Thermal and pH stability of Justicia spicigera (Mexican honeysuckle) pigments: Application of mathematical probabilistic models to predict pigments stability

• Published in: Food chemistry. Molecular sciences Vol. 6; p. 100158
• Main Authors: Jiménez-González, Oscar, López-Malo, Aurelio, González-Pérez, Julio Emmanuel, Ramírez-Corona, Nelly, Guerrero-Beltrán, José Ángel
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 30.07.2023; Elsevier
• Subjects: Anthocyanins; Color stability; Mexican honeysuckle (Justicia spicigera); Peonidin; Pigments degradation; Time-to-failure model; Peonidin; Mexican honeysuckle (Justicia spicigera); Anthocyanins; Time-to-failure model; Pigments degradation; Color stability
• ISSN: 2666-5662; 2666-5662
• DOI: 10.1016/j.fochms.2022.100158

•Color of J. spicigera turned to orange, pale-red, purple, blue from low to high pH.•Heat decrease/change the color of J. spicigera extracts, mainly for alkaline pHs.•Temperatures above 60 °C increased the thermal degradation of J. spicigera pigments.•Probabilistic models predicted the viability time of Justicia spicigera pigments.•Pigments could be used in foods due to the high range of colors at different pHs. Kinetic and probabilistic (Time-to-Failure, TTF) models were used to predict the color (L*, a*, b* total color differences (ΔE), Hue and Chroma) stability of Justicia spicigera leaves pigments subjected to different temperatures (40 – 80 °C) and pHs (2 – 12). The change in pH caused different hues (from 60° = orange red to 268° = deep-blue) due to the shift effect of anthocyanins in the extract. Temperatures higher than 60 °C increased the color degradation. High heat sensitivity was observed at pH 4 (Ea = 90.27) and 10 (Ea = 154.99 kJ/mol). The Time-to-Failure model for both ΔE and Hue describes the effect of pH and temperature in the J. spicigera extracts. High pHs and temperatures applied to the extracts increased the probability of showing ΔEs > 4 or Hue changes over 20 %. Nearby the neutral region of pH, pigments of J. spicigera were more stable. The TTF model might be a useful tool to describe and predict the behavior of pigments added to foods.