Study On Important Organic Ingredients And Its Content In Acorn Of Quercus Variabilis In Shaanxi Province

Quercus variabilis is the important constructive specie in warm temperate deciduous forest and subtropical evergreen-deciduous broad-leaved mixed forest of our country.It is widely distributed in about 22 provinces that is in the North China,the Central China,the South China and the Southwest China(N22°?42°;E99°?122°,an altitude of 500 to 1,500 meters).QinLing Mountain in Shaanxi Province is the core distribution area that can produce a lot of acorns every year that is an important kind of forest products.Combined with field sampling and indoor control experiments this study was to compare the differences of Quercus variabilis acorn starch,sugar,protein,free amino acid,tannin content in three regions of Shaanxi Province and four different types.And the analysis of the impact of environmental factors and genetic differences on these important organic ingredients can provide a scientific basis for the further development and utilization of Quercus variabilis acorns.The main conclusions are as follows:1.Shaanxi Quercus variabilis acorn starch content decreases gradually decreased as the environment changes from south to north.The acorn starch content in the Loess Plateau is the lowest.Qinling south slope is higher than the Qinling North Slope,but there is no significant difference between the both slopes of the Qinling Mountains.The Quercus variabilis acorn starch content of four types showed that shallow crack type was higher than deep crack type.When the type was shallow crack type,thin bark was better than thick bark.When the type was deep crack type,there was no significantly difference between the two types.The reducing sugar content and total sugar content showed the opposite trend in the environmental gradients.The Quercus variabilis acorn total sugar content decreases as the environment changes from south to north,while reducing sugar content increased gradually.In addition to the thin bark and shallow crack type,the total sugar content in the other three types was high.The reducing sugar content of the thick bark was higher than the thin bark type.2.There was no significant difference in Quercus variabilis acorn protein content between the north slope and south slope of Qinling Mountains,but he Loess Plateau region was significantly higher than the Qinling Mountains.The Quercus variabilis acorn protein content of thick bark type was significantly higher than thin bark type.The cork oak acorn protein content of the shallow crack type was higher than the deep crack type when the bark type was thick.But there was no significant difference.When the type was thin the content of protein in deep crack type was higher than shallow crack type.3.In the determination of 17 kinds of Quercus variabilis acorn free amino acids,except cysteine and glycine were not detected,the rest were all present and there were differences.The amount of free proline accumulation was generally high.The highest region was the Loess Plateau region while the highest type was thick bark type.Different regions,different types of Quercus variabilis acorn free amino acids had a significant positive correlation with the corresponding region and type on Quercus variabilis acorn protein content.The sort of the Quercus variabilis acorn free amino acid contents in different areas by descending order was Loess Plateau>Qinling South Slope>Qinling North Slope;The sort of the Quercus variabilis acorn free amino acid contents of different types by descending order was Thick bark and shallow crack type>Thick bark and deep crack type>Thin bark and deep crack type>Thin bark and shallow crack type.The free amino acid content of Thick bark type acorns was significantly higher than thin bark type.4.The Quercus variabilis acorn tannin content in the Loess Plateau region was significantly less than the Qinling Mountains.The Quercus variabilis acorn tannin content in Qinling north slope was higher than the south slope.Compared to the thick bark type,acorn tannin content of thin bark type was lower.Thin bark and shallow crack type was the least tannin content type.In actual production,considering tannin removal costs,select the Loess Plateau area and the thin bark type Quercus variabilis acorns of an ideal choice.Concisely put forward for the acorns food processing can refer to the removal process optimization criteria.Under the conditions of ultrasonic power 100w,select 0.5%sodium carbonate solution,removal time 12h,the temperature 65 ? of more suitable tannin removal conditions.When water is used as reagent for removing tannin,immersed 6 days or more can achieve good removal effect.