A metabolomics approach to evaluate the effect of lyophilization versus oven drying on the chemical composition of plant extracts.

ElNaker, Nancy A.; Daou, Mariane; Ochsenkühn, Michael A.; Amin, Shady A.; Yousef, Ahmed F.; Yousef, Lina F.

Lyophilization is the "gold standard" for drying plant extracts, which is important in preserving their quality and extending their shelf-life. Compared to other methods of drying plant extracts, lyophilization is costlier due to equipment, material and operational expenses. An alternative method is post-extraction oven-drying, but the effects of this process on extract quality are unknown. In this study, crude extracts from Arthrocnemum macrostachyum shoots were compared using three post-extraction drying methods (lyophilization and oven drying at 40 and 60 °C) and two extraction solvents (water and aqueous 50% ethanol). Untargeted metabolomics coupled with chemometrics analysis revealed that post extraction oven-drying resulted in the loss of up to 27% of molecular features when compared to lyophilization in water extracts only. In contrast, only 3% of molecular features were lost in aqueous 50% ethanol extracts when subjected to oven drying. That is to say, ethanol used as a solvent has a stabilizing effect on metabolites and enhances their resistance to thermal transformation in the oven. Collectively, oven-drying of extracts was as effective as lyophilization in preserving metabolites in extracts only when 50% ethanol was used as a solvent. The results presented in this paper demonstrate the value of selecting solvent-appropriate post-extraction drying methods.

CHEMICAL composition of plants; PLANT extracts; DRYING; FREEZE-drying; METABOLOMICS; PLANT drying; SOLVENT extraction; ETHANOL

Scientific Reports, 2021, Vol 11, Issue 1, p1

2045-2322

Academic Journal

10.1038/s41598-021-02158-6