Studies on the preservation of crab processing waste and evaluation of the quality of the protein from crab waste

Three experiments were conducted to determine the effect of different chemicals on the preservation of crab waste at room temperature. In Exp. 1, .2 and .4% NaOCI and H₂O₂ were used and the waste was stored for 17 d. In Exp. 2, NaCI (10%), NaNO₂ (1%), NaOCI (.4%), NaN₃ (.065%), KN0₃ (.1%), Tert butyl hydroperoxide (TBHP) (50 ppm), and I₂ (25 ppm) were used. After mixing with the chemicals the waste was stored for 21 d. In Exp. 3, the waste was treated with NaCI (100/0), NaNO₂(10/0) and NaN₃(.065%) and the mixtures were kept for 20, 30 and 40 d. In the first experiment the waste treated with .4% NaOCI preserved better than for the other treatments, with lower (P < .05) NH₃ and trimethylamine (TMA). In Exp. 2, treatment with NaCI, NaNO₂ and NaN₃ did not produce any change in the physical characters of the crab waste. The TMA, indole and NH₃ were lower (P < .05) and no H₂S was detected in the waste treated with those chemicals. In Exp. 3, treatment with NaCI did not alter the physical characteristics of crab waste. The waste had lower (P < .05) NH3, TMA and indole on d 20, 30 and 40 than those treated with NaNO₂ and NaN₃.