Study On Extraction And Stability Of ?-carotene From Sweet Potato

?-carotene can be converted into vitamin A in the body,and it was widely used in the medical,food and feed industries,which accounts for roughly 90%of carotenoids from sweet potato.Sweet potato will be a new resource for the extraction of ?-carotene from plants.The material of sweet potato were porvided by Hebei Academy of Agriculture and Forestry Sciences.The study focous on the extraction technology of P-carotene and the stability of P-carotene.In this way we will promote cultivation and processing sales of orange-fleshed sweet potato in Hebei province.Results of the study are as follows:1)Distribution differences of ?-carotene content in sweet potato peels of different varieties during the storage root thickening are small,while larger in the pulp.The content of ?-carotene from sweet potato before the 21 days swell faster,it declined later.The advantage of Weiduoli varieties was visible during the final period,growth of root and accumulation rate of(3-carotene is higher.2)A series of experiments based on single factor and orthogonal array designs was carried out to study the optimal parameters.The results showed that the optimum extraction conditions were obtained as follow:extraction temperature 47?,extractionl time 90min,ratio of solvent to material 1:17.Under such conditions the predicted value of extraction yield of total ?-carotene was 52.8mg/100g dry matter,which was very consistent with the experimental value with a relative error of 0.56%.3)The sun drying and high temperature conditions had negative effects on stability of?-carotene,while ?-carotene is stable on the conditions of indoor natural light,dark,low temperature and room temperature.HCl would damage ?-carotene,KOH could promote stability of ?-carotene.Citric acid,sucrose and sorbic acid potassium had little influence on stability of(3-carotene,Ascorbic acid would damaged(3-carotene.When the concentration of metal ions is 10-3 mol/L,?-carotene was obviously influenced by metal ions except Zn2+,when metal ions concentration is 10-6 mol/L,retention of p-carotene from sweet potato changed a little.4)Retention of ?-carotene in dried sweet potato is higher than the direct drying.Best temperature of hot-air drying is 60?,drying shape impact on retention of P-carotene,hot air drying will accelerate the loss of ?-carotene.Steaming cooking had worse effect on retention of ?-carotene than boil cooking.