Study on analytical characteristics of Nicotiana tabacum L., cv. Solaris biomass for potential uses in nutrition and biomethane production

Abstract

In order to limit the smoking tobacco sector crisis, a new non-GMO Nicotiana tabacum L. cv. Solaris was proposed as oil seed crop. Residues of oil extraction were successfully used in swine nutrition. The aim of this study was to explore the full potential of this innovative tobacco cultivar as multitasking feedstock non interfering with the food chain. In the triennium 2016-2018, samples from whole plant, inflorescence and stem-leaf biomass were collected in three experimental sites and analysed for chemical constituents, including fibre fractions, sugars and starch, macro-minerals and total alkaloids. The KOH soluble protein content and the amino-acid profile were also investigated as well as the biochemical methane potential. All the analyses were performed according to official methods and results were compared with values reported in literature for conventional lignocellulosic crops and agro-industry residues. The average protein content, ranging from 16.01 to 18.98 g 100 g^-1 dry matter respectively for stem-leaf and whole plant samples, and their amino-acid profile are consistent with values reported for standard grass plant. These findings suggest the potential use of cv. Solaris in industrial food formulations. Moreover, considering the average content of both fibre available for fermentations (72.6% of Neutral Detergent Fibre) and oils and fats (7.92 g 100 g^-1 dry matter), the whole plant biomass of cv. Solaris showed good attitude to anaerobic fermentation, confirmed by the biochemical methane potential of whole plant (168 Nm³ t^-1 organic matter). Similarly, results allow to define the cv. Solaris biomass as a good quality forage apt to ensiling for its chemical composition. The low total alkaloids content of cv. Solaris, in average 0.3 g 100 g^-1 dry matter, was previously reported not to affect growth performances and welfare traits of dairy heifers. These are the first results showing the multitasking potential use of cv. Solaris biomass, that could allow the recovery of tobacco cultivation know-how especially in marginal areas.