Cocktail enzyme-assisted alkaline extraction and identification of jujube peel pigments

Dongbei Shen; Xiaohong Kou; Caie Wu; Gongjian Fan; Tingting Li; Jinfeng Dou; Hanbo Wang; Jinpeng Zhu

doi:10.1016/j.foodchem.2021.129747

Cocktail enzyme-assisted alkaline extraction and identification of jujube peel pigments

Food Chem. 2021 Apr 8:357:129747. doi: 10.1016/j.foodchem.2021.129747. Online ahead of print.

Authors

Dongbei Shen¹, Xiaohong Kou², Caie Wu³, Gongjian Fan⁴, Tingting Li⁴, Jinfeng Dou⁵, Hanbo Wang⁶, Jinpeng Zhu⁶

Affiliations

¹ College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, PR China. Electronic address: SDB@njfu.edu.cn.
² School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
³ College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, PR China; Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China. Electronic address: wucaie@njfu.edu.cn.
⁴ College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, PR China; Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China.
⁵ College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, PR China; College of Life and Health Sciences, Anhui Science and Technology University, Fengyang 233100, China.
⁶ College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, PR China.

PMID: 33892359
DOI: 10.1016/j.foodchem.2021.129747

Abstract

Jujube peel (JP) is rich in pigments, which appears red to deep red in color. This study optimized conditions for cocktail enzyme-assisted extraction of jujube peel pigments based on response surface method (RSM). A Box-Behnken design (BBD) was utilized to analyze the effects of buffer liquid volume (BLV), pH, temperature, and incubation time on the total polyphenols content (TPC), total flavonoids content (TFC) and color (L*, a*, b*). Optimal extraction conditions, for the highest concentrations of TPC, TFC and a* values, were 16 mL BLV, pH 7.0, temperature 43 °C, and incubation time 97 min. Finally, concentrations and identities of the eight main constituents (p-coumaric acid, (-)-epicatechin, quercetin-3-O-robinobioside, rutin, kaempferol 3-O-robinobioside, quercetin 3-O-α-l-arabinosyl-(1 → 2)-α-l-rhamnoside, quercetin 3-O-β-d-xylosyl-(1 → 2)-α-l-rhamnoside, quercetin) in jujube peel pigments were determined using UPLC-MS/MS. The study provides guidance for valorisation of jujube peel, specifically valuable food-safe pigments, during industrial production.

Keywords: Jujube peel; Pigments; Response surface method; UPLC-MS/MS.

Published by Elsevier Ltd.