Far Infrared Drying Characteristics of the Microwave-Steamed Sweet Potato

다국어 초록 (Multilingual Abstract)

In this study, we aimed to investigate far infrared drying characteristics of microwave-steamed sweet potatoes and to establish optimum far infrared drying conditions. The sweet potatoes steamed by microwave for 15 min were far-infrared-dried to a final moisture content of 25 ± 0.5% (w.b.) base on the dried sweet potato sold on the market. The thickness conditions were 2 conditions of 8 mm and 10 mm. The far infrared drying conditions were drying temperature of 60, 70, and 80 °C and air velocity of 0.6 and 0.8 m/s. Optimum microwave steam time for sweet potatoes was 15 min. The far infrared drying time of microwavesteamed sweet potatoes showed a tendency to shorten as the drying temperature was high, the air velocity was fast, and the thickness was thinner. The color difference was lower in the condition of low drying temperature, the slow air velocity, and the thin thickness. Soluble solids contents after far infrared drying increased by 3.09~6.49 Brix compared with that of before drying.
Moreover, the soluble solids contents were increased with thinner thickness, higher drying temperature, and slower air velocity.
The energy consumption to remove 1 kg of moisture was decreased in the condition of high drying temperature, slow air velocity, and thin thickness. Using of microwave steam process instead of conventional water steam process as pre-treatment before the drying of sweet potato was considered to have the advantage such as decreased drying time, lower color difference, and lower energy consumption.

참고문헌 (Reference)

1 이동일, "증자 호박고구마의 원적외선 건조특성" 한국산업식품공학회 21 (21): 42-48, 2017

2 신미영, "온풍건조 조건에 따른 증절간 고구마의 물리적 특성과 기호도" 한국식품조리과학회 27 (27): 73-81, 2011

3 리혁, "산삼배양근의 원적외선 건조특성" 한국농업기계학회 34 (34): 175-182, 2009

4 이재학, "고려인삼의 마이크로파 처리 효과" 한국식품영양학회 23 (23): 405-410, 2010

5 Korea Food and Drug Administration, "NLS standard operating procedure analytical methods" Osong 99-111, 2012

6 Lee, D. I, "Far infrared drying characteristics of steamed sweet potato" Chungbuk National University. 2015

7 Lee, J. H, "Drying characteristics of seasoned red-pepper sauce using far infrared dryer" Chungbuk National University 2015

8 Ning, X. F, "Drying characteristics and quality of agricultural products using combined drying of microwave and far infrared" Chungbuk National University 2012

9 강태환, "Drying Characteristics of Squids According to Far Infrared and Heated Air Drying Conditions" 한국농업기계학회 36 (36): 109-115, 2011

10 Cho, K. W, "A theory of microwave heating" 22 (22): 68-80, 1997