| Acorn starch resources is abundant in China. Whereas, by for now, the studies on physicochemical and functional characteristics of acorn starch have not been reported. In this paper, twelve species of acorns besides Castanea henryi were taken as experimental materials. Some ordinary physicochemical analytical methods, orthogonal experiment, micrography, X-ray diffraction examination and 1-butnol recrystallization were used. The starch in acorn kernel was measured, extracted and bleached. Amylose and amylopectin were separated and purified. Comprehensive investigation had been done on the properties of amylose and amylopectin, granules, solubility, gelatinization and viscosity. The results were as follows:(l)The contents of starch from twelve species of acorns were 63.62% of Castanea henryi, 60.04% of Castanea seguinii, 60.54% of Castanopsis carlesii, 51.34% of Quercus variabilis, 62.01% of Lithocarpus glaber, 60.09% of Lithocarpus hancei, 59.34% of Lithocarpus petelotii, 62.89% of Lithocarpus calophylla, 54.17% of Lithocarpus henryi, 58.58% of Cyclobalanopsis nubium, 56.37% of Cyclobalanopsis myrsinaefolia, and 55.51% of Cyclobalanopsis jenseniana, respectively.(2)The optimum conditions for bleaching acorn starch were 5:l(v/w) water to starch, 1.0% H2O2 and 40癈, pH 11 and 5h. On these conditions, the whiteness values of bleached starch were above 73%.(3)Granules of acorn starch had comparatively regular figures, were mostly sphericity and ellipsoid. The visible black cross was observed by the polari-microscope. For the granules of twelve species of acorn starch , the length of long-axis was in the range of 2.0-34.Sum and crystallinity 27.48%~31.74%.(4)The contents of amylose and amylopectin of each acorn starch were in the range of 14.08%-20.16% and 68.38%~74.68% respectively. After several recrystallizations, the yields of amylose and amylopectin were about 50% and 40% of their unfeigned contents. For acorn amylose and amylopectin, iodine affinity values were in the range of 18.94%-19.19% and 0.35%-0.52%, blue values 0.74-1.20 and 0.14-0.19 and Amax of I2-KI blue colour 600-620nm and55550~570nm, respectively. The purity of each acorn amylose was almost above 95%.(5)With the rising of temperature, both the swell value and solubility of each acorn starch were inclined to increase. The swell values were less below 70癈, while rapidly grew at 75~95癈. The swell of acorn starch consisted of two phases. Accordingly, acorn starch was a restrictive swell starch.(6)The gelatinization temperatures of twelve species of acorn starch were not too different, generally in the range of 63.5~79.5癈.(7)Seven species of starch from Castanea henryi, Castanea seguinii, Quercus variabilis and Lithocarpus Bulme had bad freeze-thaw stability. Thereinto, Castanea henryi and Castanea seguinii starches could not be freeze-thawed, Quercus variabilis and five species of Lithocarpus Bulme starch could be freeze-thawed only once. Whereas there was better freeze-thaw stability of each starch from Castanopsis carlesii, Cyclobalanopsis nubium, Cyclobalanopsis myrsinaefolia and Cyclobalanopsis jensenian.(8)If each paste of acorn starch was placed too long, its clarity would slowly decrease and the volume of separated water also gradually add. Except for starch paste of Cyclobalanopsis nubium, the volumes of separated water of other pastes ultimately reached stabilization and exceeded 70%.(9)The ratios of enzymatic hydrolyzation to acorn starch pastes were all in the range of 77.83%~82.92%.(10)For each starch paste from twelve species of acorn, the higher concentration, the higher its viscosity, whereas the quicker rotation and temperature, the lower its viscosity. Its viscosity was comparatively high in pH 6.0-8.0, but began decreasing on the condition of hyperacidity and alkali.
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