Caviar-like hydrogel beads containing different concentrations of NaCl and melanin-free squid ink

Abstract

Different concentrations (0, 0.25, 0.5, 1 and 2%) of melanin-free ink (MFI) obtained from squid (Loligo vulgaris) discards was incorporated into alginate hydrogels containing different concentrations (3 and 5%) of NaCl to produce a blackish colored caviar-like product. Addition of MFI up to 1% into the caviar-like beads (CLB) solution increased physicochemical and sensorial properties but further (2%) addition significantly decreased sensorial properties such as odor, taste and liking scores. An increase in NaCl concentration in the bead formulation from 3 to 5% significantly increased the bulk density, MFI releasing rate, turbidity and hardness values of CLB, whereas L* color values decreased. CLB containing 3% NaCl were almost spherical shape compared to beads containing 5% NaCl which were tear shape. Addition of MFI into the CLB formulation did not affect the shape of beads. At 3% NaCl, the MFI and alginate were strongly attractive and so the MFI was better retained within the beads during storage. The CLB containing 3% NaCl and 1% MFI was the most preferred product for the hedonic sensory test and it could be an alternative to sturgeon caviar. Encapsulation of MFI in alginate beads as a colorant and bioactive compound could be a promising technique for caviar-like hydrogel bead production.