Adsorpcijske izoterme i kinetičko modeliranje uklanjanja fenolnih spojeva pomoću aktivnog ugljena, iz otpadnih voda dobivenih pri proizvodnji maslinovog ulja

The adsorption of phenolic compounds from olive oil wastewater by commercial activated carbon was studied as a function of adsorbent quantity and temperature. The sorption kinetics and the equilibrium isotherms were evaluated. Under optimum conditions (8 g of activated carbon per 100 mL), the maximum sorption capacity of activated carbon expressed as mg of caff eic acid equivalent per g of activated carbon was 35.8 at 10 °C, 35.4 at 25 °C and 36.1 at 40 °C. The pseudo-second-order model was considered as the most suitable for kinetic results, and Langmuir isotherm was chosen to bett er describe the sorption system. The results confi rmed the effi ciency of activated carbon to remove almost all phenolic compound fractions from olive mill effl uent. The preliminary results obtained will be used in future studies. The carbohydrate fraction of this upgraded residue could be employed to produce bioethanol, and adsorbed phenolic compounds can be recovered and used in different industries.U radu je ispitana ovisnost adsorpcije fenolnih spojeva iz otpadnih voda, dobivenih pri proizvodnji maslinovog ulja, o količini adsorbensa (komercijalni aktivni ugljen) i temperaturi. Proučene su kinetika sorpcije i ravnotežne izoterme. Pri optimalnim uvjetima (8 g aktivnog ugljena na 100 mL) najveća je sposobnost sorpcije, izražena u mg ekvivalenata kafeinske kiseline po g aktivnog ugljena, iznosila 35,8 pri temperaturi od 10 °C, 35,4 pri 25 °C i 36,1 pri 40 °C. Dobivene kinetičke rezultate najbolje je opisao model pseudo drugog reda, dok je za opisivanje sorpcije odabrana Langmuirova izoterma. Rezultati potvrđuju učinkovitost aktivnog ugljena u uklanjanju gotovo svih fenolnih spojeva iz otpadnih voda. Ovi će se preliminarni rezultati upotrijebiti u daljnjim istraživanjima. Ugljikohidrati preostali nakon uklanjanja fenolnih spojeva iz otpadnih voda mogli bi se upotrijebiti za dobivanje bioetanola, a adsorbirani se fenolni spojevi mogu naknadno koristiti u raznim granama industrije

Conversion of Lignin to Chemical Intermediates:a Study of Pyrolysis of Kraft Lignin

Experiments of pyrolysis of commercial Kraft lignin have been realized in the 250-550 °C range. Product analyses have been performed by FTIR, GC-MS, EDX analyses. The main goal of the work is to optimize the experiments in terms of liquid yield, reduction of oxygen content in the resulting biochar, and removal of sulfur, found mainly in the gas phase. It has been concluded that the amount of the starting lignin charged in the reactor must be limited to be fully positioned in the heating chamber also during high temperature treatment. Sulfur may be partially removed in the gas phase as H2S and CH3SH mainly, by a pre-treatment at 250 °C. The maximum amount of liquid product, mainly constituted by methoxy- and alkyl-methoxy-phenols, and the maximum solid deoxygenation are both obtained at 550 °C

Influence of fructooligosaccharides on the fermentation profile and viable counts in a symbiotic low fat milk

Abstract This study evaluated the effects of prebiotics on fermentation profile and growth of Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus rhamnosus, and Bifidobacterium lactis in co-cultures with Streptococcus thermophilus. Acidification rate and viability were positively influenced by the co-culture with B. lactis and by both inulin or oligofructose in low fat milk

Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

The enormous quantity of food wastes discarded annually force to look for alternatives for this interesting feedstock. Thus, food bio-waste valorisation is one of the imperatives of the nowadays society. This review is the most comprehensive overview of currently existing technologies and processes in this field. It tackles classical and innovative physical, physico-chemical and chemical methods of food waste pre-treatment and extraction for recovery of added value compounds and detection by modern technologies and are an outcome of the COST Action EUBIS, TD1203 Food Waste Valorisation for Sustainable Chemicals, Materials and Fuels

