Taro
According to the US Department of Agriculture, there was over $2.3 million worth of dasheen, a form of taro, that was exported to the US back in 2014. However, there was a problem with taro: taros would usually turn slightly yellow or a bit blackish after an hour of being peeled, but there are taros that would retain their white color after a long time of being pilled. These taros were found in Wenzhou City, Zhejiang County. According to several sources, some shopkeepers would add dangerous amounts of sulfur dioxide to keep the peeled taro and potatoes from discoloring after being peeled.
Taro
Corn
According to the US Department of Agriculture, the United States had imported over 4.1 million pounds of frozen sweet corn from China in 2009. However, there was a problem with the corn that had been imported: some vegetable producers from China put sodium cyclamate in the corn, which is banned by the FDA. The corn would retain its bright yellow color because of the said food additive. The said additive could damage the liver if taken in large quantities.
Corn