The aim of this study was to investigate the method validation for the determination of loganin content in Cornus officinalis (CO). This medicinal plant reportedly mainly included loganin. The specificity, linearity, precision, accuracy, limit of detection (LOD), and quantification (LOQ) were measured by HPLC/DAD. Our results showed that high linearity in the coefficient of calibration correlation (R2) for loganin standard was 1. LOD and LOQ for loganin were 0.007 and 0.026 mg/mL, respectively. The recovery rate of loganin was revealed to be in the high range of 95.14-105.45%. The relative standard deviation of intra- and inter-day precision of loganin in CO was 1.8% and 2.3%, respectively. The loganin content of CO from Gurye, Uiseng, Ichoen, and China were 7.81, 3.41, 7.42, and 6.52 mg/g, respectively. In conclusion, these methods were validated for the detection of loganin in CO.

This study was performed to investigate the content of carotenoid (α-carotene, β-carotene, β-cryptoxanthin, capxanthin, lutein, lycopene, zeaxanthin) and physicochemical characteristics (size, color, dietary fiber, total tannin content) of unripen and ripen persimmons (Diospyros kaki) by seven cultivars. The length of the unripen and ripen persimmons ranged from 40.87-64.75 and 48.80-80.29 cm, the width were from 44.03 to 66.73 and 57.65 to 91.53 cm, respectively. Ripen persimmons were showed in the highest Hunter’s L, a and b values. Total tannin content were resulted of unripen- and ripen persimmons ranged from 7.58 to 19.80 and 2.36 to 5.85 mg/g. Total carotenoid content were from 1.09 to 6.45 and 7.46 to 29.46 μg/g, respectively. From the above results, unripen- and ripen persimmon fruit could be useful for the health functional food.