Abstract

This study was performed to investigate the antioxidative properties of sea buckthorn (Hippophae rhamnoides L.; leaf, fruit and stem) and the quality characteristics of brown rice sulgidduk prepared using a powder of sea buckthorn leaves. First, the antioxidative activities of sea buckthorn were measured to choose the most effective part of this plant. By analyzing the measured values, we concluded that the effective part of sea buckthorn was its leaves. The $IC_{50}$ value of the DPPH radical scavenging activity and the ABTS radical scavenging activity in sea buckthorn leaves were $7.78{\mu}g/mL$ and $264.04{\mu}g/mL$, respectively. The total polyphenol and total flavonoid contents of sea buckthorn leaves were 3.80 mg/mL and .19 mg/mL, respectively. Therefore, the brown rice sulgidduk was prepared using a powder of sea buckthorn leaves in the weight ratio of 0%, .5%, 1.0%, 1.5%, 2.0% and 2.5%. For analyzing the quality characteristics of the prepared sulgidduk, proximate compositions, color and texture profiles were measured and a sensory evaluation was conducted. With an increase in the added content of the sea buckthorn leaf powder (SBLP), the L-value significantly decreased while the a-value and the b-value increased. In the case of texture profiles, the control group (control A) had a higher score for hardness than the case groups in which the SBLP was added. However, springiness, chewiness and adhesiveness were not significantly different among the groups. In the sensory evaluation, the sample containing 1.5% SBLP yielded the best results. Therefore, we suggest that the powder of sea buckthorn leaves is a good ingredient for increasing the consumer acceptability and functionality of sulgidduk.

Keywords

• antioxidative activity;
• sea buckthorn leaf powder;
• sulgidduk;
• quality characteristics