spanish broom spartium junceum l as new fiber for biocomposites the effect of crop age and microbial retting on fiber quality

Recently, there has been a revival of interest in Spanish broom (Spartium junceum L.) as a possible source of fibers to be used in biocomposite materials. The aim of this work was to evaluate the role of two selected strains of Clostridium felsineum (NCIMB 10690 and NCIMB 9539) in the retting of Spanish broom vermenes. Chemical composition and physical, mechanical, and morphological properties of fibers were investigated. The obtained results indicate that the process provides an ecofriendly method for Spanish broom retting and support the hypothesis that these fibers can be successfully used in composite materials

Aspetti qualitativi e salutistici dei frutti da consumo fresco

E’ oramai accertato scientificamente come il consumo quotidiano di frutta e verdura giochi un ruolo importante nel prevenire numerose malattie croniche degenerative come il cancro, cardiopatie, osteoporosi, arteriosclerosi e l’invecchiamento cellulare. Gli effetti benefici del consumo abituale dei prodotti ortofrutticoli sono dovuti alla presenza di minerali, fibre, acqua ma in particolare al loro alto contenuto in composti antiossidanti, normalmente conosciuti in letteratura come fitochimici quali i composti fenolici, i carotenoidi e la vitamine C ed E. Con vari meccanismi i composti fitochimici sono in grado di contrastare l’eccessiva formazione dei radicali liberi, ovvero le specie reattive dell’ossigeno (ROS). Per questa ragione i prodotti ortofrutticoli assumono lo status di cibi funzionali in quanto, oltre al basso apporto calorico, sono una fonte di utili agenti antiossidanti. Il consumatore moderno ha preso coscienza di quest’ultimo aspetto ed infatti ricerca sempre più la salubrità del prodotto, che per ottenerla implica numerosi aspetti del processo produttivo sia in pre- che in post-raccolta. Lo scopo della ricerca era la valutazione di alcuni fattori di pre- e post-raccolta sugli aspetti qualitativi e salutistici di frutti da consumo fresco: la pesca ed il kiwi. Le analisi effettuate erano relative alla determinazione delle principali caratteristiche organolettiche (pezzatura, consistenza della polpa, contenuto in solidi solubili ed acidità titolabile) nonché di quelle nutraceutiche (capacità antiossidante, contenuto in fenoli, acido ascorbico, carotenoidi). I fattori presi in esame sono stati: - genotipo, visto nelle sue due accezioni di cultivar e di portinnesto - epoca di raccolta - posizione del frutto sulla pianta e conseguentemente effetto della diversa intercettazione della radiazione luminosa - managment idrico - modalità di conservazione (effetto della conservazione in cella frigorifera e a temperatura ambiente) Le pesche utilizzate in questa tesi provenivano dall’l’Azienda Sperimentale del Dipartimento di Coltivazione e Difesa delle Specie Legnose “G. Scaramuzzi” dell’Università di Pisa, a Colignola (PI), mentre i kiwi sono stati forniti dall’Azienda Agricola Camillo Pacini e Figli di Rigoli (PI). Lo studio relativo all’influenza del genotipo sulle caratteristiche qualitative delle pesche ha dimostrato come la diversità genetica giocasse un ruolo prioritario nel determinare la capacità antiossidante. E’ stato visto come quest’ultima fosse maggiormente correlata alla singola cultivar in esame piuttosto che al gruppo di appartenenza (pesche a polpa gialla, a polpa bianca, percoche e nettarine). Il risultato più significativo ha evidenziato come la capacità antiossidante non era determinata dal contenuto totale in fenoli, ma dalla struttura chimica di questi composti. Per quel che riguarda l’influenza del portinnesto i risultati ottenuti non ci hanno permesso di delineare un comportamento comune per quelli di egual vigoria; infatti, l’Mr.S.2/5, tipico portinnesto a bassa vigoria, ha dimostrato indurre nei frutti di Flavorcrest un’elevata capacità antiossidante, non registrabile nei frutti delle piante innestate su Ishtara, anch’esso di bassa vigoria. Non è ancora chiaro, tuttavia, in che modo il portinnesto eserciti la sua influenza sulla qualità; certamente importanti fattori sono coinvolti in questo processo come ad esempio la struttura della chioma, la quantità di luce intercettata, la disponibilità di nutrienti ed acqua, la concentrazione di regolatori della crescita. Anche l’epoca di raccolta essere un importante fattore nel determinare le proprietà organolettiche e nutrizionali del frutto. Nel kiwi, un ritardo dell’epoca di raccolta determinava una riduzione del contenuto in acido ascorbico, principale fitochimico di tale frutto, mentre non si registravano variazioni significative nella capacità antiossidante. Nelle pesche, l’epoca di raccolta influenzava significativamente sia il contenuto in fitochimici che la capacità antiossidante, anche se non era possibile correlare il contenuto di fenoli totale della polpa con lo stadio di maturazione del frutto. Diversamente, nella buccia, ritardando l’epoca di raccolta si determinava un accumulo significativo dei composti fenolici. Inoltre, lo stadio di maturazione determinava un incremento del -carotene nella polpa a seguito dell’aumento del processo di carotenegenesi. La disponibilità idrica ha dimostrato essere importante ai fini delle caratteristiche organolettiche (pezzatura e contenuto in solidi solubili) e fitochimiche (acidi idrossicinnamici, antocianine e procianidine) in frutti di pesco. Questi risultati suggeriscono come un risparmio idrico possa essere efficacemente utilizzato per migliorare la qualità dei frutti e delle produzioni. Un importante fattore studiato è stato la modalità di conservazione nei frutti di kiwi. I risultati hanno dimostrato come la frigoconservazione, indipendentemente dall’epoca di raccolta determinasse effetti negativi sulla consistenza della polpa e sulla capacità antiossidante. Le sostanze fenoliche a seguito di una lunga frigoconservazione (5 mesi a 0°C) subivano un incremento così come dopo la permanenza dei frutti per una settimana a temperatura ambiente. Allo stesso modo, la conservazione a temperatura ambiente induceva un aumento in acido ascorbico. Da tutto ciò si può evincere come frutti caratterizzati da elevate proprietà nutrizionali mostravano sfortunatamente basse caratteristiche organolettiche, soprattutto in relazione ad un’elevata riduzione della consistenza della polpa. In virtù di ciò si è cercato di studiare il fenomeno del softening attraverso le analisi delle attività enzimatiche delle poligalatturonasi e delle -galattosidasi in frutti di kiwi mantenuti in cella frigorifera per 2 mesi. I risultati dimostravano come l’attività delle poligalatturonasi aumentasse durante la conservazione in cella frigorifera e subisse un ulteriore incremento al termine della successiva settimana a temperatura ambiente. L’attività delle -galattosidasi, in frutti raccolti precocemente, diminuiva durante la conservazione, mentre nessuna variazione era registrata in frutti raccolti commercialmente. Questi risultati dimostrano come l’attività dei due enzimi sia sequenziale. In conclusione, questa ricerca ha dimostrato come alcuni tra i principali fattori di pre- e post-raccolta esercitino un’azione, direttamente ed indirettamente, nella definizione di prodotto frutticolo

