Rice Flour Dough Research Articles

Physico-Chemical Changes and Stability of Nutraceutical in Rice Bran Oil During Simulated Domestic Frying

Simulated frying studies were carried out by frying circular sheets of rice flour dough in rice bran oil, heated to 180±2°C. The total frying time was up to 8 hrs. At the end of every 2 hrs, the oil samples were drawn and physicochemical changes were determined. Results showed that the changes were markedly rapid in the initial phase of frying which is first the 2 hrs. The Lovibond colour values for 0 to 2 hrs were from 12.1±0.5 to 43.1±0.95. During the same period, peroxide value (PV), free fatty acid (FFA), anisidine value (AV), total polar material (TPM), saturated fatty acid (SFA), monounsaturated fatty acids (MUFA) and viscosity were found to increase from 0.2±0.01 to 3.5±0.05 Meq.O2/kg, 0.25±0.05 to 0.69±0.05%, 5.0±0.05 to 11.1±0.2, 1.0±0.05 to 1.9±0.05 %, 25.6±0.05 to 26.2±0.05 %, 43.7±0.01 to 43.9±0.05 % and 107±0.01 to 108±0.2 mPas, respectively. Beyond 2 hr, a gradual increase in these parameters was observed till the end of frying. Similarly, more than 50 % of the tocopherol present was lost at the end of 2 hr of frying. Marginal decrease was observed in oryzanol content from 1.6±0.05 to 1.4 ±0.05 %, polyunsaturated fatty acids (PUFA) 30.5±0.01 to 28.6±0.05 % and iodine values from 100.2±0.05 to 96.8±0.05 even after 8 hr of frying. Keywords: Rice bran oil, fatty acid, oxidation, nutraceutical, simulated frying, tocopherol, oryzanol.

RHEOLOGICAL CHARACTERIZATION AND MODELING OF RICE FLOUR DOUGH: EFFECT OF PARBOILING TIME, MOISTURE CONTENT AND GUM ARABIC

ABSTRACTSmall‐deformation compression and stress relaxation studies in addition to nonoral sensory assessments were performed on rice flour doughs, obtained by parboiling at different times (0–60 min), moisture (48–60%) and gum Arabic contents (0–0.5%). The response functions were the rheological (firmness and compression energy, initial and equilibrium moduli and relaxation time) and nonoral sensory attributes (ease of extrusion, cohesiveness and stickiness) of dough. Compression energy increased with parboiling time but decreased with moisture content. Relaxation time varied from 0.15 to 20.2 s, meaning a wide variation in the behavior of dough is possible to achieve. The viscoamylographic studies indicated that parboiled rice pastes exhibited more stable status toward retrogradation and showed lesser shear‐thinning phenomenon compared with their counterpart raw rice samples. The stress decay curves could be modeled by three‐element spring‐dashpot Maxwell–Voigt model (r ≥ 0.81, P ≤ 0.01). The optimum condition for obtaining a dough with minimum stickiness and maximum ease of extrusion was computed.PRACTICAL APPLICATIONSRice is extensively used in various forms of food as whole grain as much as flour. Because of nonglutinous properties, rice dough from raw flour cannot be easily flattened or shaped, whereas thermal treatment like parboiling and the use of gum Arabic can make the dough suitable for formulating different products. The addition of gum during dough preparation can retain more water and modify its rheological properties, improving the dough handling characteristics and textural attributes of the finished products. The specific applications of reported findings lie in the development of rice‐based products such as ready‐to‐eat and ready‐to‐fry/bake snacks, baby foods and breakfast cereals.

RHEOLOGICAL PROPERTIES OF RICE–SOYBEAN PROTEIN COMPOSITE FLOURS ASSESSED BY MIXOLAB AND ULTRASOUND

ABSTRACTThe rheological behavior of gluten‐free composite flours formulated with rice flour and increasing amounts of soybean protein (SP) isolate (0–2%, w/w, flour blend basis) in the presence and absence of transglutaminase (1%, w/w) was assessed using two complementary approaches, the Mixolab device and ultrasonic measurements. Dough was subjected to dual mechanical and thermal constraints, namely mechanical changes due to mixing and heating in the Mixolab and in parallel measurements of ultrasonic attenuation and velocity were performed at two different temperatures (25 and 65C). Main differences were observed during the mixing process, where SPs and transglutaminase induced an important increase of the dough consistency. Results from ultrasonic measurements were in accordance with those obtained with the Mixolab device, both approaches being able to assess the empirical rheological behavior of gluten‐free matrixes and even to detect the effects induced by protein ingredients and processing aid.PRACTICAL APPLICATIONSTwo complementary approaches, the Mixolab device and ultrasonic measurements, are proposed for assessing rheological behavior of gluten‐free doughs. Mixolab provides information of gluten‐free dough empirical rheology following the dough physicochemical changes associated with dual mechanical shear stress and temperature constraint. Ultrasound also may be used to determine consistency changes in gluten‐free dough, resulting in an interesting potential for future development of a quality control system intended for the industrial production process of dough. Consequently, Mixolab and ultrasounds could be regarded as promising tools in order to investigate rice flour dough properties and the changes induced by other ingredients and processing aids.

