Analysis Of Nutritional Quality Of Takifugu Rubripes And Research On Preliminary Usage Of Collagen Peptide

In 2016,China had liberalized the processing and management of Takifugu rubripes conditionally.It will inevitably drive the domestic market demand for Takifugu rubripes and promote the development of aquaculture and processing industries of Takifugu rubripes.Taking Takifugu rubripes as the main research object in this paper,the main component content of water,crude fat,crude protein,ash and total sugar,amino acids and fatty acids were analyzed.The optimal process for preparing collagen peptide was optimized.The chelating effect of collagen peptides containing different molecular weight and Ca²⁺was investigated.In combination with the Box-Benhnken central combinatorial optimization principle,a response surface experiment based on chelating temperature,peptide calcium mass ratio,and pH was established to optimize the process of collagen peptide chelating calcium and determine the optimal chelating conditions.What's more,the physicochemical parameters of collagen peptides chelated calcium were analyzed.The main conclutions of the study were as follows:1.The main nutritional ingredient of Takifugu rubripes were analyzed.In muscle,the content of essential amino acids?EAA?accounts for 42.49%of the total amino acid?AA?content and accounts for 73.89%of the total amount of non-essential amino acids?NEAA?,which conformed to the ideal protein model of amino acids recommended by FAO/WHO.The content of protein in skin reached 27.93%,which was significantly higher than that in liver and muscle?P<0.01?.The rate of delicious amino acid content in the composition of amino acid reached 55.06%in skin,and the collagen content was abundant.The crude fat content in liver was significantly higher than that in muscle and skin?P<0.01?,it was up to60.82%.The content of polyunsaturated fatty acid in liver accounted for 24.59%in the total fatty acid content,of which DHA content was 15.49%.2.Collagen peptide from Takifugu rubripes skin were prepared.The suitable choice among five proteases was acid protease.The optimal preparation conditions for collagen peptides were as follow:the enzymolysis time was 3h,the amount of enzyme added was5%,and the ratio of solid to liquid was 1:40.Five different molecular weight collagen peptides with Mr<1000 Da,1000<Mr<3000 Da,3000<Mr<5000 Da,and 5000<Mr<10000Da were isolated by ultrafiltration of the enzymatic hydrolysate.Experimental verification showed that the smaller the molecular weight and the better chelating effect with CaCl₂.3 Optimization of the collagen peptide chelating calcium process of Takifugu rubripes skin.Collagen peptide with Mr<1000Da was selected as raw materials to prepare collagen peptide chelatng calcium.The optimal chelating process optimized by response surface were as follows:pH value was 9.18,mass ratio of peptide to calcium was 20.55:1 and reaction temperature was 45.26?.In that condition,the predicted chelating rate was89.98%.Considering the actual conditions,the temperature 45.3?was selected to verify the model prediction conditions.The result showed that the chelation rate was up to91.02%,the relative deviation was 1.18%,the optimal process was reliable.The protein and calcium contents of the purified collagen peptide chelating calcium was 77.06%and2.15%respectively.In the ultraviolet spectrum,the collagen peptide had the maximum absorption wavelength at 224 nm,while the maximum wavelength of the collagen peptide chelating calcium migrated to 208 nm,the maximum absorption peak shifted obviously.Compared with the infrared spectrum,the-NH2 of collagen peptide had absorption peak at 3275.13cm^-1,but the-NH2 of collagen peptide chelating calcium migrated to 3408.22 cm^-1.Meanwhile the C=O of the collagen peptide had the absorption peak at 1654.92cm^-1,while the C=O absorption peak of the collagen peptide chelating calcium shifted to 1624.06cm^-1.According to the UV spectral and IR spectral analysis,it could be deduced that the-NH₂and-COOH in collagen peptide chelated with Ca²⁺.This study provided a theoretical basis for the processing and utilization of the Takifugu rubripes,and had a great significance guiding to promote the development of industrialization.