A preliminary multistep combination of pulsed electric fields and supercritical fluid extraction to recover bioactive glycosylated and lipidic compounds from exhausted grape marc. (15th April 2023)

• Record Type: Journal Article
• Authors: Salgado-Ramos, Manuel; Martí-Quijal, Francisco J.; Huertas-Alonso, Alberto J.; Sánchez-Verdú, M. Prado; Moreno, Andrés; Barba, Francisco J.
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 180(2023)
• Publication Date: 2023-04-15
• Subjects: Pulsed electric fields -- Supercritical fluid extraction -- Bioactive compounds -- Exhausted grape marc -- Process intensification mechanisms; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2023.114725
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: This article reports the first multistep combination of pulsed electric field (PEF; 3 kV/cm, 100 kJ/kg, 2 Hz, 100 ms) and supercritical fluid extraction (SFE) with CO2 (10–20 MPa, 25 mL/min [10% EtOH], 50 °C, 60 min) for exhausted grape marc (EGM). This current protocol was mainly created to recover bioactive glycosylated and lipidic compounds. In this regard, total antioxidant capacity (TAC) was enhanced up to 68% after PEF treatment compared to conventional soaking. However, re-extracting PEF-treated EGM after the application of SFE (PEF + SFE) boosted the efficiency by up to 87%. Several polyphenols (kaempferol, luteolin, scutellarin, and resveratrol, among others), together with other glycosylated structures, were identified by liquid chromatography coupled with mass spectrometry analysis. The bioactive lipidic compounds extracted by SFE, along with the carbohydrate fraction (free sugars) favourably extracted by PEF pre-treatment (mainly glucose, but also fructose and sucrose), were concurrently detected by nuclear magnetic resonance. The remaining solid fraction after treatment was also characterised. Different microscopic morphology was observed by scanning electron microscopy (SEM) on untreated, PEF, and PEF + SC–CO2 –treated EGM. Differential thermogravimetric (DTG) curves determined by thermogravimetric analysis (TGA) also suggested alternative and potential means for the valorisation of this matrix. Highlights: PEF + SFE efficiently recovered BACs and sugars from exhausted grape marc (EGM). PEF + SFE boosted up to 87% the efficiency of TAC compared to conventional soaking. Different microscopic morphology of untreated, PEF- and PEF + SFE-treated biomass. Remaining solid after PEF + SFE suggested alternative valorisation towards zero-waste .