Separation of aroma compounds from industrial hemp inflorescences (Cannabis sativa L.) by supercritical CO2 extraction and on-line fractionation

The use of supercritical carbon dioxide (Sc-CO2) extraction at 10 and 14 MPa and 40 \ub0C and on-line fractionation using two separators (Sep 1: 7 MPa/25 \ub0C; Sep2: 5 MPa/15 \ub0C) to recovery volatile compounds from the inflorescences of fiber type Cannabis sativa L. was investigated by HS-SPME/GC\u2013MS and direct GC\u2013MS and compared with hydrodistillation. The best results were obtained by Sc-CO2 extraction carried out at 10 MPa and 40 \ub0C. Under these operating conditions, cuticular waxes covering the surface of flowers were collected in the first separator and volatile compounds (100%) in the second. The superior quality of this last extract was proved by the perfect overlapping of its HS-SPME/GC\u2013MS volatile profile to that of inflorescences. The recovery of fractions with different composition and biological properties, made the inflorescences of fiber type Cannabis sativa L suitable for cosmetic and/or food industry

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

[Image: see text] 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

Application of Supercritical Fluids Technology on winery by-products

Winemaking process produces a large amount of solid wastes, including grape marc and wine lees. In 2014, the Italian production of grapes was estimated to be 6 million tons, which corresponds to about 1.5 million tons of grape marc. The new European regulations about the organization of winery sector and waste management (EC 479/2008 and EC 555/2008) have revoked the compulsory distillation of the by\u2013products of winemaking, creating a great problem on winery waste handling and disposal. Grape marc has a heavy environmental impact for the high content of phenols that considerably increase chemical and biochemical oxygen demands. This biomass could be disposed and valorised first by extraction of added-value bioactive compounds and then by production of biopolymers and bio-fuels. One of the higher value options is the recovery of polyphenols, which could be used in pharmaceutical, cosmetic and food industry. In this regard, this PhD thesis aimed to study the application of Supercritical Fluid Extraction (SFE) and Supercritical Anti-Solvent (SAS) process to recover bioactive compounds of high-added value from grape marc, in particular polyphenols, which show beneficial effects on human health against several diseases. SFE with supercritical carbon dioxide (SC-CO2) has been widely used for the extraction from natural products. It is an environment-friendly technology, which represents an alternative to conventional extraction techniques and offers several advantages over classical solvent extraction methods. For the extraction of polar compounds, such as polyphenols, a co-solvent/modifier is necessary to add to SC-CO2. Three different \u201cgreen\u201d SC-CO2 co-solvents were investigated: ethanol, water and an ethanol aqueous mixture with 57%(v/v) ethanol concentration. The effect of pressure, temperature, CO2 flow rate and percentage of co-solvent, which are the main process parameter of a SFE process, were studied for each co-solvent used. The results indicated that SFE process carried out using the ethanol aqueous mixture (57% v/v) as co-solvent at 8 MPa, 40\ub0C, 6.0 kg/h of CO2 flow rate added with 10% of co-solvent, showed the best results for Total Polyphenol Content (TPC), Antioxidant activity and Proanthocyanidins. A combination of ultrasound assisted extraction (UAE) and supercritical carbon dioxide (SC-CO2) extraction to maximize polyphenols recovery from grape marc was studied. It is well known that ultrasounds waves can improve the extraction processes with their cavitational effect. The effect of temperature and time of UAE on polyphenols compounds was investigated by 22 full factorial design. The highest concentration of polyphenols was obtained at 80\ub0C and 4 minutes of ultrasound extraction. The obtained UAE-Raffinates were extracted by supercritical carbon dioxide. The overall extraction curves (OECs) of the UAE-Raffinates extracted by SC-CO2 were described and evaluated. The performance of the combined process has been checked by comparison of total polyphenol content, proanthocyanidin fractions and antioxidant activity with both UAE and SC-CO2 extraction. Supercritical Fluids can be used not only for extraction methods, but also for other purposes. The peculiar properties of supercritical fluids can be exploited in micronization processes. The precipitation of pharmaceutical and natural products has attracted great attention in recent years. The conventional techniques, including spry-drying, freeze-drying, liquid antisolvent crystallization or milling processes, show several disadvantages: (1) production of coarse particles, (2) mechanical or thermal degradation of the products, and (3) final products with low purity. For these reasons, a micronization process with supercritical carbon dioxide (SC-CO2), namely supercritical anti-solvent (SAS) process, was applied to recover polyphenol compounds from grape marc extract. A 23 factorial design was applied to study the effect of the main SAS process parameters (pressure, temperature and CO2 molar fraction) on recovered particles, total polyphenol compound (TPC) and antioxidant activity. The precipitates with high quality was obtained at 12 MPa, 45\ub0C and 0.99 of CO2 mole fraction. Fractionation of proanthocyanidins, as well as HPLC-DAD analysis of polyphenols and scanning electronic microscopy (SEM) analysis were performed on the best products obtained by SAS. Economic considerations, based on the literature