Taiwanese prosecutors will appeal against the surprise acquittal of a tycoon accused of selling tainted cooking oil, amid public anger over a series of food safety scares.

Wei Ying-chung, who could have faced a 30-year jail term if convicted, was found not guilty along with five others by the district court in the central county of Changhua on Friday.

The former chairman of Ting Hsin Oil and Fat Industrial Co. was accused of selling oil intended for animal food. The case prompted a recall, with hundreds of tonnes of products taken off the shelves.

"We will appeal according to the law, seeking to overturn the inappropriate verdict... to put food safety regulations into effect and curb unscrupulous business behaviour," the Changhua prosecutors' office said in a statement Sunday.

Ting Hsin Oil is a unit of food giant Ting Hsin International Group -- founded by Wei and his three brothers -- which owns the Master Kong instant noodle brand popular in Taiwan and China.

Wei was also chairman of Wei Chuan Foods Corp -- also under the Ting Hsin group -- which was involved in two other scandals including selling "gutter oil" -- reclaimed from used cooking oil. 

Wei Chuan also recalled tens of thousands of bottles of cooking oil tainted with a banned colouring agent in late 2013.

The head of another Taiwan firm was given a 20-year-sentence in July for his role in a "gutter oil" scandal in which hundreds of tonnes of cakes, bread, instant noodles and dumplings had to be removed from shelves in Taiwan and Hong Kong.

Taiwan's government passed a tougher food safety law in 2013 but has since pushed for an amendment to raise jail terms and fines still further.