Medium- and short-sized antioxidant peptides from simulated gastrointestinal digestion of muscle and hydrolysed by-products of blue whiting [DATASET]

Fish consumption is rapidly increasing worldwide, leading to increased production of related by-products and waste that can represent a suitable resource for recycling and sustainability solutions aimed at a sustainable economy. Fish-derived peptides can be exploited as food, cosmetic or pharmaceutical ingredients, due to their wide variety of biological activities. In this study, the effect of simulated gastrointestinal digestion (GID) on the generation of antioxidant peptides from blue whiting muscle and from by-products hydrolysates obtained by alcalase hydrolysis and ultrasound-assisted alcalase hydrolysis was investigated. Results showed that GID led, in general, to an increase of the antioxidant activity when measured by ABTS and ORAC assays, whereas it mostly decreased when tested with DPPH and FRAP assays. A total of 1246 medium-sized and 415 short-sized peptides were identified by nano- or ultra-high-performance liquid chromatography coupled to mass spectrometry. In this context, GID led to a significant reduction in the number of identified medium-sized peptides in all samples, while increasing the quantity of short peptides identified in the digested muscle and keeping those in the by-product hydrolysates practically unchanged. Peptides containing proline, aspartate, histidine, tryptophan or glycine residues were the most resistant to GID. In silico studies of the identified peptides predicted 36 short-sized sequences resistant to GID with high potential to be bioactives. The results of this research underline the potential antioxidant activity of fish peptides obtained from GID of the edible part of the muscle. On the other hand, the retrieval and reuse of by-products with antioxidant properties provides sustainability and economical throughput, thus promoting circular economy in aquaculture.