This study investigated the effects of blanching conditions on the quality characteristics of burdock, lotus root, and garlic scape. The selected plants were blanched at varying temperatures (70-100oC) for 1-5 min, and moisture content, shear force, color, and total microbial count were analyzed. Burdock exhibited browning discoloration when it was blanched at a relatively low temperature (70-80oC). In addition, thermal tenderization of burdock was not evident in the blanching conditions adopted in this study. Blanching affected the tenderness and moisture content of lotus root without deteriorative discoloration. In particular, low temperature blanching (80oC) was favorable to blanching lotus root. Alternately, thermal tenderization of garlic scape was possible by blanching at 80- 100oC for 3-5 min, while discoloration of the blanched garlic scape dominated at high-temperature blanching (100oC). Consequently, the result indicated that low temperature for a long time (80oC and 3-5 min) provided a better blanching condition for lotus root and garlic scape than high temperature applied at a short time (100oC and 1-3 min).

본 연구에서는 재배조건(하우스재배, 노지재배), 수확시기(어린잎, 성잎) 열처리에 따른 영양성분 및 항산화활성의 변화를 비교 분석하여 국가표준성분표 발간을 위한 기초자료로 활용하고자 하였다. 일반성분 4종(수분, 지질, 회분, 단백질), 무기질 5종(칼슘, 철, 마그네슘, 칼륨, 나트륨), 비타민 3종(비타민 C, 엽산, 베타카로틴)의 영양성분을 분석하였고 폴리페놀 화합물과 DPPH 라디칼 제거능을 각각 측정하였다. 연구결과 일반성분의 경우 시료 간에 유의적인 차이를 나타내지 않았으나 무기질의 경우 Ca, Mg, Na은 하우스 재배가 노지재배 보다 유의적으로 높은 함량을 나타내었다. 비타민함량과 폴리페놀 함량 및 항산화 활성의 경우 수확시기보다는 재배방법과 열처리에 의해 함량변화가 큰 것으로 나타났다. 하우스보다 노지 재배된 갯기름나물의 비타민 C, 엽산, 폴리페놀 화합물과 항산화활성이 증가하였으며 열처리할 경우 비타민 C, 베타카로틴, 폴리페놀 화합물, 항산화활성이 각각 증가하였다. 비타민 C의 기존 보고된 이론과 상이한 결과가 도출되어 다양한 열처리온도와 시간을 적용한 성분 변화 연구가 필요할 것으로 생각된다. 베타카로틴과 폴리페놀 화합물의 열처리에 의한 증가는 산화가수분해 효소의 불활성화와 세포조직의 견고성 저하로 인한 활성물질의 추출 효율증가로 설명될 수 있다. 따라서 나물을 데쳐서 섭취할 경우 미생물 오염방지 등 안전성을 확보할 수 있을 뿐만 아니라 나물 세포조직이 연해져 베타카로틴과 같은 우리 몸에 유익한 성분의 소화흡수율이 증가될 것으로 생각된다.

This study was performed to determine the effects of the blanching condition (immersion ratio 1:15 (w/v) for 3 min at 95oC, and solution containing 1% sodium chloride) and selected forming agents (dextrin DE=10, dextrin DE=20, β-cyclodextrin; each forming agents added 5%) on the phytochemical compounds and quality characteristics of Ligularia fischeri leaves. The moisture was not affected by the forming agent. The color of a, b and chroma values were low in the blanching treatment groups and were significantly lowest with β-cyclodextrin (CD). The polyphenol and flavonoid contents in the blanching treatment groups were higher than those in the non-blanching-treatment group. The ascorbic acid content was higher in the non-blanching-treatment group and was significantly highest in the group treated with dextrin (DE=10) whereas the blanching treatment groups showed lower dehydroascorbic acid content than the non-blanching-treatment group. The water absorption was higher in the non-blanching-treatment group and was significantly highest in the group treated with CD. The water solubility in the blanching treatment groups treated with dextrin (DE=20) and CD was higher than that in the blanching treatment group treated with DE=10. The total chlorophyll and chlorophyll a and b contents were high in the blanching treatment group treated with CD, and for the total carotenoid contents, the same tendency as that seen with the chlorophyll content was observed. With regard to the particle diameter, those in the blanching treatment groups were lower than that in the non-blanching-treatment group and was significantly lowest in the blanching treatment groups treated with DE=20 and CD. The result of SEM observation showed that the spray-dried powders in blanching treatment groups treated with the DE=20 and CD forming agents had uniform particle distribution.