Alcoholic fermentation with Pichia kluyveri could improve the melatonin bioavailability of orange juice

Abstract

Fermentation of orange juice (OJ) by Pichia kluyveri enhances the content of melatonin, a molecule with potent antioxidant effect. This study explores the levels of urine 6- sulfatoxymelatonin (6-SMT) in healthy subjects after fermented orange juice (FOJ) intake, and their association with antioxidant activity status. Nine participants ingested 500 mL of FOJ and their urine was collected at baseline and after 2, 5, 10, 15 and 24 h. After a two-week washout period, the intervention was repeated with OJ. 6-SMT levels were quantified by ELISA and antioxidant activity by TAC, FRAP and ORAC assays. A significant increase in both 6-SMT levels and antioxidant activity in urine was observed after FOJ ingestion compared to OJ. A positive correlation between TAC and 6-SMT levels was observed only after FOJ intake. This study shows for the first time that fermentation process increases melatonin bioavailability of OJ associated with an enhancement in antioxidant status.

This research was funded by the Andalusian Government [project P09-AGR4814M] and the PAIDI Program from the Andalusian Government [CTS160, BIO311]. I.C.-C. was supported by a postdoctoral fellowship from the Andalusian Government Ministry of Economy, Knowledge, Business, and University [DOC_00587/2020]. G.S.-S. was supported by a FPU grant from the Spanish Ministerio de Educación, Cultura y Deporte [FPU16/02339]. N.A.-S. was supported by a fellowship from the National Net RETICEF for Aging Studies [RD12/0043/ 0012 from the Instituto de Salud Carlos III, Spanish Ministerio de Ciencia e Innovación]. The authors are grateful to the volunteers who participated in the study and to Grupo Hesp´erides Biotech S.L. for providing the fermented orange juice. Supplementary data to this article can be found online at https://doi. org/10.1016/j.jff.2022.105325.