Impact of Dehulling on the Nutritional Composition, Bioactive Compounds, and Antioxidant Potential of Moroccan Faba Bean (Vicia faba L.) Varieties

Background: Faba bean (Vicia faba L.) is a nutrient rich yet underutilized legume endowed with considerable potential for enhancing food security and plant-based nutritional sustainability. In Morocco, however, the compositional diversity of local varieties and their biochemical response to processing interventions remain insufficiently characterized, thereby constraining the optimal valorization of this crop within sustainable dietary systems.

Aims: This study aimed to evaluate the nutritional composition, phytochemical profile, and antioxidant properties of nine Moroccan faba bean varieties, and to assess the influence of dehulling on their biochemical composition.

Materials and Methods: A comparative cross-sectional analysis was conducted on nine Vicia faba L. varieties cultivated in Morocco. Both whole seed (WS) and dehulled seed (DS) fractions were analyzed for proximate composition, mineral content, amino acid and fatty acid profiles, and phytochemical constituents. Antioxidant activities were determined employing three complementary assays: DPPH radical scavenging, ABTS radical cation decolorization, and ferric reducing antioxidant power (FRAP).

Results:  Significant varietal and processing effects were observed across all measured parameters. Crude protein content ranged from 20.05% (Alfia 21, WS) to 28.43% (Zina, DS), with dehulling consistently increasing protein concentration across varieties. Lysine and leucine were identified as the most abundant essential amino acids, with particularly elevated levels recorded in the Alfia 17 variety. Fatty acid profiling revealed a predominance of unsaturated fatty acids— most notably linoleic acid (45.31 – 54.42%)—, the proportion of which increased in DS fractions, whilst palmitic acid decreased correspondingly. Among macro-elements, potassium was the most abundant, followed by phosphorus and sulfur; iron and zinc constituted the principal microelements. Dehulling reduced calcium content (by up to 52.9%), whilst increasing phosphorus and sulfur concentrations. Total polyphenol content ranged from 2.86 to 4.26 mg GAE/g DM in WS fraction and declined significantly in DS fractions following seed coat removal. Antioxidant activities were higher in whole seeds across all varieties and assays.

Conclusions: Moroccan Vicia faba L. varieties exhibit substantial nutritional diversity, characterized by elevated protein content and favorable unsaturated fatty acid profiles. Dehulling enhances protein concentration and improves the bioavailability of select minerals; however, it concurrently diminishes antioxidant capacity as a consequence of phenolic compound loss associated with seed coat removal. These findings underscore the imperative to optimize processing strategies that reconcile nutrient enrichment with the retention of bioactive compounds, thereby maximizing the nutritional and functional value of faba bean in food system applications.