Preparation of Lipid-Soluble Bilberry Anthocyanins through Acylation with Cinnamic Acids and their Antioxidation Activities

Abstract

To enable the use of anthocyanins in food with high oil content, bilberry anthocyanins were acylated with cinnamic acids to address their poor lipid solubility. Structural analyses based on Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and 1 H nuclear magnetic resonance analyses indicated that cinnamic acids were efficiently grafted onto 6-OH of glucoside and galactoside and 5-OH of arabinose through an esterification reaction. The higher the dose of the acylating agent, the higher the acylation degree (AD) and the lower the total anthocyanidin content (TAC) of bilberry anthocyanins. An-Ci4 presented the highest AD value (6.61%), and An-Ci3 exhibited the lowest TAC value (50.16 mg/g). After acylating with lipophilic cinnamic acids, the lipid solubility of acylated bilberry anthocyanins significantly improved. The color of the native bilberry anthocyanin solution dissolved in ethyl acetate and dioxane was transparent. By contrast, the acylated anthocyanin solution dissolved in these solvents was unmistakably red. In terms of the antioxidant activity, acylated bilberry anthocyanins demonstrated inferior performance in 2,2-diphenyl-1-picrylhydrazyl (DPPH) clearance but a better inhibition ratio in β-carotene bleaching assay compared with native bilberry anthocyanins. As AD value increased, the DPPH clearance of acylated anthocyanins decreased and their inhibition ratio increased in β-carotene bleaching assay.

Acetylated pelargonidin-3-O-glucoside exhibits promising thermostability, lipophilicity, and protectivity against oxidative damage by activating the Nrf2/ARE pathway

“…Although the recent study mainly focused on modifications of C3G, more different types of acylation of Pg3G need to be further explored. 40,41 Moreover, the acylation of anthocyanins had been reported to play a critical role in the increase of cell membrane affinity, 7 demonstrating that the cellular absorption of anthocyanin could potentially be enhanced by acylation. Thus, based on this hypothesis, whether the biological activity of acylated Pg3G can be improved was further evaluated.…”

Hydrophobic Interface Starch Nanofibrous Film for Food Packaging: From Bioinspired Design to Self-Cleaning Action

“…Figure 5a shows the FTIR spectrum of raw starch materials and SNF before and after STA coating. The FTIR spectrum of starch had a main wide absorption band at ∼3382 cm −1 , which corresponded to the O−H stretching; 43 another peak at 1643 cm −1 was attributed to bound water molecules. 44,45 Peaks at ∼1157 and ∼1014 cm −1 were ascribed to the C−O stretching vibration of the pyranose ring in the glucose monomer.…”

Cold Stress in Citrus: A Molecular, Physiological and Biochemical Perspective

“…As previously cited, pigmented citrus varieties turn out to have a high anthocyanin content, which makes them very interesting to study. Anthocyanins are water-soluble pigments from the flavonoid family and are to processes like development, defense and adaptation to unfavorable environments, such as damage from excess UV light and cold [151], as stated above. Anthocyanins are glycosides and acylglycosides of anthocyanidins.…”