Impact of nitrogen supply on growth, steviol glycosides and photosynthesis in Stevia rebaudiana Bertoni

This work investigated the agronomic, physiological and biochemical response of Stevia rebaudiana Bertoni grown under different nitrogen (N) rates. A pot trial in open air conditions was set up in 2012 with the aim to evaluate the effect of four N rates on the biometric and productive characteristics, steviol glycoside (SG) content as well as on leaf gas exchanges, chlorophyll fluorescence, photosynthetic pigments, Rubisco activity and N use efficiency. N deficiency caused a decrease in leaf N content, chlorophylls and photosynthetic CO2 assimilation, resulting in a lower dry matter accumulation as well as in reduced SG production. The application of 150 kgNha21 seems to be the most effective treatment to improve rebaudioside A (Reb A) content, Reb A/stevioside ratio, photosynthetic CO2 assimilation, stomatal conductance, N use efficiency, ribulose-1,5-bis-phosphate carboxylase/oxygenase (Rubisco) and PSII efficiency. The results demonstrate that by using an appropriate N rate it is possible to modulate the SG biosynthesis, with a significant increase in the Reb A content and in the ratio between Reb A and stevioside. This finding is of great relevance in order to obtain a raw material designed to meet consumer needs and bio-industry requirements for high-quality, Reb A content, and safe and environmentally friendly products

