• Energy Research

Vegetable biomass is one of the most promising renewable sources of energy and chemicals. Indeed, its exploitation for biofuels and chemicals production has been the focus of research over the last years since the gradual shift toward the so-called bio-based economy (an economy system based on exploitation of renewable resources), has determined a global increasing demand for goods mainly derived from vegetable biomass. In line with the biorefinery approach for the re-use of waste biomass, the residues of industrial processing of lemon (Citrus limon), tomato (Lycopersicon esculentum var. ‘‘Hybrid Rome’’), fennel (Foeniculum vulgare var. dulce) and carrot (Daucus carota), were used as sources of two kinds of value addedproducts i.e polysaccharides and polyphenols. Here we described the main properties of the polyphenol extracts and the polysaccharides fractions that could be obtained by each selected waste biomass. Both the polyphenol and polysaccharides fractions were investigated for their chemical composition and for the biological and biotechnological properties.

Cardoon seed oil (CO), derived from the nonedible Cynara cardunculus plant, growing in marginal and contaminated soils of Mediterranean regions, was successfully epoxidized (ECO) in a fed-batch mod...

Cardoon, Cynara cardunculus L. represents a biorefinery crop with a great potential in the bioplastic field. This work investigates the valorization of different cardoon components into high added value products, finally recombined into novel upgraded bioplastics. Bioprocesses for Polyhydroxybutyrate (PHB) and medium-chain-length Polyhydroxyalkanoates (mcl-PHA) production were set up starting from root inulin and seed oil respectively, highlighting the effect of process conditions on polymer properties. The ternary blend, in which the PHB polymer matrix was added with mcl-PHA and epoxidized cardoon oil, evidenced a synergic effect of both additives in modulating PHB structural and thermal properties, promoted by the physical interaction occurring among the components. This proof-of concept frames the paper in the holistic approach of circular economy applied to bioplastic production.

An innovative biodegradable coating that can be sprayed was developed and tested as suitable alternative to low density polyethylene (LDPE) films for soil mulching in horticulture. A mulch was created by spraying onto the soil a sodium alginate water-based solution that, at the end of the cultivation cycle, could be tilled into the soil to be biodegraded. The mechanical and radiometric properties, the functionality of the spray coating, and its biodegradation were assessed by means of laboratory measurements and cultivation field tests. In the field, during the cultivation of strawberries, the spray coating was compared with a LDPE mulching film and a straw mulch. The mechanical properties of the coating degraded when exposed in the field, but the coating kept its mulching effect for 6 months. The radiometric properties varied without regular trends, but the coating maintained its capacity to suppress weeds. The biodegradation tests showed that the spray coating samples biodegraded by 65% after 6 months into the soil.

In order to develop new eco-sustainable technologies to set up biodegradable films for agricultural activities, spray mulching coating have been planned, prepared and tested on experimental fields. The suitable polymers used to this purpose were Arabic Gums and Agarose. Cellulose fibres were added to the polymeric water solution to improve the mulching power and to increase the tensile strength of the composite; glycerol as plasticizer was added in order to improve the mechanical response of mulching coatings. On the composites sprayed and naturally aged on the soil, both in greenhouse and in open field, mechanical, water vapor transmission rate and morphological analyses were carried out; the different environment influenced the outcomes of studied properties, evidencing better results and promising perspectives for composites employed and aged under controlled atmosphere of greenhouse.

The use of plastic materials in agriculture causes the serious drawback of huge amount of wastes to be disposed of. In order to overcome this problem a new generation of biodegradable materials has been developed based on raw materials coming from renewable source. These materials retain their physical and mechanical properties during their lifetime and when they are integrated directly in the soil, the bacterial flora transforms them in carbon dioxide or methane, water and biomass. Biodegradable films can be made using natural polymers, such as starch, cellulose, chitosan, alginate and galactomannans. These materials can be obtained by means of thermoextrusion process, solvent casting and spraying technique. Mulch coatings can be realized directly in field by spraying water solutions based on natural polysaccharides, thus covering the cultivated soil with a protective thin geo-membrane. In this paper a focused overview on the formulation development, processing understanding, field performance and mechanical properties of these innovative materials for soil mulching is presented, in comparison to oil-based non renewable films. During their using time in field, the biodegradable mulches showed suitable mechanical properties if compared to the low density polyethylene films. At the end of their lifetime the biodegradable materials were shattered and buried into the soil together with plants. The film residues disposed of in the soil biodegraded in almost 1 month for the water borne coatings and in about 12 months for the biodegradable starch- based extruded films.