Elements for optimizing a one-step enzymatic bio-refinery process of shrimp cuticles: Focus on enzymatic proteolysis screening

- Acid Stable Protease (ASP) reached deproteination rates better than 95%, both at pH 3.5 and pH 4.0.
- Five proteases exceed the deproteination rate of 95% at pH 3.5.
- Glycine is less solubilized than the other amino acids except with pepsin enzyme.
- Pepsin and the others enzymes acts differently in two groups in light of the results obtained by exclusion chromatography of aqueous phase.

This article complements an earlier work published in 2015 Baron et al. (2015) that showed the interest of a shrimp shells bio-refining process. We compare here the effect of eleven commercial proteases at pH 3.5 or 4.0 on a residual amount of shrimp shells proteins after 6 h at 50 °C. The two pH are obtained when respectively 40 and 25 mmol of formic acid are added to 5 g of mild dried shell. Deproteinisation yield above 95% are obtained. Residual amino acids profile in the solid phase was identical for the eleven proteases except for pepsin which was similar to the raw material profile. A significant relative increase in the proportion of Glycine is observed for the ten other cases. Likewise, shapes of size exclusion chromatograms of the dissolved phase are similar except with pepsin.

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