Anthocyanins of Asian bird cherries ( Prunus nepalensis L.): An untapped source for natural food colorants

Abstract

Interest in the processing and application of natural anthocyanin pigments is intensifying. In this work, we developed a protocol for obtaining anthocyanins from wild Asian bird berries (Prunus nepalensis L.) using ultrasound‐assisted extraction (UAE) and response surface methodology. The chemical profile, antioxidant activity, and co‐pigmentation of the anthocyanin extract were also investigated. The results showed that the maximum anthocyanin yield was achieved under optimal conditions of 60°C, 300 W ultrasonic power, and 30 min ultrasonic time. Using UHPLC‐ESI‐MS2 analysis, two major anthocyanins and 19 other phenolics were identified in the anthocyanin extract, which displayed significant antioxidant potential in vitro. In addition, the color stability of the anthocyanin extract was thermodynamically improved by phenolic acids and organic acids where oxalic acid was the most effective co‐pigment. These results revealed that Asian bird berries anthocyanins could be effectively recovered by UAE, and further stabilized by co‐pigments. Novelty impact statement The chemical instability of anthocyanins poses a significant challenge for their preparation and implementation as food colorants. In this study, the anthocyanins obtained from P. nepalensis L. fruits were modulated, for the first time, with the help of co‐pigments such as oxalic acid, citric acid, ascorbic acid, gallic acid, tannic acid, and pyrogallic acid. These results could open up the possibility of large‐scale applications of anthocyanins sourced from many uncultivated plants.

Color-Stabilizing Effects and Mechanisms of Schisandra Lignans on the Anthocyanins Enriched with Petunidin-3-O-glucoside

“…Generally, the color intensity values gradually increased with the increase of lignan concentration, while the color hue values showed an opposite trend . A similar trend was also observed in our previous study, which stabilized the P3G-enriched anthocyanins using phenolic and organic acids . Furthermore, the increase of color intensity was closely related to the hyperchromic effect and bathochromic shift documented above.…”

“…14−17 Our previous study also showed several phenolic acids and organic acids capable of stabilizing petunidin-3-O-glucoside (P3G) extracts from Asian bird cherries (Prunus nepalensis L.). 18 As recently reported by Zhao, 19 delphinidin-3-O-glucoside (D3G) and P3G were less stable than the other two common homologues like cyanidin-3-O-glucoside (C3G) and malvidin-3-O-glucoside (M3G) in model wine solution, where they can be stabilized by gallic acid, (−)-epicatechin, and quercetin-3-O-glucoside, respectively. Given the rich diversity of phenolic molecules in nature, it is clear that there is substantial untapped potential for more phenolics less studied to act as copigments.…”

“…The copigmentation analysis followed previously detailed procedures by our laboratory . In short, the copigmentation buffer was made of disodium hydrogen phosphate (0.1 M) and citric acid (0.1 M) and regulated to a pH of 3.3.…”

“…P3G-enriched anthocyanins were prepared and identified according to a previous report from our laboratory, with the P3G amount of 27.79 g C3G per kg DW. 18 Chromatographic-grade acetonitrile was purchased from Tianjin Kermel Chemical Reagent Co., Ltd. (Tianjin, China). The standards of schisandrol A, schisandrol B, schisantherin A, schisantherin B, gomisin J, schisandrin A, schisandrin B, schisandrin C, and schisanhenol were delivered with purities exceeding 95.0% from Beijing Solarbio Science and Technology Co., Ltd. (Beijing, China).…”

“…The specific experimental procedures for measuring total anthocyanin content (TAC), total phenolic content (TPC), and total flavonoid content (TFC) were identical to those previously reported by our laboratory. 18 The results of TAC, TPC, and TFC were expressed as mg of cyanidin-3-O-glicoside (C3G) per g dry weight (DW) of dried fruit, mg of gallic acid equivalent (GAE) per g DW of dried fruit, and mg of rutin equivalent (RE) per g DW of dried fruit, respectively. When measuring TAC, the obtained extracts were diluted twice with buffers of pH 1.0 (potassium chloride, 0.1 M) and pH 4.5 (sodium acetate, 0.5 M), respectively.…”