Effects Of Different Concentrations Of Colloidal Calcium Phosphate On Gastric Rennet And Digestion Of Camel Milk Protein

Camel milk is rich in nutrients,so it has become popular among consumers in recent years and the market demand has gradually increased.However,camel milk contains a large amount of calcium,in which glial calcium phosphate dissolves in the stomach to produce calcium ions,and the high concentration of calcium ions can lead to coagulation of casein in the stomach,which affects the transport of amino acids and thus the digestion and absorption of nutrients in humans.Therefore,in order to improve the digestive utilization of proteins in camel milk,this experiment was conducted by adjusting the content of colloidal calcium phosphate in camel milk casein and constructing an in vitro gastrointestinal digestion model for infants and adults to perform in vitro digestion experiments on mineralized camel milk and determine and analyze the digestion products.The results obtained were as follows:1.Effect of colloidal calcium phosphate content on the degree of curd in camel milk stomach.The results showed that camel milk samples with lower mineralization(p H 4.5)produced less curd and looser milk during digestion.The p H value of each milk sample increased and then decreased steadily with digestion time;the lower mineralized p H 4.5camel milk samples had the lowest wet and dry weights of 3 g/100 m L and 0.29 g/100 m L,respectively;in particular,the morphology of the curd was observed at the macroscopic level,and the p H 4.5 camel milk samples produced softer and more dispersed curd than the other camel milk samples.Also,the increase in tanδ value at the rheological level was greater in the p H 4.5 camel milk samples compared to the p H 6.5 camel milk samples,indicating that the casein micelles in the less mineralized camel milk samples were less stable and more easily hydrolyzed into small molecules.2.Effect of colloidal calcium phosphate content on in vitro digestion of proteins in camel milk.By simulating the in vitro digestion of adults and infants,the microstructure of the milk samples changed significantly at all stages of digestion,the free amino acid content increased gradually with digestion time,and the protein hydrolysis degree of each milk sample was significantly different(P<0.05),among which the p H 4.5 camel milk samples had the highest protein hydrolysis degree(89%)under adult digestion conditions.Finally,the peptide analysis of the digested products showed that most of the peptides were from αS1-CN,αS2-CN and β-CN.16 peptides with ACE inhibitory activity and DPP-IV inhibitory activity were screened out,which were more helpful for human digestion and provided a theoretical basis for the biological value of mineralized camel milk and the development of bioactive peptides for mineralized camel milk.