However, despite the fact that RM by-product could be largely used as a feedstock in livestock farming, the presence of some anti-nutritional components like glucosinolates, phenolics, phytates, and lignocellulosic fibres could negatively affect protein digestibility [11], especially when increasing levels of this by-product are used to feeding monogastric armed animals [12]. Similar limitations have been reported also in terms of its utilisation as a food ingredient since, if it is to be used as a natural source of proteins with versatile functional properties (e.g., foaming, emulsification, film-forming), the proteins need to be extracted and isolated from the residual press cakes and meals [1]. Moreover, the presence of intense bitter and stringent off-flavours, due to a wide range of phytometabolites such as glucosinolates and phenolic compounds, limiting the palatability in human consumption, still poses a challenge to the use of protein isolates in the food and beverage sector [13]. Therefore, in order to comply with a more circular and environmentally friendly European common agricultural policy (CAP), innovative solutions should be explored to support and boost the recycling of these protein-rich meals from the rapeseed oil industry [14]. This includes their processing into powder ingredients that are especially enriched in bioactive and/or superior taste profile molecules. Among these natural bioactive compounds, polyphenols are a wide and varied chemical family characterised by one or more aromatic rings substituted with hydroxyl groups in their structure, and they have been found to exhibit many beneficial biological activities [8]. Indeed, residuals after oil extraction from many varieties of rapeseed have been reported to have large amounts of polyphenols, which have strong antioxidant properties associated with anti-mutagenic and anti-inflammatory effects [15; 16; 17]. Several studies on animal models have reported that dietary supplementation with polyphenols isolated from oilseeds, including polyphenols isolated by using an ethanol extract, could help ameliorate metabolic disorders [18; 19]. It has already been demonstrated that the use of washing solvents is a powerful approach to extract desirable healthy compounds, such as polyphenols, from raw oilseed by-products. Among these biorefinery protocols, the use of ethanol seems to be effective to recover bioactive compounds while also avoiding the interactions with anti-nutritional substances (i.e., soluble non-protein components) from by-product meals, as well as an authorised process within the food industry [20]. Furthermore, the use of ultrasounds as an effective pre-treatment method for obtaining targeted changes in both the molecular profile and compound-related biological activities has already been suggested [21; 22]. Similarly, treatment based on microwave irradiation affected the composition of phenolic compounds such as sinapine, sinapoyl glucose, sinapic acid, and sinapoyl malate [23]. However, an in-depth characterisation of powdered ingredients through a comprehensive metabolomic approach, which can identify and quantify the presence of bioactivecompounds and systematically provide information on the effects of a specific on-going physical and/or chemical processing at a metabolite level, remains a challenge [24]. The metabolomics analysis performed by high resolution mass spectrometry (HRMS) has several advantages. The ability of HRMS to precisely measure mass-to-charge ratios allows for more accurate compound detection and elemental composition determination [25; 26]. Furthermore, it facilitates the distinction between isobaric molecules, which possess equivalent nominal masses. More recently, a plethora of innovative analytical techniques, including ambient ionisation mass spectrometry (AIMS) [27], have been coupled to HRMS and proposed with the objective of obtaining a comprehensive understanding of the composition of by-products and of their nutritionally enhanced derivatives, as well as of novel food.