Effect of Wheat Bran Addition and Screw Speed on Microstructure and Textural Characteristics of Common Wheat Precooked Pasta-Like Products.

The present paper describes the wheat bran addition on microstructure, texture, colour and sensory characteristics of enriched precooked pasta-like products. Precooked pasta-like products were processed on a single screw extrusion-cooker TS-45 with L:D=16:1, shaped on the circular open die. Screw speed during the extrusion-cooking ranged from 60 to 120 rpm. Wheat bran were added in the amount from 5 to 25% of common wheat flour mass. The microstructure showed unmodified bran fractions at low screw speed, in turn higher rpm disrupted wheat bran cell walls. Hardness of dry pasta-like products, evaluated with the cutting test, was diminishing with a higher bran content in the recipe and was increasing with rpm applied. The firmness of hydrated products was decreasing with increasing bran addition (20 and 25% of bran in the recipe), whilst processing at low rpm caused poor quality of pasta-like products with great adhesiveness and stickiness. The higher bran content affected also the lower sensory notes. Colour measurement showed lower L* values for both raw and hydrated products with higher bran addition.