Health-Promoting Compounds in Stevia: The Effect of Mycorrhizal Symbiosis, Phosphorus Supply and Harvest Time

This work aimed to establish the synergic role of arbuscular mycorrhizal fungi (AMF) symbiosis, phosphorus (P) fertilization and harvest time on the contents of stevia secondary metabolites. Consequently, steviol glycosides (SVglys) concentration and profile, total phenols and flavonoids as well as antioxidant assays, have been assessed in inoculated and no-inoculated plants, grown with or without P supply and collected at different growth stages(69, 89 and 123 days after transplanting).The obtained results suggest that the synthesis of stevia secondary metabolites is induced and/or modulated by all the investigated variability factors. In particular, AMF symbiosis promoted total SVglys content and positively influenced the concentration of some minor compounds (steviolbioside, dulcoside A and rebaudioside B), indicating a clear effect of mycorrhizal inoculation on SVglys biosynthetic pathway. Interestingly, only the mycorrhizal plants were able to synthesize rebaudioside B. In addition, P supply provided the highest levels of total phenols and flavonoids at leaf level, together with the maximum in vitro antioxidant activities (FRAP and ORAC). Finally, the harvest time carried out during the full vegetative phase enhanced the entire composition of the phytocomplex (steviolbioside, dulcoside A, stevioside, rebaudioside A, B, C. total phenols and flavonoids). Moreover, polyphenols and SVglys appeared to be the main contributors to the in vitro antioxidant capacity, while only total phenols mostly contributed to the cellular antioxidant activity (CAA). These findings provide original information about the role played by AMF in association with P supply, in modulating the accumulation of bioactive compounds during stevia growth. At the cultivation level, the control of these preharvest factors, together with the most appropriate harvest time, can be used as tools for improving the nutraceutical value of raw material, with particular attention to its exploitation as functional ingredient for food and dietary supplements and cosmetics

Valorisation of hemp inflorescence after seed harvest: Cultivation site and harvest time influence agronomic characteristics and essential oil yield and composition

Cannabis sativa L. is a multipurpose crop, whose industrial varieties, complying with the 0.2% Δ9-tetrahydrocannabinol (THC) threshold set by the EU legislation, can be cultivated without restrictions by farmers. Other than its traditional use as a source of bast fibres from the stems, the fixed oil extracted from its seeds represents a valuable nutritional product. Its inflorescence is also a further exploitable threshing residue originating from seed harvest, as they can be used for the extraction of the essential oil (EO), a high-value added product. This study aims at contributing to the re-evaluation of industrial hemp cultivation as an agro-environmentally sustainable crop for the diversification of Mediterranean cropping systems, by exploring the possibility of recovering the EO from the inflorescence after seed harvest. The influence of the cultivation site (lowland and upland of Pisa province, Tuscany, central Italy) and the harvest time (August and September) have been investigated on the ‘Fedora 17’ monoecious hemp cultivar: the main agronomic traits in term of stem, seed and inflorescence production, as well as essential oil yield and composition have been evaluated. The crops harvested in September exhibited higher total dry yield as well as higher inflorescence and stem yields, while neither the site nor the harvesting period influenced the seed production, which was significantly influenced by harvest time x cultivation site interaction. Both seed fixed oil and crude protein content were affected by the cultivation site only, but in the opposite sense: the highest seed oil content was reached in the upland area, while the plants grown in the plain area exhibited the largest seed protein content. All the extracted EOs were rich in sesquiterpenes (mostly β-caryophyllene and its oxidized derivatives, and α-humulene), but monoterpene hydrocarbons were significantly represented as well (mainly α- and β-pinene, and myrcene). The EOs extraction yields were slightly higher in the earlier harvest for both sites

Agronomical evaluation and chemical characterization of Linum usitatissimum L. as oilseed crop for bio-based products in two environments of Central and Northern Italy

