Extraction, Purification, and Stability of Anthocyanins from Lonicera caerulea

Abstract:

Objective The influences of environmental factors on the stability of Lonicera caerulea (L. caerulea) anthocyanins were studied to provide a theoretical basis for the processing and storage of anthocyanin-rich beverages and expand the application of L. caerulea in food processing.Method Anthocyanins of L. caerulea were obtained by ultrasonic-assisted extraction and macroporous resin purification. The retention rates of L. caerulea anthocyanins at different temperatures, pH, light conditions, oxidation-reducing agents, preservatives, sugars, and metal ions were determined by the pH differential method, and the environmental stability of L. caerulea anthocyanins was analyzed. At the same time, the thermodynamic characteristics of L. caerulea anthocyanins were analyzed according to the degradation kinetics at different pH and temperatures.Result Anthocyanins were sensitive to 50~90 ℃ and pH 1.0~7.0. The retention rate of anthocyanins decreased with the increases in pH and temperature, and the degradation conformed to the first-order kinetic equation. The thermal stability of anthocyanins exhibited strong at pH 2.0 and pH 3.0, and the thermal degradation of anthocyanins was a non-spontaneous endothermic reaction. Light, oxidation-reducing agents, and preservatives exerted adverse effects on the stability of anthocyanins. Sucrose outperformed glucose in maintaining the stability of anthocyanins at low concentrations and within a short time period. At high concentrations, glucose was more conducive to the stability of anthocyanins than sucrose. The color of anthocyanins was enhanced in the presence of Zn²⁺, Ca²⁺, and Mg²⁺. In contrast, Fe²⁺, Fe³⁺, Cu²⁺, and Al³⁺ destroyed the color.Conclusion Environmental factors such as temperature, pH, light, oxidation-reducing agents, and preservatives have adverse effects on the stability of anthocyanins, and the concentrations and types of sugars added and the types of metal ions have different effects on the stability of anthocyanins. The findings provide a scientific basis for the application of anthocyanins in food processing.