• Korean Journal of Food Science and Technology
• /
• v.18 no.4
• /
• pp.306-312
• /
• 1986

Color changes of a mixture of 0.8 M glucose, fructose or sucrose and 0.8 M glycine were evaluated by Hunter 'L', 'a', 'b' values during Maillard reaction at the temperature range of $70^{\circ}-100^{\circ}C$. The results suggested the reaction to be devided into three stages. In initial reaction the 'L' and 'a' values decreased slowely, and 'b' rapidly increased to maximum, which were followed by a rapid decrease in 'L' and 'b' and rapid increase in 'a' values at intermediate stage. At final reaction period the both 'L' and 'b' were slowed down in their reduction rate while 'a' decreased rapidly from its maximum point. All of the Hunter values were reached to nea. zero. Linear equations, which can be used for prediction of cole. change in Maillared reaction, of $1/\sqrt{(L_t-L_{\circ})^2\;+\;(a_t-a_{\circ})^2\;+\;(b_t-b_{\circ})^2}\;=\;a(1/t)\;+\;b$ for Hunter values and $1/\sqrt{X\;+\;Y\;+Z}\;=\;a(1/t)\;+\;b$ for CIE tristimulus values were found to have a very high correlation coefficient. Relationships between 'L' and 'a', 'L' and 'b' and 'a' and 'b' were also graphcally compared.

• Korean Journal of Human Ecology
• /
• v.20 no.6
• /
• pp.1229-1237
• /
• 2011

The objective of this study was to evaluate the quality characteristics of Cheongpomook prepared with five different levels of mungbean powder (0, 25, 50, 75, and 100%). We conducted the Hunter's color values, the rheological characteristics, sensory evaluations, and pasting properties of the Cheongpomook samples. The more mungbean powder was added, the more the luminance and Hunter's a values of Cheongpomook samples were decreased, but in Hunter's a values was reverse. With regard to the rheological properties of the Cheongpomook samples, the more mungbean powder was added, the values of hardness, springiness, gumminess, and chewiness were significantly decreased. In color, taste, and overall quality, the value of 25% mungbean powder added Cheongpomook (MP1) and 50% added Cheongpomook (MP2) were significantly higher than those of others. The resulting RVA viscogram, peak viscosity, hold viscosity, break down, setback, and final viscosity of Cheongpomook were decreased with an increase in mungbean powder, but the pasting temperature was increased slightly. Therefore, an addition of 25% mungbean powder appears to be an acceptable approach to enhance the quality of Cheongpomook without reducing acceptability.

• The Korean Journal of Food And Nutrition
• /
• v.22 no.1
• /
• pp.63-68
• /
• 2009

Powders prepared from three different varieties Korean Ginsengs(white, red and black) are readily available ingredients and are consumed daily by many Korean as a functional food material. These variants of Ginsengs are known to exert a variety of physiological effects. Therefore, in this study, we assessed the physiochemical characteristics of Korean Ginseng Dasik prepared with different 3 types of Ginseng powder. We conducted a sensory evaluation analysis, and assessed the mechanical characteristics, Hunter's color values, and general compositions of 3 types of Korean Ginseng Dasik stored at room temperature(20$^{\circ}C$). The results of our sensory evaluation showed that there were significant differences in the color, taste and overall quality of the samples(p<0.05), but there were no significant differences in odor or texture. With regard to the mechanical properties of the samples, we noted significant differences in he Hardness, Cohesiveness, Gumminess and Chewiness of the samples(p<0.05), but no differences in springiness were detected. The luminance of the black Ginseng Dasik was significantly less than that of the red, white, and control samples(p<0.05), We noted significant differences in Hunter's b values, but no significant differences in Hunter's a values among the samples were detected. No significant differences in the general compositions of the samples were noted. In conclusion, red Ginseng Dasik among the samples evaluated herein, has the most commercial value.

