Abstract:
In this work, the contents of main nutrients, harmful factors and pesticide residues of 25 mulberry leaves in three major growing areas in Hainan Province were determined. Factor analysis was used to analyze the mulberry leaf indexes of different varieties refer to its pesticide residue and the comprehensive scores were calculated and sorted. The results showed that the average crude protein content of mulberry leaf samples in Qiongzhong and Wanning regions were 26.81% and 27.04%, which were higher than the average crude protein content of mulberry leaf samples in Luzhou region by 23.39%. The average cellulose content of mulberry leaves in Qiongzhong area was the highest;the average cellulose content in Qiongzhong region was 43.54%. The Cu content of 25 varieties of mulberry leaves was distributed between 6.45 to 9.90 mg/kg, with an average of 8.18 mg/kg;the Zn content was distributed between 23.30 to 41.30 mg/kg, with an average of 35.52 mg/kg;Pb content was distributed between 0 and 0.500 mg/kg, with an average of 0.103 mg/kg;Cd content was distributed between 0.0014 and 0.0220 mg/kg, with an average of 0.0052 mg/kg;As content was distributed between 0.028 and 0.230 mg/kg, the average was 0.099 mg/kg. The content of heavy metal elements of mulberry leaves varied greatly in different regions, but the detection amount did not exceed the pollutant limit value of food national safety standards. After factor analysis, 4 common factors were extracted, and the cumulative contribution rate reached 74.96%. After comprehensive evaluation of mulberry leaf quality, the organochlorine and organophosphorus pesticide residues were tested, four kinds of organochlorine and organophosphorus pesticide residues were detected in mulberry leaves, including bifenthrin, cypermethrin, hexachlorobenzene and chlorpyrifos. The residues of the above four pesticides were less than the maximum residue limits of leaf food of corresponding pesticide types specified in the national food safety standard maximum residue limits of pesticides in food (GB2763-2016). The first four common factors extracted could better reflect the comprehensive quality of mulberry leaves. All the information, the top three in the comprehensive ranking are the"Lianxuan"No. 5, 007, 009 three mulberry varieties, the three mulberry leaves with good traits and abundant yield could be used to develop edible mulberry, medicinal mulberry the candidate mulberry varieties.