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 .…”

Metabolomics-Guided Elucidation of Plant Abiotic Stress Responses in the 4IR Era: An Overview

“…In the context of plant metabolomics, only a few of these methods have been applied. For instance, the use of SPE to obtain insights into complex phenolic composition of tea and other plant samples [ 44 ], SPME to extract metabolites that reflect the changes in the ‘HoneyCrisp’ apples metabolome [ 71 ], extraction of phenolics with DLLME for chromatography analysis has been reported by [ 72 ], EME with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze plant hormones in citrus leaf samples [ 73 ], ASE was used in the analysis of natural products in green tea ( Camellia sinensis L.) [ 55 ], SFE had been applied to extract tetrahydrocannabinol (THC) from Cannabis sativa L. [ 74 ], pharmaceutical and nutraceutical natural compounds from Berberis species have been extracted with MAE [ 75 ], and UAE has been applied in the extraction of phytochemical compounds from apricot by-products (pulp) [ 76 ]. These methods, including HF-LLME and SDME, have not yet been reported in metabolomics studies of plant responses to abiotic stresses.…”