The dip solution, PQSL 2.0, could help food processors targeting the convenience market, meet food safety regulations and improve product quality.

PQSL 2.0 is the result of research conducted by scientists at the US Department of Agriculture (USDA).

PQSL 2.0 is a breakthrough for wash solutions because it not only maintains an apple slice's color, firmness, aroma and flavor, but also reduces levels of Listeria and Salmonella bacteria.

USDA Agricultural Research Service (ARS) microbiologist Arvind Bhagwat and his team tested the solution against three other commercial wash treatments available on the market.

Blind taste tests were conducted with Fuji and Granny Smith apples. Participants found no notable taste or coloring differences between PQSL 2.0 and other wash treatments, Bhagwat said.

In separate tests, PQSL 2.0 was added to four anti-browning wash treatments and exposed to five common pathogens.

The tests showed an almost complete reduction in pathogen levels. The additive also reduced harmful microflora on pre-sliced sanitized apples.

Microflora can produce toxins that cause diarrhoea, mucosal invasion and carcinogenesis.

The team's preliminary investigations into the protection against Listeria and Salmonella have been promising.

Low doses of each pathogen were placed on apple slices along with PQSL 2.0.The tests showed that the solution worked to inhibit and eliminate Listeria and Salmonella after one, two and three weeks.

Protection against Listeria and Salmonella in fruit has been a major concern, especially among the school and grocery industry, since large outbreaks of Salmonella in 2004 caused 561 illnesses across 18 states.