Antioxidant potential of Juglans nigra, black walnut, husks extracted using supercritical carbon dioxide with an ethanol modifier

作者：Wenzel Jonathan; Samaniego Cheryl Storer; Wang Lihua; Burrows Laron; Tucker Evan; Dwarshuis Nathan; Ammerman Michelle; Zand Ali

来源：Food Science & Nutrition, 2017, 5(2): 223-232.

DOI：10.1002/fsn3.385

<jats:title>Abstract</jats:title><jats:p>The black walnut, <jats:italic>Junglas nigra,</jats:italic> is indigenous to eastern North America, and abscission of its fruit occurs around October. The fruit consists of a husk, a hard shell, and kernel. The husk is commonly discarded in processing, though it contains phenolic compounds that exhibit antioxidant and antimicrobial properties. For this study, black walnut husks were extracted using supercritical carbon dioxide with an ethanol modifier. The effects of temperature, ethanol concentration, and drying of walnut husks prior to extraction upon antioxidant potential were evaluated using a factorial design of experiments. The solvent density was held constant at 0.75 g/<jats:styled-content style="fixed-case">mL</jats:styled-content>. The optimal extraction conditions were found to be 68°C and 20 wt‐% ethanol in supercritical carbon dioxide. At these conditions, the antioxidant potential as measured by the ferric reducing ability of plasma (<jats:styled-content style="fixed-case">FRAP</jats:styled-content>) assay was 0.027 mmol trolox equivalent/g (mmol <jats:styled-content style="fixed-case">TE</jats:styled-content>/g) for dried walnut husk and 0.054 mmol <jats:styled-content style="fixed-case">TE</jats:styled-content>/g for walnut husks that were not dried. Antioxidant potential was also evaluated using the total phenolic content (<jats:styled-content style="fixed-case">TPC</jats:styled-content>) and 1,1‐diphenyl‐2‐picryl‐hydrazyl (<jats:styled-content style="fixed-case">DPPH</jats:styled-content>) assays and the <jats:styled-content style="fixed-case">FRAP</jats:styled-content> assay was found to linearly correlate to the <jats:styled-content style="fixed-case">TPC</jats:styled-content> assay.</jats:p>

• 出版日期2017-3