In the recent years, new perspectives for linseed (Linum usitatissimum L.) are open as renewable raw material for bio-based products (Bb), due to its oil composition, and the interesting amounts of coproducts (lignocellulosic biomass). Therefore, the possibility to introduce linseed crop in two environments of central and northern Italy, traditionally devoted to cereal cultivation, has been evaluated. Twoyears field trials were carried out in the coastal plain of Pisa (Tuscany region) and in the Po valley (Bologna, Emilia Romagna region), comparing two linseed varieties (Sideral and Buenos Aires). Agronomical evaluation (yield and yield components), seed and oil characterization (oil, protein content, and fatty acid composition), together with carbon (C) and nitrogen (N) content of the residual lignocellulosic biomass were investigated. The two varieties, grown as autumn crop, showed a different percentage of plant survival at the end of winter, with Sideral most resistant to cold. The achieved results showed significant influence of cultivar, location and growing season on yield and yield components, as well as on chemical biomass composition. In particular, Sideral appeared to be the most suitable variety for tested environments, since higher seed yield (3.05 t ha–1 as mean value over years and locations) and above-ground biomass (6.98 t ha–1 as mean value over years and locations) were recorded in comparison with those detected for Buenos Aires (1.93 and 4.48 t ha–1 of seed production and lignocellulosic biomass, respectively). Interestingly, in the northern area, during the 1st year, Buenos Aires was the most productive, despite its low plant survival at the end of winter, which determined a strong reduction in plant density and size. In such conditions, the plants produced a larger number of capsules and, consequently, high seed yield (3.18 t ha–1). Relevant differences were also observed between the two years, due to the variability of climatic characteristics (temperature levels, and moisture regimes). All these findings confirmed as, in linseed, yield and yield components are quantitatively inherited and influenced by both genotype and environment (location and climate). Varietal and environmental effects were also recorded for oil content and yield, and, generally, good oil percentages, for both genotypes, were found (ranging from 44 to 49% on dry matter basis). Oil from the two varieties was characterized by a stable proportion of polyunsaturated fatty acids with a high content of alpha-linolenic acid (more than 57%), that makes this oil suitable to be used in paints, resins, varnishes, linoleum, polymers and oleochemicals. Finally, our results pointed out as above- and below-ground biomasses, were different in terms of quantity, and chemical characteristics (N, C and C/N ratio). Interesting amounts of N and C could return into the soil by crop residues (stem portions and roots), thus underling the possibility to maintain and/or increase the soil organic matter pool

Ramie fibers in a comparison between chemical and microbiological retting proposed for application in biocomposites

Due to light weight, renewability, sustainability and generally moderate costs, natural fibers are addressed for the production of composites for application in packaging, automotive and other indus- tries. Several approaches are under investigation to improve compatibility with polymer matrices and improve mechanical performances of composites with natural fibers. The retting process is the major limitation to efficient and high-quality natural fiber production. The conventional retting is normally done chemically by treatment of decorticated fibers with hot alkaline solutions. Such a process requires high energy input and produces hazardous wastes. Microbiological and enzymatic methods represent a reliable replacement, however their application on ramie (Boehmeria nivea (L.) Gaud.) has not yet been optimized and tuned for use on a large scale. Consequently, the aim of this work was to evaluate the role of microbiological retting on the morphological, chemical and physical–mechanical properties of the derived ramie fibers for application in biocomposites. The decorticated ramie fibers, obtained by mature crop stands grown at the experimental station of the Department of Agriculture, Food and Environment (DAFE) of the University of Pisa, were subjected to a water based microbiological degumming performed with the use of two selected strains of Clostridium felsineum L. at 30◦C for 7 days. The results obtained with this method were compared with those recorded adopting the conventional chemical process with NaOH water solution at 100 ◦ C for 2 h. The morphological, chemical (hemicellulose, cellulose, lignin and ash) and physico-mechanical (tensile strength, elastic modulus and elongation at break) properties of retted ramie fibers were investigated. The fibers produced were evaluated for the production of compos- ites by using polyhydroxyalkanoates (PHAs) as polymeric matrix, as targeted in the EC running project OLI-PHA. Significant differences were observed between the two types of degumming in terms of yield and quality of the fibers. Even if the highest fiber yields were recorded with chemical retting, the perfor- mances of fibers modified by microbiological treatments were comparable with those of the composite prepared with fibers modified by chemical treatment. Scanning electron microscopy analysis revealed a good removal of non-cellulosic gummy material from the surface of ramie fibers. According to the mechanical properties, the ramie fibers obtained by both degumming processes, were suitable for use in PHAs composites

