Technology for Blending Recombined Flour: Substitution of Extruded Rice Flour, Quantity of Addition, and Impact on Dough

In a previous study, rice bread was prepared using a combination of rice-wheat mixed flour. To investigate the impact of the partial adoption of extruded rice flour (ERF) on mixed flour (MF) and mixed dough (MD), the effects of adding ERF on the pasting, mixing characteristics, texture, and water retention of the MF and MD were examined by a rapid visco analyzer (RVA), Mixolab, texture profile analysis (TPA), and a low-field nuclear magnetic resonance analyzer (LF-NMR). The PV, TV, BD, FV, and SV of the MF declined as the incorporated amount of ERF increased. There was no significant difference in the PT at the 5-15% addition level (p < 0.05), but it showed an increasing trend at the 20-30% level (p < 0.05). The incorporation of ERF led to a significant increase in the water absorption (WA) of the MD, while the DT, ST, C2, C3, C4, and C5 exhibited a declining trend. The texture analysis revealed a significant decrease in the dough hardness with the addition of ERF, with a 55% reduction in the hardness of the 30% improved mixed dough (IMD), and the cohesiveness increased significantly (p < 0.05). The IMD was mainly composed of weakly bound water. The content of weakly bound water increased with the ERF amount.

Comparative study on nutritional and technological properties of two varieties of black wheat flour and their noodle-making potential

Comparative studies were conducted on physicochemical and technological properties of two black wheat (BW) varieties (cultivated in Shanxi Agricultural University) and their noodle-making potential. Whole-grain BW noodles showed acceptable cooking loss (≤10%) and strong antioxidant capacity. However, their textural quality remains to be enhanced. Regarding refined flour (RF) of the two BW varieties, Yunhei 14207 showed more anthocyanins, brighter color, and greater thermal stability (as reflected by the higher pasting temperature). 16W16 resulted in greater gluten content and better gluten quality of flour and higher dough stability, which contributed to the lower cooking loss and stronger tensile property of noodles. RF noodles of Yunhei 14207 displayed brighter appearance, although they had weaker tensile property. The stronger gluten network in noodles of 16W16 protected phenolics from release and degradation during drying, cooking, and steaming. Despite phenolics loss, RF noodles of Yunhei 14207 showed antioxidant capacity up to 14.97 mg TE/100 g. This research would promote understanding of characteristics of BW varieties. Considering the stronger gluten network of 16W16, its fortification in common wheat noodles at high proportion (>50%) may be promising to develop antioxidant noodles with further improved sensory quality.

Effects of Germination, Fermentation and Extrusion on the Nutritional, Cooking and Sensory Properties of Brown Rice Products: A Comparative Study

In this study, cooked brown rice (BR), germinated brown rice (GBR), fermented brown rice (FBR) and white rice (WR) were prepared by traditional cooking techniques, and extruded brown rice (EBR) was obtained by extrusion processing technology. The nutritional, cooking and sensory properties of different BR products were investigated. The results indicated that the soluble dietary fiber (SDF) content, free total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity (DPPH, ABTS, T-AOC) in processed BR products were significantly higher than those in cooked BR and WR. The values of SDF, free TPC, TFC and T-AOC in EBR increased by 38.78%, 232.36%, 102.01% and 153.92%, respectively, compared with cooked BR. Cooked FBR and EBR had more nutrients, required less cooking time, had a softer texture and were whiter than cooked GBR and BR, especially EBR. In addition, the water absorption rate of EBR was 14.29% and 25.41% higher than that of cooked FBR and GBR. The hardness of EBR was significantly lower than that of cooked FBR and BR, even lower than that of cooked WR. However, there was no significant difference between the hardness of cooked GBR and that of cooked BR. The flavor compounds in EBR were similar to that of cooked WR, while those in cooked GBR and FBR did not differ greatly compared to cooked BR. Collectively, cooked FBR and EBR had better nutritional value, cooking and sensory properties than cooked BR, and the comprehensive value of EBR was higher.

