• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.799-804
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• 2002

Optimum conditions of freeze-dried carrots were determined using response surface methodology. Physicochemical and sensory properties of freeze-dried carrot prepared at different plate temperatures and chamber pressures were evaluated. Drying time increased with decreasing plate temperature and chamber pressure. Rehydration ratio decreased inversely with chamber pressure at low plate temperature, but increased proportionally with chamber pressure at high temperature. Density, color, and sensory off-flavor were not affected by the plate temperature and chamber pressure. Sensory color, tenderness, and carrot flavor increased with decreasing plate temperature, but were not affected by chamber pressure. Based on the drying time, rehydration ratio, and sensory attributes, optimum plate temperature and chamber pressure for the preparation of freeze-dried carrot were determined as $43^{\circ}C$ and 700 micronHg, respectively.

• Food Science and Preservation
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• v.24 no.1
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• pp.74-83
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• 2017

This study was conducted to obtain the optimal conditions of hot air drying for Cudrania tricuspidata by response surface methodology (RSM). The independent variables were blanching time (60, 120, 240 sec), drying temperature (40, 60, $80^{\circ}C$) and drying time (12, 24, 36 h). The dependant variables were total polyphenol content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity (DPPH), and color difference (${\Delta}E$). Viable cell colony was counted according to changes of blanching time. It was confirmed that microorganisms gradually decreased with increasing blanching time. From RSM results, the predicted values of TPC, TFC, DPPH, and ${\Delta}E$ were 8.62 mg GAE/g, 56.65 mg RE/g, 40.26% and 11.69, respectively. Experimental values within the optimal range (240 sec, blanching time; $60^{\circ}C$, drying temperature; 24 h, drying time) were 10.06 mg GAE/g, 49 mg RE/g, 44.99% and 10.53, respectively. The predicted values were similar to the experimental values. Comparing drying tendency according to changes of blanching time, moisture reduction was bigger in the blanched sample than that in control at $40^{\circ}C$. However, the differences between blanched and control decreased with increase of drying temperature. Viable cell gradually decreased as increasing blanching time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.192-197
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• 2000

To develop plain dried products of large anchovy, Engraulis japonica, lipid oxidation during drying of large anchovy and optimal drying condition were investigated. The moisture contents of large anchovy on 7 hrs dryness were $ 9.0{\%},\;34.0{\%},\;38.0{\%} and\;38.8{\%}\;in\;60^{\circ}C$ hot-air drying (wind velocity, 1.4m/sec), $40^{\circ}C$ hot-air drying (wind velocity, 1.4 m/sec), sun drying($30{\pm}5^{\circ}C$) and $20^{\circ}C$ cold-air drying (wind velocity, 3.1 m/sec), respectively. The cold-air drying depressed remarkably the lipid oxidation of large anchovy during drying, resulting from AV, POV, COV and the formation of browning pigment. The fatty acid composition of large anchovy was $35.8{\%} in saturates, 20.0{\%} in monoenes and 44.2{\%}$ in polyenes. Saturates and monoenes were increased in proportion to the increase of drying time, while polyenes were decreased. The contents of 20 : 5 and 22 : 6 of polyenes were decreased remarkably in proportion to the progress of lipid oxidation, while 14 : 0, 16 : 0, 16 : 1 and 18 : 1 of saturates and monoenes were increased. The changes in fatty acid compositions by drying conditions were remarkably clarified in sun drying, followed by $60^{\circ}C$ hot-air drying $40^{\circ}C$ hot-air drying and $20^{\circ}C$ cold-air drying in order.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.251-252
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• 2023

본 연구에서는 오염물의 선택적 흡수가 가능한 반응재료의 분광정보 예측을 위하여 반응재료 배합 조건에 따른 분광정보와 최대건조단위중량의 상관관계를 평가하였다. 그 결과, 배합 조건에 따라 최대건조단위중량 증가하게 되면, 최대분광반사율은 감소하였고, 이를 바탕으로 분광정보 경향의 예측이 가능하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1297-1301
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• 2003

