Stability of anthocyanin extracts from chokeberry, grape, hibiscus, and purple sweet potato in ω-3-fatty acid rich oil-in-water emulsions

• Published in: Food chemistry 2024-11, Vol.459, p.140385, Article 140385
• Main Authors: Klinger, Evelyn, Salminen, Hanna, Bause, Karola, Weiss, Jochen
• Format: Article
• Language: English
• Subjects: Anthocyanins; Anthocyanins - chemistry; Antioxidants; Emulsions - chemistry; Fatty Acids, Omega-3 - analysis; Fatty Acids, Omega-3 - chemistry; Food dyes; Hibiscus - chemistry; Ipomoea batatas - chemistry; Kinetics; Lipid oxidation; Plant extracts; Plant Extracts - chemistry; Vitis - chemistry; Water - chemistry
• ISSN: 0308-8146; 1873-7072; 1873-7072
• DOI: 10.1016/j.foodchem.2024.140385

The food industry is actively investigating the stability of natural red pigments to replace artificial food colorants from all food applications in the near future. In this study, the stability of coloring extracts from chokeberry, grape, hibiscus, and purple sweet potato was investigated in ω-3 fatty acid-rich flaxseed oil-in-water emulsion during storage. The red color of the oil-in-water emulsions faded within 4 days, indicating that the anthocyanin extracts were susceptible to lipid oxidation reactions of the ω-3 fatty acids. The color stability varied between all used extract sources: The chokeberry (degradation constant k = 19.6 h−1) and grape (k = 15.2 h−1) extracts showed similar degradation kinetics, whereas purple sweet potato extract (k = 10.7 h−1) degraded significantly slower, and hibiscus extract (k = 110.2 h−1) significantly faster. The differences can be explained by the different anthocyanins contained in the plant extract, especially by the proportion of acylated anthocyanins. [Display omitted] •Understanding color stability of anthocyanin extracts in lipid-based foods prone to lipid oxidation.•Characterization and anthocyanin identification of plant extracts from chokeberry, grape, hibiscus, and purple sweet potato.•The color stability of anthocyanin extracts in emulsions depends on the molecular configuration of the anthocyanins.•Acylation has a major impact on the stability of anthocyanins in emulsions.•Color stability in lipid-based foods can be facilitated by selecting the right source of pigments for food colors.