• agronomic improvement
• Camelina sativa
• food and feed applications

In the current situation, where the sustainable intensification and diversification of cropping systems are recommended, and the bio-based economy is fast-growing, alternative and multipurpose oilseed crops could respond both to weather challenges and to provision of renewable and valuable feedstocks for biorefinery processes. Among these, camelina (Camelina sativa (L.) Crantz) was identified as relevant for Europe, being considered as valuable climate-resilient crop for agroecological transition. This crop can provide important ecosystem services (e.g., biodiversity increase, soil erosion protection, biotic and abiotic stresses alleviation) as well as valuable opportunities for European farmers to diversify their cropping systems, also in marginal soils, by introducing a crop capable of growing with a lower environmental footprint and with the potential of sourcing several high added-value products for the bio-based industry. Furthermore, the lacking domestic production of vegetable oil and proteins makes Europe and Italy almost fully dependent on imports from foreign countries with related problems due to the lack of traceability. Thus, the development of a value chain based on new multi-purpose crops such as camelina, could allow to address several strategic key-points of the agri-food system.
Camelina is renowned for its unique oil composition, boasting a fatty acids profile comprising more than 50% essential fatty acids as linoleic (C18:2, omega-6) and linolenic (C18:3, omega-3), along with a good protein content and bioactive compounds such as tocopherols, flavonoids, and phenolic acids. However, as all brassica species, camelina seeds contain several antinutritional molecules such as glucosinolates (GLSs), sinapine, condensed tannins, trypsin inhibitors, and phytic acid. Among these, GLSs are the most undesirable ones, because even if conferring protection against pathogens, their presence in the seedcake limits the use as animal feed because their breakdown products could cause goiter especially in monogastrics. For this reason, breeders are moving to create camelina lines with reduced GLS seed content allowing major valorisation of camelina by-products and maintaining, at the same time, the disease-protective effects of GLSs in other plant organs.
The main aim of this Thesis was fully exploited camelina as a resilient crop for the Mediterranean basin and suitable for obtaining high added-value products, through the evaluation of the effects of genetic characteristics, pedo-climatic conditions and agronomic management on its productive performances and quality.
The Thesis consists of 5 chapters. The first two chapters concern on an overall introduction and the aim of the PhD Thesis. The third chapter aimed at evaluating the effect of sowing time on growth, seed yield and final quality of products and co-products (seed and cake) of two newly released camelina lines in comparison with a commercial variety. To achieve this goal, plot trials were conducted, both in autumn and spring sowing, for three consecutive growing seasons (2019-20, 2020-21, and 2021-22) at the Experimental Centre of the Department of Agriculture, Food, and Environment (DAFE) of the University of Pisa, located at San Piero a Grado, Pisa (46°67’ N latitude; 10°31’ E longitude, altitude 1 m a.s.l. and 0% slope). The two improved camelina lines were Alan (supplied by CNR-IBBA, Italy) characterized by a low glucosinolate content, and Pearl (supplied by Smart Earth Camelina, Canada) whose fatty acid profile is characterized by low linoleic acid content and improved omega-3/omega-6 ratio. They were compared to Calena (supplied by Saatbau, Austria), a commercial variety used as reference. The results showed that camelina productive performance and seed quality significantly varied among cultivars, sowing time, and growing seasons. Alan and Pearl showed higher agronomic and productive performances compared to the commercial variety Calena, both in autumn and spring sowing. The cultivar Pearl proved to be an optimal source of healthy oil with high omega-3:omega-6 ratio, while Alan was identified as a suitable source of cake for poultry feeding thanks to its low glucosinolate content. Moreover, camelina seeds were analysed for the content of bioactive compounds, such as polyphenols, and the related antioxidant activity. The most abundant phenolic compound identified in camelina seeds was rutin, followed by quercetin, catechin, epicatechin, sinapic acid derivatives, and isorhamnetin. Thanks to the high content of phenolic acids and flavonoids, camelina seeds own the potential to be developed as ingredients in functional foods and nutraceuticals providing human health benefits.
Overall, the results obtained in this experiment confirmed the great agronomic potential of the two newly released camelina lines in the tested environment of central Italy, both in autumn and spring sowing. Furthermore, camelina provided both high-valuable oils and proteins, contributing to domestic production of these raw materials. Therefore, all these favourable characteristics makes camelina seeds and cake very appealing for food and feed applications as well as for biobased industry.