The response surface methodology was peformed by central composite design based on drying temperature and time of Citrus, to monitor quality property change caused by drying and make dried products with a good overall palatability. In result, water activity, hardness and softness were affected by drying temperature; water activity decreased and hardness increased with increase of drying temperature. Softness was also high at low temperature and short time of drying. In the range of overall palatability having high score, hardness was shown in 2.01 ∼ 3.20${\times}$10$^{6}$ dyn/$\textrm{cm}^2$ and softness was 62.54 ∼ 146.37 cm/kg. Drying conditions satisfying this range were predicted as 66 ∼ 75$^{\circ}C$ of drying temperature and 8 ∼ 14 hr of drying time.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.111-115
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• 2009

This study was conducted to develop the ultrasonic dryer because present drying methods (heat convection, microwave, vacuum, etc.) could not improve the drying consumption energy, decrease of quality and drying ratio by physical limitation. The drying tests were conducted with four levels (No. 1 only non-heated air, No. 2 only ultrasonic, No. 3 only heated air and No. 4 ultrasonic with heated air) and measuring weight of samples after drying carrot and ginseng slices for 30 minutes. The result of test is that the drying ratio was highest in the level of No. 4 ultrasonic with heated air. The sliced carrot's drying ratio was 22.4% (w.b.)/h and sliced ginseng's drying ratio was 3.8% (w.b.)/h. The discoloration and twist of samples was appeared on using only heated air like No. 3.

• Food Science and Preservation
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• v.13 no.6
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• pp.740-748
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• 2006

The Chunma (Gastrodia elata Blume) requires a simple pre-treatment, due to inconvenience or preservation, toxicities, and pungencies in intact state. Various drying conditions were examined to establish the physicochemical properties of Chunma by the response surface methodology (RSM). Weter activity and total phenolic acid contents of Chunma dried extracts were optimal at $79.56^{\circ}C$ and $79.64^{\circ}C$ for 7.17 hr and 8.74 hr, respectively, for their characteristics. Electron-donating ability and nitrite-scavenging activity were optimal at 79.79 and $7.99^{\circ}C$ for 8.57 and 8.07 hr. We generated a regression equation for each variable and then superimposed the optimal condition in acquiring values for each frying process factor, physicochemical properties, resulting in that the optimal drying condition was at $75{\sim}80^{\circ}C$ for $8{\sim}9 hr$.

• Korean Journal of Medicinal Crop Science
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• v.4 no.4
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• pp.283-287
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• 1996

As a part of studies on the quality control for drying methods in Lycii Fructus. Dried Lycii Fructus were obtained from several treatments to examine the control of the extracts and its physical properties, and also to analyze the inorganic elements and proximate compositions. The results were summerized as follows; the changes of solid matter contents dried at $50^{\circ}C\;for\;4\;hrs\;and\;60^{\circ}C$ for 28 hrs were highest. The changes of Hunter values were 66 in lightness, 5.0 in redness and 51.3 in yellowness, respectively in treatment No. 1. And also the viscosity of treatment No. 1. was some high compared to the other treatment. The desirable drying temperature were at $50^{\circ}C$ for 2hrs in initial and at $60^{\circ}C$ for 24hrs in final temperature and it was the best conditions as a quality, economics and chemical compositions of Lycii Fructus.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.284-288
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• 1993

Tow Kinds of Soils, vertisol and alfisol, were selected and analyzed pore space distribution(PSD) by mercury intrusion method and soil water potential after freeze-drying from different water conditions, such as 0.033MPa, 1.5MPa and ovendry. The PSD values measured by mercury intrusion method were higher in large pores than the values from soil water potential. Also, there were big differences of PSD by the changes of the water content befor freeze-drying.

• Journal of Forest and Environmental Science
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• v.11 no.1
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• pp.50-60
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• 1995

This study was carried out to estimate drying schedules of Larix Leptolepis and Pinus koraiensis by oven-drying at $100^{\circ}C$ which aimed to elucidate the characteristics such as current moisture content, drying process. initial check, collapse, internal check and drying rate during drying following each board thickness (2, 3. 4, 5, 6cm). the results were summerized as follows; Current moisture content of each board showed a rapid drying curve with the decrease of board thickness. At 20% moisture content, the drying rate of Larix leptolepis was higher than that of Pinus koraiensis and the drying rate of boards was lower with the increase of board thickness. From the estimated drying schedules. the initial conditions of drying of Larix leptolepis had to be milder than those of Pinus koraiensis and the boards thickness of 5cm, 6cm had to be most mild conditions.