Study On In Vitro Simulated Digestion Of Pyropia Haitanensis In Different Treatments

Pyropia haitanensis is an important economic seaweed in China,rich in nutrients,delicious,inexpensive and unique in taste.At present,it is not clear about the nutrient digestion and food composition changes of P.haitanensis during human ingestion.In order to improve the bioavailability of P.haitanensis,this paper explores the digestion of important nutrients of it in the entire digestive process by in vitro simulated digestion,and compares the research on high-temperature baking,hydrolysis,acid hydrolysis,alkaline hydrolysis,high-pressure steam and oil baking.The main research results are as follows:1)The digestive conditions of mouth,stomach and intestine were studied,and a complete in vitro model was constructed.The stimulate enzyme concentration(salivary amylase,pepsin,trypsin)were1.29?g·mL^-1?2.65?g·mL^-1and 10?g·mL^-1;the addition amount of digestive juice(saliva,gastric juice,intestinal juice+bile salt)were 12.5 mL,15 mL,37.5 mL+10 mL;the digestion time were 5 min,4.0h and 5h;The pH value were 6.8(±0.05),1.0(±0.2),and 7.0(±0.05).2)The in vitro simulated digestion of P.haitanensis was studied under different temperature(120?-200?)for 30s.The results showed that,180? baking it cells organization structure change after in vitro digestion,the content easy ooze,the color change,and important nutrients content(free amino acid,soluble protein,soluble sugar,reducing sugar)release and antioxidant activity index(DPPH^·radical scavenging,ABTS^+·radical scavenging,FRAP reduction ability and K₃Fe(CN)₆reduction capacity)is better.During the whole process of digestion,the contents of free amino acids and soluble proteins are mainly released in the process of gastrointestinal digestion,the contents of soluble sugars and reducing sugars are mainly released in the process of gastric digestion,and the antioxidant activity reaches the peak in the process of gastric digestion.The results showed that the P.haitanensis was suitable for digestion after baked at 180? for 30s.3)The in vitro simulated digestion of P.haitanensis under different temperature conditions(20?-100?)after hydrolysis for 20 min was studied.The results showed that with the increase of hydrolysis temperature,the digestibility of it was increased,and over 60?hydrolyzed,it cell wall was seriously damaged after gastrointestinal digestion.The contents of free amino acids of it hydrolyzed at 100? was higher after gastrointestinal digestion,and the content of soluble polysaccharides and reducing sugars was higher after gastric digestion,and the four antioxidant activities reached a peak after gastric digestion.The results showed that the P.haitanensis was suitable for digestion after hydrolysis at 100? for 20 min.4)In vitro simulated digestive processes of P.haitanensis by different processing methods of common foods were compared and studied,including acidolysis(0.01 mol·L^-1HCl for 20 min),alkaline hydrolysis(0.01 mol·L^-1NaOH for 20 min),high-pressure steam(103.4 kPa,121.3? for 20 min)and oil baking(2g peanut oil for 30s at 180?).The results showed that the cell structure was completely destroyed after gastrointestinal digestion,the release of four important nutrients(free amino acids and soluble proteins,soluble sugars and reducing sugars)reached a peak,and the antioxidant activity was strong after gastric digestion.The results showed that the P.haitanensis by oil baked was suitable for digestion.