This study assessed dried vegetables derived from sweet potato petioles to promote the use of typically discarded aerial parts. The length (18.25 to 35.00 cm) and thickness (4.59 to 6.66 mm) of the petioles varied by variety, with ‘Hophungmi’ and ‘Tongchaeru’ showing promise for dried vegetable processing due to their longer and thicker petioles. In terms of color, ‘Hophungmi’ and ‘Shinmi’ exhibited high lightness, ‘Tongchaeru’ and ‘Hayangmi’ displayed strong redness, and ‘Pungwonmi’ had high yellowness. Rehydration rates and hardness increased over the harvest period, with ‘Pungwonmi’ and ‘Tongchaeru’ demonstrating excellent rehydration capacity. Additionally, ‘Hayangmi,’ ‘Shinmi,’ ‘Tongchaeru,’ and ‘Hophungmi’ maintained lower hardness levels, appealing to consumers who prefer a softer texture. Notably, the substantial polyphenol content (10.70 to 16.20 mg GAE/g) and flavonoid content (4.79 to 8.11 mg CE/g), along with antioxidant activity (DPPH: 1.11 to 2.14 mg, ABTS: 5.51 to 7.78 mg TE/g), indicate their potential as antioxidant-rich functional foods. This research supports the development of dried vegetable products tailored to consumer preferences.

This study investigated the antioxidant characteristics of sweet potato according to different plant parts and drying methods. The sweet potato plant parts were divided into root tubers, stems, stalks, leaves, and tips, and the drying methods were freeze-drying and hot air drying. Total polyphenol and flavonoid contents and radical scavenging activity of the sweet potato plant parts were significantly different depending on the plant parts and drying methods. The total polyphenol content of freeze-dried sweet potato leaves and tips were 52.76 and 46.19 mg chlorogenic acid equivalents/g sample, and the total flavonoid contents were 222.47 and 214.12 mg quercetin equivalents/g sample, respectively, and decreased with hot air drying. DPPH radical scavenging activity was higher in freeze-drying than hot air drying and was significantly different depending on the plant parts. The ABTS radical scavenging activity of freeze-dried sweet potato leaves and tips were 43.48 and 44.68 mg Trolox equivalents/g sample, respectively, and decreased with hot air drying. Therefore, additional studies on the functionality of using by-products from sweet potato cultivation are needed.

This study examined the quality characteristics of Makgeolli to investigate the availability of Korean sweet potato cultivars as alcoholic beverages. The following sweet potato varieties were used: Gogunmi, Daeyumi, Shingunmi, Shinyulmi, Shincheonmi, Jinyulmi, Jinhongmi, Jeungmi and Pungwonmi; their alcohol contents ranged from 12.20% to 14.20%, with the lowest value in Makgeolli made with Jeungmi and the highest value in Makgeolli made with Jinhongmi. The DPPH radical scavenging activity was in the range of 37.51~77.02%, with the lowest value in Makgeolli made with rice (control) and the highest value in Makgeolli made with Gogunmi. As a result of analyzing the aroma component of sweet potato Makgeolli, 27 kinds of aroma components were detected, and six kinds of alcohols, 13 kinds of esters, four kinds of acids, and four kinds of other compounds were found. Regarding the number of aroma compounds, Makgeolli made with Shinyulmi showed the lowest number with 14 kinds, while Makgeolli made with Pungwonmi showed the highest number with 27 kinds.

본 연구에서는 고구마(Ipomoea batatas L.) 수확 후 버려지는 잔재물의 활용가치를 위해 이들로부터 추출한 발효 추출물과 열수 추출물의 생리활성과 세포독성을 분석 하였다. 추출물의 pH는 모두 산성을 나타내었고, 유기물 함량은 발효 추출물과 열수 추출물에서 각각 0.98%와 0.97%로 비슷하게 나타내었다. 다량원소 중 인산, 칼륨, 칼슘, 마그네슘 성분의 함량은 열수 추출물에서 발효 추출물보다 모두 높게 나왔고, 질소 함량만 두 추출물에서 동일하게 나왔다. 미량원소 함량은 아연을 제외하고 발효 추출물보다 열수 추출물에서 높게 나타내었다. 총 폴리페놀 함량은 열수 추출물에서 60.5±2.7 mg/g로서 발효 추출물의 총 폴리페놀 함량의 22.7±4.2 mg/g 보다 37.8 mg/g 높은 함량을 나타내었다(p<0.05). 총 플라보노이드 함량은 열수 추출물에서 50.7±2.7 mg/g로서 발효 추출물의 함량인 14.0±2.1 mg/g 보다 36.7 mg/g 높은 함량을 나타내어 총 폴리페놀 함량과 마찬가지로 열수 추출물이 발효 추출물보다 높은 함량을 나타내었다(p<0.05). DPPH와 ABTS radical 소거능력은 모두 열수 추출물에서 발효 추출물 보다 높은 항산화력을 보였다(p<0.05). MTT assay를 이용한 추출물의 세포독성 실험에서는 두 추출물의 모든 농도에서 세포독성이 미약한 것으로 확인되었다. 따라서 고구마 수확 후 잔재물의 추출물이 향후 각종 바이오 소재로 이용 시에도 큰 문제가 없을 것이라 판단된다.

