A slew of food safety scandals has stoked China's hunger for higher quality products that would sustain consumption of protein-rich farm commodities even as its economy slows, a top executive of leading commodities trader Cargill Inc said. China is toughening its fight against food safety violators in the face of rising incidents of food scares since a deadly scandal in 2008 when dairy tainted with industrial chemical melamine led to the deaths of at least six infants.