Curing and low-temperature combined post-harvest storage enhances anthocyanin biosynthesis in blood oranges

• Published in: Food chemistry 2021-04, Vol.342, p.128334-128334, Article 128334
• Main Authors: Carmona, Lourdes, Alquézar, Berta, Diretto, Gianfranco, Sevi, Filippo, Malara, Tatiane, Lafuente, M. Teresa, Peña, Leandro
• Format: Article
• Language: English
• Subjects: Anthocyanins - biosynthesis; Citrus; Citrus sinensis - metabolism; Cold Temperature; Flavonoid biosynthesis; Food Handling; Food Storage; Fruit - metabolism; Health; Heat conditioning; Phytochemicals
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.128334

•Anthocyanin content was higher in cured blood oranges followed by storage at 9 °C.•Curing treatment plus storage at 9 °C led to a higher flavonoid content.•This concurred with enhanced upregulation of genes from the pathway.•Curing plus 9 °C storage may be used to enrich flavonoids in blood orange juice. Anthocyanins are pigments present in blood oranges which can be enriched by post-harvest cold storage. Additionally, citrus fruits contain appreciable levels of other flavonoids, whose content increases under post-harvest heat treatments. Here, we investigated the effects of curing (37 °C for 3 days) and storage at low-temperature (9 °C) during 15, 30 and 45 days on accumulation of anthocyanins and other flavonoids in Moro and Sanguinelli Polidori blood oranges (Citrus sinensis L. Osbeck). Cured fruits reached up to 191.4 ± 1.4 mg/L of anthocyanins in their juice after cold storage and a 3-fold enrichment of other flavonoids such as flavones and flavanones, compared to 85.7 ± 3.3 mg/L anthocyanins from fruits with cold storage alone. Concomitantly, qPCR analysis showed that curing enhanced upregulation of the main structural and transcription factor genes regulating the flavonoid pathway. GC–MS analysis showed that no unpleasant compounds were generated in the cured plus cold-stored juice volatilome.