The effect of durum wheat bran particle size on the quality of bran enriched pasta

Sammanfattning: Eating wheat bran has many positive effects on human health including reduced risk of cardio vascular diseases and type 2 diabetes. Still, many food products on the market are made from refined wheat flour because consumers tend to prefer the quality and texture in these products. Knowledge on factors influencing quality and texture in products containing whole grain wheat or added wheat bran making them less attractive is therefore of value. This study aimed to examine the influence of bran particle size and different bran fractions on the quality of pasta. Pasta incorporated with high levels of different bran fractions (coarse bran, fine bran and pollard flour) and different bran particles sizes (85-150 μm, 150-250 μm and 250-400 μm) were developed. Relative water absorption was measured and a descriptive sensory analysis was used to evaluate the quality in cooked pasta. Stained and unstained cross sections of 5 μm thick pasta was also studied using light microscopy. The result indicated that bran particle size but not bran fraction influenced the relative water absorption. Small bran particles had a significant lower water absorption compared to pasta with medium and large bran particles. The sensory evaluation of the pasta indicated that bran particle size had an impact on the quality attributes stickiness, surface roughness and likeability. Surface roughness in pasta became more evident with larger bran particles. Stickiness decreased with decreasing bran particle sizes and the pasta containing the smallest particles were significantly less preferred compared to the pasta with larger bran particles. The particle size of bran did not have any significant effect on the quality attributes whole grain flavor, elasticity and firmness. The microscopy evaluation indicated a small difference in the degree of gelatinization of starch granules across a section of the pasta. This difference indicated a higher degree of gelatinization of starch granules in the outer and intermediate parts of the pasta containing medium and large bran particles compared to the pasta containing the smallest bran particles.