Research And Development Of Reconstituted Duck Bone Soup

Duck bone,which has very high nutritional value,is very cheap.It is the main by-product of duck slaughter and processing.All along,our country is not only a big country to raise ducks,but also a big consuming country.As China's duck yield continues to grow,the yield of duck bone is also more and more.In this paper,duck bone was used as raw materials,which was aimed at the study of a nutritious and convenient duck bone soup by atmospheric cooking,enzymatic hydrolysis,acid hydrolysis,flavoring and spray drying technology.The effect of different boiling time and bone-water ratio on the boiling process was studied.The optimum extraction time and the ratio were determined by single factor experiment,and the optimal boiling time was 45 min,and the best bone-water ratio was 1:2.5.In this study,alkaline protease was used to hydrolyze protein in bone,and the effects of enzymatic hydrolysis time,enzymatic hydrolysis temperature,enzyme dosage and substrate concentration on hydrolysis degree were studied.The hydrolysis degree was determined by pH-stat method.The enzymatic hydrolysis conditions were optimized by single factor and orthogonal experiments.The optimum conditions were as follows:enzymatic hydrolysis time 3 hours,temperature 55 ?,substrate concentration 4.5%,enzyme concentration 7 × 103U/g.The hydrolysis degree of enzymatic hydrolysis of duck bone soup reached 24.15%.The content of peptide in duck bone soup before and after enzymatic hydrolysis was compared by Folin phenol method.The content of peptide was 43.2 g/mL before hydrolysis and 139 g/mL after hydrolysis,and after enzymatic hydrolysis is 3.22 times as high as that before.It was found through the study of the antioxidant activity of polypeptide.The hydroxyl radical(·OH)Fe3+scavenging ability,reducing power,DPPH scavenging and superoxide anion scavenging ability after enzymatic hydrolysis had improved obviously than before enzymatic hydrolysis.The amino acid content of bone soup before and after enzymolysis was studied by amino acid analyzer.The results showed that it was 178.33 mg/g before enzymatic hydrolysis,and it was 206.50 mg/g after enzymolysis,and it was increased by 15.80%.The calcium ion of bone dregs after enzymatic hydrolysis was dissociated.The results of the study found that citric acid dissociation was better than the effect of acetic acid and lactic acid.The effects of citric acid concentration,reaction time,reaction temperature and material-liquid ratio on the dissociation of citric acid were studied.Through single factor and orthogonal test,the best conditions of citric acid dissociation are:acid concentration 1.25 mol/L,hydrolysis time 40 min,acid hydrolysis temperature 60?,the ratio of material-liquid 5:1,under this condition,and the dissolution rate of the calcium ion is 45.24%.This paper studied the formulation of duck bone soup.By sensory evaluation,the best flavor formula was:perilla juice 3.0%,black tea juice 1.0%,ginger 0.4%,liquor 5.0%;the best seasoning formula was:salt 0.4%,sugar 0.2%,chicken powder 0.3%,five spice powder 0.15%.Duck bone soup after seasoning was concentrated in vacuo and spray dried,namely the reconstituted duck bone soup.The solubility,dispersion,stability and main nutrients,microorganisms of soup were measured,and the results showed that:the quality of duck bone soup was in line with industry standards.