaction rate of caramel type browning reaction of xylose(XY), glocose(GL), sucrose(SU), glucose+citric acid(GLCA), glucose+sodiumcitrats(GLSC), glucose+glycine(GLGC) heated at 60, 80, 100, 120 and 140$^{\circ}C$ for 24 hours, respectively. 1. The color intensity (absorbance at 490 nm) of the browning reaction mixtures tends to increase as the browning reaction time gets longer and the browning of reaction temperature gets higher. But the degree of the intensity of SU and GLCA changes very little. 2. The reaction rate constant (K) was increased rapidly above 120$^{\circ}C$ and appeared maximum at 140$^{\circ}C$, especially GLGC (140.25) was the highest. The activation energy (Ea) of sugars. XY had the highest value (124.36 J/mol), while SU the lowest(104.68 J/mol). Mixtures of GLGC was shown to have higher activation energy (144.94 J/mol) than the sugar alone and Q$\_$10/ values of GLGC were 1.68-2.85. 3. The residual amount of reactants such as xylose, glucose, sucrose, citric acid, sodium citrate and glycine in each browning mixture were decreased upon the browning reaction temperature increasing. In the GLCA, GLSC and GLGC browning mixtures, respectively, the residual amounts of glucose were less than those with amino acid, organic acid and their salt.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1349-1351
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• 2008

This study examined the effects of temperature, D-psicose concentration, pH, and various amino acids on the Maillard browning reaction of D-psicose and glycine mixture and compared browning color intensity with those of other sugars, such as sucrose, D-glucose, D-fructose, and D-tagatose. When D-psicose (0.1 M) and glycine (0.1 M) mixture was heated at $70-100^{\circ}C$ for 5 hr, the absorbance at 420 nm increased with increasing reaction temperature and time. The Hunter a, b values, and color difference (${\Delta}E$) increased with increasing D-psicose concentration and pH within the range of pH 3-7 except at pH 6, while the L value decreased. The rate of Maillard browning reaction was in order of D-tagatose>D-psicose $\fallingdotseq$ D-fructose>D-glucose>sucrose. The browning color intensity of the D-psicose-basic and non-polar amino acids mixtures was higher than that of the D-psicose-acidic amino acids.

• Food Science and Preservation
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• v.4 no.3
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• pp.265-270
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• 1997

Effect of modified atmosphere packaging conditions on quality changes of dry jujube was investigated. Dry jujubes with moisture content of 26.7% were packaged in PET/Al/PE film pouches with modified atmospheres. The tested packages include those with normal air, vacuum, CO2 flushing, N2 flushing and O2 scavenger. Packages were stored at 25$^{\circ}C$ for 6 months, during which ascorbic acid concentration, browning level, titratable acidity and surface color were measured. Generally modified atmosphere packages could improve quality retention of dry jujubes except that vacuum package resulted in large surface color change. CO2-flushed package showed the best quality retention of high ascorbic acid content and low browning during 112 days, but caused high amounts of ascorbic acid destruction and browning in longer storage. In all the modified atmosphere packages titratable acidity reached a maximum followed by decline and subsequent rise, while it increased linearly with time in normal air package. Considering ascorbic acid retention browning level and surface color changes during 112 days, the packages of CO2 flushing and N2 flushing were better than others.