Preparation Of Compound Calcium Powders From Shrimp Shell And Bioavailability

The production of shrimp has undergone a dramatic increase. However, comprehensive utilization of shrimp waste is become less and less. Protein, mineral（CaCO₃）, chitin, carotenoids（astaxanthin） which benefit to human beings are accumulated in sharmp waste. However, this passage is based on what predecessors have done with bioactive extract and application in shrimp waste. As well as people’s needs which should been cansidered. This current review article present a new method to utilize the shrimp waste to make calcium supplement food products without using chemical process in order to expoit a environmental protection way.Extraction of calcium supplementation from shrimp shell（Penaeus vannamei） by trypsin combined with organic acids was investigated. The main component of calcium supplementation were further authenticated. To study optimum preparation technology of blended calcium powders and its calcium absorption in rats. Extraction of blended calcium powders from shrimp shell（Penaeus vannamei） by trypsin combined with citric acids was investigated. Furthermore, the effect of calcium powder on growth, calcium absorption in rats by establishing calcium deficiency model was studied. The optimized condition was:（1）Trypsin condition:2.5×103 U/g, pH 8.0, 45 ℃for 1.5 h;（2）Citric acid condition:0.35 mol/L, 20 mL, for 1.5 h. In this condition, protein hydrolysis degree was 57.24%, the calcium dissolution rate of 85.78%. Furthermore, content of calcium power were as follows: calcium 19.6%, total amino acid 18.3% in calcium powder.To evaluate bioavailability of protein hydrolysate-citrate calcium（PHC-Ca） from shrimp shell. 4 weeks SD rats were randomly divided into 6 groups with 10 rats in each, and then gavaged with PHC-Ca, CaCO₃, calcium citrate, calcium gluconate, shrimp shell powder based on low calcium diet and low calcium control diet for 8 weeks. The calcium gavage dose to rats was 66.5 mg Ca/（kg·d）. Calcium metabolic test was conducted by the end of the forth week. Moreover, the index related to serum and bone were assayed by the end of the 8th week. Result: The rats’ growth index in low calcium was lower than other group except CaCO₃.The calcium absorption rate of PHC-Ca group was remarkable high than other groups except low calcium control. Furthermore, the level of ALP, BGP, in serum indicated that PHC-Ca improved calcium absorption in serum level significantly（p<0.05）. Moreover, the bone index showed the bioavailability in PHC-Ca group（p<0.05）. PHC-Ca prepared from shrimp shell could be promote calcium absorption, its bioavailability was better than same calcium content of calcium citrate and shrimp shell powder, which could be used as sources of dietary calcium supplement.Animal experiments showed that calcium powder prepared from shrimp shell improved calcium absorption in rats significantly（P<0.05）, and gavage dose of 66.5（mg /kg?d）（calculate by calcium content and body weight of rats） can improve the content of calcium, phosphorous in serum. Trypsin combined with citric acid is a mild and effective way to extract blended calcium powder from shrimp shell, which exhibited better absorption than the same calcium content of CaCO₃.