The chapter 4 deals with the optimization of nitrogen (N) management, that represents another important aspect for improving crop yield and quality, through a precision farming approach. At this regard, the literature about camelina response to different nitrogen fertilization rates, as well as on the use of remote/proximal sensing for evaluating its N status, is very scarce. So, a two-year experimental study was conducted to evaluate the effects of different N fertilizer regimes (rate and timing) on camelina growth, productivity (seed yield and yield components) and quality (protein and oil seed content), along with destructive and non-destructive (Dualex portable sensor and UAVs equipped with RGB and high-definition multispectral cameras) evaluations. In the 2021 and 2022 growing seasons, field plot trials were performed at the Experimental Centre of DAFE (located at San Piero a Grado, Pisa) with the aim of evaluating the spectral response of spring camelina to four different N fertilization regimes (i.e., T0 = control: no N application; T1 = top dressing apporting 60 kg N ha−1 before stem elongation; T2 = basal dressing apporting 60 kg N ha−1 at sowing; T3 = basal + top dressing combination apporting 60 kg N ha−1 at sowing + 60 kg N ha−1 before stem elongation). Remote (UAV) and proximal (leaf-clip Dualex) sensing techniques have been used. Good seed yields and high Nitrogen Use Efficiency (NUE), as well as good seed oil content, were reached with the application of 60 kg N ha−1 before sowing in spring camelina. UAV-derived vegetation indices during flowering phase represent a good seed yield predictor in camelina. In particular, Fractional Green Canopy Cover (FGCC) was the only vegetative index (Vis) capable of providing an indication of camelina nutritional status. Although preliminary, the obtained results demonstrated the feasibility of utilizing remote sensing techniques from UAVs for predicting seed yield in camelina. This could help in developing proper strategies for N application rates for camelina and for site-specific recommendations for its cultivation in central Italy.
Since very few studies on camelina cultivation at farm level have been conducted in Europe, the chapter 5 aimed to evaluate the scaling up of this crop through on-farm experiments carried out in central Italy, combining empirical and scientific knowledge. With the aim of evaluating the feasibility of camelina cultivation at farm level, a multilocation trial was conducted in four Tuscany farms, located at Fauglia (FA - Pisa province), Fucecchio (FU - Firenze province), Santa Luce (SL - Pisa province), and Arezzo (AR - Arezzo province) by farmers who were approaching this crop for the first time. The commercial Calena variety was sown in spring by adopting low-input agricultural practices (i.e. organic and integrated management) and crop growth, productive potential and seed quality have been evaluated in each farm. Remarkable variability has been observed in seed yield and quality, depending on cultivation site and on-farm agronomic management, demonstrating however the good potential of the crop. In fact, this preliminary multilocation study underlined the suitability of camelina to be managed under real operation conditions, contributing to design new sustainable and innovative cropping systems and value-chains, also in marginal areas.
Furthermore, in chapters 6 and 7, in order to address to the lack of vegetable oils and protein sources, camelina cake has been evaluated as potential ingredient for poultry feeding and healthy food products. In chapter 6, the effect of the animal dietary inclusion of camelina cakes (15%), deriving from Alan, Calena, and Pearl cold-pressed seeds, was assessed on the live performance, slaughter traits, and breast meat quality of broiler quails (Coturnix japonica L.). Quail has been chosen as animal model for food-producing farmed birds to test the camelina cakes due to its fast growth, short production cycle, small body size, and early sexual maturity. Such characteristics allowed to design time-saving experiments, achieving reliable results that could be replicable/extendable also on chickens. The results indicated that camelina cake can be considered as alternative feedstuff ingredient for broiler quails’ feed formulations, having not compromised carcass traits and meat quality. However, a 15% inclusion level seemed excessive as live performances were impaired.
Finally, in chapter 7, the possibility to fortify bread with camelina cake as carrier of bioactive substances was evaluated. Breadmaking tests were conducted at the Food Technology Laboratory of the DAFE, University of Pisa, by substituting the type '0' wheat flour with increasing concentrations of camelina cake: 0.5%, 1.5%, and 2.5 %. The inclusion of camelina cake had greatly altered bread organoleptic characteristics, nutraceutical properties and flavour profile. Bread enriched with 1.5% of camelina cake was individuated as the best formulation due to positive physical-chemical, sensorial analyses as well as nutritional and nutraceutical features, offering a very promising healthy alternative to consumers.