• The Korean Journal of Food And Nutrition
• /
• v.14 no.1
• /
• pp.59-64
• /
• 2001

Treating pork loins with lactic acid cultures (Lactococcus lactis subsp. ATCC 11454 grown in 10% milk solids) during storage at 4$^{\circ}C$ were studied. 2-Thiobarbituric acid (TBA), color. and drip loss evaluations of refrigerated pork loins were assessed. Pork loins were immersed in solutions containing 0∼10% individual lactic acid cultures for 0∼5 min. Pork loins treated with 3.96 log units of lactic acid cultures after storage of 1 days as 4$^{\circ}C$ had no significant difference (P > 0.05) TBA values compared to those of controls. Pork loins treated with 3.96 log unitss of lactic acid cultures during storage of 9 days at 4$^{\circ}C$ had no significant difference (P > 0.05). Hunter color L* and b* values compared to those of controls. However, pork loins treated with 4.10 and 4.23 log unitss of lactic acid cultures after storage of 1 and days at 4$^{\circ}C$ had a significant difference (P < 0.05) Hunter color a* values compared to those of controls. Pork loins treated with 4.10 and 4.23 log unitss of lactic acid cultures after storage of 4 days at 4$^{\circ}C$ had a significant difference (P < 0.05) drip loss values compared to those of controls.

• The Korean Journal of Food And Nutrition
• /
• v.23 no.2
• /
• pp.196-202
• /
• 2010

The principal objective of this study was to evaluate the quality characteristics of black ginseng jelly prepared with different 5 levels(0, 0.5, 1.0, 1.5, and 2.0%) of black ginseng extract. We assessed the ginsenosides level of white and black ginseng for comparison between white and black ginseng. And we conducted the pH, sugar content, Hunter's color values, the mechanical characteristics and sensory evaluation of black ginseng jelly samples. The levels of ginsenoside $Rg_3,\;Rh_1$, and $Rh_2$ of black ginseng were higher than those of white ginseng. The more black ginseng extract was increased, the sugar contents of black ginseng jelly were significantly increased(p<0.05). We noted that the luminance and Hunter's b values of jelly samples were decreased according to black ginseng extract was increased, but in Hunter's a values 0.5% black ginseng jelly was the highest of the all. With regard to the mechanical properties of the black ginseng jelly samples, the score of hardness, gumminess and chewiness were significantly increased. In color, taste and overall quality, the score of jelly with 1.0% black ginseng extract was significantly increased than those of the all.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.11 no.1
• /
• pp.25-30
• /
• 1982

To evaluate the quality of commercial dehydrated tea-products, the relationships between particle sizes, densities, moisture absorption & desorption and color appearance were studied by using Hunter-lab tristimulus colorimeter and spectrophotometer. Among the tea-products was held no significant relation between particle sizes and color appearance but red ginseng extract powder (RGEP) was included L, a and b values when was reduced particle size. appearance color of tea-products indicated red-orange color, L, a and b values were ranged 32.7 to 48.0, 4.0 to 10.0 and 5.6 to 18.0, respectively, densities of tea-products ranged 0.232 to 0.898 g/ml and increased L values, Hunter's a/b ratio values was included in 0.61 to 0.90. Color stability in this products was well agreed with decrease of total color difference value ($\Delta$E) and chromaticity difference value ($\Delta$C) of the Hunter-lab color data.

• Food Science and Preservation
• /
• v.16 no.6
• /
• pp.884-892
• /
• 2009

We determined the chemical changes occurring in oil after exposure to high temperatures for various periods of time. Alterations in the chemical parameters of oil after heating for 30, 60, 90, and 120 min at 120C were investigated. The study involved cold-pressed perilla oil (CPPO), virgin perilla oil (VPO), and commercial heat press-extracted perilla oil (CHPEPO), and we assessed quality properties such as Hunter's color values, browning color intensity, acid value, conjugated dienoic acid level, peroxide value, total phenolic content, electron-donating ability, and fatty acid concentration. Hunter L values were higher for CPPO than for VPO or CHPEPO, whereas browning color intensity was greatest for CHPEPO. Peroxide value data showed higher levels of oxidation products in CPPO than in VPO or CHPEPO, whereas conjugated dienoic acid level was most increased in CHPEPO. The content of total phenolics and electron-donating ability were higher in CHPEPO than in CPPO or VPO. After thermal treatment, fatty acid content was most altered in CPPO; in particular, the level of polyunsaturated fatty acids dropped significantly. Hunter L value, acid value, conjugated dienoic acid level, and peroxide concentration also increased whereas Hunter a and b values, browning color intensity, and total phenolic content were decreased in perilla seed oils after thermal oxidation treatment.