Comparative Study of the Effect of Incorporated Individual Wheat Storage Proteins on Mixing Properties of Rice and Wheat Doughs

The aim of this work was to compare the effects of incorporated wheat storage proteins on the functional properties of rice and wheat flours. The advantage of rice as a base flour compared to wheat is that it does not contain any wheat flour components and, therefore, has no interactive effect between wheat glutenin proteins. The incorporation of individual HMW glutenin subunit proteins (Bx6, Bx7, and By8) in different ratios had significant positive effects on the mixing requirements of both rice and wheat doughs. Reconstitution experiments using two x+y type HMW-GS pairs together with a bacterially expressed LMW-GS have been also carried out in this study. The largest effects of polymer formation and mixing properties of rice flour dough were observed when Bx and By subunits were used in a 1:1 ratio and HMW and LMW glutenin subunits in a 1:3 ratio. However, using the same subunit ratios in wheat as the base flour, these synergistic effects were not observed.

Technological Assessment of Chestnut Flour Doughs Regarding to Doughs from Other Commercial Flours and Formulations

The technological assessment of chestnut flour doughs was studied using Mixolab® apparatus, establishing a comparison with gluten (soft, hard and whole wheat) and gluten-free (rice and yellow corn) flour doughs as well as corn starch pastrymaking and breadmaking formulations. This equipment measures the torque in function of temperature and time, firstly at 30 °C (mixing curve) and secondly the mixing during heating (4 °C/min up to 90 °C) and cooling (4 °C/min up to 50 °C) steps (complete curve). Different hydrations of doughs ranging from 41.4% to 68.5% (flour basis) were necessary to reach the torque of 1.10 ± 0.07 Nm. Parameters of mixing such as water absorption, development time, stability and mixing tolerance index were obtained. Parameters of heating and cooling cycle related to weakening of proteins, gelatinization starch, amylase activity and starch retrogradation as well as range of gelatinization temperatures were also determined. Chestnut flour showed suitable parameters in the mixing stage such as arrival time (1.93 ± 0.1 min), stability (12.1 ± 0.4 min) and departure time (14.0 ± 0.3 min). In the heating cycle, chestnut flour exhibited close behaviour to soft wheat flour with cooking stability of 1.12 ± 0.01 min and seems to be suitable for pastrymaking products. Finally, in the cooling cycle the behaviour revealed that products of this flour can present problems of staling and crumbs firmness due to high values (2.88 Nm) of C5 parameter.

유기산과 증점제를 첨가한 쌀국수의 품질 특성

쌀을 주원료로 국수를 제조하기 위해 유기산과 증점제를 이용하고 단백질, 텍스트린, 정제염을 첨가하였다. 혼합 유기산과 증점제를 사용한 쌀가루 반죽의 증숙 후 물성은 최대응력(max weight)은 평균 <TEX>$2040.00\;g/cm^2$</TEX> 이었고 탄성 139.12%, 응집력 66.05%, 씹음성 1,396.13 g, 깨짐성 190,456.12 g으로 나타났다. 이상의 결과 쌀가루를 이용한 쌀국수제조에 적합한 조건은 다음과 같다. 원료쌀의 수침은 <TEX>$20{\sim}25^{\circ}C$</TEX>에서 12시간 실시하고 <TEX>$35^{\circ}C$</TEX>이하 온도에서 분쇄를 2회 실시하는 것이 적합하였고, 쌀가루의 물성을 변화시키기 위해 혼합유기산 0.255%(무수 구연산 0.10%, 사과산 0.75%, adipic acid 0.03%, 양조식초 0.05%), 혼합 증점제 2.820%(산탄검 1.00%, 구아검 0.80%, 알긴산나트륨 0.96%, 폴리아크릴산나트륨 0.06%), 글루텐 3.00%, 덱스트린 1.00%, 카제인나트륨 1.00%, 정제염 3.88%를 혼합한 쌀가루로 국수를 제조하는 것이 적합한 조건으로 판단되었다. In order to manufacture noodles using rice flour as its main ingredient, organic acid and thickening agents have been used, and protein, dextrin, and refined salt have added. The rice flour dough that had been baked using organic acids and thickening agent showed the max weight of <TEX>$2040.00\;g/cm^2$</TEX>, elasticity value of 139.12%, cohesiveness of 66.05%, chewiness of 1,396.13g, and brittleness of 190,456.12g respectively. The appropriate conditions for manufacturing rice noodle using rice flour were that the rice was to be soaked for 12 hours at temperature of <TEX>$20{\sim}25^{\circ}C$</TEX> and to be milled twice at temperature lower than <TEX>$35^{\circ}C$</TEX>. Additionally, the most ideal condition to manufacture noodles was to use the rice flour by combining protein, dextrin and refined salt using 3.88% organic acid blend and 2.82% blend of thickening agents in order to change the rice flour properties

