"Some products in some places do have problems due to varied reasons, and we should not be 'too optimistic' on solving these problems…… But there's one thing I can assure you and that is, we are 'zero tolerant' on these issues," Han said.

"We are obligated to make sure that people eat safe and well," he said, adding that he knows pesticide residues can still be found in vegetables as well as in fruits, and illegal food additives are still used in animals and aquatic by-products.

His assurance comes as issues concerning food security have been raised in the past few years, notably in dairy and rural products, triggering nationwide fear among Chinese people.

China rolled out a food security law in 2009 in an effort to better streamline the sector while shoring up confidence of consumers.

"Regulation system remains weak, that's a major reason. Meanwhile, the production pattern, especially in rural areas, is relatively small and scattered, making it even harder to regulate," Han said.

"The road is tough, and needs our continuous efforts. But we are working on it," he said.