• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.466-470
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• 2001

Response surface methodology was used for monitoring extraction conditions, based on quality properties of old pumpkin extracts. Hunter's color L value of extracts was maximized at 101℃, 2.6 hr and decreased gradually after maximum point. The polynomial equation for Hunter's color L value showed 10% of significance level and 0.8799 of R². Hunter's color a value was minimized at 117℃, 3.9 hr and R² of polynomial equation was 0.9852 within 1% significance level. Hunter's color b value and ΔE value increased as the extracting temperature and time increased. Extraction yield of old pumpkin was maximized at 110℃, 4 hr and increased in proportional to the extracting temperature and time, but decreased after 113℃ and 2 hr. Viscosity of pumpkin extracts were maximized at 120℃, nearly 3 hr. R² of polynomial equations for yield, viscosity and sugar content were 0.9532, 0.9812 and 0.8869, respectively. Optimum ranges of extraction conditions for quality properties of old pumpkin were 102∼109℃, 2.5∼3.5 hr, respectively. Predicted values at the optimum extraction condition agreed with experimental values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.355-360
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• 2002

Effect of additive on color reversion of green tea extract, whose undesirable color had been removed by irradiation, was studied during storage. Hunter color L-vague of irradiated sample was significantly higher than that of nonirradiated control. The color of green tea extract with butylated hydroxyanisole (BHA) did not differ from that of the control but the green tea extract with ascorbic acid had higher L-value than the control during the whole storage (p<0.05), However, the sample irradiated at 20 kGy showed a faster color reversion than the sample with 5 or 10 kGy of irradiation. Hunter color a-values were decreased by irradiation and the sample with ascorbic acid showed the lowest. The result of Hunter color b-value was also similar to that of Hunter color a-value, indicating that when the irradiation technology is used for color improvement of green tea extract, the ascorbic acid can be added to minimize color reversion of the extract during delivery or storage.

• Food Science of Animal Resources
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• v.21 no.4
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• pp.323-328
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• 2001

Meat quality of the domestic pork carcasses(n=330) classified in 3 groups according to the Hunter L values postmortem($\leq$50, 50.1∼55.0 and $\geq$55.1) was investigated. The carcass temperature(3, 5, 10 and 15hr postmortem) and temperature falling rate of postmortem increased as the Hunter L value increased. The pH postmortem(pH$\_$ohr/, pH$\_$24hr/) decreased as the Hunter L value decreased. In physical traits, the water holding capacity(WHC) increased and the purge loss decreased as the Hunter L value increased. However, shear force, cooking loss and fat hardness were not significantly different among different. Hunter L value groups(p<0.05). The meat color indices(CIE L*, a*, b*, chroma, hue and ΔE) increased as Hunter L value increased. The sensory characteristics had no significant difference among different Hunter L value groups(p<0.05). In conclusion, the results suggested that Hunter L values were related with pork quality such as temperature, pH, physical traits and color.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.831-837
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• 1997

Response surface methodology(RSM) was applied in roasting processes of Polygonatum odoratum roots in order to monitor Hunter color parameters and to optimize organoleptic properties of the tea. In roasting processing based on the central composite design with variations in roasting temperature (110~19$0^{\circ}C$) and roasting time(15~75min), coefficients of determinations($R^{2}$) of the models were above 0.9827(p<0.01) in Hunter color parameters and above 0.7748 in organoleptic properties. Hunter color L and $\Delta$E values of the powdered samples decreased with the roasting processes, whereas Hunter color a and b values increased up to around 59 min at 136$^{\circ}C$ and thereafter showed a decreased tendency. Organoleptic qualities on color, taste and aroma of Polygonatum odoratum tea were improved along with roasting processes, thereby estimating the optimum roasting conditions by RSM for the maximized qualities of organoleptic properties as a range from 127$^{\circ}C$ to 135$^{\circ}C$ and from 60min to 66 min. Hunter color a value(redness) was found to generate a similar response surface to that of organoleptic properties, showing the possibility of quality index in roasting processes of Polygonatum odoratum roots.

• Korean journal of food and cookery science
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• v.2 no.1
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• pp.45-53
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• 1986

This study was conducted to investigate the effects of the properties of sugar (20％, 30%) and starch (l5％, 20%, 25％) to Angdo on Angdo Pyun's preference, texture and color_ Textural characteristics were examined through sensory evaluation, Rheometer. Color test by Color and color difference meter. The properties through sensory evaluation were appearance, color, flavor, hardness, thickness and acceptability. With Rheometer, compression force, work ratio, adhesive work and gumminess were measured. With Color and Color difference meter, L, a ana b were measured. The results were as follows: 1. Sensory evaluation indicated that with the increase of starch addition, the Angdo Pyun maintained a worse apperance and got hardened and thickened. As the amount of suger increased, the Angdo fyun maintained better in color and flavor as well as its acceptability. 2. Rheometer measurement indicated that a compression force, work ratio, adhesive work and gumminess tended to increase, as the starch proportion increased. As the amount of sugar increased, the Angdo Pyun maintained a greater adhesive work, work ratio and gumminess. 3. Color and Color difference meter indicated that figure L ana a tended to increase and b, ΔE and ΔC decrease, as the starch proportion increased. 4. In the analysis of correlation between hardness and compression force, it was found that they are highly related. In view of the above results, it came to the conclusion that Angdo Pyun with the addition of 30％ sugar and 15％ starch could give the best result among the groups studied.

