• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.171-175
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• 1999

Changes in physicochemical characteristics of steamed rice during roasting were investigated. Steamed rice was roasted at various temperature $(150{\sim}220^{\circ}C)$ for various time $(10{\sim}30min)$. L and b Hunter color values of steamed rice were decreased, but E value was increased by roasting. The water absorption index and the water solubility index were gradually with increasing roasting temperature and time up to $200^{\circ}C$ for 30min, but decreased at $220^{\circ}C$ for 20min. The yield of water extracts from steamed and roasted rice were sharply increased with increasing roasting temperature and time, however, precipitates and turbidity were decreased. The content of reducing sugar was slowly increased up to $200^{\circ}C$ and remarkably increased above it. The contents of amino acids were decreased by roasting. Among them, cystine, lysine and serin were significantly reduced with increasing roasting temperature.

• Food Industry And Nutrition
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• v.9 no.3
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• pp.45-52
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• 2004

볶음조건에 따라 치커리의 유리당 함량은 무처리구에서는 sucrose 4.78%, fructose 0.81% 및 glucose 0.53%이었는데 볶음온도가 증가하고 볶음시간이 길어질수록 감소하여 16$0^{\circ}C$ 40분 볶음처리구에서는 sucrose 2.21%, fructose 0.35% 및 glucose 0.20%로 전체 유리당 함량으로는 약 45.10% 잔존하였다 아미노산은 18종이 분리되었고, 그 중 유리아미노산 함량은 arginine이 504.49 mg%, asparagine이 500.78 mg%, glutamic acid가 97.82 mg%이었고, 충아미노산 함량은 arginine이 676.7 mg%, glutamic acid가 583.9 mg%, aspartic acid가 319.2 mg%, prolineol 297.4 mg%로 다른 것에 비하여 높게 나타났다 볶음온도가 증가하고 볶음시간이 길어질수록 아미노산의 함량은 감소하였고, 그 정도도 다르게 나타났다. 전체함량으로 보면 유리 아미노산의 경우 무처리구에서는 1728.6 mg%이었던 것이 16$0^{\circ}C$ 40분 처리구에서 4.37 mg%로 약 0.25%만 잔존하였고, 총아미노산의 경우 무처리구에서 3159.4 mg%이었던 것이 16$0^{\circ}C$ 40분 볶음처리구에서는 1732.5 mg%이었다.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.2
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• pp.129-135
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• 2000

This study was attempted to develop dandelion tea under various roasting conditions. The quality properties of tea were evaluated by measuring soluble solid. total yield, pH, color value, turbidity, browning degree, and sensory evaluation induced by various roasting time and temperature. The total yield and soluble solid content were the highest at the roasting process at 23$0^{\circ}C$ for 10 min. pH value was higher in non-treatment than pre-drying treatment and was not different among the roasting times. L value was reduced with increasing roasting time. Turbidity and browning degree of dandelion tea were the highest at the roasting condition at 23$0^{\circ}C$ for 10 min. Palatability was the highest at the roasting condition at 23$0^{\circ}C$ for 5 min without pre-drying. The higher solid yield was obtained with an increase in roasting temperature. Turbidity and browning degree increased under the roasting conditions at 230 and 26$0^{\circ}C$, respectively. Palatability in sensory evaluation increased at the roasting condition at 26$0^{\circ}C$ for 10 min. The higher savory taste value was obtained with an increase in roasting temperature.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.96-106
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• 2004

Response surface methodology (RSM) was applied in roasting processes of perilla leaves to develop a high quality perilla leaf tea. The Hunter color parameters and electron donating ability were monitored to optimize organoleptic properties of perilla leaf tea. The roasting processes were based on the central composite design with primary variables-roasting temperature $(140{\sim}220^{\circ}C)$, time $(5{\sim}25)$, and reaction variables-sensory test, electron donating ability. From the variables, the roasting condition was optimized using statistical analysis system (SAS) program as developing the functional tea using perilla leaf. Hunter color L and b values of the powdered samples increased with the roasting processes, but Hunter color a value decreased. Electron donating ability was influenced by roasting temperature (p<0.01) and time (p<0.01), and optimum condition selected was at $220^{\circ}C$ for 15 min with coefficient of determinations $(R^2)$ above 0.98. After preference test of perilla leaf tea using parameter of taste, color, and flavor, we can estimate that the optimal roasting condition of preilla leaf for function tea manufacturing are $210{\sim}220^{\circ}C$ for $10{\sim}20$ min by response surface methodology (RSM). Tyrosinase, xanthine oxidase and electron donating ability were 10.14, 14.37 and 59.19% of perilla leaf tea.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.736-741
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• 1995

This study was conducted to investigated the change of volatile flavor components of Cassia tora seeds during roasting treatments. The flavor components of Cassia tora seeds were analyzed by gas chromatography(GC) and combined gas chromatography-mass spectrometry(GC/MS). Among the flavor compounds collected by simultaneous steam distillation and extraction(SDE) method, 38 components were separated and identified. They consisted of 3 pyrazines, 4 pyrroles or pyridine, 4 alcohols, 11 aldehydes or ketones, 9 furans or phenols and 7 others. The flavor compounds collected from unroasted Cassia tora seeds were 7 components. During roasting process, many other flavor components were formed and increased in their contents. The contents of pyrazines and furans were highest and increased conspicuously, whereas, the contents of aldehydes, ketones, alcohols and pyridines were not increased significantly.