Addition of rice bran oil to soybean oil during frying increases the oxidative stability of the fried dough from rice flour during storage

Abstract The effect of proportion of soybean oil to rice bran oil on lipid peroxidation inhibition in fried dough with rice flour during storage was investigated. Rice flour dough was fried in 100% soybean oil and mixtures with 25, 50 and 75% of rice bran oil at 160 °C for 1 min, then stored in the dark at 60 °C for 10 days. During 10-day storage, polyunsaturated fatty acid decreased rapidly in fried dough frying in 100% soybean oil and mixtures with 25% rice bran oil, while saturated fatty acid increased. Furthermore, total tocopherol content ( p ⩽ 0.05) and headspace oxygen concentration in vial headspace ( p ⩽ 0.05) were significantly rapidly decreased in fried dough frying in 100% soybean oil and mixtures with 25% rice bran oil, while peroxide and p -anisidine values were significantly lower in fried dough with using oil mixtures (50%, 75% and 100% rice bran oil) during storage ( p ⩽ 0.05). However, an increase of FFA was significantly higher in fried dough with frying in 100%, 75% and 50% of rice bran oil during storage ( p ⩽ 0.05). There was no significant difference in decreasing gamma-oryzanol contents of fried dough during storage ( p > 0.05). These results demonstrated the effect of soybean oil mixtures with 50% and 75% rice bran oil on retardation of oxidative rancidity and hydrolytic rancidity in fried dough during storage.

Oxidative stability of fried dough from rice flour containing rice bran powder during storage

The aim of this study was to evaluate the efficiency of rice bran powder on lipid peroxidation inhibition of fried dough from rice flour during storage. Rice flour dough containing rice bran powder at 5, 10 and 15 g rice bran powder/100 g mixed rice flour were fried in soybean oil at 160 °C for 1 min and stored in dark at 60 °C for 10 days. Lipid peroxidation of fried dough was determined by change of fatty acid compositions, oxygen absorption in vial headspace, lipid hydroperoxides, TBA values including decreasing tocopherol and gamma-oryzanol contents during storage. Polyunsaturated fatty acid decreased rapidly in fried dough without rice bran powder, while an increase of oxygen absorption in vial headspace, lipid hydroperoxide and TBA values were significantly lower ( p⩽0.05) in fried dough containing rice bran powder. In addition, tocopherol degradation was significantly lower in fried dough containing rice bran powder during storage ( p⩽0.05). However, there was no significant difference in gamma-oryzanol contents among fried dough during storage ( p>0.05). These results demonstrated that rice bran powder shows the antioxidative effects on fried dough during storage.

Effect of different protein isolates and transglutaminase on rice flour properties

The effect of the addition of different protein isolates (pea, soybean, egg albumen and whey proteins) on the viscosimetric and rheological properties of the rice flour dough, and the development of a protein network through the use of microbial transglutaminase (TG) were evaluated. Protein isolates significantly ( p < 0.05) modified the gelatinization and gelling behaviour of the rice starch determined in the rapid viscoanalyser (RVA). Pea, soybean and whey proteins significantly ( p < 0.05) decreased the final viscosity in addition, whey protein also promoted a significant decrease (27.3%) in the peak viscosity. The elastic modulus value (G′) recorded in the oscillatory tests was significantly ( p < 0.01) affected by both the protein isolates and the TG. The extent of the effect was dependent on the protein source; pea and soybean increased this parameter, whereas egg albumen and whey protein drastically decreased it. A modification in the emulsifying properties was also observed by the addition of protein isolates and the TG treatment. The decrease in the amount of free amino groups after TG treatment confirmed the protein crosslinking catalysed by TG. Therefore, the use of protein isolates and TG broads the applications of rice flour in the bakery industry, and brings about an increase in the protein content with the subsequent nutritional improvement of the resulting products.

