Abstract: The granular morphology of starch isolated and purified from Jack-fruit seeds was investigated, including the shape,X-ray diffractive pattern, the content of starch chain and branch, solubility and swelling power. The experiment indicated:Optical microscopy of the starch showed half-round or round with typical polarization cross. The granular size of starch rangedfrom 5 to 25μm and with average value of 15μm in diameter. Its X-ray diffraction graph appeared as C pattern. The startingpoint of gelatinization temperature of Jack-fruit seed starch was 68.2℃ and the end was 78.3℃, Gelatinization parametersdetermined by polarization cross disappeared. The content of starch chain and branch was 24.2% and 75.8% respectively.Swelling power and solubility of Jack-fruit seed starch differed from those of corn starch and after 76℃ the two values of Jack-fruit seed starch increased rapidly and exceeded the related values of corn starch.

Key words: Jack-fruit seeds, starch, granular property