Environmental assessment of flax straw production for non-wood pulp mills

Nowadays, there is an increasing interest for using non-woody fibres as raw materials for production of paper´s pulp. The present work aims to identify and quantify the environmental impacts associated with the production of flax fibres, through 3-year field experiment, carried out in Bologna and Pisa representative of the pedoclimatic characteristics of central Italy. Life Cycle Impact of “a one ton of fibre ready to be processed in a pulp mill” was assessed taking into account: farming, straw process (drying, scutching and baling) and transport. Inventory data for agricultural inputs and outputs were obtained directly from field experimentation and from bibliographic data about heat, transport and electricity consumption on straw processing. An economic allocation approach to assign impacts within flax seed and processed straw has been used. The CML baseline 2000 methodology was selected to quantify the potential environmental impact associated to the crops. Specifically, global warming (GWP), acidification (AP), eutrophication (EP) and photochemical oxidant formation (POP) were evaluated together with energy use (EU). Major impacts contribution arise from fertilizers use and straw processing. Cultivation phase of flax fibre at Pisa reported higher values (approximately 3 times greater) for all the impact categories. The lower impact in the flax cultivation scenario at Bologna was due to no use of mineral fertilizer and the higher flax-straw yield. It resulted also a strong reduction of the impacts with respect to those of hemp pulp in Spain as well as to the impacts of the conventional wood-pulp reported in Simapro. Furthermore, LCA tool aided to identify the materials and process that most affected the impacts: fertilizers use, diesel consumption and straw processing were identified as hot spots in both crops. Finally, non-wood pulp derived from Bologna´s Flax straw represents an opportunity to replace conventional wood pulp in Italian paper industry

Precision Nitrogen Management In Camelina: Preliminary Results From A Case Study In Central Italy

Nowadays, the use of advanced technologies in agriculture is mandatory in order to increase cropping system sustainability and quality. To guarantee a higher yield, farmers need to ensure the best health of their crops with, at the same time, the least environmental impact. Particular attention is generally paid to nitrogen fertilization since nitrogen use efficiency in modern agriculture is very low. It means that a lot of synthetic chemicals are wasted rather than utilized by crops with consequent environmental issues. The use of spectral reflectance indices, such as the normalized difference vegetation index (NDVI) and chlorophyll index (Dualex), are reliable indicators to determine N status of crop plants. In this contest, very scarce knowledge is available about the response of camelina - a promising oilseed crop for food, feed, and the bio-based industry - to different N rates as well as on the use of remote/proximal sensing. So, this study aimed to evaluate the effect of N fertilization rate and timing on camelina seed yield and quality. At the same time, biochemical parameters and NDVI by using proximal sensing techniques were assessed with the aim to optimise camelina agronomic management

Hydrothermal Carbonization of MunicipalWoody and Herbaceous Prunings: Hydrochar Valorisation as Soil Amendment and Growth Medium for Horticulture

In this study, we investigate the suitability of hydrochar, produced at industrial scale by hydrothermal carbonization of municipal woody and herbaceous prunings, to be used as soil amendment and peat substitute in organic growth medium for horticulture. Fresh hydrochar and the products of two different hydrochar post-treatments (i.e., washing and aging) were compared in terms of potential phytotoxicity throughout physicochemical characterization and germination tests, performed with a sensitive species (Lactuca sativa). The results showed that the fresh hydrochar obtained from municipal green wastes complies with the Italian regulated parameters for the use as soil amendment. Moreover, hydrochar exhibits biological activity and a high content in organic C, Ca, and other micronutrients (Mg, Zn, Cu, Na, Cl). On the other hand, post-treatments are needed before application of hydrochar as peat substitute in potting mix, since appreciable phytotoxic effects on lettuce seed germination and radicle length of plantlets were observed (e.g., germination percentage of 56% and 54%, with 5 and 10 wt % of hydrochar in the blend, respectively). The inhibition of germination could be mainly attributed to the presence of polyphenols (tannins) and volatile fatty acids, which were most effectively removed through the aging post-treatment