Extrusion method developed for tasty lentil snacks

Despite extrusion being a time and money saving technology commonly used in processing, the machinery regurgitates food through several compartments, so taste and texture are sometimes lost.

The research agency, part of the US Department of Agriculture (USDA) uses extrusion cooking, where a variety of processes such as mixing, compressing, kneading and expanding take place in one machine, to make the crunchy snacks.

"Extrusion technology isn't new," researcher Jose Berrios told BakeryandSnacks.com.

"But we are the first to determine the processing speeds, heating temperatures, amounts of moisture and formulations that create consistent, desirable textures and tastes from every batch of legume flour."

Several breakfast-cereal type foods and snacks, "from crisp bits to tubular puffs" are currently being developed, he added.

They have already proven popular with 550 tasters at a Lentil Festival in Washington, US, who were encouraged to try the products in 2006.

The ARS presented festival-goers with barbeque, cheese, classic and plain flavour snacks, as well as sweet and plain cereal foods, then asked them to rate the product on a sliding scale from "like a lot" to "dislike a lot".

"The combined result of flavour preferences demonstrated that overall average liking percentage for the coated snack type lentil products was about 80 per cent, independently of the type of coating used, and about 60 per cent for the plain snack," Berrios said.

"Also, that the overall average liking percentage for the breakfast cereal type product coated with brown sugar was above 80 per cent, and above 60 per cent for the plain one," he added.

And as the snacks are made from lentils, peas, beans and garbanzos, also known as chick peas, they are good for human health, the ARS claims.

Legume pulses are low in sodium and fat, cholesterol-free, as well as being rich in protein and fibre, so reduce the risk of a variety of health problems such as obesity, heart disease, cancer and diabetes, Berrios said.

The ARS is currently looking for industry partners to commercialise and market the snack, both "in the US and the international market," he added.

The research body often develops new products that as well as being innovative, are used to encourage US consumers to eat healthier foods such as fruit and vegetables.

In September, it developed an apple and berries fruit bar, that stay moist for 24 months without the need for artificial preservatives, scientists claimed, while earlier this year the ARS created low fat peanut flour for baked goods.