ZHANG Chunyi, JIANG Chunyang, WU Qiujie, HUANG Xiaolan, LI Jinjin, ZHU Dewen, WANG Sen, WU Yingmei, ZHOU Nong
The contents of 25 elements such as N, Ca, K, P, Mg, Al, Fe, Zn, Cu, Sr, Ba, Mn, Na, B, Pb, Ni, Cr, Mo, Co, As, Se, CD, Sb, and Hg in 18 mulberry branch samples from different producing areas were determined by automatic Kjeldahl nitrogen determination method, inductively coupled plasma mass spectrometry and atomic fluorescence spectrometry to evaluate the quality and safety of mulberry branches. Result showed that 24 elements expressed a good linear relationship in their respective concentration ranges except for N, and with a correlation coefficient that R2≥0.999 2. The 25 elements were detected in all of the 18 mulberry branch samples and there is a large difference in the content structure of the 25 elements between samples. The highest average content was Ca (13.23 mg/g), followed by N (12.75 mg/g), K (7.99 mg/g), P (2.62 mg/g), Mg (1.39 mg/g), and the lowest average content was Hg (0.022 μg/g). The Pb content in S4 (Morus australis from Anlan town, Ba’nan District, Chongqing) and the Cu contents in all samples exceeded the standard limits. The sample S4 had the highest general score of principal components, followed by S8 (M. australis from Huangjueya Town, Nan′an District, Chongqing), S9 (M. cathayana from Huangjueya Town, Nan′an District, Chongqing), and S14 (M.australis from Xinmin Town, Fengjie county, Chongqing). The result of cluster analysis showed that S4 could be clustered as the first group, S8, S9, and S14 could be clustered as the second group, and the rest 14 samples could be clustered in the third group. This study could provide theoretical and basic data for the quality and safety evaluation, and the development and utilization of the medicinal value of the mulberry branch.
