Food Research International 179 (2024) 114011 Available online 11 January 2024 0963-9969/© 2024 Elsevier Ltd. All rights reserved. A critical review on the stability of natural food pigments and stabilization techniques Tharuka Wijesekara a, b , Baojun Xu a, * a Food Science and Technology Program, Department of Life Sciences, BNU-HKBU United International College, Zhuhai, Guangdong 519087, China b Department of Food Science and Technology, University of Peradeniya, Peradeniya 20400, Sri Lanka A R T I C L E INFO Keywords: Pigment stability Anthocyanins Betalains Carotenoids Chlorophyll ABSTRACT This comprehensive review article delves into the complex world of natural edible pigments, with a primary focus on their stability and the factors that infuence them. The study primarily explores four classes of pigments: anthocyanins, betalains, chlorophylls and carotenoids by investigating both their intrinsic and extrinsic stability factors. The review examines factors affecting the stability of anthocyanins which act as intrinsic factors like their structure, intermolecular and intramolecular interactions, copigmentation, and self-association as well as extrinsic factors such as temperature, light exposure, metal ions, and enzymatic activities. The scrutiny extends to betalains which are nitrogen-based pigments, and delves into intrinsic factors like chemical composition and glycosylation, as well as extrinsic factors like temperature, light exposure, and oxygen levels affecting for their stability. Carotenoids are analyzed concerning their intrinsic and extrinsic stability factors. The article empha- sizes the role of chemical structure, isomerization, and copigmentation as intrinsic factors and discusses how light, temperature, oxygen, and moisture levels infuence carotenoid stability. The impacts of food processing methods on carotenoid preservation are explored by offering guidance on maximizing retention and nutritional value. Chlorophyll is examined for its sensitivity to external factors like light, temperature, oxygen exposure, pH, metal ions, enzymatic actions, and the food matrix composition. In conclusion, this review article provides a comprehensive exploration of the stability of natural edible pigments, highlighting the intricate interplay of intrinsic and extrinsic factors. In addition, it is important to note that all the references cited in this review article are within the past fve years, ensuring the most up-to-date and relevant sources have been considered in the analysis. 1. Introduction 1.1. Defnition and classifcation of edible natural pigments Edible natural pigments are organic compounds found in various plants, fruits, vegetables, and other natural sources that contribute to the coloration of food products. These pigments are typically extracted from these sources and used as coloring agents in the food industry (Di Salvo et al., 2023). They are distinct from synthetic food colorants. Edible colorants are primarily employed in food processing to counteract po- tential color loss that may occur during the manufacturing process. Consequently, it is essential to employ suitable techniques for rejuvenating the visual appeal of these products and thereby enhancing their presence in the expanding food industry (Malabadi et al., 2022). These natural pigments also serve the purpose of enhancing or intensi- fying the original color, ensuring consistent coloration, bestowing color to initially colorless foods, and linking these procedures to overall im- provements in food quality (Lu et al., 2021). Edible natural pigments do more than just add color as they also bring the potential for benefcial health effects as intriguing bioactive substances (Pailli` e-Jim´ enez et al., 2020). These substances have a multitude of practical uses. Research has revealed that synthetic colorants can exert adverse impacts on both human well-being and the environment (Zerin et al., 2020). Synthetic dyes are resistant to biodegradation, have the potential for Abbreviations: AE, Activation energy; CSE, Conventional solvent extraction; EDTA, Ethylenediaminetetraacetic acid; FTIR, Fourier transform infrared spectros- copy; HPLC, High-performance liquid chromatography; NCCs, Nonfuorescent chlorophyll catabolites; PAO, Pheophorbide a Oxygenase; PCL, Polycaprolactone; PPO, Polyphenol oxidase; SACB, Senescence-associated chlorophyll breakdown; UV, Ultraviolet; UV–Vis, Ultraviolet–Visible; WPI, Whey Protein Isolate. * Corresponding author at: 2000 Jintong Road, Tangjiawan, Zhuhai, Guangdong 519087, China. E-mail address: baojunxu@uic.edu.cn (B. Xu). Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres https://doi.org/10.1016/j.foodres.2024.114011 Received 4 November 2023; Received in revised form 5 January 2024; Accepted 9 January 2024