"Export of onions has been banned and the import duty has been made zero. Besides, some imported onions are reaching the market. The prices have come down," he told reporters at his residence in Kolkata.
"The government is taking all possible steps and things will be in control soon," he added.
While retail prices of onions have started easing from their peak of Rs 70-85 per kg earlier this week, tomato and garlic rates remain high, at Rs 40-60 per kg and Rs 250-300 per kg respectively.
Prices of onions had surged due to crop damage in the major producing region of Maharashtra, besides hoarding.
Onion prices at retail outlets in the national capital dropped further to Rs 40-50 a kg today from the Rs 50-60 per kg level seen in the last two days, traders said.
There was a decline in the prices of onions in Kolkata and Chennai, too. Prices of the commodity fell by Rs 10 a kg and were ruling at Rs 40-50/kg in the two metros, depending on the quality.
However, prices remained high in the financial capital of Mumbai, where the going rate was Rs 60-75 a kg.
In order to maintain adequate supply of onions in the city, the Delhi government kept Azadpur market (Asia's biggest wholesale fruits & vegetables market) open even on Sunday to facilitate the sale and purchase of the politically sensitive item.
"Not much sale was witnessed in the mandi today. Fresh arrival of onion was very low. There was some sale from yesterday's stock," Onion Merchants Association General Secretary Rajendra Sharma told PTI.
Explaining the reason behind the rise in food prices, Mukherjee said: "Some fruits, vegetables and milk have an element of seasonality in them and sometimes in the market, there is gap in the demand and supply of products, which leads to the increase in their prices... Ultimately, it depends on the series of the core chain."
Sources in the Azadpur market claimed that in order to cash in on the exorbitant prices of garlic (at Rs 300 a kg in retail and Rs 120-180/kg in the wholesale market), some traders were illegally bringing garlic from China into the country via Nepal.
India had banned the import of garlic from China two years ago following the detection of fungus in consignments of Chinese garlic.
Chinese garlic is being illegally brought into India through Nepal. From the Himalayan states, it is being transported to Delhi, Chennai, Mumbai and Coimbatore through trains from Bihar, which shares a border with Nepal, they claimed.
There was some fall in retail prices of tomato in the Eastern metropolitan city of Kolkata, where it was being sold at Rs 25/kg, as against Rs 30-40/kg yesterday, traders said.
However, the vegetable continued to be sold at high rates in the three other metros.
Tomatoes were available at Rs 40-50 a kg in the national capital, while it was Rs 60/kg in Mumbai and Rs 45/kg in the Southern metropolis today, the same as yesterday's levels, traders said.
The price rise of all three crops has been attributed to unseasonal rains in the major producing regions. However, in the case of onions, a politically sensitive item, the government has also blamed hoarding and speculation.
Food and Agriculture Minister Sharad Pawar had yesterday said at Ahmedabad that he expects the situation to improve further with the arrival of new crops.
Rates of garlic, which is used both as a vegetable and to make Ayurvedic medicines, have increased sharply to Rs 300/kg at present in Delhi, compared to Rs 160-180 per kg a month back, trade sources said.
The commodity was being traded in the range of Rs 250-280 a kg earlier this week. However, the price has gone up to Rs 300 a kg since Friday.