Sample preparation Dragon fruit peel waste were obtained from Fah Thai market, Muang District, Chiang Rai. he peels were weighed and washed with tapping water and then air dried. The peels were then cut into 2 cm square and dried by a hot oven flow at 55°C. The sheet of peels were ground at twice then filter the powder to small with Hammer mill at 250 um sieving. The peel powder was stored at -20 °C until used