• Horticultural Science & Technology
• /
• v.29 no.2
• /
• pp.144-150
• /
• 2011

This study was conducted to investigate the nutrient components and physicochemical properties of general ('Superior') and colored potato. Proximate composition, reducing sugar, free sugars, free amino acids, organic acids, minerals were analyzed, and Hunter color values were measured in the study. 'Rose' and 'Blue' (colored potatoes) contained high levels of reducing sugar, and total free sugar content was greatly different according to varieties. Glutamic acid, arginine and ${\gamma}$-aminobutyric acid were detected to be the three major amino acids in colored potato, and the major organic acids of general potato were oxalic acid, tartaric acid, malic acid and citric acid. All potato contained high level of potassium, calcium and magnesium. The Hunter 'L' value was the highest in 'Jaseo'; Hunter 'a' value was high in 'Blue' and 'Jasim'; Hunter 'b' value was the highest in 'Haryoung'. Overall, colored potato had higher amount of nutrients and physicochemical properties than 'Superior'. Therefore, colored potatoes are expected to be highly valuable items for the development and applications of a functional food. In addition, these results will provide fundamental data for improving sitological value, breeding of new cultivar and promoting of roughage usage.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.4
• /
• pp.641-646
• /
• 1994

changes in HMF content, capsanthin content, Hunter tirstimulus values, color-preference, and pruchasing intent were investigated during storage of industry-produced kochujang packed with polyethylene and nylon complex film at 13, 27 and 37$^{\circ}C$. HMF content, which was very low at initial , did not showed significant increase during storage at 13$^{\circ}C$ for 180 days, but the accumulation of HMF was accelerated by higher temperature. Capsanthin content decreased more rapidly at higher temperature . L values decreased up to 60 days of storage and the storage temperature had little influence on the rate . But, after 60 days, L value decreased more slowly at 13 than at 27 and 37$^{\circ}C$ , a and b values showed linear decrease at 37$^{\circ}C$, but increase in a and b values at 13 and 27 $^{\circ}C$ during early storage was followed by decrease. ΔE decreased more rapidly at higher temperature . Color-preference and purchasing-intent for kochujang decreased during storage at 27 and 37 $^{\circ}C$, but did not show significant changes during storage at 13 $^{\circ}C$ for 180 days. L, and ΔE values of kochujang stored at 37 and 27Δ showed positive correlation with color-preference, but Hunter tristimulus values of Kochujang stored at 13$^{\circ}C$ did not show not any significant correlation with color preference.

• Korean Journal of Food Science and Technology
• /
• v.29 no.1
• /
• pp.21-25
• /
• 1997

Application of the color indicators to kimchi packages was investigated in order to monitor the ripeness of commercial kimchi products during storage and distribution. Kimchi was packed in polypropylene (PP) tray and nylon/cast polypropylene (Ny/CPP) lid where the indicating sachet consisting of $CO_2$ absorbent and chemical dye (bromocresol purple and methyl red) was attached. The ripeness of kimchi during storage at $0{\sim}20^{\circ}C$ was measured in terms of pH and titratable acidity (TA), which were compared with Hunter color values of the indicators. The color of bromocresol purple dye turned from light blue to purple, while that of methyl red turned from light yellow to red. Regardless of the storage temperatures, Hunter b values of bromocresol purple type and Hunter a values of methyl red type appeared to be proportional to both the pH and TA values of kimchi. These results suggest that the color indicators be employed as one of the effective techniques for sensing the ripeness of packaged kimchi products without destructing the package.