• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.47-52
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• 1999

Comparative effects of phosphine fumigation and gamma irradiation were evaluated on the qualities of white ginseng prepacked in a commercial laminated film in terms of water absorption, Hunter color parameters(L, a, b) and organoleptic properties(overall color/appearance, flavor) during 6 months of storage at ambient(20oC, 70% RH) and accelerated(40oC, 90% RH) conditions. Moisture content of packed white ginseng(initial 8.44%) linearly increased with storage period, thereby reaching to about 10% (r=0.9966) in ambient and more than 15%(r=0.9886) in accelerated conditions, respectively, at the 6th month of storage. The storage at severe conditions resulted in remarkable changes in Hunter's color values, decrease in whiteness(L) and increase in redness(a) and yellowness(b), while both treatments, phosphine and irradiation less than 5kGy, did not cause any significant changes in color parameters. Phosphine fumigation was shown detrimental to overall flavor of white ginseng(p<0.01), however or ganoleptic qualities of stored samples were effectively maintained by irradiation less than 5kGy(p< 0.05). As the index on the guality of white ginseng stored at severe conditions its organoleptic quality was highly correlated with moisture content(r= 0.9777) and Hunter color values(over 0.9), suggesting the critical values of 15.5% moisture and 72.56, 7.15, 21.45 in Hunter's L, a, b values, respectively.

• 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.

• 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.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.410-413
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• 1991

Prefried chicken patties were irradiated at dose levels of 0, 2, and 4 kGy using $Co^{60}$ source and stored at $3{\pm}1^{\circ}C$ and $-10{\pm}1^{\circ}C$, separately for the evaluation of color and sensory characteristics. Irradiation dose of 4 kGy slightly darkened the internal color of chicken patties. Except for the internal portion of the frozen samples, an increase (p<0.05) in Hunter 'L' values was observed for both the surface and interior of patties during storage. Upon refrigerated storage, Hunter 'a' values, both on the surface and internally, decreased as the storage period progressed. Only storage period affected (p<0.05) the Hunter 'b' values of patty surfaces and interiors. No difference (p<0.05) in odor, taste, color, and texture of the patties was observed for irradiation dose and storage period as evaluated by triangle tests except between 2 kGy and 4 kGy irradiated samples before forzen storage.

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

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.219-225
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• 2000

Physicochemical changes of refrigerated chicken legs treated with acetic acid and trisodium phosphate (TSP) during storage at the temperature of 1$\pm$2。C or 4。C. Chicken (average weight of 500$\pm$30 g) legs were treated with 2.5-10% (w/v) TSP and 0.5-2%(v/v) acetic acid soluions at exposure times of 10 min. pH values of chicken legs treated with 2.5-10% TSP significantly (P<0.05) increased at initial days compared to control, which were consistent with the results of treatments of 5-10% TSP solutions fur storage of 8 days at retail levels. Thiobarbituric acid (TBA) values of chicken legs treated with 2.5-10% TSP or 0.5-2% acetic acid solutions significantly increased from initial days to 4days of storage compared to controls. pH values of chicken legs treated with 0.5-2% acetic acid significantly decreased at initial days compared to control, which were consistent with the results of treatments of 1.5-2% acetic acid solutions for storage of 16 days at 4。C. Chicken legs treated with 0.5-2% acetic acid solutions were a significantly different Hunter color L$^+$ values during storage of 4 and 8 days compared to the controls. Chicken legs treated with 1-2% acetic acid solutions were a significantly different Hunter color a$^+$ values during storage of 16 days compared to the controls. Chicken legs treated with 0.5-2% acetic acid solutions were a significantly different Hunter color b$^+$ values during storage from 4 to 12 days compared to the controls.

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

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