Sweet potato (Ipomoea batatas L.) shoot tips grown in vitro were successfully cryopreserved by encapsulationvitrification. Encapsulated explants are very easily manipulated, due to the relatively large size of the alginate beads, and a large number of samples can be treated simultaneously. In this study, the effects of sucrose preculture, cryoprotectant preculture, and post-warm recovery media on regrowth, following liquid nitrogen (LN) exposure, were investigated to establish an efficient encapsulation-vitrification protocol for sweet potato. Shoot tips of plants grown in vitro were precultured in 0.3 M sucrose for 2 d before encapsulation. Encapsulated shoot tips were pre-incubated in liquid MS (Murashige and Skoog) medium containing 0.5 M sucrose for 16 h, before preculturing in sucrose-enriched medium (0.7 M sucrose) for 8 h. Shoot tips were osmoprotected with 35% plant vitrification solution 3 (PVS3) for 3 h, before being dehydrated with PVS3 for 2 h at 25°C. The encapsulated and dehydrated shoot tips were transferred to 2 mL cryotubes, suspended in 0.5 mL PVS3, and plunged directly into liquid N. High levels of shoot formation were obtained for the cv. Yeulmi (65.7%) and Yeonwhangmi (80.3%). The regrowth rates of cryopreserved samples in Yeulmi (78.9%) and Yeonwhangmi (91.3%), following culture on ammonium-free MS medium for 5 d, were much higher than those cultured on standard MS medium (65.7% and 80.3%, respectively). This encapsulation-vitrification is a promising method for the long-term preservation of sweet potato.

본 연구에서는 국내산 자색고구마(Ipomoea batatas L. Lam.) 추출물을 제조하고 이들 추출물에 대하여 항산화 활성을 측정하였다. 자색고구마 추출물은 70% 에탄올 추출물과 그 추출물로부터 에틸아세테이트 분획으로 제조하였다. 추출물 및 분획의 수율은 건조 분말 당 각각 39.2% 및 3.49%이었다. 이들 추출물/분획에 대한 항산화 활성을 확인하기 위해 자유 라디칼(1,1-phenyl-2-picrylhydrazyl, DPPH) 소거활성과 루미놀 발광법을 이용한 총항산화능 그리고 세포손상에 대한 보호효과를 측정하였다. 자유 라디칼 소거활성(FSC50)은 70%에탄올 추출물과 에틸아세테이트 분획이 각각 90.16μg/mL와 7.69μg/mL를 나타내었다. 비교 대조군으로 사용한 (+)-α-tocopherol의 라디칼 소거활성은 8.98μg/mL로, 에틸아세테이트 분획의 라디칼 소거활성이 보다 큼을 알 수 있었다. 루미놀 발광법을 이용한 70% 에탄올 추출물과 에틸아세테이트 분획의 총 항산화능(OSC50)은 각각 5.75μg/mL와 1.92μg/mL이었다. 비교 대조군으로 사용한 항산화 효능이 매우 우수한 L-ascorbic acid의 항산화능은 1.50μg/mL로 추출물의 에틸아세테이트 분획과 유사한 활성을 나타내었다. 1O2로 유도된 사람 적혈구의 세포손상에 대한 보호 효과 실험에서 에틸아세테이트 분획은 농도 의존적(5∼50μg/mL)으로 세포보호 효과를 나타내었다. 에틸아세테이트 분획의 세포보호활성(τ50)은 5μg/mL에서 45.6 min으로 모든 농도에서 비교 대조군인 (+)-α-tocopherol 보다 더 높은 세포보호 효과를 나타내었다. 이상의 결과들로부터 자색고구마의 에틸아세테이트 분획은 뛰어난 항산화능을 나타내며, 이는 피부노화 억제를 위한 항노화 기능성 화장품원료로 응용될 수 있는 가능성을 시사하였다.