Abstract: In order to make good use of the calcium resource in tilapia bone, the technology of preparation of CMC active calcium by mixed acids of citra acid and malic acid applied to tilapia bone powder was studied. Wistar rat was used as an animal model for evaluating the bioavailability of this product. The results showed that the optimum conditions of preparation of CMC active calcium were:adding citra acid with malic acid in the concentration ratio of 3:2 respectively, under 121℃ to extract the tilapia bone powder 1h, adjusting the pH of the pure liquid to 7 and then vacuum dried. The calcium withdraw rate was 92.1%. The product was dissolved in hot water up to 88%. The animal metabolism experiment showed that in regard to the level of serum calcium and bone calcium, the CMC active calcium apparent retention was higher in different degree than that of the control group. CMC active calcium was absorbed and utilized more easily than calcium carbonate. It could effectively complement calcium quality. For this reason, the product was a kind of highly absorbable calcium nutraceutical.

Key words: Tilapia bone, CMC active calcium, bioavailability, Wistar rat