Carotenoids in dehydrated persimmon: Antioxidant activity, structure, and photoluminescence

• Published in: Food science & technology 2021-05, Vol.142, p.111007, Article 111007
• Main Authors: González, Cristina M., García, Adrián López, Llorca, Empar, Hernando, Isabel, Atienzar, Pedro, Bermejo, Almudena, Moraga, Gemma, Quiles, Amparo
• Format: Article
• Language: English
• Subjects: Fluorescence; Hot air drying; Light microscopy; Rojo brillante; β-carotene
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.111007

In this study, the effect of two hot air drying conditions (40 °C for 23 h and 60 °C for 9 h) on the content, antioxidant activity, microstructure, and luminescence properties of persimmon carotenoids in three ripening stages was studied. Based on the results from total carotenoids content and HPLC analysis, the carotenoid's content increased with the advance of ripening, highlighting the β-cryptoxanthin fraction. In addition, drying treatments did not affect the carotenoid content and profile but decreased the antioxidant activity. Microstructural studies showed that the ripening progress and/or drying treatments, led persimmon tissues to lose integrity, allowing the diffusion of carotenoids and their degradation. Photoluminescence measurements evidenced the synthesis of β-cryptoxanthin during the fruit ripening. After drying, a new emitting specie at 340 nm was attributed to the carotenoid's isomerisation while the emission at 500 nm experienced a shift that was related to the formation of thermal degradation products. Both facts could explain the loss of antioxidant activity in persimmon submitted to drying treatments. In this sense, photoluminescence, in combination with spectrophotometric, chromatographic and structural techniques, helps to understand the phenomena caused by both, ripening and drying treatments, in the persimmon's carotenoids fraction. •Drying treatment influenced the antioxidant activity but not carotenoid content.•Drying treatment allowed the diffusion of carotenoids from persimmon tissue.•Luminiscence showed two emission wavelengths regarded to cis/trans carotenoids forms.•Luminescence allowed to support other techniques to study evolution of carotenoids.