Table 6-4 Comparison of Fruit Quality of Representative Myrica rubra Varieties from Different Producing Areas in Zhejiang Province
(According to Qin Sui Chu 1989)
In addition, the content of heavy metals in fruits also has a certain influence on the quality of bayberry. Cheng Xiaojian et al. (2006) determined the contents of Cd, Hg, Pb, As and Cu in 50 bayberry fruit samples of Zhejiang 13 counties (cities, districts) 10 varieties, and compared them with national standards. The average contents (mg/kg) of cadmium, mercury, lead, arsenic and copper are 0.006 3, 0.0010.5, 0.060 65, 0.047 56 and 0.458 8 respectively. Except for a few samples whose cadmium and mercury exceeded the standard, 94. 1.2% of the samples met the national standard, and the contents were all in a small order of magnitude.
Table 6-5 Comparison of Heavy Metal Contents of Myrica rubra Fruit Samples from Different Producing Areas in Zhejiang Province Unit: mg/kg
(According to Cheng Xiaojian et al., 2005)
Statistics show that Cd, As and Cu are all detected in the samples, indicating that these three elements are ubiquitous in fruits. Hg is not detected in 37.25% of the samples, but a few samples have exceeded the standard. The contents of cadmium and lead are increasing and expanding. It is found that heavy metal elements in soil have certain background values. The difference of heavy metal content in Myrica rubra fruit samples from different regions is not only related to the soil background, but also related to the atmosphere, water pollution and unreasonable application of fertilizers and pesticides in the environment.