Physicochemical properties of glutinous rice in the presence of alkali and borax

Abstract

The influences of alkali, represented by sodium hydroxide (NaOH), and sodium tetraborate (borax) on the physicochemical properties of glutinous rice (RD6 cultivar) were investigated. The results showed that NaOH and borax treatment differently influenced the properties of glutinous rice. NaOH-treated flour (NTF) had the highest pH value, followed by borax-treated flour (BTF), and the control sample, respectively. NaOH caused a significant decrease in the protein content while borax had no effect. These results related to scanning electron micrographs of NTF which showed a smoother surface than that of the others. The BTF had the highest peak and final viscosity, possibly due to cross-linkages between borate ions and hydroxyl pairs on the polysaccharide chains. The results of pasting properties were in line with the hardness of the flour paste. Gelatinization temperature of both NTF and BTF was significantly higher than in the control, but enthalpy was not significantly different. This information provides a greater understanding of the behavior of NaOH and borax on glutinous rice and is useful for applications of NaOH and borax in food and non-food products. It is also important to understand borax's effect on starch and to find a suitable substitute. Starch/Stärke 2015, 67, 930-936 Physicochemical properties of glutinous rice. . .

Effects of honey types and heating treatment on the textural, thermal, microstructural, and chemical properties of glutinous rice flour gels

“…All the three gels revealed a morphology of porous structure. Starch granules were completely ruptured during the heating process (gel preparation), and the honeycomb-like structure (pores) was caused by the water loss during freeze-drying process (Anupapsamosorn & Charoenrein, 2015). Network structure within congel gel was denser and more uniform than kelugel and honeygel.…”

Physicochemical properties of rice flour as affected by alkaline soaking and washing treatments

“…Rice flour was soaked in an alkaline solution (0.12 mol L À1 NaOH, saturated Ca(OH) 2 or limewater) at a ratio of 1:2 w/v and left to stand at 30 AE 2°C for 2 h. We reduced the soaking time from 18 h (Colussi et al, 2014) to 2 h because a longer soaking time resulted in an unpleasant fermented odour in the flour. The concentration of 0.12 mol L À1 of the NaOH solution was chosen according to the study of Karim et al (2008) and Anupapsamosorn & Charoenrein (2015). Before and after the alkaline treatment, pH of the flour suspension was measured to determine changes in pH due to soaking.…”

Selected physicochemical properties of rice flour, modified tapioca starch, and their mixtures after a limewater soaking treatment

“…They impart a sheen surface, viscous and smooth texture, and neutral taste to the products (Petracci et al, 2013;Hughes et al, 1998). Blending of flours and starches from different botanical sources is not an uncommon approach to improve the product quality (Liu et al, 2021a(Liu et al, , 2021b, for instance, modification of hardness of rice flour paste (Lin et al, 2013;Anupapsamosorn & Charoenrein, 2015). Seetapan et al (2015) reported that rice flour had higher protein content, pasting temperature, final viscosity, and setback and required higher temperatures to gelatinise than tapioca starch.…”