The aroma of bacon and onion frying in butter should be wafting down the hallways of the nation's nursing homes an impassioned Maggie Beer has told the Royal Commission into Aged Care.

But the celebrity chef said her work through advocacy group the Maggie Beer Foundation found meals were too often prepared with little regard to presentation, aroma or nutrition.

"Everyone wants to smell proper food. You cannot make good food with bad ingredients," she said.

Ms Beer told the second day of hearings in Cairns that relatively minor reforms such as increased specialist training and salaries for chefs, tailored menus, and budget increases could lift the abysmal standard of food in aged care.

Maggie Beer said she was shocked by the evidence she heard. ( ABC North Coast: Samantha Turnbull )

"Without it — the energy that comes from good food — [residents] don't have the will to or the physicality to be involved," she said.

Her comments came after a morning of gastronomical horror stories in which the commission learned the quality of food often hinged on how much a provider was likely to pay.

Cutting corners

Earlier, a roundtable of three chefs with almost 100 years of experience in a range of aged care services and kitchens between them suggested an answer to why food standards were so poor.

The commission heard the quality of aged care menus — described by one panellist as "the one thing [residents] get to look forward to" — came down to what the facility paid per resident.

For $16 a day, the residents of the unnamed facility Lindy Twyford manages were served salt-and-pepper squid, fillet mignon, and occasional portions of frozen but high-quality produce.

Pureed food served in a home in Western Australia. ( Supplied )

At the other end of the spectrum, a home spending $7 would rely on secondary cuts of meat and mass-ordered vegetables, some of which would be thrown out at the expense of serving sizes.

"You're having to cut corners, you're having to use frozen foods, you're having to use processed foods just to feed residents," chef Nicholas Hall said.

Mr Hall said food costs at some facilities he formerly worked at were inflated by an ordering system beyond supermarket prices, in one instance by as much as 100 per cent.

Chef Timothy Deverell raised concerns about the lack of training to create texture-modified foods, menus that had no input from residents until they complained, and food served on open-air trolleys that was often cold by the time it reached some residents.

Some homes would place food orders using a "restrictive" system in which a drop-down box offered just a handful of options, Mr Hall said.

Food from a nursing home in Perth supplied as part of an ABC investigation into food in aged care. ( Supplied )

Facilities would opt for finger food platters because they were "low-risk", cheap, and didn't require a chef.

Some meals would be repeated up to three or four times a week as providers made a bid to reduce costs.

"They're racing to the bottom to see who can feed for the lowest amount of cost," Mr Hall said.

Maggots, rotten food

The commission was also told of one "upmarket residential aged care facility" which had a maggot-infested rubbish store between service trolleys and a nearby fridge containing enough rotten food to fill a trailer.

"[I've seen] reusing food that's already been out, served to residents and come back to the kitchen," Mr Deverell said.

"They use that for texture-modified diets."

Mr Hall said food safety audits were too infrequent and services were given advance notice, meaning extra cleaners could be hired to bring facilities up to scratch.

He said nutritionists failed to properly engage with residents and their needs.

The commission heard a home spending $7 a day on residents would rely on secondary cuts of meat and mass-ordered vegetables. ( ABC News: John Gunn )

"Nutritionists are there solely, in my experience, so the home or third party facility can say 'we have a dietician or nutritionist'," he said.

"You see residents wasting away because they're not given enough food. It's just a joke."

Ms Beer said a meagre budget increase to $10.50 per person, per day could vastly improve the issue.

"It's not possible to feed them with a combination of nutrition, flavour and pleasure — it is not possible, full stop, at $7 a day," she told media outside the hearing.

She said the evidence presented at the commission was the worst she'd heard.

"Without a doubt, and yes I am shocked. Nothing can forgive that and nothing can accept that.

"We owe it to our elderly residents and also those in the community who are alone and no longer cooking for themselves. We need to look after them."