Nucleation of amino acid‐rich crystals on the surface of dried scallop (Chlamys farreri) during storage: formation mechanism and influence of environmental relative humidity

Abstract

Summary Formation of crystals on the surface of dried scallop (Chlamys farreri) adductor muscle is often observed during storage. The composition of these white crystals was determined, and the effect of relative humidity (RH) during storage on their formation was also studied. The white crystals were determined as the crystal of free amino acids, mainly composed of taurine (Tau) and glycine (Gly). The main polymorphic form of glycine in the crystals was further confirmed as the γ‐form. Besides free amino acids, another major part of the crystal composition was ions, such as Na+, NH4+, K+, PO43− and Cl−. The presence of various free amino acids and Na+ and K+ might contribute to the crystallisation of γ‐glycine. RH particularly at 65% and above significantly increased the amount of crystals. RH of 43% and below was recommended to prevent the formation of amino acid‐rich crystals on dried scallops during storage.