• 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%).

• 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.

• 한국수산과학회지
• /
• 제33권3호
• /
• pp.192-197
• /
• 2000

본 연구는 대멸치로 소건품을 제조하기 위하여 건조조건에 따른 수분함량의 변화와 지질의 산화를 조사하였다. 수분은 $60{\circ}C$ 열풍건조 (풍속 1.4 m/sec), $40{\circ}C$ 열풍건조 (풍속 1.4 m/sec), 천일건조 ($30{\pm}5{\circ}C$) 및 $20{\circ}C$ 냉풍건조 (풍속 3.1 m/sec)하였을 때 건조 7시간에 각각 $9.0{\%}, 34.0{\%}, 34.0{\%}, 38.8{\%}$의 함량을 나타내었다. 건조중 산가, 과산화물가, 카보닐가 및 지용성 갈변도는 건조온도가 높을수록 빠르게 증가하였으며, $20{\circ}C$ 냉풍건조하였을 때 지질의 산화가 가장 현저하게 억제되었다. 건조방법에 따른 지방산의 조성변화는 천일건조가 가장 라르고, 그 다음으로 $60{\circ}C$ 열중건조, $40{\circ}C$ 열풍건조, $20{\circ}C$ 냉풍건조의 순이었다. 건조 중 대멸치의 지방산 조성은 폴리엔산 (20 : 5, 22 : 6)은 감소하고 포화산 (14 : 0, 16 : 0)과 모노엔산 (16 : 1, 18 : 1)은 증가하였다. 대멸치의 적정 건조 조건은 온도 $20{\circ}C$, 상대습도 $30{\%}$ 정도에서 냉풍건조하는 것이 지질의 산화억제에 효과적이었다.

• 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.

• 동력기계공학회지
• /
• 제5권1호
• /
• pp.44-49
• /
• 2001

Low temperature vacuum drying technique shows very excellent energy efficiency and prominent drying performances compared with the conventional hot air drying technique. This study was focused on the thermal characteristics of the low temperature vacuum drying technique. From the results of this study, it was confirmed that the time consumption for drying with the new drying technique could be shortened to about 1/3 of the time consumption with the conventional hot air drying technique under the same drying conditions for wet products. Also, the maximum drying rate with the new drying technique reached to about $0.35kg/m^2h$ at about 400% of moisture content.

• 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.

• 동력기계공학회지
• /
• 제15권3호
• /
• pp.46-51
• /
• 2011

Low temperature vacuum drying technique, whose drying time and quantity of exhausting energy is about 25~30% of hot air drying, is very excellent in the drying efficiency. This paper is made out in the aspects of heat engineering with the object of developing Korean drying machine which can dry once a large quantity of objects to be dried in the state of low temperature and vacuum. As the results, it took about 17 hours(3~4 days in case of hot air drying) for material to reach about 18% of the final moisture content in order to store products for a long time, from about 78~80% of the early moisture content at the beginning of drying, and maximum drying rate comes to about 0.35 kg/m2hr at about 400% of the moisture content.

• 한국식품조리과학회지
• /
• 제23권6호
• /
• pp.800-809
• /
• 2007

To develope Hanbang beef jerky as health food, six kinds of beef jerky were prepared by adding sugar (A), licorice (B) and three kinds of spice extracts (clove: C, fennel fruit: D and Chungyang green pepper extract: E) and mixture of all extracts (F). The effects of the drying method and added spice extracts on the quality characteristics of the beef jerky were evaluated. In general, the air-blast dried beef jerky contained $31{\sim}33%$ moisture, $50.0{\sim}51.2%$ crude protein, $7.2{\sim}7.8%$ crude lipid and $3.0{\sim}3.3%$ crude ash. For the mineral content of the air-blast dried jerky, the most prevalent mineral was Na $(1540.08{\sim}1838.17$ mg%), followed by K, P, Mg, and Ca. The Ca content of the beef jerky was highest in the mixed extract group (88.53 mg%), and the lowest content was in sugar-added group (53.12 mg%). For the color properties, the L-value (lightness), a-value (redness) and b-value (yellowness) were higher in the air-blast dried beef jerky than in the hot air dried samples. The drying methods showed their greatest affect on the redness (a) for all six jerkies (p<0.001). For the preference by sensory evaluation, the beef jerky samples with added sugar (A) and licorice extract (B) had significantly higher scores than the beef jerky samples with the added spice extracts, for both of air-blast drying and hot air drying (p<0.05). Preference for the air-blast dried beef jerkies with added clove (C) and fennel fruits (D) were significantly higher, in terms of taste, color, softness and aftertaste as compared to the respective hot air dried jerkies (p<0.01). Considering all the obtained results, we concluded that licorice and spice extracts can be used as natural preservatives in the development of health foods and the air-blast drying method is recommended to improve the quality characteristics of beef jerky.

• 한국영양학회:학술대회논문집
• /
• 한국영양학회 2001년도 춘계연합학술대회 초록
• /
• pp.195.2-195
• /
• 2001

• 한국식품과학회지
• /
• 제33권2호
• /
• pp.245-251
• /
• 2001

양송이버섯을 열풍건조, 진공건조, 동결건조를 이용하여 건조하고 건조조건 및 방법에 따른 물리적 특성을 비교 분석하였다. 양송이버섯은 초기수분함량이 90%(w.b.) 이상의 높은 수분함량을 가진 농산물이며, 건조방법에 따른 건조시간을 비교 분석한 결과 열풍건조시 가장 빠른 건조시간(12 h)을 나타내었으며, 동결건조의 경우 열풍건조에 비하여 약 8시간정도 오래 걸리는 것으로 나타났다. 색차를 나타내는 ${\Delta}E$값은 높은 온도와 빠른 풍속, 그리고 낮은 진공도에서 점차 증가하는 경향을 나타내었다. 전체적인 색도변화는 동결건조된 양송이버섯이 생버섯과 비교할 때 변화가 가장 적었으며, 열풍건조된 양송이버섯은 색차가 크게 나타났다. 갈변도 변화는 열풍건조에서 높은 값을 나타내었고 동결건조에서 갈변도 변화가 가장 적었으며, 건조풍속 및 진공도의 영향보다 건조온도의 영향을 더 많이 받는 것으로 나타났다. 표면 경도의 경우 열풍건조에서 가장 높은 값을 나타내었으며 반면에 동결건조에서 경도변화가 가장 적었다. 재수화 특성을 분석한 결과 동결건조의 경우 조직사이의 공극이 크기 때문에 열풍건조 및 진공건조의 경우보다 흡수량이 많았으며 흡수되는 시간도 초기에 급격히 증가하는 경향을 보였다.