• 한국식품과학회지
• /
• 제36권1호
• /
• pp.25-31
• /
• 2004

Characteristics of good-quality red pepper powder produced using $N_{2}$-circulated low-temperature drying method were compared with those made through conventional sun and hot-air drying methods. Kimchi and kochujang were prepared with different types of red pepper powder, and their physicochemical and sensory properties were compared. Results revealed Hunter L (lightness), a (redness), and b (yellowness) values of $N_{2}$-circulated low temperature-dried red pepper were highest. Absorbance of crude capsanthin in hot air-dried red pepper powder ($0.584{\pm}0.001$) was significantly lower than sun-dried ($0.848{\pm}0.001$) and $N_{2}$-circulated low temperature-dried products ($0.832{\pm}0.002$. Use of $N_{2}$-circulated low-temperature drying method resulted in the highest amounts at reducing sugar and total vitamin C. Capsaicin content of $N_{2}$-circulated low temperature-dried products were higher than hot air-dried ones. The aL values of kochujaug made with sun-and low temperature-dried red peppers were higher than that of kochujang made with hot-dried red peppers. Physicochemical and sensory evaluation results showed red pepper powders made using $N_{2}$-circulated low-temperature drying method have the best quality among all samples tested.

• 한국수산과학회지
• /
• 제15권1호
• /
• pp.107-110
• /
• 1982

Fixed bed drying method was selected to reduce the initial drying time of squid and the effects of drying air temperature and bed height on the drying rate were investigated, with following results. 1. The drying rate in the fixed bed dryer was faster than that of natural convection type dryer heated indirectly and that of hot air dryer heated directly. 2, Shirai-equation was applicable to squid being dried. Using the equation, drying rate constant obtained was as shown in table 1.

• 한국수산과학회지
• /
• 제52권3호
• /
• pp.232-240
• /
• 2019

Approximately 80% of the world's sea cucumbers Apostichopus japonicas are processed into dried sea cucumbers. The hot air-drying method is currently used in industry, but it has many problems, such as a short drying time, severe browning, high nutrition loss, and low recovery. In this study, the moisture absorption rate, dry recovery rate, and lipid nutrient composition of sea cucumber dried by heat pump decompression and with a hybrid dryer were investigated. The moisture absorption rates for hybrid-dried sea cucumbers at 24, 48, 72, 96, and 120 h were 241.3%, 427.7%, 652.0%, 721.0%, and 742.2%, respectively. The moisture absorption rates for hot air-dried sea cucumbers were 155.8%, 240.0%, 390.3%, 655.5%, and 667.4%, respectively. Thus, moisture absorption was faster and greater with hybrid drying than with hot air drying. The dry recovery rate at 24 h was greater for hybrid-dried sea cucumber (70.7%) than for hot air-dried sea cucumber (59.8%). Saturated fatty acid contents of the hybrid- and hot air-dried sea cucumbers were 30.0% and 37.5%, respectively. Moreover, greater ${\Sigma}n-3$ polyunsaturated fatty acid content was found in hybrid-dried sea cucumber (15.8%) than in hot air-dried sea cucumber (11.7%).

• 한국식품저장유통학회지
• /
• 제12권5호
• /
• pp.442-448
• /
• 2005

생식 제조공정 중 주요공정인 건조방법에서 효율적인 방법을 찾기 위하여 건조방법에 따른 생식 원료 곡류의 이화학적 특성 및 기능성 성분의 변화를 조사하였다. 쌀, 현미, 찹쌀, 보리의 단백질, 지방, 탄수화물, 회분, 식이섬유 등 성분의 함량은 열풍건조(50$\circC$, 55$\circC$, 60$\circC$) 및 동결건조를 통하여서는 거의 변화가 없는 것으로 나타났다. 색도 중의 b값이 열풍건조를 실시한 시료가 동결건조를 실시한 시료에 비하여 높게 나타났다. niacin의 함량은 60$\circC$에서 열풍건조를 실시한 백미, 현미, 찹쌀, 보리가 각각 0.77 mg %, 1.84 mg%, 0.68 mg%, 1.00 mg%로 다른 시험구 보다 낮게 나타났다. 보리 중의 $\beta$-glucan의 함량은 열풍건조 및 동결건조 통하여 거의 변화가 없는 것으로 나타났다. $\beta$-glucan과 같은 기능성 물질을 함유한 보리 등의 생식 원료는 열풍건조방법을 이용하는 것이 경제적일 것으로 생각되며 niacin과 같이 열에 약한 비타민을 많이 함유한 생식 원료는 동결건조 방법을 사용하는 것이 바람직할 것으로 생각된다.

