Walnut pellicle color affects its phenolic composition: Free, esterified and bound phenolic compounds in various colored-pellicle walnuts was written by Wang, Ruohui;Tian, Xin;Li, Qingyang;Liao, Liuwei;Wu, Shutian;Tang, Fubin;Shen, Danyu;Liu, Yihua. And the article was included in Journal of Food Composition and Analysis in 2022.Recommanded Product: (2R,2’R,3R,3’R,4R)-2,2′-Bis(3,4-dihydroxyphenyl)-[4,8′-bichromane]-3,3′,5,5′,7,7′-hexaol The following contents are mentioned in the article:
Although walnut kernels are a rich source of phenolic compounds, little is known about the profiles of phenolic compound forms in various colored-pellicle walnuts, which may be important for product development and utilization. In this work, the free, esterified and bound forms of phenolic compounds in various colored-pellicle walnuts were identified using ultra-high-performance liquid chromatog. coupled to tandem mass spectrometry (UHPLC-MS/MS). The total phenolics (TPCs) in pellicle, kernel without pellicle and whole kernel (with pellicle) were presented in the free form (62.6%) and bound form (1.30 %-12.2 %). Pos. correlations were found between the TPCs of three forms in pellicle and the pellicle color, with correlation coefficients of 0.920, 0.990 and 0.940. In addition, the phenolic compounds in free form in the whole kernel (with dark pellicle) demonstrated notable advantages in flavanols, flavones and flavonols contents, particularly (+)-catechin (C) (40.7 μg/g) and epicatechin (EC) (25.8g/g), which were 2-153 times higher than other phenolic compounds in free form. Furthermore, the dark group of esterified phenolic acids showed advantages, particularly ellagic acid (428 μg/g) and gallic acid (130 μg/g). This study involved multiple reactions and reactants, such as (2R,2’R,3R,3’R,4R)-2,2′-Bis(3,4-dihydroxyphenyl)-[4,8′-bichromane]-3,3′,5,5′,7,7′-hexaol (cas: 29106-49-8Recommanded Product: (2R,2’R,3R,3’R,4R)-2,2′-Bis(3,4-dihydroxyphenyl)-[4,8′-bichromane]-3,3′,5,5′,7,7′-hexaol).
(2R,2’R,3R,3’R,4R)-2,2′-Bis(3,4-dihydroxyphenyl)-[4,8′-bichromane]-3,3′,5,5′,7,7′-hexaol (cas: 29106-49-8) belongs to alcohols. Alcohols are weak acids. The most acidic simple alcohols (methanol and ethanol) are about as acidic as water, and most other alcohols are somewhat less acidic. Secondary alcohols are easily oxidized without breaking carbon-carbon bonds only as far as the ketone stage. No further oxidation is seen except under very stringent conditions.Recommanded Product: (2R,2’R,3R,3’R,4R)-2,2′-Bis(3,4-dihydroxyphenyl)-[4,8′-bichromane]-3,3′,5,5′,7,7′-hexaol
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts