Evaluation of composition and in vitro solubility rate of by-products of the Atlantic shellfish industry as alternative calcium sources

Abstract

SUMMARY Mineral composition and in vitro solubility rates for 14 different Atlantic calcium (Ca) sources were assessed. Fourteen test Ca sources [commercial limestone, granular limestone, shell mix, AIM-limestone, oyster shell, crab shell (CS), lobster shell (LS), blue mussel shell, blue mussel shell–clean, surf-clam shell, soft-clam shell, scallop shell, quahog shell, abalone shell, and whelk shell] were separated into their particle size groups that ranged from 1.0 to 1.41 to <2.83 mm. Average concentration of Ca was 36 g/kg in all Ca sources (except CS and LS). Calcium content was 20.35 and 20.32% in CS and LS, respectively. The mineral composition analysis showed values of P varying from 0.03 to 1.8%, Mg from 0.01 to 1.2%, K from 0.005 to 0.32%, Na from 0.02 to 0.81%, Mn from 7.22 to 2168 mg/kg, Zn from 23.8 to 120.5 mg/kg, Fe from 0 to 37.9 mg/kg, Cu from 10.4 to 41 mg/kg, and boron from 0 to 163 mg/kg. There was significant interaction (P < 0.05) between Ca sources and time for solubility for different particle size of Ca sources. In vitro solubility was dependent upon Ca source and particle size (P < 0.0001) with small particle generally having a greater in vitro solubility than large particle at the same time. The in vitro solubility rate of these Ca sources would provide a new and adequate source of Ca and a steady rate of Ca during the dark period. It was concluded that the observed mineral concentration and in vitro solubility differences between the examined Ca sources could be exploited to ensure optimum supply of Ca and most minerals, but lower in vitro solubility and Ca content of CS and LS would likely limit the use of CS and LS.