Functional characterization of brown rice flour in an extruded noodle system

Tomographical, rheological, and structural effects of soy protein concentrate in a gluten-free extruded noodle system

Global interest in high-protein foods has been rapidly increasing and the gluten-free products are no exceptions. Gluten-free extruded noodles made from rice flour were thus fortified with soy protein concentrate (SPC) (0%, 15%, 30%, and 45% by weight), and the physicochemical properties of the noodles were characterized in terms of tomographical, rheological, and structural features. SPC-rice flour blends showed higher water absorption and swelling power at room temperature with increasing levels of SPC, which were reduced upon heating. The flour blends with high-levels of SPC also had lower pasting viscosities. Thermal analysis showed lower enthalpy values and higher temperatures derived from starch gelatinization. When the SPC-rice flour blends were applied to extruded gluten-free rice noodles, the noodles tomographically showed a dense and compact structure, that could be favorably correlated with their textural changes (increased hardness and reduced extensibility). FTIR analysis presented the structural changes of the noodles containing different levels of SPC by showing higher intensity of protein-related absorption peaks and lower starch peak intensity, which could be associated with the reduced cooking loss. Moreover, there existed two water components with different mobilities in the noodles whose spin-spin relaxation times had a tendency to increase with increasing SPC content. The results obtained from this study provided fundamental insights into the processing performance of protein-rich ingredients in gluten-free extruded noodles, probably promoting the development of a wider variety of protein-fortified gluten-free products.

Effects of food hydrocolloids on quality attributes of extruded red Jasmine rice noodle

The aim of this study was to examine the quality characteristics of extruded red Jasmine rice flour (RJF) noodle that had been prepared with hydrocolloids, namely guar gum (GG), carboxymethyl cellulose (CMC), and xanthan gum (XG) at the concentrations of 0.0 (control sample), 0.2, and 0.4% (w/w), respectively. The use of hydrocolloids had no effect on total phenolic contents, antioxidant properties (DPPH, ABTS, and FRAP), color, and X-ray diffraction patterns (p > 0.05). In contrast, the hydrocolloids tended to increase the expansion ration of the noodle. GG and CMC improved cooking, textural, and sensory properties. Ultimately, 0.2%-GG showed the lowest cooking loss (5.07%) when compared with others. Moreover, it also provided the noodle with better textural properties such as tensile strength, extensibility, hardness, cohesiveness, and chewiness (p < 0.05). For these reasons, the highest acceptability (6.75) for the noodle was achieved with GG02. XG resulted in lower overall acceptability (5.05), particularly the 0.4%-XG recipe (p < 0.05). Thus, usage of 0.2%-GG was the best option for improving the qualities of extruded RJF noodle. XG was deemed ineffective for improving the noodle.

Application of pulverization and thermal treatment to pigmented broken rice: insight into flour physical, functional and product forming properties

The utilization of rice for food purposes involves pulverization and thermal processing which may affect its quality characteristics. Hence pigmented broken rice was processed in plate mill and hammer mill followed by thermal treatment by toasting to study the physical, and functional characteristics and their effect on rice noodle quality. Results showed that plate milled rice flour showed high concentration of particles with size below 148 µm particle (44%), increased redness (21%), bulk density (17%), sedimentation value (75%), damaged starch (72%), peak viscosity (17%), and caused microstructural changes compared to the hammer mill. The toasting of plate milled red and black rice flour caused an insignificant influence on particle size, color, and bulk density. However, it increased the sedimentation value to 134% and 94% and damaged starch by 44% and 19% in red and black rice flour respectively. Further, a reduction in peak viscosity (22%) in red, and increase (16%) in black, along with microstructural changes were also observed. The rice noodle prepared using plate milled, and toasted red rice flour was sensorily acceptable and exhibited excellent textural properties. The study showed that plate milling and thermal treatment significantly affect the quality characteristics of pigmented rice flour and end-product quality.

Innovative processing techniques for altering the physicochemical properties of wholegrain brown rice (Oryza sativa L.) - opportunities for enhancing food quality and health attributes

Rice is a globally important staple consumed by billions of people, and recently there has been considerable interest in promoting the consumption of wholegrain brown rice (WBR) due to its obvious advantages over polished rice in metabolically protective activities. This work highlights the effects of innovative processing technologies on the quality and functional properties of WBR in comparison with traditional approaches; and it is aimed at establishing a quantitative and/or qualitative link between physicochemical changes and high-efficient processing methods. Compared with thermal treatments, applications of innovative nonthermal techniques, such as high hydrostatic pressure (HHP), pulsed electric fields (PEF), ultrasound and cold plasma, are not limited to modifying physicochemical properties of WBR grains, since improvements in nutritional and functional components as well as a reduction in anti-nutritional factors can also be achieved through inducing related biochemical transformation. Much information about processing methods and parameters which influence WBR quality changes has been obtained, but simultaneously achieving the product stabilization and functionality of processed WBR grains requires a comprehensive evaluation of all the quality changes induced by different processing procedures as well as quantitative insights into the relationship between the changes and processing variables.

Effect of degree of milling on physicochemical, structural, pasting and cooking properties of short and long grain Indica rice cultivars

The effects of degree of milling (DOM) between 0 and 8% on physico-chemical, structural, pasting and cooking properties of short and long grain Indica rice cultivars were studied. Ash, protein, lipids and minerals decreased while blue value and crystallinity increased with increase in DOM. The colour parameters (a∗, b∗) and cooking time (CT) decreased while L∗(lightness) increased with increase in DOM. Elongation ratio (ER), gruel solid loss (GSL), length/breadth (L/B) and paste viscosities during cooking increased with increase in DOM. Short grain rice contained lower ash, protein, lipids, Mn, K, Ca, CT and GSL than long grain while the later showed higher crystallinity, Mn, P, K, Ca and ER. Paste and dough characteristics measured using Rheometer and Mixolab, respectively correlated well and differed with cultivar and DOM. Short and long grain cultivars showed variation in loss of different chemical constituents during varied DOM causing variation in cooking characteristics.