Production and use of mussel shell protein in dry fish sauce

The objective of the study was to obtain protein ingredients from mussel shell valves and to examine their potential application in the production of dry sauce with regard to the impact on organoleptic and physicochemical parameters, and rheological properties. The organic component of the shells, designated as conchix, is primarily composed of proteinaceous substances with low solubility in water (14.86% at pH 7), as well as in diluted solutions of acids (13.56% at pH 3 and 13.06% at pH 5) and alkalis (16.51% at pH 9 and 28.48% at pH 11). The enzymatic treatment of conchix with pancreatin resulted in the production of a hydrolysate with a high content of readily available protein substances (53.19%) and a degree of hydrolysis of 17.54%. Four product samples with varying proportions of hydrolysate added (1–3% of hydrolysate, 2–6%, 3–9%, and 4–12%) and a control sample were prepared to investigate the impact of hydrolysate dosage on sauce characteristics. Dry sauces with hydrolysate supplementation had higher protein concentrations (17.97%, 18.21%, 18.71%, and 19.01% in samples 1, 2, 3, and 4, respectively) than the control sample (17.60%). An organoleptic evaluation was conducted to ascertain the impact of the hydrolysate on the appearance, color, taste and aftertaste, odor and consistency of the prepared sauces. Sample 4 scored lowest, while sample 1 scored highest. The recommended dosage of hydrolysate in the sauce formulation is between 3 and 9%. The hydrolysate had no significant impact on the rheological characteristics of sauces. The obtained results indicate the possibility of processing shellfish shells into a valuable protein ingredient applicable in the technology of dry sauces.