Household waste could make for sweeter tomatoes

The contents of household bins could be the secret to tastier tomatoes.

New research from the University of Queensland found the flavour and aroma of tomatoes improved when compost made from food organics and garden organics, or FOGO, was added to the soil.

The FOGO compost is produced at an industrial scale and can contain a broader mix of organic materials than traditional green-waste compost, including meat, which can contribute to higher nutrient levels.

As part of the trial, the compost was applied to only half of a Solanum lycopersicum cv. Ninja crop, which was otherwise grown under the same conditions.

Nicole Robinson, a research fellow at the university's School of Agriculture and Food Sustainability, said the tomatoes were analysed five and 12 days post-harvest to mimic the supply chain.

"We didn't pick up any differences in yield, but we did have this change in the food quality in terms of the sensory and the biochemical component after storage time," Dr Robinson said.

A group of volunteers blind-taste-tested the fruits.

"They thought the FOGO-grown tomatoes aligned with the descriptions of a bit sweeter, more aromatic and less bland," Dr Robinson said.

A chemical analysis also revealed a higher sugar concentration, lower malic acid and elevated umami-associated amino acids, which helped create a sweeter flavour.

Putting scraps to the test

Tastier tomatoes may not be the only potential benefit from FOGO.

Researchers hope the findings could encourage more food and garden waste to be diverted from landfills where it produces greenhouse gases.

Molly Chapman from End Food Waste Australia said about 7.6 million tonnes of food was thrown away nationally every year.

"About 70 per cent of that is edible and the equivalent of throwing away 29 million plates of food a day, and about $36 billion a year of money wasted,"

she said.

Ms Chapman believed the study would show the value of investing in systems needed to turn waste into agricultural products.

"There's a lot of information out there but, through the research, we're able to test and robustly demonstrate the positive environmental and economic outcomes," she said.

The National Food Waste Strategy was released in 2017 to halve the country's food waste by 2030.

The strategy included the introduction of green-lid wheelie bins to collect food and garden organics.

More than 160 councils in Australia offer the kerbside service; however, in some local government areas trials have been discontinued due to a lack of composting facilities, high costs and frustrations over collection timeframes.

A commercial supplier provided the compost for the research trial, but Dr Robinson suggested the waste collection and processing systems needed to work effectively if they were going to be useful for farmers.

"Having an efficient FOGO collection, where it's producing a quality feedstock for the composters, is a key area that's been identified that needs to be optimised," Dr Robinson said.

Researchers are now trying to determine whether the benefits of the additional compost can extend to other horticultural and broadacre crops.

The commercial reality

For farmers, the promise of better-tasting tomatoes may not justify potential costs.

North Queensland Farmers chair Carl Walker said growers prioritised soil improvements, adding that many factors could be manipulated to influence the quality of the crop.

"Different water, soil types, whether you pick it half colour or full colour," he said.

Mr Walker said the possibility of rolling out FOGO compost on commercial farms would hinge on economics.

"When it comes down to how much we need on a farm, we're talking about hundreds of tonnes," he said.

"You'd want to see a massive increase in flavour and texture to actually invest a lot of money in a new product."