The quality and antioxidant characteristics of apios (Apios americana Medikus) according to different harvest periods and steaming treatment were investigated. The quality and antioxidant characteristics of apios were significantly different depending on harvest periods. Total starch contents was higher in 1st harvesting period as 62.32 g/100 g than other harvesting period. The water binding capacity and water solubility index was higher in 1st harvesting period as 228.65 and 11.29% than other harvesting period. The sucrose and total free sugar contents were 3.64~8.67 and 4.49~9.54 g/100 g, respectively. Total polyphenol and flavonoid contents of apios was the highest 2nd and 4th harvesting period at 4.21 mg GAE/g and 611.11 μg CE/g, respectively. DPPH radical scavenging activity was higher in 1st harvesting period as 84.96 mg TE/100 g than other harvesting period, and decreased as the harvest periods were delayed. ABTS radical scavenging activity and ferric-reducing antioxidant power were 43.81~47.89 mg TE/g and 231.20~264.07 mM/100 g, and increased to 50.58~51.44 mg TE/g and 342.55~384.29 mM/100 g after heat treatment. As a result, it is thought that studies on change of quality and physicochemical characteristics according to cultivation characteristics should be preceded for cultivation stability of apios.

The effect of drying temperature and steaming time on the browning and antioxidant activity of dried Platycodon grandiflorum was investigated. Thirteen treatment conditions were constructed using central composite face-centered design containing 5 center points. Drying temperature and steaming time (as factors) were 45-75oC and 15-45 min. According to treatment conditions, dried Platycodon grandiflorum was assessed for color characteristic, degree of browning, total polyphenol content, and DPPH and ABTS free radical scavenging (as responses). When increasing drying temperature within a given steaming time, dried Platycodon grandiflorum exhibited decreased lightness, increased redness, degree of browning, and total polyphenol contents, and enhanced antioxidant activities. Except for total polyphenol contents and antioxidant activities, steaming time within a given drying temperature exhibited similar effects to those observed in drying temperature. However, steaming time did not likely influence total polyphenol contents and revealed the opposite trends observed for the effect of drying temperature on their antioxidant activities. The overall results suggested that drying temperature was the main factor for changes in the browning and antioxidant activity of dried Platycodon grandiflorum.

Background : Polygonati rhizoma is used for medicine using rhizome of Polygonatum sibiricum Redoute belonging to Liliaceae. This study was carried out to find proper method to establish the guideline of GAP post-harvest management. Methods and Results : Six-years-old polygonati rhizoma harvested in march in Geumsan was used for this study. Steaming was treated for 1, 2, and 3 hours respectively and drying was treated at 45℃, 50℃, 55℃, and 60℃ using hot-air drying machine with checking moisture content at intervals of a day. Moisture contents of polygonati rhizoma according to drying temperature after steaming showed that drying was faster in higher drying temperature treatment after steaming. Moisture content was below 10% as 9.6% and 9.4% at 55℃ drying treatment after steaming for 1 hour and 2 hours respectively. Color value according to treatments was as follows, L-value was lower in longer steaming and higher drying temperature. a-Value was higher in steaming an higher drying temperature. Conclusion : In steaming and hot-air drying treatment to establish the guideline of GAP post-harvest management, moisture content was most proper as 9.4% below 10% in 2-hour steaming and 55℃ hot-air drying for 6 days. L-value was 27.49 and a-value and b-value were 4.38 and 9.73 in this treatment and dried rhizome looked glossy and transparent with higher quality. Proper drying method for polygonati rhizoma was considered as 2-hour steaming and 55℃ hot-air drying for 6 days.

본 연구에서는 우엉의 활용성 증진을 위하여 우엉차를 제조하였으며 기호성과 기능성 증진을 위하여 증숙 및 볶음 처리에 따른 우엉차의 품질특성 및 항산화 활성을 검토하였다. 색도는 증숙처리하여 건조한 우엉차(SHD)보다는 건조 후 볶음 처리를 한 HDR과 증숙 후 건조하여 볶음처리한 SHDR에서 높은 황색도를 나타냈다. pH는 시료 간의 유의적인 차이는 없었으나 탁도에서는 증숙처리 후 건조한 우엉차에서 높은 값을 나타내었으며, 총당의 경우 볶음 처리시 비교적 높은 함량을 보였다. 우엉차의 항산화 활성을 평가하기위해 ABTS 및 DPPH 라디칼 소거능과 환원력을 실시하였으며, 전체적으로 볶음 처리를 하였을 때 활성이 높아지는 경향을 보여 증숙 처리보다는 볶음처리에서 우수한 것으로 나타났다. 또한 우엉차의 관능적 특성으로는 색, 향, 단맛, 떫은 맛, 구수한 맛 및 종합적 기호도를 평가하였으며 증숙처리 후 건조한 구간보다 볶음처리 시 떫은맛이 감소되고 단맛, 구수한 맛이 향상되었고, 풍미, 색상 및 종합적 기호도가 향상되었다. 이러한 결과를 종합하여 볼 때 우엉차 제조 시 열처리는 기능성 및 기호도가 증진시켜 품질의 향상에 영향을 주며 증숙과 볶음 공정을 적절히 적용하여 제조하는 것이 효과적인 것으로 생각된다.