Search

Adhering to a healthy diet has a protective effect on human health, including a decrease in inflammatory diseases due to consuming fiber. The purpose of this manuscript was to obtain and compare two extracts based on fiber (BF and IF-C), derived from two plants particularly present in the Mediterranean region: bergamot (Citrus bergamia) and prickly pear (Opuntia ficus-indica). The parts used by these plants have been the “pastazzo” for the bergamot and the cladodes for the prickly pear. In addition to in vitro evaluations, the antioxidant activity was also measured on human neurons under inflammatory conditions. Furthermore, the extracts of interest were examined for their effects on the cell cycle and the regulation of pro-apoptotic proteins, caspase 9 and 3, induced by LPS. The results indicated that both extracts had a protective effect against LPS-induced damage, with BF consistently exhibiting superior functionality compared to IF-C. Moreover, the extracts can reduce inflammation, which is a common process of disease. By exploring this avenue, studying the consumption of dietary fiber could enhance our understanding of its positive effects, but additional experiments are needed to confirm this.

Green diesel is a real solution for the decarbonization process of the world, reducing in this way, carbon dioxide emissions to the atmosphere. The present work proposes a flexible biorefinery design where green diesel is produced by catalytic hydrotreatment of four vegetable oils: soybean, sunflower, palm, and cardoon oil feedstock. The process was simulated in Aspen Plus®. A multi-bed reactor composed of four catalytic beds with quenching cooling is designed and simulated in the presence of Ni-W/SiO2-Al2O3 catalyst, in addition to a separation phase train to obtain the green diesel. Sensitivity analyses were carried out to determine the parameter conditions of the unit operations. The results of the model reflex a molar conversion of triglycerides above 97% and overall mass yield into diesel fraction above 79%. Total capital costs and operating costs of the process were determined in the economic analysis, where a base case is considered for the calculations, obtaining the maximum vegetable oil market price can be sustainable to make economically convenient the biorefinery. Soybean oil resulted in the worst feedstock due to the high percentage of unsaturated bonds, while cardoon oil can be considered the best source to produce green diesel thanks to higher conversion yields.

The lignocellulosic biomass valorisation is a central challenge of the bioeconomy transition, which passes through optimization of the entire value chain, from feedstock availability, sustainable conversion processes, to final target products. In this framework, the oleaginous yeasts represent a versatile tool to produce biobased chemicals and intermediates. They are flexible microbial factories able to grow on different side-stream carbon sources such as those deriving from lignocellulosic biomass, and this characteristic makes them excellent candidates for integrated biorefinery processes through the production of microbial lipids/oils. This work aims at a techno-economic analysis of a lignocellulosic biorefinery producing microbial oils by oleaginous yeasts (Lipomyces tetrasporus). The wheat straw residues were considered as the lignocellulosic feedstock thanks to a huge amount in the European territory. Experimental data obtained by a complete lab-scale 2G-sugars platform (steam explosion pretreatment, enzymatic hydrolysis, fermentation) were used for the analysis until microbic growth. Commercial/literature data were considered for the lipids extraction and purification stages. An assessment of the mass and energy balances, equipment sizing, costs estimation was carried out with the main results showing a production cost of the microbial oil about 4 €/kg with the enzymes supply as the major cost contribution.

Inulin is accumulated as a reserve carbohydrate in the roots and tubers of many plants belonging to the Asteraceae family. At present, most of the inulin for nutraceutical purposes is produced from Jerusalem artichoke (Helianthus tuberosus L.) and Chicory (Cichorium intybus L.), and cardoon is proved to synthetize and store a high quantity of inulin in roots. Inulin in the roots of cardoon reaches the maximum content before the beginning of flowers formation in May. Due to the limited favorable period for harvesting the roots, storage plays a key role in the supply chain. The complete drying of cardoon roots before the storage has been proved to prevent the degradation of inulin up to 6 months of storage. Because drying is a costly operation, in the present study, energy-saving and the effect on percentage inulin content in cardoon roots dried at different moisture contents before storage were assessed. From 48.2% inulin retrievable at the beginning of the investigated period (100% dry matter), after 1 month of storage, about 2% reduction was recorded on average in H0 and H12.5 treatments, while about 10% reduction was shown (with no statistical differences) in treatments at higher moisture contents (TQ, H50, and H25). These values remained constant until the end of storage, except for TQ treatment, where inulin content decreased progressively up to 38.7% w/w. From an economic point of view, limiting the drying time and storing roots at a moisture content higher than 0% leads to an income loss of 2,000–3,000 €/t of roots. Therefore, full drying is the most cost-effective solution in the optic of producing the highest possible amount of inulin and could be avoided just in the case of immediate roots extraction and processing in a few days.

Microbial lipids are renewable platforms for several applications including biofuels, green chemicals, and nutraceuticals that can be produced from several residual carbon sources. Lignocellulosic biomasses are abundant raw materials for the production of second-generation sugars with conversion yields depending on the quality of the hydrolysates and the metabolic efficiency of the microorganisms. In the present work, wheat straw pre-treated by steam explosion and enzymatically hydrolysed was converted into microbial lipids by Lipomyces tetrasporus DSM 70314. The preliminary optimization of the enzymatic hydrolysis was performed at the bench scale through the response surface methodology (RSM). The fermentation medium and set-up were optimized in terms of the nitrogen (N) source and carbon-to-nitrogen (C/N) ratio yielding to the selection of soy flour as a N source and C/N ratio of 160. The bench scale settings were scaled-up and further optimized at the 10 L-scale and finally at the 50 L pilot scale bioreactor. Process optimization also included oxygen supply strategies. Under optimized conditions, a lipid concentration of 14.8 gL−1 was achieved corresponding to a 23.1% w/w lipid yield and 67.4% w/w lipid cell content. Oleic acid was the most abundant fatty acid with a percentage of 57%. The overall process mass balance was assessed for the production of biodiesel from wheat straw.

Lignocellulosic biomass represents one of the most important feedstocks for future biorefineries, being a precursor of valuable bio-products, obtainable through both chemical and biological conversion routes. Lignocellulosic biomass has a complex matrix, which requires the careful development of multi-step approaches for its complete exploitation to value-added compounds. Based on this perspective, the present work focuses on the valorization of hemicellulose and cellulose fractionsof giant reed (Arundo donax L.) to give second-generation sugars, minimizing the formation of reaction by-products. The conversion of hemicellulose to xylose was undertaken in the presence of the heterogeneous acid catalyst Amberlyst-70 under microwave irradiation. The effect of the main reaction parameters, such as temperature, reaction time, catalyst, and biomass loadings on sugars yield was studied, developing a high gravity approach. Under the optimised reaction conditions (17 wt% Arundo donax L. loading, 160 °C, Amberlyst-70/Arundo donax L. weight ratio 0.2 wt/wt), the xylose yield was 96.3 mol%. In the second step, the cellulose-rich solid residue was exploited through the chemical or enzymatic route, obtaining glucose yields of 32.5 and 56.2 mol%, respectively. This work proves the efficiency of this innovative combination of chemical and biological catalytic approaches, for the selective conversion of hemicellulose and cellulose fractions of Arundo donax L. to versatile platform products.