Abstract: Red pitaya from Dongfang city in Hainan province were selected to analyze nutritional composition of seeds.Combined with results of white pitaya seeds,it is significant for the development and utilization of by-products in the processing of pitaya.The basic indicators are tested by National standard method.The contents of water,crude protein,crude fat,Crude fiber,ash and starch were 6.48,24.84,31.79,13.38,2.58 g/100 g and 20.39 g/100 g in fruit seeds after freezing drying at -80 ℃.High performance liquid chromatography (HPLC) analysis showed that the fruit seeds were rich in α-tocopherol and γ-tocopherol,the contents were 5.78 mg/100 g and 10.50 mg/100 g in fruit seeds.In addition,the fruit seeds are rich in unsaturated fatty acids (75.23% of the total fatty acids) and the essential amino acids required for a variety of human beings (26.62% of the total amino acids).The results provided a theoretical basis for the application of pitaya in food,medicine and daily chemical products.

Key words: Pitaya seeds, fatty acids, amino acids, tocopherols