Valorization of Common (Fagopyrum esculentum Moench.) and Tartary (Fagopyrum tataricum Gaertn.) Buckwheat in Gluten-Free Polenta Samples: Chemical-Physical and Sensory Characterization

In recent years, increasing attention has been addressed to buckwheat, an interesting minor crop with an excellent nutritional profile that contributes to the sustainability and biodiversity of the agri-food system. However, the high content of rutin and quercitin present in this pseudocereal can elicit undesirable sensory properties, such as bitterness and astringency, that can limit its exploitation in food formulations. The aim of the present study was to characterize six gluten-free porridge-type formulations (called polenta) prepared using corn and buckwheat flour. Specifically, polenta samples were prepared adding common (CB) or Tartary buckwheat (TB) flour at 20% (CB20; TB20), 30% (CB30; TB30), and 40% (CB40; TB40) to corn flour. Product characterization included sensory and instrumental analyses (electronic tongue, colorimeter, and Texture Analyzer). Products containing Tartary buckwheat were darker, firmer, and characterized by a higher intensity of bitter taste and astringency than those prepared with common buckwheat. In this context, the impact of buckwheat species seems to be more important at 30% and 40% levels, suggesting that lower additions may mask the differences between the species. The gathered information could support the food industry in re-formulating products with buckwheat. Finally, findings about the relationship between instrumental and sensory data might be exploited by the food industry to decide/choose what indices to use to characterize new formulations and/or new products.

A review of extrusion-modified underutilized cereal flour: chemical composition, functionality, and its modulation on starchy food quality

Compared with three major cereals, underutilized cereals (UCs) are those with less use but having abundant bioactive components and better functionalities after proper processing. As a productive and energy-efficient technology, extrusion has been used for UC modification to improve its technological and nutritional quality. Extrusion could induce structural and quantitative changes in chemical components of UC flour, the degree of which is affected by extrusion intensity. Based on the predominant component (starch), functionalities of extruded underutilized cereal flour (EUCF) and potential mechanisms are reviewed. Considering bioactive compounds, it also summarizes the physiological functions of EUCF. EUCF incorporation could modulate the dough rheological behavior and starchy foods quality. Controlling extrusion intensity or incorporation level of EUCF is vital to achieve sensory-appealing and nutritious products. This paper gives comprehensive information of EUCF to promote its utilization in novel staple foods.

Optimisation of the Extrusion Process through a Response Surface Methodology for Improvement of the Physical Properties and Nutritional Components of Whole Black-Grained Wheat Flour

Chronic undernourishment affects billions of people. The development of whole-grain food with high nutritional quality may provide a valuable solution to nutritional security. Black-grained wheat (BGW), as a rich source of protein and micronutrients, is a good raw material for value-added products. The objectives of this study were to investigate the effects of barrel temperature, feed moisture content, and feed rate on the physical properties and nutritional components of whole BGW flour extrudates and to optimise their processing conditions by using the response surface methodology. The increasing barrel temperature, feed moisture content, and feed rate affected the specific volume, expansion ratio, hardness, fracturability, water absorption index (WAI), water solubility index (WSI), and total starch content of the extrudates, but did not significantly affect the content of protein, ash, iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn). The extruded wheat flour had a significantly higher content of Fe and Cu, and a lower total starch content than the unextruded flour under extrusion conditions. A significantly higher content of protein, ash, Zn, Cu, and Mn, and a significantly lower total starch content were found in the extruded and unextruded flours made of whole BGW than in those made of whole white-grained wheat. According to the significance of the regression coefficients of the quadratic polynomial model, the optimum extrusion parameters were as follows: a barrel temperature of 145.63 °C, feed moisture content of 19.56%, and feed rate of 40.64 g·min-1 in terms of the maximum specific volume, expansion ratio, fracturability, WAI and WSI, and the minimum hardness. These results may be used by food manufacturers to successfully develop extruded products from whole BGW flour, meeting consumer demands and needs.