Supermarkets have had to dump food after Tuesday's storm and subsequent power cuts.
Countdown's general manager of corporate affairs Kiri Hannifin said six stores were affected by the power outages yesterday.
"The worst hit were our Grey Lynn store in Richmond Rd, which had power out until last night, and our Papatoetoe store which reopened this morning.
"Unfortunately we lost some stock due to food safety requirements.
"Wherever we could we redistributed food to other stores, but some food was disposed of for safety reasons."
All Countdown stores are now running normally.
Antoinette Laird of Foodstuffs New Zealand, which runs Pak'nSave, New World and Four Square, said only some of the smaller stores were affected.
They too had to destroy some perishable chilled and frozen product for safety concerns.
Edible food was given to foodbanks, she said.
All stores were running normally today.
A crisis team manager at Auckland City Mission said it was difficult to tell if more people had donated - or collected - food since Tuesday's storm.
"All I can say is it has been a really busy few months overall.
"Demand for food parcels is always going up, it has been like that for the past few years."
As long as food was still fine they would accept it, he said.
"As long as it has not gone off, we use just about everything.
"Donations at the drop-in service we can give out to those in need immediately, some we put into crisis care parcels and we can also use some in the breakfast and dinner service."
As parts of the Auckland region head into a third day without power this evening, Auckland Council is recommending residents play it safe with their food.
People should keep the fridge and freezer closed to keep food as chilled as possible.
Throw away any frozen food that has been exposed to temperatures above 4C for two hours or more, or that has an unusual odour, colour or texture.
If food in the freezer is colder than 4C and has ice crystals on it, it can be refrozen.
Auckland Regional Public Health Service (ARPHS) medical officer Dr David Sinclair advised people without power to follow guidelines around food spoilage to avoid food poisoning.
"After today, highly perishable foods in the fridge like meat and fish may not be safe to eat," he said.
• Throw out rotten or contaminated food quickly so it doesn't spoil other food in the fridge.
• You can still eat food like raw vegetables, cheese and bread.
• Dispose of any food from the freezer which has thawed out and been at room temperature for longer than two hours.
• When the power comes back on, it is important not to refreeze food that has defrosted.
• If the frozen food has ice crystals and the packaging is intact then it can be refrozen.
"And if you are unsure, have a closer look and smell. If the colour has changed, it has a slimy texture or if it smells off, it probably is off.
"If you eat food that has gone off, you can risk infection from salmonella, campylobacter and a range of food poisoning bacteria."
Maintaining hygiene around food preparation and cooking required more thought than normal, Sinclair added.
Always wash and dry your hands before preparing food, ensure all utensils are clean before use and cook food thoroughly.
If water is in short supply keep some in a bowl with disinfectant.