Produce snack food with moringa leaf powder using extrusion processing.

The leaves of the moringa tree (Moringa oleifera) are edible. They are cooked and consumed in many Asian, African and Latin American countries. The leaves are an exceptionally good source of vitamins A, B and C, of various minerals and of the sulphur-containing amino acids methionine and cystine.

There is no ready-to-eat snack food available with this highly nutritious ingredient. So, scientists at Kansas State University wanted to use extrusion processing to develop expanded snack products based on the moringa leaf. They succeeded in producing an expanded snack using moringa leaf powder and a steam-based extrusion technique. They found that moisture content was critical in producing this product.

The researchers used blends of moringa leaf powder with corn starch and oat flour to produce snack foods using a lab-scale twin-screw extruder. Two different levels of moringa leaf powder--10% and 30%--were used with corn starch and oat flour. The physical and mechanical properties of extrudates were evaluated.

In general, snack food that had been extruded at a 26% in-barrel moisture level was better in appearance, expansion and texture than the product that had been extruded at 19% and 22% in-barrel moisture levels. The expansion ratio of the product ranged from 1.9 to 3.0. The 30% moringa leaf powder with oat flour processed using 26% in-barrel moisture had the highest compression modulus: 180 MPa. The same formulation extruded at a 20% in-barrel moisture level had the lowest: 46 MPa.

Researchers found that snack products made with blends of corn starch and moringa leaf powder were harder and less crisp than those made using oat flour and moringa leaf powder. Higher levels of moringa leaf powder can lead to a better product.

Further information. Sajid Alavi, Department of Grain Science and Industry, 201 Shellenberger Hall, Manhattan, KS 66506; phone: [phone]; fax: [phone]; email: [e-mail].