Pasta noodles enriched with sweet potato starch: Impact on quality parameters and resistant starch content.

This research is focusing on the texture, rheology, and sensory properties of pasta products enriched with the sweet potato starch (SPS) as well as on the content of resistant starch (RS) in these products. SPS was extracted from orange sweet potatoes using 1 mol. L-1 Sodium chloride solution. Durum wheat flour semolina was partially supplemented with 10, 20, and 30% (w/w) by SPS in the pasta formulation and the influence of enrichment on the cooking quality, mechanical and sensory properties, and the color was observed. SPS addition resulted in decreased water absorption and shorter dough development time, but the stability of the dough was also decreased. The optimum cooking time for pasta was reduced, but only slightly, on the other side, the swelling index increased, which negatively impacted on the firmness of the products. Increasing of the SPS content also resulted in higher stickiness values for pasta. When up to 20% of wheat flour was replaced, the color of finished products was less acceptable. In the products, the resistant and total starch content were determined. Pasta cooking resulted in the reduction of RS content, which was then increased by storing products for 24 hr. It can be concluded that the substitution of part of semolina flour with SPS increased the level of RS, but on the other side, it caused some significant differences from the quality of pasta made from semolina only.

Quality evaluation of sweet potato powder-enriched cereal products.

The effects of wheat flour substitution by sweet potato powder on rheological parameters of wheat dough and physical parameters of cookies and crackers were analyzed. Wheat flour was substituted with sweet potato powder at level 2.5%, 5%, 7.5%, and 10%. Sweet potato powder was characterized by high water holding capacity (9.00 g/g) and swelling capacity (8.16 cm3/g). The addition of sweet potato powder significantly changed the rheological properties of wheat dough (water absorption and mixing tolerance index were increased, dough stability was reduced, and dough development time was prolonged). It was also found that volumes of cookies and crackers were decreased, and spread ratios were increased with the addition of sweet potato powder. Lightness of baked products decreased and yellowness increased with the addition of sweet potato powder. Incorporation of sweet potato powder significantly decreased the hardness of cookies and crackers. Sensory evaluation showed that the most acceptable cookies and crackers were the ones obtained after the addition of sweet potato powder at level 2.5% and 7.5%, respectively.

Effects of cellulose fiber with different fiber length on rheological properties of wheat dough and quality of baked rolls.

Powdered cellulose is often used in cereal processing industry. The effects of partial replacement (0.5%, 1%, 2% and 5%) of wheat flour by cellulose fiber with different fiber length (80, 120 and 220 µm) on rheological properties of wheat dough and qualitative parameters of baked rolls were studied. Sensory evaluation of baked products was also performed. Mixing and pasting properties of dough were determined by Mixolab. Generally, cellulose-enriched dough was characterized with higher water absorption, dough stability and parameters C2 and C3. Moreover, it was found that parameters C4 and C5 increased with increasing cellulose fiber length. From the results, it was also concluded that the physical parameters of baked rolls containing cellulose were reduced. It was also observed that the incorporation of cellulose fiber with shorter fiber length concluded in lower rolls volume compared to cellulose fiber with long fiber length. Texture analyses showed that the firmness of rolls containing cellulose at the substitution level 5% was significantly higher than those of the control, whereas the springiness of wheat rolls was not significantly affected. It was also recorded that the firmness and cohesiveness of baked rolls were higher after the addition of cellulose fiber with shorter fiber length. Sensory evaluation indicated that baked rolls with cellulose addition up to 1% were comparable with control rolls. Results also showed that higher levels of cellulose significantly decreased crust, taste, color and porosity of rolls.