Optimization Of Fresh-cut Process And Nutrition Function Of Sweet Potato

Sweet potato is rich in nutrients and has high medicinal value.It has the effects of reducing blood sugar,stopping bleeding,reducing inflammation,preventing cancer and laxative.At present,most of it is used to produce starch,dried sweet potato and vermicelli.Now the people pay more attention to nutrition,freshness,health,convenience and hygiene of food.Food researchers and processing workers are paying more and more attention to the research of fresh-cut fruits and vegetables.The effects of different preservatives,different heat treatment temperatures and different storage temperatures on the physiological and biochemical indexes of fresh-cut sweet potato were studied.The effects of compound preservatives on the physiological,biochemical and nutritional indexes of fresh-cut sweet potato were studied.The experimental results show that the optimum heat treatment temperature is 65?;the optimal storage temperature is 4?;the optimum concentration of preservative citric acid,Vc,L cysteine and sodium chloride are 2%,0.5%,0.05%,0.4%respectively.The composite preservative has the best preservation effect.Steaming,boiling and microwave are the most common heating methods in the household and food industries.Therefore,the effects of steaming,boiling and microwave on total phenol,reducing sugar,resistant starch,slow-digesting starch,fast-digesting starch,protein content and ?-carotene content in sweet potato were studied.The experimental results show that cooking and microwave have a significant effect on the nutrient content of sweet potato,which will decrease the content of protein,resistant starch and slow-digested starch,and increase the content of fast-digesting starch,total phenol,reducing sugar and?-carotene.The steaming has a significant effect on the individual nutrients of the sweet potato,which will reduce the content of resistant starch and reducing sugar,and increase the content of fast-digesting starch and total phenol.Dietary fiber is an important functional food ingredient.In this experiment,the insoluble dietary fiber and soluble dietary fiber in sweet potato were extracted by enzymatic hydrolysis.the water-holding,oil-holding and swelling of insoluble dietary fiber were analyzed.The insolubility in sweet potato was simulated in vitro.The clearance effects of insoluble dietary fiber on heavy metal ions and nitrite during digestion of the stomach and intestine were studied.The experimental results show that the insoluble dietary fiber in sweet potato has high water holding capacity,oil retention and swelling;insoluble dietary fiber in the stomach has a significant effect on the removal of lead ions and nitrite ions;but the scavenging effects of cadmium ions and chromium ions are small.The insoluble dietary fiber has a significant scavenging effect on lead ions and cadmium in the intestine ions,but almost no scavenging effect on chromium ions and nitritehas.