The objective of this work was to study the effect of far infrared ray-vacuum drying having reflection and dispersion functions(RD-FRVD) and hot air drying(HAD) on the quality changes of dried vegetable flakes. HAD was regarded as a control. Browning degrees, color value, titratable acidity and pH value were measured as chemical evaluations. Rehydration and electron micrographs were investigated as physical evaluation. Microbial cells were counted. The color value and browning degrees were increased in both RD-FRVE and HAD. In case of degree of those changes, RD-FRVD made less changes than HAD. Especially, green bean sprout had no differences in color value and browning degrees between raw material and dried-rehydrated material. There were no significance differences in titratable acidity and pH value between raw material and dried-rehydrated material. The total microbial counts were gradually reduced in RD-FRVD. The rehydration rates of dried vegetable flakes were typically increased in RD-FRVD. Also, these results were investigated electron micrographs evaluation. Therefore, these results showed that the quality of dried-rehydrated vegetable flakes was typically enhanced by using RD-FRVD.
Wild grapes have been used as traditional medicinal use and alcoholic beverage production in Korea. The objective of this study is to improve antioxidant properties in Sae-muru by far infrared ray (FIR) treatment, with expecting potential benefits of FIR treatment for wild grape products during manufacturing processes. FIR treatment in berries induced increased content of catechin, epicatechin gallate, epigallocatechin gallate, gallic acid, rutin, ellagic acid, and resveratrol, while content of epicatechin and epigallocatechin was decreased. Although FIR treatment resulted either increased or decreased chemical component groups, presenting in HPLC chromatograms, antioxidant activity in Sae-muru extract was significantly increased by the FIR treatment. Our results suggest that FIR treatment should be an efficient process in the production of high content of bioactive molecules in Sae-muru.
가래나무 잎을 원적외선 30, 40 및 50 v에서 각각 10, 20 및 30분을 처리하였다. 원적외선을 조사한 잎의 총 폴리페놀 함량, 총 플라보노이드 함량, 잎 추출물의 DPPH radical 소거 활성 등을 분석한 결과, 원적외선 30 v에서 20분간 조사한 처리구에서 총 폴리페놀 함량은 25.43 mg/g로 , 총 플라보노이드 함량은 39.38 mg/g으로 가장 높게 나타났다. 그 반면에, 원적외선 50 v에서 30분간 조사한 처리구에서 총폴리페놀 함량은 16.93 mg/g으로, 총플라보노이드 함량은 23.78 mg/g으로 가장 낮게 나타났다. 전체적으로 원적외선 처리에 의해 잎에 함유한 항산화 물질의 함량의 증가는 물론, 그 추출물의 항산화 활성도 증가하는 것을 알 수 있었다. 하지만 원적외선 처리가 가래나무에 함유한 어떠한 특정적인 물질들의 증가에 관하여서는 추후에 더욱 많은 연구가 필요할 것으로 사료된다.
Effects of surface conditions (temperature and roughness) of test specimens, when measuring emissive power of far-infrared ray, have been investigated using FT-IR spectrometer. Element metal zinc (Zn) was selected in this study as representative specimen of materials consisting of simple element. The zinc specimens were heated to four temperatures, i.e., 333K, 353K, .373K, and also their surface was finished with SiC abrasive papers of 100, 220, 360, 400, 600, 800, and 1000 mesh in size. The results shows that the emissive power (W/㎡) of the far-infrared ray increases with temperature for a given roughness and its relationship may be expressed by the following equations: Yη=1.0=0.142.T-0.937 for η=1.0, and Yη=10=0.016.T-1.286 for η=10. The emissive power is also known to increase with surface roughness for a given temperature. Their relationship can be represented by the following equations: YT=313K=0.234.ln(η)+3.53, at 313K, YT=353K=0.234.ln(η)+4.02 at 353K and YT=393K=0.243.ln(η)+4.62 at 393K.