• cake
• camelina
• crambe
• linseed
• oilseed
• safflower

In the recent years, new perspectives for oilseed crops are open as renewable and valuable feedstocks for biorefinery processes. In fact, these kind of crops are particularly suitable for obtaining, through a cascading use of total biomass, highest added-value products, such as bio-based products and industrial materials (pharmaceuticals, nutraceuticals, fine chemicals, cosmetics, agrochemicals, biomaterials), over bioenergy. In particular, oilseed cakes, deriving from plant oil extraction, represent interesting co-products. They are usually used as animal feed, due to their high protein and energy contents. The nutritional values of oilseed cakes as animal feed and the feed performance has been extensively studied. On the other hand, the oilseed cakes contain bioactive substances, such as phenolic acids, flavonoids, lignans and other antioxidant compounds, which could be used as food additive, supplement or cosmeceutical additive for the protection of foods and human health. However, there are only few reports about their phytochemical characteristics. In view of a cascading approach of biomass utilization, the extraction of these chemicals can be considered in order to increase the added value of these co-products. In the present study, four different oilseed crops are considered: camelina (Camelina sativa (L.) Crantz., var. Italia), linseed (Linum usitatissimum L., var. Sideral and Buenos Aires), safflower (Carthamus tinctorius L., var. Pieve and Montola 2000) and crambe (Crambe abyssinica L., var. Mario 2000). They were cultivated in open field conditions, during two consecutive years (2014 and 2015), in two environments of central and northern Italy (Pisa and Bologna). After the agronomical evaluation (seed yield, harvest index, oil and protein content), the cakes, obtained from oil extraction, were chemically characterized. The content of total phenolic compounds (by the Folin-Ciocalteau assay), total flavonoids (by the aluminum-chloride method), and lignan quality profile (by HPLC-PDA/UV-ESI-MS/MS) were assessed. At the same time, the radical-scavenging activity was investigated by the DPPH method.
The phytochemical characterization of the obtained seed cakes showed that these co-products contained considerable amounts of bioactive substances, varying depending on the oilseed crops. In particular, camelina seed cake showed the highest content of polyphenols and flavonoids, while safflower and linseed exhibited the strongest radical-scavenging activity. For linseed cake, the profile of lignans showed the presence of secoisolariciresinol-diglucoside as the main compound of this interesting class of chemicals.
In conclusion, this study suggests that oilseed cakes from the investigated crops, due to their interesting phytochemicals and bioactive values, would be valuable candidates as functional foods and natural dietary supplements. These results, together with the good agronomic performance in terms of crop seed yield and oil content, suggest that these novel oilseed crops can be successfully introduced into the cereal based cropping systems of the tested environmental conditions, with potential agro-environmental and economic benefits.