Encapsulation of antioxidants from Spent coffee ground extracts by spray drying

Spent coffee grounds (SCG) represent a good raw material for the recovery of bioactive compounds. Indeed, SCG extracts are rich in antioxidants, particularly in chlorogenic acid (5-caffeoylquinic acid) (CGA) and melanoidins, which are able to prevent serious neurodegenerative and cardiovascular diseases. In order to preserve the activity of these compounds, encapsulation by spray drying can be used. In this study, an extract rich in phenolic compounds from spent coffee grounds was obtained by microwave-assisted extraction, using a mixture of ethanol:water 54:46 (v/v) as solvent, operative temperature of 150 \ub0C, and extraction time of 90 min. Encapsulation process, using inulin and maltodextrin as coating agents, was studied by means of an experimental design and the response surface methodology was used for data treatments. Inulin:maltodextrin ratio and sample flow rate effects on encapsulation yield, efficiency and product features was evaluated. Results demonstrated that high encapsulation efficiency (63%) can be reached using inulin as the carrier, leading to the production of microencapsulated dried powders rich in polyphenols that can have potential industrial applications in food and cosmetic areas

Production of chocolate powdered beverage with enhanced instant properties

Instant properties of chocolate powder such as solubility and dispersibility are important factors for the quality and consequently consumer acceptance of the final powdered beverage. With the aim of producing a novel powdered chocolate beverage with enhanced instant solubility, we studied the effect of spray drying process on the components of the chocolate powder. Spray drying of chocolate beverage formulation (complete recipe provided and protected by Domori s.r.l., Italy) was performed using a mixture of cocoa powder and sucrose 30:70 (w/w). Liquid feed was prepared by dissolving 17.5 g of powder in 100 mL of deionized water at 60 \ub0C and mixed until complete homogenization. The solution was fed to a mini spray dryer B-290 (B\ufcchi, Huddersfield, UK). In this work an inlet temperature of 150 \ub0C was used. Maltodextrin concentration (0, 3.5 and 7 % w/w) and drying air flow rate (22, 27 and 32 m3/h) were varied. Powders were stored at 4 \ub0C in closed dark vessels before analysis. The results of full factorial design showed that operating at a drying air flow rate of 27 m3/h and a maltodextrin concentration of 3.5 % w/w, powder with solubility of 74.2 \ub1 6.8% and dispersibility of 58.7 \ub1 2.9% was achieved. At this operative condition, powder recovery yield was almost consistent with the industrial one (45.5 \ub1 2.5%). Therefore, spray drying presents a useful way to produce chocolate powder with better instant solubility, which can also be dissolved in less amount of water (70 mL instead of 120 mL)

A Study of the Pyrolysis Products of Kraft Lignin

In order to valorize lignin wastes to produce useful aromatic compounds, the thermal degradation pyrolysis of Kraft lignin in the absence of catalysts has been investigated at 350, 450, and 550 °C. The high content of sulfur in the fresh sample led to the formation of S-containing compounds in products whose evolution in the gas phase was monitored through GC-MS analysis. Pyrolytic gas is rich in CH4, CO, CO2, and H2S with the presence of other sulfur compounds in smaller amounts (i.e., CH3SH, CH3-S-CH3, SO2, COS, and CS2). Biochar morphology and elemental composition have been investigated by means of SEM and EDX. The carbon content reaches ~90% after pyrolysis at 550 °C, while the oxygen content showed a decreasing trend with increasing temperature. From GC-MS analysis, bio-oil resulted rich in alkyl-alkoxy phenols, together with (alkyl)dihydroxy benzenes and minor amounts of hydrocarbons and sulfur compounds. NaOH/H2O and EtOH/H2O extraction were performed with the aim of extracting phenolic-like compounds. Sodium hydroxide solution allowed a better but still incomplete extraction of phenolic compounds, leaving a bio-oil richer in sulfur