Identification of health-promoting bioactive phenolics in black walnut using cloud-based metabolomics platform

Authors: VU, DANH - University Of Missouri; PARK, JIHYUN - University Of Missouri; VAN HO, KHANH - University Of Missouri; SUMNER, LLOYD - University Of Missouri; LEI, ZHENTIAN - University Of Missouri; GREENLIEF, C. MICHAE - University Of Missouri; MOONEY, BRIAN - University Of Missouri; COGGESHALL, MARK - Us Forest Service (FS); HO LIN, CHUNG - University Of Missouri

Submitted to: Journal of Food Measurement and Characterization
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2019
Publication Date: 11/18/2019
Citation: Vu, D.C., Park, J., Van Ho., Sumner., W. Lei., Greenlief, C., Mooney, B., Coggeshall, M.V., Ho Lin, C. 2019. Identification of health-promoting bioactive phenolics in black walnut using cloud-based metabolomics platform. Journal of Food Measurement and Characterization. 14:770–777. https://doi.org/10.1007/s11694-019-00325-y.
DOI: https://doi.org/10.1007/s11694-019-00325-y

Interpretive Summary: Black walnut is one of the most valuable tree species endemic to North America. The tree provides not only high-quality lumber, but also high-value nuts with unique flavor. Research has provided strong evidence that black walnut kernels contain a variety of nutritionally and medicinally important compounds. This study aimed to identify bioactive phenolics of eleven black walnut cultivars using a cloud-based metabolomics platform. In total, 49 phenolics previously known to promote health benefits were putatively identified in the black walnut kernels. The relative abundance of these phenolics differed significantly among the studied cultivars. Antioxidant activity of the 'Mystry' cultivar extract was highest among the six examined cultivars. This study demonstrated that metabolite profiling could be an efficient analytical tool to identify potential health-promoting compounds and investigate metabolite variations among black walnuts.

Technical Abstract: This study aimed to identify bioactive phenolics of eleven black walnut cultivars using a cloud-based metabolomics platform. The metabolomics software platform, XCMS Online, was used to incorporate peak detection, peak grouping, spectra extraction and non-linear retention time correction/alignment. In total, 49 phenolics previously known to promote health benefits were putatively identified in the black walnut kernels. The relative abundance of these phenolics differed significantly among the studied cultivars. Antioxidant activity of the Mystry extract was highest among the six examined cultivars. In addition, the antioxidant activities were found to be positively correlated with the relative abundance of thirteen phenolics. The principal component analysis provided a visible differentiation in phenolic metabolite profiles among the examined black walnuts. The results of hierarchical cluster analysis showed three clusters of black walnuts. Mystry differed from the other cultivars due to its highest relative abundance of gallic acid and ellagitannins. This study demonstrated that metabolite profiling could be an efficient analytical tool to identify potential health-promoting compounds and investigate metabolite variations among black walnuts.