This study aims at total valorization of fruit and vegetable by-products, moving towards developing an original concept of “dry” bio-refinery (DBR).

No abstract

Extracts rich in antioxidants, such as rosemary extracts, are currently obtained by extraction of the plant material using hydro-alcoholic mixtures with high ethanol content. As this ratio is generally chosen by default and scarcely optimized, we intended to investigate the impact of the hydro-alcoholic composition on extract characteristics such as extraction yield, composition profile in selected compounds, and antioxidant/reducing activity such as Folin-Ciocalteu, DPPH, and ORAC. A theoretical determination of rosmarinic (RA) and carnosic (CA) acid solubilities in ethanol:water mixtures was also performed using COSMO-RS and was confronted to experiments. While the best solubilizing solvent (100% ethanol) was also the best extracting solvent for CA, it was not the case with RA since pure ethanol appeared as a poor solvent compared to 30% ethanol which was optimal. Finally, the best antioxidant activities were obtained with 30% ethanol.

No abstract

This study aims total valorization of rosemary for food applications, moving toward developing an original biorefinery concept using solar steam distillation (SSD) to extract essential oil while preserving active compounds in the raw material, mainly antioxidants, for a further extraction. The deodorization process is important to avoid the extraction of antioxidants with strong aromas which limit their utilization for food preservation. The SSD process was compared with conventional steam distillation (CSD) for essential oil extraction as well as deodorization of dried rosemary leaves. The treated leaves were recovered afterward for the extraction of antioxidants by solvent extraction to recover rosmarinic, carnosic, and ursolic acids. With standard protocol extraction and analysis, the antioxidants seem to be mostly preserved by SSD rather than by CSD. The Folin–Ciocalteu reagent was used to determine the polyphenol content, whereas diphenylpicrylhydrazyl (DPPH) was used to analyze the antiradical properties. It was found that both the polyphenol content and antioxidant activity were preserved after SSD. Scanning electron microscopy (SEM) and fluorescence microscopy showed complete destruction of glandular trichomes for both processes, which indicates that the extraction of essential oil was complete. Overall, the results specify clearly that solar steam distillation (SSD) is a green alternative, an efficient and economical process for essential oil extraction and leaf deodorization.

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