BAU, Mymensingh, July 24 -- A curious case of beef turning green while being cooked in Paikgacha municipality of Khulna has set off a wave of speculation across the country, with a food safety expert cautioning against both panic and complacency until proper tests are done.

The episode unfolded last Wednesday afternoon when a group of employees at Modern Bakery in Paikgacha were cooking beef bought for a picnic. Midway through cooking, they noticed the meat had inexplicably turned green. Startled and unnerved, they carried the pot straight to the local police station.

Days later, no one has been able to say for certain what caused the change and in the absence of answers, theories have run wild on social media, from spoiled meat to chem...