• 한국식품영양학회지
• /
• 제31권6호
• /
• pp.933-939
• /
• 2018

The objective of this study was to determine the effects of drying methods on the quality characteristics and antioxidant activities of pumpkin (Cucurbita moschata Duch.). Pumpkins were dried naturally ($25^{\circ}C$), hot-air drying ($60^{\circ}C$), and throgh freeze drying ($-40^{\circ}C$) methods. The moisture activities were highest in the freeze dried group. The soluble solid showed no significant differences among all groups. The pH was highest in the freeze dried group. The L values were increasing in freeze dried group, whereas the b values were increased in hot-air dried group. The free sugar was highest in freeze dried group. The DPPH radical scavenging activity of hot-air dried group was higher than those of the other groups. The ABTS radical scavenging activities were highest with hot-air dried group and freeze dried group. It was established that hot-air dried group is the most effective drying method for the production of high quality dried pumpkin.

• 한국식품저장유통학회지
• /
• 제7권4호
• /
• pp.389-394
• /
• 2000

단감의 수확 및 저장 중에 발생한 불량과실을 이용할 목적으로 분말화하기 위한 기초연구로서 본 실험을 행하였다. 일반성분 조성은 조단백질, 조지방, 조회분의 순으로 열풍건조 처리구는 0.9-1.1%, 15.0-39.0%, 2.3-3.3%이었으며, 동결건조 처리구는 1.3-2.2%, 27.0-49.0%, 2.5%로 나타났다. 무기성분 조성은 열풍과 동결건조 처리구 모두 potassium, magnesium, phosphorus; calcium, sodium이 주요 무기성분이었으며, 다른 미량원소는 약 3.00ppm 이하였다. 주요 지방산 조성은 열풍과 동결건조 처리구에서 capric acid, lauric acid tridecanoic acid, palmitic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid 순으로 나타났다. 동결건조 처리구의 아미노산 조성은 aspartic acid, glutamic acid가 주요 아미노산이었다. 전체적으로 열풍건조 처리구보다는 동결 건조 처리구가 다소 높은 결과를 보였다. 열풍과 동결건조에 의한 분말 제조에서는 변색과 영양적인 측면을 고려할 때 열풍건조 보다는 동결건조가 우수한 결과를 보였으며, 열풍건조가 시간은 단축되었으나 얇게 펴서 건조해야 하는 단점이 있었으며, 단순한 열풍건조 만으로는 대량생산에 의한 분말 제조는 어렵고 좀더 보완적인 방법이 강구되어야할 것으로 생각된다. 이에 반해 동결건조에 의한 건조방법은 건조시간이 다소 걸리기는 했으나 딱딱해지거나 변색의 우려가 없으며 영양학적으로도 매우 안정적이었다. 이상의 결과를 평가해 볼 때 열풍건조에 의한 분말 제조는 구체적인 보완이 필요하며, 동결건조에 의한 분말 제조가 열풍건조에서보다 우수한 것으로 결과가 나타났다. 따라서, 파찌감의 분말건조 방법은 동결건조가 효율적일 것으로 생각된다.

• Journal of Biosystems Engineering
• /
• 제42권4호
• /
• pp.314-322
• /
• 2017

Purpose: This study was conducted to investigate the hot air drying characteristics of squash slices depending on the drying conditions (input air velocity, input air temperature, and sample thickness). Methods: The developed drying system was equipped with a controllable air blower and electric finned heater, drying chamber, and ventilation fan. Squash (summer squash called Korean zucchini) samples were cut into slices of two different thicknesses (5 and 10 mm). These were then dried at two different input air temperatures (60 and $70^{\circ}C$) and air velocities (5 and 7 m/s). Six well-known drying models were tested to describe the experimental drying data. A non-linear regression analysis was applied to determine model constants and statistical indices such as the coefficient of determination ($R^2$), reduced chi-square (${\chi}^2$), and root mean square error (RMSE). In addition, the effective moisture diffusivity ($D_{eff}$) was estimated based on the curve of ln(MR) versus drying time. Results: The results clearly showed that drying time decreased with an increase in input air temperature. Slice thickness also affected the drying time. Air velocity had a greater influence on drying time at $70^{\circ}C$ than at $60^{\circ}C$ for both thicknesses. All drying models accurately described the drying curve of squash slices regardless of slice thickness and drying conditions; the Modified Henderson and Pabis model had the best performance with the highest R2 and the lowest RMSE values. The effective moisture diffusivity ($D_{eff}$) changes, obtained from Fick's diffusion method, were between $1.67{\times}10^{-10}$ and $7.01{\times}10^{-10}m^2/s$. The moisture diffusivity was increased with an increase in input air temperature, velocity, and thickness. Conclusions: The drying time of squash slices varied depending on input temperature, velocity, and thickness of slices. The further study is necessary to figure out optimal drying condition for squash slices with retaining its original quality.