data, and future perspectives regarding the application of supercritical fluids processes were discussedIl processo di vinificazione genera una grande quantit\ue0 di residui solidi, costituiti principalmente da vinacce e fecce. Nel 2014 la produzione italiana di uva ammontava a 6 milioni di tonnellate, che corrispondono a una produzione di circa 1.5 milioni di tonnellate di vinaccia. La nuova regolamentazione della Comunit\ue0 Europea riguardante il settore vitivinicolo e la gestione dei rifiuti (CE 479/2008 e CE 555/2008) ha introdotto una progressiva diminuzione, fino alla totale scomparsa, della distillazione obbligatoria dei sottoprodotti dell\u2019industria enologica. Tutto ci\uf2 ha comportato enormi problemi e disagi nella gestione e nell\u2019utilizzo di questi sottoprodotti. La vinaccia ha un enorme impatto dal punto di vista ambientale e a causa del suo alto contenuto in sostanze polifenoliche determina un aumento dei valori di COD e BOD dell\u2019ambiente. Questo sottoprodotto pu\uf2 essere sfruttato e valorizzato mediante l\u2019estrazione di composti bioattivi ad alto valore aggiunto e successivamente per la produzione di biopolimeri, energia e/o biocarburanti. Una delle opzioni di maggior interesse \ue8 il recupero di polifenoli, che possono essere utilizzati in campo farmaceutico, cosmetico e alimentare. In questo contesto, questa tesi di dottorato ha come obiettivo lo studio dell\u2019estrazione con fluidi supercritici (SFE) e il recupero mediante la tecnologia SAS (Supercritical Anti-Solvent) di composti bioattivi ad alto valore aggiunto da vinacce d\u2019uva, in particolare le sostanze polifenoliche che possiedono effetti benefici sulla salute umana. L\u2019estrazione SFE, con il diossido di carbonio allo stato supercritico (SC-CO2), \ue8 ampiamente utilizzata per l\u2019estrazione di matrici naturali. \uc8 una tecnologia eco-compatibile ed eco-sostenibile, che rappresenta un\u2019alternativa alle tecniche di estrazione convenzionali e offre diversi vantaggi rispetto all\u2019estrazione classica con solventi. Per l\u2019estrazione di composti polari, come sono i polifenoli, \ue8 necessaria l\u2019aggiunta di un co-solvente al diossido di carbonio allo stato supercritico. Tre diversi tipi di co-solvente sono stati studiati: etanolo, acqua e una miscela etanolo/acqua, con una concentrazione in etanolo del 57% (v/v). Per ciascun co-solvente utilizzato, sono stati valutati gli effetti dei principali parametri operativi dell\u2019estrazione con fluidi supercritici: pressione, temperatura, flusso di CO2 e percentuale di co-solvente utilizzato. I risultati ottenuti indicano che l\u2019estrazione con CO2 supercritico addizionato con la miscela etanolo/acqua (57% v/v) come co-solvente a 8 MPa, 40\ub0C, 6.0 kg/h di flusso di CO2 e 10% di co-solvente, ha permesso di ottenere i risultati migliori per quanto riguarda il contenuto di polifenoli totali, l\u2019attivit\ue0 antiossidante e il contenuto di proantocianidine. L\u2019accoppiamento dell\u2019estrazione assistita con ultrasuoni (UAE) e dell\u2019estrazione con CO2 supercritico \ue8 stato studiato, con l\u2019obiettivo di massimizzare il recupero di polifenoli da vinacce d\u2019uva. \uc8 noto che gli ultrasuoni permettono di migliorare i processi estrattivi grazie al fenomeno della cavitazione. Un disegno sperimentale fattoriale completo (22) \ue8 stato applicato per lo studio dell\u2019effetto della temperatura e del tempo del processo UAE. La pi\uf9 alta concentrazione di polifenoli \ue8 stata ottenuta nell\u2019estrazione con ultrasuoni condotta a 80\ub0C per 4 minuti. Successivamente, i residui solidi ottenuti dalle prove di estrazione con ultrasuoni sono stati estratti ulteriormente con l\u2019SFE. Le cinetiche di estrazione (OECs) delle prove con CO2 supercritico sono state considerate e studiate. La combinazione dei due processi estrattivi \ue8 stata valutata considerando il contenuto totale di polifenoli, l\u2019attivit\ue0 antiossidante e il contenuto di proantocianidine degli estratti ottenuti con UAE e SFE. I fluidi supercritici posso essere utilizzati non solamente nei processi estrattivi, ma anche per altri scopi ed applicazioni. Le propriet\ue0 caratteristiche dei fluidi supercritici possono essere sfruttate nei processi di micronizzazione. Negli ultimi anni i processi di precipitazione dei composti farmaceutici e naturali hanno ricevuto un enorme interesse. I processi convenzionali, come lo spry-drying, freeze-drying e i processi di macinazione, presentano diversi svantaggi: (1) produzione di particelle grossolane, (2) degradazione termica e meccanica del prodotto finito, (3) prodotto finito impuro, contenente tracce di solventi e interferenti tossici. Per queste ragioni, \ue8 stato applicato un processo di micronizzazione con fluidi supercritici, definito come SAS (Supercritical Anti-Solvent), per il recupero di polifenoli da estratti di vinaccia. Un disegno sperimentale fattoriale completo (23) \ue8 stato applicato per lo studio dell\u2019effetto dei principali parametri di processo (pressione, temperatura e frazione molare del CO2) sulla quantit\ue0 di particelle recuperate, il contenuto di polifenoli totali e l\u2019attivit\ue0 antiossidante. I campioni con i migliori risultati sono stati ottenuti a 12 MPa, 45\ub0C e 0.99 di frazione molare del CO2. I campioni migliori ottenuti nelle prove sperimentali sono stati inoltre caratterizzati mediante il frazionamento delle proantocianidine, l\u2019analisi HPLC-DAD dei polifenoli e l\u2019analisi al microscopio a scansione elettronica (SEM). Sulla base dei dati di letteratura sono state effettuate considerazioni economiche, e discusse le prospettive future delle possibili applicazioni dei fluidi supercritici nei processi industrial

