Grape by-products: extraction of polyphenolic compounds using supercritical CO2 and liquid organic solvent - a preliminary investigation.

This research focussed on the exploitation of grape by-products as a source of polyphenolic compounds, which are of interest to the food, pharmaceutical and cosmetic industries. In particular, two substrates were tested: Pinot Noir grape skins and grape seeds. Pinot Noir grape skins were extracted by supercritical CO2 added with ethanol as modifier at constant temperature (45 °C) and at variable pressure (200, 300, 400 or 500 bar). The supercritical extraction kinetics of polyphenolic compounds was obtained. Grape seeds were extracted by combining supercritical (at 40 °C and 500 bar and using CO2 or CO2 added with ethanol as modifier) with liquid ethanol extraction. The supercritical technique seemed not to be really effective in extracting polyphenolic compounds; it can be anyway utilized to selectively extract grape seed oil by avoiding any solvent contamination of the matrix which can be further extracted for the recovery of polyphenolic compounds by means of liquid organic solvent

Microalgae growth using winery wastewater for energetic and environmental purposes

Winery wastewater (WWW), produced by winemaking activities (cleaning, transferring and storage operations), is an aqueous solution containing ethanol, organic acids, sugars, aldehydes, other microbial metabolites, soaps and detergents. Nowadays, innovative wastewater treatment processes are based on bacterial and yeast species while the role of microalgae is still unclear. Arthrospira (Spirulina) platensis and Chlorella vulgaris are unicellular prokaryotic and eukaryotic microorganisms, respectively, which can be easily grown even in non-optimal conditions. Several studies reported that the amount and quality of lipids contained in microalgal cells can differ as an outcome of changes in growth conditions or growth medium characteristics (concentration of carbon, nitrogen, phosphate, iron, etc.). In this study, we investigated the influence of different concentrations of WWW (20, 40 and 60 % v/v of the medium) on the growth and chemical composition of those photosynthetic microorganisms. Microalgae were grown into vertical glass bubblers (250 mL). The biomass concentration was quantified daily by measuring the optical density at 560 and 625 nm for A. platensis and C. vulgaris, respectively. Total Carbon and total Nitrogen concentrations, both in the media (mg/L) and in microalga biomass (g/100g), were monitored by a CHNS-O analyser. In order to quantify the influence of WWW-enrich media on the lipid concentration and composition, biomass was collected at the beginning of the stationary phase and the lipid fraction was extracted. Results suggested that the two tested microalgae can growth in media enriched with WWW and the total Nitrogen concentrations decreased up to 90 and 100 % for A. platensis and C. vulgaris, respectively. In conclusion, WWW could be successfully used for the growth of the tested microalgae, leading to a reduction of the environmental impact of this wastewater

Deoxygenation of non-edible vegetable oil to produce hydrocarbons over Mg-Al mixed oxides

none7noopenRomero, Max; Pizzi, Andrea; Toscano, Giuseppe; Casazza, Alessandro Alberto; Busca, Guido; Bosio, Barbara; Arato, ElisabettaRomero, Max; Pizzi, Andrea; Toscano, Giuseppe; Casazza, Alessandro Alberto; Busca, Guido; Bosio, Barbara; Arato, Elisabett

Innovative Treatment of Digestate and Biogas Upgrade Using Chlorella Vulgaris

In the era of energy transition, the research efforts are devoted to find sustainable solutions to enable the transition to a decarbonised energy and production system, by renewable energy sources promoting products circularity, green technologies and safer processes. Anaerobic digestion is a bioprocess involving organic substrate breakdown by various microbial species in the oxygen absence. It yields two valuable products: digestate and biogas. Digestate can be used as fertilizer after stabilization and reduction of its polluting load. Through an upgrading process, biogas can be converted into biomethane, a widely utilized resource in energy and transportation. In this study, a non-conventional method has been investigated to achieve simultaneous biomethane production and reduction of digestate polluting power using Chlorella vulgaris, resulting in two valuable products. A 6-liter anaerobic digester was fed with simulated municipal organic waste every 3 days. Biogas was fed into a photobioreactor, where C. vulgaris was cultivated under mixotrophic conditions, utilizing CO2 from biogas as a carbon source. Biogas was converted into biomethane with over 90% methane content, while digestate was treated in the same photobioreactor, reducing its chemical oxygen demand (COD) by up to 80%. Using CO2 from biogas, maximum cell concentration of 1.332 g/L, maximum specific growth rate of 0.091 day-1 and biomass productivity of 0.057 gBS/L d were obtained at 70 µmol/m2 s. Biogas was analyzed by gas chromatography, and digestate was assessed for suspended solids, total solids, and COD. After cultivation, biomass was harvested, dehydrated, and characterized for total lipids and calorific value. Combining both approaches transforms waste into valuable biomethane and microalgal biomass, supporting the zero-waste objective

Fermentacija mlijeka obogaćenog mljevenom kominom grožđa s pomoću bakterije Lactobacillus acidophilus

