Expanding the Role of Sub-Exploited DOE-High Energy Extraction and Metabolomic Profiling towards Agro-Byproduct Valorization: The Case of Carotenoid-Rich Apricot Pulp

Abstract

Traditional extraction remains the method-of-choice for phytochemical analyses. However, the absence of an integrated analytical platform, focusing on customized, validated extraction steps, generates tendentious and non-reproducible data regarding the phytochemical profile. Such a platform would also support the exploration and exploitation of plant byproducts, which are a valuable source of bioactive metabolites. This study deals with the incorporation of (a) the currently sub-exploited high energy extraction methods (ultrasound (UAE)- and microwave-assisted extraction (MAE)), (b) experimental design (DOE), and (c) metabolomics, in an integrated analytical platform for the extensive study of plant metabolomics and phytochemical profiling. The recovery of carotenoids from apricot by-products (pulp) is examined as a case study. MAE, using ethanol as solvent, achieved higher carotenoid yields compared to UAE, where 1:1 chloroform-methanol was employed, and classic extraction. Nuclear magnetic resonance (NMR)-based metabolomic profiling classified extracts according to the variations in co-extractives in relation to the extraction conditions. Extracts with a lower carotenoid content contained branched-chain amino acids as co-extractives. Medium carotenoid content extracts contained choline, unsaturated fatty acids, and sugar alcohols, while the highest carotenoid extracts were also rich in sugars. Overall, the proposed pipeline can provide different the phytochemical fractions of bioactive compounds according to the needs of different industrial sectors (cosmetics, nutraceuticals, etc.).

Optimization of Ultrasound- and Microwave-Assisted Extraction for the Determination of Phenolic Compounds in Peach Byproducts Using Experimental Design and Liquid Chromatography–Tandem Mass Spectrometry

“…Polar solvents are also ideal for MAE because -OH bonds enable microwave (MW) energy absorption, and as consequence enable the increase in temperature in the extraction system that promotes the release of the compounds of interest into the solvent [ 15 ]. According to recently published studies [ 18 , 19 , 20 ], higher values of US power implemented at relatively short extraction times result in higher extraction yields of bioactive compounds. Thus, US power was set at 600 W and extraction temperature was kept constant at 35 °C by immersing the extraction vessel into an ice bath.…”

Towards the Optimization of Microwave-Assisted Extraction and the Assessment of Chemical Profile, Antioxidant and Antimicrobial Activity of Wine Lees Extracts

“…In order to assure that DOE models provide unbiased results, the real values of the extraction variables, which are expressed in different physical units (i.e., Watt, minutes, volume-to-weight, etc. ), were transformed to coded normalized dimensionless values (x 1 , x 2 , x 3 ) [ 52 ]. Real and normalized values of the extraction factors for the two DOE models are presented in Table S5 .…”

Unveiling the Potential of Apricot Residues: From Nutraceuticals to Bioenergy

“…The research by Tsiaka et al [62] focused on the integration of underutilized high-energy extraction techniques, specifically ultrasound-assisted extraction, and microwave-assisted extraction, along with the implementation of experimental design and metabolomics. The objective was to establish an integrated analytical platform for a comprehensive investigation of plant metabolomics and phytochemical profiling.…”