Extraction kinetic modelling of total polyphenols and total anthocyanins from saffron floral bio-residues: Comparison of extraction methods

Analysis of the extraction kinetic modelling for natural compounds is essential for industrial application. The second order rate model was applied to estimate the extraction kinetics of conventional solid-liquid extraction (CSLE), ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) of total polyphenols (TPC) from saffron floral bio-residues at different solid-to-liquid ratios (RS/L)(1:10, 1:20, 1:30, 1:50gml 121), ethanol 59% as solvent and 66 \ub0C temperature. The optimum solid-to-liquid ratios for TPC kinetics were 1:20 for CLSE, 1:30 for UAE and 1:50 for MAE. The kinetics of total anthocyanins (TA) and antioxidant activity (AA) were investigated for the optimum RS/L for each method. The results showed a good prediction of the model for extraction kinetics in all experiments (R2 > 0.99; NRMS 0.65\u20133.35%). The kinetic parameters were calculated and discussed. UAE, compared with the other methods, had the greater efficiency for TPC, TA and AA

ULTRASOUND TECHNOLOGY: A NEW TOOL FOR LOW-INPUT RED WINEMAKING

The present work resumes the pluriannual researches carried out at laboratory and pilot-scale, aimed to study the effect of ultrasound during different steps of the red winemaking process, using respectively: a static laboratory sonifier and a pilot plant at continuous mode. The effect of the main ultrasound process parameters was studied at laboratory scale, on anthocyanins, tannins, and color stability indices of two young red wines. A number of technological experiments at pilot-scale level were carried out on different grape cultivars from different wineries and producing areas, to study properly the potential effectiveness of ultrasound on the winemaking process. Potential effects of ultrasound on some chemical reactions, involved during wine aging, have been considered. Ultrasound can be considered as a sustainable technology that can be applied on the maceration step, to increase the extraction of grape compounds and reducing times, with several economic and management advantages for wineries. The sonication treatments should be opportunely modulated considering several factors, such as grape variety and oenological aims. Ultrasound could be an alternative technology to be applied in several steps of winemaking processes, from maceration to red wine aging

Biotransformations Performed by Yeasts on Aromatic Compounds Provided by Hop—A Review

The biodiversity of some Saccharomyces (S.) strains for fermentative activity and metabolic capacities is an important research area in brewing technology. Yeast metabolism can render simple beers very elaborate. In this review, we examine much research addressed to the study of how different yeast strains can influence aroma by chemically interacting with specific aromatic compounds (mainly terpenes) from the hop. These reactions are commonly referred to as biotransformations. Exploiting biotransformations to increase the product’s aroma and use less hop goes exactly in the direction of higher sustainability of the brewing process, as the hop generally represents the highest part of the raw materials cost, and its reduction allows to diminish its environmental impact

Innovations on red winemaking process by ultrasound technology

High power ultrasound has been recently recognized one of the most promising technologies in winemaking processes, especially after the recent OIV resolution, concerning the application of ultrasounds on crushed grapes to promote the extraction of skin compounds. The present work resumes the pluriannual researches carried out at laboratory and industrial scale, aimed to study the effect of ultrasounds during different steps of the red winemaking process, using respectively: a static laboratory sonifier (20 kHz) and a pilot plant at continuous mode (27 kHz). A number of technological experiments were carried out on different grape cultivars from different wineries and producing areas, to study properly the potential effectiveness of ultrasounds on the maceration process. In all the industrial experiments, the crushed grapes were split into equal and homogeneous aliquots by an appropriate Y-valve to ensure the comparison of untreated and sonicated samples. Sonication induced a higher extraction rate of polyphenols compounds from grape skins and seeds, and allowed a 40-60% reduction of the maceration time, giving besides significant advantages from an energetic and economic point of view. Ultrasound showed nonetheless remarkable advantages on color stability and sensorial characteristics. The effect of ultrasound amplitude and treatment time was also studied, at laboratory scale, on anthocyanins, tannins, and color stability indices. Anthocyanins and chromatic properties are preserved by ultrasounds and a potential chemical effect on the evolution of some analytical indices during wine aging has been highlighted. Ultrasound could be considered as an emerging technology aimed to reduce the inputs of red winemaking process and to develop a novel practice