Quantification of free and bound carotenoids in pigmented fruit and vegetable matrices has previously been challenging due to carotenoid instability, degradation during extraction, and the prevalence of predominant carotenoid esters. The aim of the present study was to develop an optimized extraction procedure that minimises the loss of free and bound carotenoids by utilising a combination of extraction solutions, followed by an improved saponification process. A mixture of hexane, dichloromethane, ethanol and water achieved the highest extraction efficiency (>97%) from the chili/capsicum matrix. The study also addressed the previously unexplained loss of carotenoids during saponification by adding phosphate buffer to the sample–extract mixture, which prevented soap micelle formation. Additionally, the duration and temperature of the saponification procedure and pH of the final extraction solution were further optimised to achieve a higher total carotenoid recovery. A total of 48 free and bound carotenoids were identified in the capsicum fruit samples using UHPLC-DAD-MS/MS. The total carotenoid content within six bell pepper and chili fruits ranged between 1.63 (green bell capsicum) and 32.08 mg/100 g fresh weight (sweet red baby capsicum). The current methodology potentially could be used in a broad range of different carotenoid-containing matrices and commodities.

Mango (Mangifera indica L.) cultivars display a wide range of ripe flesh colours, from deep-orange to pale-yellow, largely linked to differences in carotenoid profiles. This study examined the relationship between carotenoid profile and flesh colour across 25 mango cultivars. Flesh colour was measured using chroma (intensity) and hue angle (colour) and correlated with carotenoid content quantified using ultra-high performance liquid chromatography with diode-array detection (UHPLC-DAD). Chroma and hue angle displayed a second-order inverse polynomial relationship with chroma increasing as hue angle decreased. At lower hue angles, a wider range of chroma values was observed. Regression analysis showed that chroma correlated most strongly with total carotenoid concentration (TCC) (R² = 0.54), followed by total orange carotenoid concentration (R² = 0.47) and all-trans β-carotene concentration (R² = 0.45). Hue angle correlated most strongly with the total orange carotenoid concentration (R² = 0.76), then all-trans β-carotene concentration (R² = 0.73) and TCC (R² = 0.64). Interestingly, pale-yellow cultivars often exhibited low carotenoid concentrations, high titratable acidity and low soluble solids, suggesting incomplete ripening may also contribute to their pale colouration. These results provide insight into carotenoid-colour relationships and offer direction for phytochemical-based breeding programmes targeting mango flesh colour traits.