Trace elements in kernels of Chinese hickory（Carya cathayensis） grown in limestone and non-limestone soils

Key words: 
• cash forestry /
• Carya cathayensis /
• limestone soils /
• non-limestone soils /
• kernel

Abstract: Because of only a few direct research reports，a field survey was conducted to determine kernel quality of Chinese hickory （Carya cathayensis），a reputed healthy food in China，grown in limestone soils，which are believed to be better for the trees than other soils. Soils were divided into two groups，namely limestone soils and the other non-imestone soils. Next，nuts of C. cathayensis with corresponding soil samples were collected. Kernel quality was analyzed for crude protein，crude fat，and trace elements and then compared using a t test. Results showed that the kernels were rich in crude protein （ranging from 90 to 109 g·kg-1） and crude fat （ranging from 665 to 694 g·kg-1），but there were no significant differences between the two soil groups. The kernels were also rich in many nutritional trace elements，especially Zn （30 － 51 mg·kg-1） and Fe （36 － 94 mg·kg-1）. However，concentrations of most analyzed trace elements in the kernels were higher when collected from the trees grown in non-limestone soils，whereas Se was only detected in kernels grown in some of the limestone soils. Thus，more effort is needed to develop high quality C. cathayensis kernels rich in Zn，Fe，and Se for healthy and nutritious food products. ［Ch，4 tab. 13 ref.］