Improved Sustainability in Wine Industry Byproducts: A Scale-up and Economical Feasibility Study for High-Value Compounds Extraction Using Modified SC-CO₂

Abstract

The objective of the present work was to optimize the operating conditions (P, T cosolvent %) and to study the scale-up and the feasibility of the supercritical fluid extraction (SFE) process for polyphenols from grape pomace, the main solid byproduct of the wine industry. Pilot-scale equipment (1 L extraction vessel) was used to study the scale-up prediction for extraction vessels of 50, 100, 500, and 1000 L capacity. The adopted scale-up criteria consisted of maintaining and keeping constant the solvent mass-to-feed mass ratio and the bed geometry dimension. The results indicated an excellent predictive level obtained by Sovová’s model and success of the adopted scale-up criteria. At industrial scale, yields were close to 2.3 g GAE /100 g DM , a value obtained using the pilot-scale equipment. High concentrations of high-added-value phenols such as cis -resveratrol glucoside, cis -coutaric acid, trans - p -coumaric acid, quercetin, and proanthocyanidins were found in the extract. An economic evaluation of the process indicated the feasibility of an industrial SFE plant with a capacity of 500 L for producing in 60 min an extract with an expected phenolics’ concentration of approximately 133 g GAE /kg extract at an estimated 67€ /kg extract cost of manufacturing. Notably, all values are better than those currently reported in the literature.

Grape Pomace as a Renewable Natural Biosource of Value-Added Compounds with Potential Food Industrial Applications

“…In addition, the choice of extraction solvent and even the sample/solvent ratio are important in achieving good recovery of the compounds. Several researchers have reported the design and optimization of emerging extraction procedures, such as supercritical fluid extraction (SFE) [31,32], microwave-assisted extraction (MAE) [33][34][35], PLE [16,36], ultrasound-assisted extraction (UAE) [35,37], enzymatic extraction [38], among others, to maximize the yield of value-added compounds (e.g., phenolic compounds, anthocyanins, fibers, proteins) from grape pomace for various applications in food, agriculture, pharmaceuticals, and cosmetics [12,[39][40][41][42]. These emerging extraction techniques have been proposed for the recovery of phenolic compounds from grape pomace with the main objective of reducing extraction time, solvent volume, and cost, as well as increasing sustainability [30,43].…”

The Optimization of Operating Conditions in the Cross-Flow Microfiltration of Grape Marc Extract by Response Surface Methodology

“…Microwave-assisted extraction (MAE) [ 26 , 27 , 28 ], ultrasound-assisted extraction (UAE) [ 29 , 30 , 31 ] and supercritical fluid extraction (SFE) [ 32 , 33 , 34 ] are emerging technologies for extracting bioactive compounds, including phenolic compounds, from plant matrices. These “green” techniques are able to minimize the limitations arising from conventional techniques (i.e., maceration, Soxhlet extraction and hydrodistillation) such as the formation of toxic residues, long extraction times and high solvent and energy consumption [ 22 , 31 ].…”