Effects of Mixtures of Calcium Carbonate and Magnesium Salts on the Thermal and Physical Properties of Non-glutinous Rice Flour Dough and Effect of Cooking on Those Contents

Effects of Mixtures of Calcium Carbonate and Magnesium Salts on the Thermal and Physical Properties of Non-glutinous Rice Flour Dough and Effect of Cooking on Those Contents

Effects of Mixtures of Calcium Hydroxide and Magnesium Salts on the Thermal and Physical Properties of Non-glutinous Rice Flour Dough

Effects of Mixtures of Calcium Hydroxide and Magnesium Salts on the Thermal and Physical Properties of Non-glutinous Rice Flour Dough

Rheological Control of Kneaded Glutinous Rice Flour Dough to Improve the Manipulation

Rheological Control of Kneaded Glutinous Rice Flour Dough to Improve the Manipulation

Functionality of rice flour modified with a microbial transglutaminase

Abstract Rice flour is one of the most valuable cereal flours from a nutritional viewpoint. However, its use is limited to unfermented baked products since rice proteins are unable to hold gas produced during fermentation. Protein functionality can be modified by cross-linking. Rice flour was treated with different concentrations of a microbial transglutaminase (TG). The extent of the modification was evaluated by quantifying amino and thiol groups. The addition of TG improved the dynamic rheological properties of rice flour doughs, resulting in a progressive increase of the viscous (G″) and elastic (G′) moduli with increase in TG concentration. The improvement in rice protein functionality became evident in breadmaking, since it was possible to obtain rice bread with an increased specific volume and softer crumb at 1% TG level in the presence of 2% hydroxypropylmethylcellulose. Analyses showed that rice proteins are polymerised through the TG reaction, providing a protein network necessary for holding the gas produced in fermentation.

Improvement of the breadmaking quality of rice flour by glucose oxidase

Bread from rice flour is very difficult to bake as it lacks gluten like proteins but modification of the rice flour proteins with enzymes like glucose oxidase (GO) to improve its breadmaking properties is an interesting option. In this study the effect of GO on rice flour dough rheology, protein modification and bread quality has been reported. GO modified the rice flour proteins by lowering the thiol and amino group concentration. Protein modification was also confirmed by the changes observed in the free zone capillary electrophoregrams of the rice glutelins. The addition of GO promoted an increase in the elastic and viscous modulus. Rice bread with better specific volume and texture was obtained with GO addition allowing the decrease of the hydroxypropylmethylcellulose (HPMC) levels in the rice bread recipe.

うるち粉生地の力学特性に及ぼすカルシウム剤およびマグネシウム剤の影響

粳米粉を用いたトルティーヤ様食品の主に力学特性に及ぼすカルシム剤およびマグネシウム剤添加の影響について検討した結果,水酸化カルシウム添加粳米粉では未加熱試料の強度は増加し,水浸漬による影響が4種の添加剤の中で最も小さかった.従って,水分の多い具材をのせて食べる場合には,生地の強度低下の割合は小さく,食べやすさは向上すると考えられる.一方,炭酸カルシウムでは,本実験内では粳米粉生地の強度増加に寄与しなかった.硫酸マグネシウム添加未加熱粳米粉は,濃度が高くなると取り扱い難くなったが,加熱により生地の強度は高まり食する際には破けにくく,また吸水率は粳米粉単独試料と有意差がなく(p>0.05),水分の吸収は低下しない塩であることが示された.塩化マグネシウム添加では,加熱試料の強度も濃度が増すと増加して破れにくくなり,水浸漬においては吸水率が低下した.

Correlations between the physicochemical and functional properties of rice

Three typical U.S. rice varieties were studied for differences after storage for 1 year at temperatures between 4 and 40 o C. In this manner, rice samples with a relatively wide range of physicochemical and functional properties were obtained. From the experimental results it became apparent that water intake by cooked grains, stickiness after cooking, and rice flour dough leavening were all correlated to the quality determining factors: the average molecular weight of denatured oryzenin (rice storage protein) and the binding of denatured oryzenin to starch