Isolation Of Oyster Protein And The Modification Of Nutritional Properties

As a kind of marine food with large yield and nutrient-rich health care function,the deep processing of Oyster protein has received more and more attention.In this paper,the in vitro digestibility of oyster protein and the sequence of peptide in the digestive juice and its angiotensin-converting enzyme(ACE)inhibitory activity were studied.The effects of heat treatment on the digestion and biological activity of oysters were investigated,and the suitable oysters were screened out to be prepared before protein extraction.The impact of biological activity and provide the basis for the treatment of the next oyster protein extraction raw material.On the other hand,through the optimization of the ratio of material to liquid,the time of beating,the temperature and time of water extraction,the specific process of extracting oyster protein from water and acid is determined.Then the oyster protein is processed by different physical processing to determine the changes of structure and functional properties of oyster protein..Provide a theoretical basis for the development and utilization of oyster protein.The samples with high solubility in the three physical processes were subjected to in vitro simulated digestion,and the peptide sequences were determined for potential activity analysis.The results showed that the digestibility of raw oysters was better than that of oyster protein after heat treatment,but the oyster hydrolysate treated at 100 °C for 15 min contained more peptides that may have antihypertensive activity,and the oyster hydrolyzate after heat treatment.Has better in vitro ACE inhibitory activity.From the raw oyster with high digestibility,according to the ratio of material to liquid of 1:1,the beating time is 45 s,the extraction temperature is 20 °C,the extraction time is 2 h,the acid precipitation p H value is4.8,the extraction of protein,oyster water extraction.The solubility of acid precipitation protein is less affected by temperature.High-pressure homogenization and high-power ultrasound will greatly improve protein solubility.Under low-pressure homogenization conditions and high-power ultrasound conditions,the oyster protein has the best foaming and emulsifying properties.The protein under high pressure homogenization has the best water holding capacity of 15.17 g/g,and the oyster protein with high power ultrasound has the best oil holding capacity of 7.61 g/g.After hydrolysis of the most soluble protein in each physical processing,it was found that the oysters in the control group had the most types of peptides,about 337,and the oyster proteins treated at 100 °C identified the fewest types of peptides.247 proteins were identified in the enzymatic hydrolysate of 100 MPa homogenized protein,and 271 proteins were identified in the enzymatic hydrolysate of 900 w sonicated protein.The Peptide-Ranker score showed that the heat-treated oyster contained a high proportion of potentially active peptides.In addition,molecular docking with the 4ZBR protein showed that peptides of the sequences NWNDMELIWH,NWDDMEKIWH,EYSAKVFNRG,and KNGEWKDGLL were highly likely to have ACE inhibitory activity.By studying the effects of heat treatment on the digestion characteristics of oyster protein and ACE inhibitory activity,it provides a theoretical basis for the scientific consumption of oysters,enriching the research status of oyster thermal processing.At the same time,the process of oyster protein extraction was optimized,and the effects of different physical processing on the structure,function and potential activity of oyster protein were studied,which provided a theoretical basis for the deep processing of oyster protein.