At the Multi Commodity Exchange, mentha oil for August month contract declined by Rs 5.80 or 0.79 per cent to Rs 728 per kg in a business volume of 169 lots.
Similarly, the oil for delivery in October month contract eased by Rs 3.70 or 0.49 per cent to Rs 751.50 per kg, in a business turnover of 20 lots, while September month contract fell by Rs 3.50 or 0.47 per cent to Rs 742 per kg in 250 lots.
The fall in mentha oil prices was mostly due to profit-taking by speculators due to fall in demand in the spot market, traders said.