• Food Science and Preservation
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• v.20 no.4
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• pp.532-538
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• 2013

This study was done in order to monitor the quality properties of the granule using Bokbunja (Rubus coreanus Miquel) extracts. In order to prepare the granule depending on operational parameters such as content of Bokbunja extract ($X_1$, 0.4~1.2 g), sugar content ($X_2$, 6~10 g) and citric acid content ($X_3$, 0.1~0.3 g), a response surface methodology was applied to monitor the optimum recipes on the organoleptic properties and Hunter's color. The optimum recipe on the organoleptic color showed extract content of 0.96 g, sugar content of 7.05 g and citric acid content of 0.232 g. The optimum recipe on the organoleptic flavor showed extract content of 0.86 g, sugar content of 6.04 g and citric acid content of 0.215 g. The optimum recipe on the organoleptic taste showed extract content of 0.92 g, sugar content of 6.39 g and citric acid content of 0.251 g. The optimum recipe on the overall palatability showed extract content of 0.86 g, sugar content of 6.65 g and citric acid content of 0.272 g. The response surface of the Hunter's color b value was similar to the response of the overall palatability; therefore, the optimum conditions accepted by the consumers were 0.8 g Bokbunja extract content and 0.6 g sugar content in the Hunter's color a value of 6.0.

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

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.938-944
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• 1999

Response surface methodology (RSM) was used for monitoring the changes of Hunter's color and organoleptic colors of roasted doraji tea with variations in threonine concentration of soaking solution and roasting condition. In soaking and roasting processes based on the central composite design with variations in threonine concentration of soaking solution, roasting temperature and roasting time, coefficients of determinations $(R^{2})$ of the models were above 0.87 (p<0.05) in Hunter's color parameters and organoleptic color. Hunter's color L value of roasted doragi tea was maximized in 0.09% threonine concentration of soaking solution, $142.37^{\circ}C$ and 21.94 min in roasting condition. Hunter's color a value of roasted doragi tea was maximized in 1.24% threonine concentration of soaking solution, $154.01^{\circ}C$ and 28.59 min in roasting condition, minimized in 1.67% threonine concentration of soaking solution, $137.61^{\circ}C$ and 24.62 min in roasting condition, Hunter's color b value of roasted doragi tea was maximized in 1.10% threonine concentration of soaking solution, $154.72^{\circ}C$ and 27.12 min in roasting condition. The maximum quality of organoleptic color of roasted doragi tea was soaked in 1.25% threonine concentration, and roasted at $141.81^{\circ}C$ for 34.14 min.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.2
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• pp.155-161
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• 1998

Response surface methodology (RSM) was used for optimizing preparation conditions and monitoring the quality of buckwheat mook prepared using buckwheat starch. The textures(hardness, adhesiveness, cohesiveness and gumminess) of buckwheat mook were decreased in inverse proportion to the increase of water content. the L and b values of Hunter color parameters in buckwheat mook were increased in proportion to the increase of water content. However, The a value of Hunter color parameters of buckwheat mook were decreased in inverse proportion to the increase of water content. Organoleptic properties(color, form, taste and mouth-feel) of buckwheat mook showed a maximum score in 700ml(water content), 14min(gelatinization time)

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.426-430
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• 1985

The effects of temperature on the visual color deterioration of Lithospermi radix were investigated under steady conditions of various pH and temperature. The changes of Hunter L, a, b, and ${\Delta}E$ values related to the color deterioration were sharply increased above $50^{\circ}C$ and the deteriorations were expressed linear relationships with the temperature above $60^{\circ}C$. Linear regression coefficients of Hunter L, a, b values decreased with an increase of heat treatment time, whereas the color difference was increased. The linear regression coefficients of Hunter L, a, b, ${\Delta}E$ values in 66.7% ethanol extract solution of Lithospermi radix for 1 hr were -0.3696, -0.4124, -0.2279, and 0.5983, respectively. Inear regression coefficients in color difference (${\Delta}E$) could be calculated from the coefficients in Hunter L, a, b values. The low pH treatment of extract from pH 6.07 to pH 1.35 led to decrease of Hunter a value and a little increase of Hunter L, b values, but the high pH treatment above pH 6.07 decreased all Hunter values. Particularly, the visual color of the extract of Lithospermiradix was appeared to be faborable at pH 4.0-6.5, which was a bright red color.