Influence of dietary ascorbate derivatives on tissue copper, iron and zincconcentrations in grass shrimp, Penaeus monodon

Effects of three ascorbate derivatives namely, L-ascorbyl-2-sulfate (C2S), L-ascorbyl-2-monophosphate-Mg (C2MP-Mg) and L-ascorbyl-2-polyphosphate(C2PP ) on tissue (hepatopancreas and muscle) copper, iron and zinc concentration in juvenile grass shrimp, Penaeus monodon, were studied. The control diet contained 12 mg/kg copper, 318.1 mg/kg iron, 125.8 mg/kg zinc and 0 mg/kg a scorbate supplemented with either adequate or high (5 X adequate) dietary l evels of C2S, C2MP-Mg and C2PP. Each diet was fed to triplicate groups of s hrimp (mean initial weight: 0.67 +/- 0.05 g) for 8 weeks. Significantly (P < 0.05) higher tissue iron and lower copper concentrations were observed in shrimp fed diets containing ascorbate and high ascorbate, respectively, th an shrimp fed the control diet regardless of the ascorbate source. Shrimp f ed C2MP-Mg- and C2PP-containing diets had higher tissue iron concentrations than shrimp fed C2S-containing diets regardless of ascorbate supplementati on level. Lower hepatopancreas copper concentrations were observed in shrim p fed C2MP-Mg- and C2PP-containing diets than in shrimp fed C2S-containing diets at the high ascorbate supplementation level. Tissue zinc concentratio ns in shrimp were not affected by either ascorbate source or ascorbate supp lementation level. (C) 1999 Elsevier Science B.V. All rights reserved.