Red cabbage anthocyanins: Stability, extraction, biological activities and applications in food systems

•Red cabbage anthocyanins are mainly derivatives of cyanidin-3-diglucoside-5-glucoside.•Solvent extraction is the common method used for red cabbage anthocyanins.•Red cabbage anthocyanins change from reddish-purple to blue-green in pH ranges of 2–9.•Copigmentation and encapsulation are commonly used for stability of RC anthocyanins.•Red cabbage anthocyanins have been widely applied as pH indicator in packaging films. Red cabbage anthocyanins are of great interest as natural food colorants in the food industry; as they represent the color over a broad range of pH-values compared to anthocyanins from other natural sources. It is important to select an appropriate technique with high recovery of anthocyanins from red cabbage, among which extraction with organic solvents is the most applied extraction method. Currently, novel extraction techniques are employed as an alternative to the solvent extraction method, providing advantages such as higher anthocyanin recovery in a shorter time, lower solvent utilization, and minimum quality degradation. However, the incorporation of extracted anthocyanins into foodstuffs and pharmacological products is limited due to their low bioavailability and relative instability toward environmental adverse conditions, such as pH, temperature, enzymes, light, oxygen and ascorbic acid. In addition to increased structural stability of anthocyanins through glycosylation and acylation, their stability could be improved by copigmentation and encapsulation.