Enzymatic production of bioactive peptides from scotta, an exhausted by-product of ricotta cheese processing.

The present work reports the enzymatic valorisation of the protein fraction of scotta, a dairy by-product representing the exhausted liquid residue of ricotta production. Scotta was subjected to ultra-filtration with membrane cut-offs from 500 to 4 kDa and the obtained protein-enriched fractions were used for the optimization of enzyme-based digestions aimed at producing potentially bioactive peptides. Nine different commercial proteases were tested and the best digestion conditions were selected based on protein yield, fraction bioactivity and foreseen scale up processing costs. Scale up of the 3% Pancreatin or 5% Papain processes was performed up to 2 L (37°C or 60°C respectively, 1 h incubation), and the digestion efficiency increased with the reaction volume as well as antioxidant activity (up to 60 gBSA eq/L and to 1.7 gAA eq/L). Retentate 1 digested fractions also showed, for the first time in dairy-based peptides, anti-tyrosinase activity, up to 0.14 gKA eq/L. Digested proteins were sub-fractionated by means of physical membrane separations and 30-10 kDa fraction from Papain treatment showed the highest antioxidant and anti-tyrosinase activities. The peptide sequence of the most bioactive fractions was achieved.

Déclaration de conflit d'intérêts

The authors [MS, FM, CR, BP, TT, PB, TA] declare no financial or personal conflicts of interest. We have the following interests: Angelo Vittorio Zambrini and Emanuela Donati are employed by Granarolo S.p.A. There are no patents, products in development or market products to declare. This not alter our adherence to PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.