Anthocyanins, Flavonols, and Free Radical Scavenging Activity of Chinese Bayberry (Myrica rubra) Extracts and Their Color Properties and Stability
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- 作者：Jinsong Bao ; Yizhong Cai ; Mei Sun ; Guoyun Wang ; and Harold Corke
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2005
- 出版时间：March 23, 2005
- 年：2005
- 卷：53
- 期：6
- 页码：2327 - 2332
- 全文大小：148K
- 年卷期：v.53,no.6(March 23, 2005)
- ISSN：1520-5118
文摘
Characterization of anthocyanins and flavonols and radical scavenging activity assays of extractsfrom four Chinese bayberry (Myrica rubra) varieties with different fruit colors were carried out. Onedominant anthocyanin and three major flavonols were isolated by HPLC, and cyanidin-3-O-glucosideand two of three flavonols, myricetin and quercetin-3-O-rutinoside, were identified by cochromatography with authentic standards. Both DPPH
and ABTS+ cation assays indicated that the blackvarieties (Biji and Hunan) demonstrated much higher radical scavenging activities than the pink(Fenhong) and yellow (Shuijing) varieties, which may be attributed to much higher levels ofanthocyanins, flavonoids, and total phenolics in the black varieties. Biji and Hunan had 6.49 and6.52 mM Trolox equivalent antioxidant capacity (TEAC) per 100 g of fresh weight, whereas the pink(Fenhong) and yellow (Shuijing) bayberries had 1.32 and 1.31 mM TEAC/100 g. Different fruit colorwas reflected by the surface color and pigment extract color. Color stability of the pigment wasdependent on pH, and the pigment was more stable at low pH (pH ~1.5). The lightness (L*) increasedwhile the chroma (C value) decreased with increase of pH until pH 5, but higher pH caused a smalldecrease for L* and an increase for C.Keywords: Chinese bayberry; Myrica rubra; flavonoids; anthocyanins; flavonols; antioxidant; radicalscavenging activity; color; stability
and ABTS+ cation assays indicated that the blackvarieties (Biji and Hunan) demonstrated much higher radical scavenging activities than the pink(Fenhong) and yellow (Shuijing) varieties, which may be attributed to much higher levels ofanthocyanins, flavonoids, and total phenolics in the black varieties. Biji and Hunan had 6.49 and6.52 mM Trolox equivalent antioxidant capacity (TEAC) per 100 g of fresh weight, whereas the pink(Fenhong) and yellow (Shuijing) bayberries had 1.32 and 1.31 mM TEAC/100 g. Different fruit colorwas reflected by the surface color and pigment extract color. Color stability of the pigment wasdependent on pH, and the pigment was more stable at low pH (pH ~1.5). The lightness (L*) increasedwhile the chroma (C value) decreased with increase of pH until pH 5, but higher pH caused a smalldecrease for L* and an increase for C.Keywords: Chinese bayberry; Myrica rubra; flavonoids; anthocyanins; flavonols; antioxidant; radicalscavenging activity; color; stability