Abstract: The physicochemical properties and antioxidant activity of Cucurbita moschata Duch. powder with different particle sizes were investigated. The results showed that the samples with smaller particle size had higher protein and fat contents and a narrower range of total amino acid contents of 16.58–17.12 mg/g. The contents of total sugar and reducing sugar increased first and then decreased, and the contents of Fe, Zn and Mn decreased with the decrease in particle size. Smaller particle size resulted in lower density, water-holding capacity, and expansibility, but higher moisture absorption, brightness, and yellowness. Total phenol content decreased with the decrease in particle size, but β-carotene increased. As incubation time prolonged, the 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity of Cucurbita moschata Duch. powder was enhanced, and the percentage scavenging reached 94.94% after one hour of incubation with Cucurbita moschata Duch. powder with a particle size of 100–200 mesh. The highest percentage of superoxide anion radical scavenging activity of Cucurbita moschata Duch. powder of 37.62% was observed at a particle size of 100–200 mesh.

Key words: Cucurbita moschata Duch., different particle sizes, physicochemical properties, antioxidant activity