Bioactive Compounds Assessment in Six Moroccan Rapeseed (Brassica napus L.) Varieties Grown in Two Contrasting Environments

Abstract

Rapeseed (Brassica napus L.) is the world’s second-largest oilseed crop after soybean. It contains functional compounds, including fatty acids and phenols, which are known for their health and nutritional benefits. In Morocco, rapeseed was introduced as a promising oilseed crop that has shown good adaptation and great potential. Six genotypes were registered and released as the most high-performance Moroccan varieties in terms of both seed yield and oil content. Apart from their ‘00′ quality, i.e., oil without erucic acid and meal with very low glucosinolate content, there is no information on other important quality traits. Therefore, this research aimed to characterize the lipochemical and phenolic attributes of those varieties, namely Baraka, Narjisse, Moufida, Lila, Alia, and Adila, grown at two contrasting sites (Allal Tazi and Douyet) so as to assess the environmental impact on oil quality. A set of 14 parameters were analyzed, comprising seed yield, oil content (Oil C), protein content (PC), acidity index (IA), peroxide index (IP), refractive index (IR), iodine value (IO), total phenolic content (TPC), total flavonoids, total carotenoid contents, free-radical scavenging activity (FRSA), half-maximal inhibitory concentration, fatty acid composition, and omega 6/omega 3 ratio. The results displayed significant differences (p < 0.001) between the two sites for all the abovementioned traits, except for IA, with an outperformance of Allal Tazi over Douyet. Additionally, variety and variety by site interaction had a significant effect on all the studied parameters, except for IA, IP, IR, and TPC. Over both environments, the varietal effect generated variations in yield of 10.9 to 17.1 q/ha, Oil C of 36.7 to 39.9%, PC of 21.3 to 25.9%, IO of 94.1 to 100 g I2/100 g, FRSA of 22.7 to 42.9%, and an omega6/omega3 ratio of 1.8 to 2.3%. It is noteworthy that the Moufida and Alia varieties displayed a low-magnitude effect of the environment, as they maintained similar high performance over both sites. They, thus, represent Moroccan genetic material of interest from an agronomic and nutritional perspective. Therefore, they should be promoted and encouraged for cultivation in Morocco, mainly in the Allal Tazi area and similar regions.