Study On The Extraction,features And Application Of Peony Seed Protein

The peony seed oil was known as the "treasure of vegetable oil”,while The peony seed meal after oil extraction was often used as animal feed or fertilizer,reducing the utilization value of peony seeds.This paper studied the extraction process of peony seed protein in the mealand its functional properties.It opened up a new road for developing and using the peony seed protein through using peony seed protein along with other protein products scientifically and reasonably as a kind of compound nutritional protein powder.The extraction of peony seed protein was improved based on the traditional alkali-solution and acid-isolation method,the quality and purity of protein product had been greatly improved and enhanced because of a certain amount of ascorbic acid in acid-isolation process.Solid-liquid ratio,extraction pH,extraction temperature and extraction time were chosen for single factor test,then protein extraction rate as the index for the response surface optimization test.The optimal peony seed protein extraction conditions were determined as follows:solid-liquid ratio(g/mL)1:25,extraction pH9.25,with extraction temperature 53?and extraction time 68.74 min.The protein extraction was 62.95% under this condition,while the protein product purity was 82.65% with adding 0.02% ascorbic acid in acid-isolation processPeony seed protein functional properties is influenced by many factors.Solubility,water holding capacity,emulsification and emulsion stability were good at 50?while the foaming ability was 30?.Increasing protein concentration appropriately can improve the emulsification and emulsion stability,foaming ability and foam stability in a certain degree.Solubility,water holding capacity,emulsifying and foaming properties and emulsion stability were poor near the isoelectric point,but the foam stability was good.Effect of NaCl concentration on the foaming and foam stability was not particularly,however,it can influence solubility,water holding capacity,emulsification and emulsion stability,foaming and foam stability obviously.There were 18 kinds of amino acids in peony seed protein,in which the essential amino acids accounted for 36.20%.According to the value of the essential amino acid pattern among different ages in the human body that FAO/WHO recommended in 1985,this research used peony seed protein and other protein products,creating the compound protein powdersuitable for 2~5 years old,10~12 years old and adult respectively.The peony seed protein was used fully and reasonably as the main ingredient.Animal test results showed that the length was not significantly different from casein protein group.The weight changes and the protein efficiency ratio of experimental groups as well as viscera weight compared with casein group there were significant difference(p<0.05)or extremely significant difference(p<0.01),but the dirty body ratio had no significant difference(p>0.05).It could be concluded that the protein of experimental group can satisfy the demand for protein and essential amino acids in the growth stage of rats,and also promote normal growth and development of rats.