Hae-Yeon Choi

A comparative study of antioxidant activity in some Korean medicinal plant used as food materials

The antioxidant properties of ten Korean medicinal plants were analyzed using various antioxidant assays, including their ability to scavenge the DPPH free radical, ABTS radical, superoxide anion, and nitrite, and their reducing powers. The contents of total phenolic compounds and flavonoids were also determined. Of the ten plants, Ulmus pumila L. (UP) and Rubus coreanus Miq. (RC) possessed strong antioxidant activity for all models tested. The half-maximal inhibitory concentration (IC50) for DPPH free radicals of UP and RC was 4.16 and 4.87 μg/mL, respectively. The IC50 for superoxide anion of UP and RC was 145.7 and 136.3 μg/mL, respectively. In addition, the ABTS radical scavenging activity of these materials was higher than that of Trolox. The total phenol content of UP and RC was also significantly higher than in the other herbs. UP had the highest flavonoid content of the ten materials. A correlation was observed between the antioxidant activity and total phenol content.

Antioxidant activity of Salvia miltiorrhiza Bunge, a novel foodstuff

The potential antioxidant activities of different fractions from methanolic extract of Salvia miltiorrhiza (S. miltiorrhiza) Bunge were assayed in vitro. All of the fractions exception of n-hexane and H2O showed a strong antioxidant activity, especially, the ethylacetate (EtOAc) fraction, which showed the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity (IC50=12.12 μg/mL). The results of 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity and ferric reducing antioxidant power (FRAP) assay showed the concentration-dependency and the EtOAc fraction appeared a better result than the other fractions at the same concentration in this studies. And, when the total phenolic contents of fractions were measured, the EtOAc fraction contained the highest level. Meanwhile, correlation analysis indicated a high correlation between the antiradical activity and the total phenolic contents. Additionally, its EtOAc fraction was not induced the DNA damage in mouse lymphoma cells. It suggests that fractions obtained from the methanolic extract of S. miltiorriza Bunge have wide potential for use as sources of antioxidant material.

Antioxidant Activity and Quality Characteristics of Mung Bean Starch Gel Prepared with Ginkgo Nut Powder

Abstract This study was conducted to investigate the effects of persimmon powder on the antioxidant activity and quality characteristics of mung bean starch gel. Mung bean starch gels were prepared with different amounts (0%, 1%, 3%, 5%, 7% and 9%) of persimmon powder. The antioxidant activity was estimated by the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging activity and by the total phenolic acid content in the persimmon powder and mung bean starch gel. For analyzing the quality characteristics, syneresis, pH, color, texture profile analysis, and sensory evaluations were measured. The syneresis in the control group was higher than that in the treated group, but the mung bean starch gel prepared with 9% persimmon powder was higher than that of the control group (p<0.001). The pH, b values, total phenolic acid content, and DPPH free radical scavenging activity of mung bean starch gels significantly increased with increasing persimmon powder (p<0.001), while the L values and a values of the mung bean starch gels significantly decreased with increasing persimmon powder (p<0.001). In the texture profile analysis, the mung bean starch gel with 9% persimmon powder showed significantly lower levels of chewiness, gumminess, and cohesiveness (p<0.05). The hardness and springiness of the mung bean starch gel did not show any significant difference. The consumer acceptability score for the mung bean starch gel prepared with 7% persimmon powder ranked significantly higher than that for the other groups in overall preference, appearance, flavor, and color (p<0.05). From these results, we suggest that persimmon powder is a good ingredient for increasing consumer acceptability and the functionality of mung bean starch gel. Key words: antioxidant activity, persimmon, mung bean starch gel, quality characteristics, sensory evaluations