Comparison of phenolic compounds extracted from Diaphragma juglandis fructus, walnut pellicle, and flowers of Juglans regia using methanol, ultrasonic wave, and enzyme assisted-extraction. (15th August 2020)

• Record Type: Journal Article
• Authors: Zhang, Yi-Ge; Kan, Huan; Chen, Sheng-Xiong; Thakur, Kiran; Wang, Shaoyun; Zhang, Jian-Guo; Shang, Ya-Fang; Wei, Zhao-Jun
• Is Part Of: Food chemistry. Volume 321(2020)
• Publication Date: 2020-08-15
• Subjects: p-Hydroxybenzoic (PubChem: CID 15044216) -- Protocatehuic acid (PubChem: CID 72) -- p-coumaric acid (PubChem: CID 637542) -- Hydroxymandelic acid (PubChem: CID 328) -- 7-hydroxy-methylcoumarin (PubChem: CID 15028257) -- Caffeic acid (PubChem: CID 689043) -- Methyl gallate (PubChem: CID 7428) -- Azelaic acid (PubChem: CID 2266) -- Quinic acid (PubChem: CID 6508) -- Syringic acid (PubChem: CID 10742) -- Chrysin (PubChem: CID 5281607) -- Luteolin (PubChem: CID 5280637) -- (+)-catechin (PubChem: CID 9064) -- Ellagic acid (PubChem: CID 5281855) -- Quercetin (PubChem: CID 5280343) -- Taxifolin (PubChem: CID 439533) -- Monogalloyl-glucose (PubChem: CID 71308210) -- Coumaroylquinic acid (PubChem: CID 9945785) -- Afzelin (PubChem: CID 5316673) -- Quercitrin (PubChem: CID 5280459) -- Myricitrin (PubChem: CID 5281673) -- Isoquercitrin (PubChem: CID 5280804) -- (epi)gallocatechin-(epi)catechin (PubChem: CID 176920) -- Trigalloyl-glucose (PubChem: CID 90116889) -- Tetragalloyl-glucose (PubChem: CID 442692) -- Naringin (PubChem: CID 442428); Diaphragma juglandis fructus -- Walnut pellicle -- Flower of Juglans regia -- Phenolic compounds -- Antioxidant; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2020.126672
• Languages: English
• ISSNs: 0308-8146

Abstract

Graphical abstract: Highlights: 50 phenolics were identified by HPLC-MS/MS, with 41 from DJF, 32 from WP, and 29 from FJR. The effect of tissue parts on the composition and content of phenolic substances was greater than that of extraction methods. The contents of total phenolic compounds, flavonoids and tannins in WP was higher than those in DJF and FJR. WP extractions displayed the highest antioxidant ability. Abstract: The phenols in Diaphragma juglandis fructus (DJF), walnut pellicle (WP), and flowers of Juglans regia (FJR) from walnut were extracted using three methods (methanolic condensation reflux extraction, ultrasonic wave extraction, and enzyme assisted-extraction), and phenolics and antioxidant capacities of different extractions were compared. Overall, 50 phenolics were identified by HPLC-MS/MS with 41 compounds in DJF, 32 in WP, and 29 in FJR. It was observed that tannins in WP was higher than those in DJF and FJR. As for PCA, more than 70% of the variance was explained with the obvious comparison between the phenolic constituents. The phenolics in walnut contributed to remarkable antioxidant effect, with the highest effect observed in WP. This study presents the analysis and comparison of the phenols can be further extended for the development of functional walnut instant foods.