• 한국식품조리과학회지
• /
• 제18권2호
• /
• pp.173-178
• /
• 2002

본 연구는 표고버섯의 비타민 D$_2$함량을 증가시키기 위해 표고버섯의 자실체 안쪽에 자외선 B파를 0, 2.5, 5.0, 7.5, 10.0 J/$\textrm{cm}^2$ 조사하여 버섯내 비타민 D$_2$함량 변화를 측정하였으며 열풍건조시 자외선 B파 조사 시기를 달리하여 천일건조 버섯과 열풍건조 버섯의 비타민 D$_2$함량의 변화를 비교하여 다음과 같은 결론을 얻었다. 1. 자외선 B파 조사 부위(자실체 안쪽과 바깥쪽)에 따른 표고버섯내 비타민 D$_2$함량은 각각 유의적인 차이가 있었다. 즉 버섯 자실체의 안쪽에 자외선 B파를 조사하였을 때 비타민 D$_2$함량이 더욱 증가하였다. 2. 0, 2.5, 5, 7.5, 10.0 J/$\textrm{cm}^2$의 자외선 B파 조사로 비타민 D$_2$함량은 각각 21.51, 120.78, 144.38, 168.08, 187.69$\mu\textrm{g}$/g로 측정되었다. 즉 자외선 조사량에 의해 비타민 D$_2$함량도 유의적으로 증가하였다(p〈0.05). 3. 열풍건조시간에 따라 버섯내 비타민 D$_2$함량이 변화되어 열풍건조 시간이 길어질수록 비타민 D$_2$함량이 대조군에 비해 모두 유의적으로 감소하였다. 4. 자외선 B파 조사 & 열풍건조 복합군은 천일건조군과 열풍건조군 버섯에 비해 유의적으로 비타민 D$_2$함량이 증가하였다.

• 한국염색가공학회지
• /
• 제21권4호
• /
• pp.23-32
• /
• 2009

The objective of this study is to investigate the efficacy of leaf powder colorants as substitutes for traditional indigo dyeing. Leaf powder colorants were prepared by hot air($50^{\circ}C$) and room temperanrre($25^{\circ}C$) drying methods from fresh leaves. The presence of indigo in the leaf powder colorants was confirmed by UV/Visible absorption spectra. All the powder colorants showed broad absorption at 602 nm as same as synthetic indigo. Dyeing was done by reduction method with sodium hydrosulfite and sodium hydroxide. Leaf powder colorants produced blue color on silk fabrics, showing similar color to the one dyed traditionally with fresh juice extract. The powder colorants prepared at room temperature drying were more stable for long term storage than that prepared by hot air drying. Thus, the powder colorants prepared by room temperature drying was reduced and dyed in one-step process without sodium hydroxide in the dyebath for further investigate dyeing properties. K/S value of the fabric dyed without sodium hydroxide was much higher than one dyed with sodium hydroxide. Regardless of the addition of sodium hydroxide, rubbing fastness was fairly good showing above 4 rating. Fastness to dry cleaning and light of the fabrics dyed without sodium hydroxide were mote higher than that dyed in alkaline condition.

• 한국식품저장유통학회지
• /
• 제13권1호
• /
• pp.37-42
• /
• 2006

본 연구는 경상도지역에서 예로부터 먹어오던 무말랭이 김치(골곰짠지, 오그락지)의 품질 변화를 연구하기 위하여, 천일건조와 열풍건조 그리고 천일건조의 문제점을 보완한 냉풍건조를 이용하여 말린 무말랭이의 품질 특성을 연구하였다. 건조방법에 따른 건조 속도는 열풍건조가 가장 빨랐으며 냉풍건조가 가장 낮은 건조속도를 나타내었다. 건조시 갈색도는 $10^{\circ}C$ 냉풍건조가 가장 낮은 수치를 보였고 열풍건조에서 가장 높게 나타났으며, Vitamin C의 함량은 $10^{\circ}C$냉풍건조가 가장 높은 함량을 보였고 천일건조가 가장 낮은 함량을 보였다. 환원당의 경우 천일건조와 $10^{\circ}C$ 냉풍건조 그리고 $70^{\circ}C$ 열풍건조 모두 유사한 수치를 보였으나 텍스처 측정에서는 $10^{\circ}C$ 냉풍건조가 가장 우수한 것으로 나타났으며 이는 관능검사 결과와도 일치하였다. 따라서 무말랭이 김치의 원료인 말린 무는 $10^{\circ}C$의 냉풍에서 건조하는 것이 가장 우수한 것으로 나타났다.