• Food Science and Preservation
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• v.21 no.5
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• pp.646-651
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• 2014

To evaluate the processing adaptability of burdock (Arctium lappa L) tea, the physicochemical properties of burdock tea treated with steaming and roasting were investigated. The tea treatments included hot-air drying after roasting (HDR, drying at $60^{\circ}C$ for 6 hr), steaming after hot-air drying (SHD, steaming at $100^{\circ}C$ for 10 min), and steaming and then hot-air drying followed by roasting (SHDR, roasting at $250^{\circ}C$ for 3 min). The physicochemical properties, antioxidant activities, and sensory properties of the HDR, SHD, and SHDR teas were measured in hot water, and the tea was extracted from each sample. The color values of lightness (L) and yellowness (b) were lower in the HDR and SHDR teas, and the total sugar content of the SHDR tea was significantly higher than that of the other teas. The ABTS and DPPH radical scavenging abilities of the SHDR tea with a 500 mg% concentration were significantly higher than those of the SHD tea. In the sensory evaluation, the SHDR tea was ranked significantly higher than the other samples as to its color, flavor, taste, and overall acceptability. The results suggest that SHDR can be applied to burdock tea to achieve high quality and functionality.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.2
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• pp.136-141
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• 2000

This study was conducted to analyze the properties of the roasted dandelion tea prepared after various pre-treatments such as pre-drying, steaming and air blast drying. The dandelion tea was prepared by roasting the pre-treated dandelion leaves and its total yield, pH, soluble solid content, turbidity, browning and sensory value were evaluated. Total yield and soluble solid content were the highest in case of air blast drying. Turbidity and browning degree were similar in all the teas regardless of their pre-treatment including pre-drying, steaming or air blast drying. The best palatability in the sensory evaluation was obtained at the steaming condition for 60 sec without pre-drying. Longer air blast drying time resulted in the increase in the a and b values. turbidity, browning degree, total yield and soluble solid content in the air blast dried tea.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.99-103
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• 2007

In order to evaluate innate flavor during the roasting process, the components responsible for the aroma of unroasted Polygonatum odoratum root and the volatile odor components released during the roasting process were evaluated using the solid phase-microextraction (SPME) headspace method. The raw P. odoratum root contained aldehyde, alcohol, hydrocarbon and acid components, which gave it a grass-like smell. 2-Methylpyrazine was not revealed from the roasted P. odoratum root at $110^{\circ}C$ and $130^{\circ}C$, but was extracted at $150^{\circ}C$. The 2,5-dimethylpyrazine component was the greatest at $130^{\circ}C$. The hexanal component was greater when the root was roasted at $110^{\circ}C$, compared with those at $130^{\circ}C$ and $150^{\circ}C$. The production of 2-acetyl-1-pyrroline component was the greatest when it was roasted at $130^{\circ}C$. Quantitative descriptive analysis of P. odoratum after roasting revealed a high concentration of 2,5-dimethylpyrazine at $130^{\circ}C$ and $150^{\circ}C$, but a low concentration at $110^{\circ}C$. Most of the 2-acetyl-1-pyrroline, which significantly affected its smell, was revealed at $130^{\circ}C$.

• Food Science and Preservation
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• v.19 no.5
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• pp.735-743
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• 2012

Purple sweet potato (PSP, Ipomoea batatas) has various biological effects including antidiabetic, anti-inflammatory, and antioxidant activities. In this study, the antioxidant activity of PSP after roasting were compared using DPPH, ABTS, and FRAP assays. In addition, the total phenolics and flavonoid contents, Maillard reaction products, and phenolic acid contents were measured to identify the factors that changed PSP,s antioxidant activity due to roasting. The roasted PSP exhibited significantly higher antioxidant activity than unroasted PSP. In particular, the PSP roasted at $200^{\circ}C$ for 10 min showed the highest antioxidant activity among all the PSPs that were roasted under different conditions. The total phenolic and flavonoid contents, Maillard reaction products and phenolic acid contents markedly increased, corresponding to the general increase in antioxidant activities after roasting. These results suggest that roasted PSP extracts are potential source of natural antioxidants that may be used in certain food applications.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.413-418
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• 1998

To renew interest in Chicory roots (Cichorium intybus L.) as a food material, some functional and sensory properties were investigated under various roasting conditions. Browning color intensity of extracts increased with roasting processes. Electron-donating and nitrite-scavenging abilities of extracts increased with roasting processes, showing more than 2 and 3,6 times higher than those of the unroasted control in their activities, respectively. The amounts of total phenolic compounds and antioxidative activity of Chicory extracts showed the highest values at the roasting condition of $160^{\circ}C$ and 30 min. Sensory scores of Chicory tea generally increased with roasting processes, which showed a decreasing tendency at roasting conditions more than $170^{\circ}C$ and 30 min. Electron-donating ability showed a positive correlation with both browning color intensity and the amount of total phenolic compounds. Induction period by peroxide value showed a highly positive correlation with the amount of total phenolic compounds. Similarly, nitrite-scavenging ability of Chicory extracts showed a highly positive correlation with both browning color intensity and electron-donating ability.