Some by-products of wine industry still contain nutrients and functional compounds that make them potential ingredients to formulate new high value-added food products. The aim of this study is to develop milk fermented with Lactobacillus acidophilus fortified with marc flour of different cultivars of Vitis vinifera from wine production and to evaluate their influence on fermentation kinetics, probiotic counts, phenolic compounds, sugar content and antioxidant activity. The acidification time was significantly shortened by these enrichments (by up to 2.7 h), and the bacterial count during cold storage resulted in stronger fortification of samples (up to 4.13 %) when compared to control tests. Fermented milk containing grape marc showed considerable amounts of phenolic compounds with notable antioxidant activity, as well as significant amounts of total sugars. The most important aspect of this paper is the feasibility of using winery by-products, rich in phenolic compounds, as natural supplements to fortify probiotic-fermented milk.Neki nusproizvodi u proizvodnji vina sadržavaju hranjive i funkcionalne tvari, pa se mogu upotrijebiti za razvoj novih prehrambenih proizvoda s dodanom vrijednošću. Svrha je ovoga rada bila proizvesti mlijeko obogaćeno mljevenom kominom različitih sorata grožđa i fermentirano s pomoću bakterije Lactobacillus acidophilus, te odrediti utjecaj dodatka komine na kinetiku fermentacije, broj probiotičkih mikroorganizama, udjele fenolnih spojeva i šećera, te antioksidativnu aktivnost fermentiranog mlijeka. Vrijeme fermentacije obogaćenog mlijeka znatno se smanjilo (do 2,7 h), a broj bakterija tijekom skladištenja u hladnjaku povećao (do 4,13 %) u usporedbi s kontrolnim uzorkom. Fermentirano je mlijeko obogaćeno mljevenom kominom grožđa imalo veće udjele fenolnih spojeva i ukupnih šećera, te izraženiju antioksidativnu aktivnost. Najveći je značaj ovog istraživanja u tome što dokazuje da se nusproizvodi vinske industrije bogati fenolnim spojevima mogu upotrijebiti kao prirodni dodaci mlijeku fermentiranom s pomoću probiotika

Treatment by microalgae of emerging pollutants in wastewater from anaerobic digestion of pig manure

Anaerobically digested pig manure are effluents still rich in ammonium, with high chemical oxygen demand, which contribute to the phenomenon of water eutrophication. Moreover, due to excess use of antibiotics in animal husbandry, unmetabolized drugs can still be found in manure and then in anaerobic digestion effluents, thus requiring further treatment. Microalgae could potentially offer many advantages in this treatment, being able to use the organic carbon as well as inorganic nutrients such as nitrogen and phosphorus from wastewater for their heterotrophic growth. The aim of this research was to investigate the effect of emerging pollutants added to digested swine manure on the growth of the microalga Chlorella vulgaris. C. vulgaris cultures were performed with different amounts of digested pig manure to achieve ammonium concentrations of 60, 120 and 170 mgN/L in the medium. Additional runs were performed in water enriched with pure ammonium at the same concentrations as above. These runs were compared with those carried out in classic Bold Basal Medium taken as a control. Moreover, after reaching the stationary phase of cultures with 60 mgN/L ammonium from manure we added 14.0 mg/L of Micospectone, an antibiotic mixture containing 33.3% Lincomycin and 66.6% Spectinomycin. Preliminary studies evidenced that higher antibiotic concentrations (56-112 mg/L) in medium lead to microalga growth inhibition. Biomass concentration was daily quantified spectrophotometrically by optical density measurements at 625 nm wavelength, while total ammonium and phosphate concentrations were monitored periodically. Optical and Scansion Electronic Microscopies were used to observe fresh and dried biomass, respectively. In the presence of digested manure and the antibiotic, C. vulgaris biomass reached concentrations around 1.3 gDB/L. Ammonium was removed efficiently, at rates of 5.6 and 3.4 mg/Ld when present in initial concentrations of 60 and 120 mgN/L, respectively, whereas higher ammonium level (170 mgN/L) strongly inhibited microalgal growth and almost suppressed its own remova

Thermocatalytic Pyrolysis of Exhausted Arthrospira platensis Biomass after Protein or Lipid Recovery

Microalgae and cyanobacteria are unicellular microorganisms that contain high-added value compounds. To make their extraction economically feasible the biorefinery concept is the only solution. In this study, the residue resulting from lipid or protein extraction from Arthrospira platensis biomass was valorized by catalytic pyrolysis using ZSM5 zeolite or amorphous silica-alumina as catalyst. The reaction was performed in a quartz reactor, and the catalyst was placed in a fixed bed to force the reaction gases to pass through it. The reaction products were analyzed by FTIR and GC-MS analyses. The reaction gases and liquids obtained from the extraction residues had higher hydrocarbon contents compared to untreated biomass. Moreover, pyrolysis of biomass after protein or lipid extraction led to fractions with lower contents of nitrogenated or oxygenated components, respectively. This study showed that the pyrolysis process could be used to valorize the microalgae extraction residues aiming to make biofuels production and extraction of high added-value products more economically feasible