The price of dried pasta rose by 8.6% during March as shoppers rushed to stockpile cupboard essentials at the outset of the coronavirus pandemic, research shows.
The new 'lockdown index' from Ulster Bank has tracked the price of sought-after goods using the Government's consumer price inflation (CPI) measurement.
Ulster Bank chief economist Richard Ramsey said that, while the overall CPI rose 0.1% month-on-month in March, the overall cost of key items like pasta, toilet roll, liquid soap and tinned tomatoes soared by four times the rate.
Supermarkets saw empty shelves and long queues last month, while some stores ended multi-buy promotions on popular items as demand rose.
While the price of pasta came to the boil at the fastest rate of 8.6%, the cost of basmati rice also rose rapidly at 5.3% over the month.
Baked beans rose in price by 0.9% - and despite being the item most notoriously coveted by stockpiling shoppers, the price of toilet roll rose by just 0.2%, and was 1.5% cheaper than in March 2019.
The shopping basket of items used to compile the CPI is reviewed each year. For example, this month gluten-free cereal was added. But the pandemic has changed habits, Mr Ramsey said.
"Consumer spending habits have changed rapidly in recent weeks over a very short period of time due to measures introduced by Government to ensure social distancing in the face of the pandemic," he said.
"Things like dry pasta, liquid soap and toilet rolls have been very high on consumers' shopping lists, whilst some other items may have fallen off the list entirely.
"It is therefore perhaps unsurprising that we are seeing some volatility in the prices of items in high demand for a range of reasons and we think it is interesting and useful to track this currently and over the months ahead."
He said the index revealed some surprises - despite a rush on products to keep our hands clean, the price of liquid soap was down 0.9% month-to-month.
However, the price had risen by 2.3% over the year.
Mr Ramsey said that the CPI index just provided only an average and that prices could vary from shop to shop.
"We would also assume that the intense fears that drove stockpiling in recent times have now passed given that supply chains have held up relatively well and demand from some of the items in the index will therefore settle to more normal levels over the months ahead," Mr Ramsey added.
Tesco, which is Northern Ireland's biggest grocer with 50 stores and a market share of 35.6%, said it had not increased its prices.
A check on its website reveals that a 500g bag of pasta shells costs 53p, with its rival Asda charging the same, while Sainsbury's charges 60p.
However, Asda charges £1 for two packs of the product, though it is understood Tesco is no longer doing multi-buys on the most sought-after products.
A Tesco spokeswoman said: "These are challenging times and we are facing unprecedented demand. We are doing everything we can to ensure customers get what they need, including setting purchase limits on our products.
"In the current climate, when we have a limited amount of stock, promotions such as multi-buys are irresponsible. It means some products have gone back to their pre-promotion prices. We are working tirelessly with our suppliers to maintain supply and keep stores stocked."