High Amylose Rice Flour Research Articles

Artificial intelligence classification and amylose content prediction of rice flour varieties from their pasting features

The pasting features of eight varieties of rice flour with varying amylose content were characterized and then subjected to machine learning analysis in order to classify the rice varieties and predict their amylose content. The waxy rice flour with the least amylose showed a peak viscosity in the early stage of heating, and the high amylose rice flours had the highest final viscosity. Principal component analysis showed that 87.2% of the total variability was explained by the two principal components, which were mainly related to peak temperature and final viscosity. When the pasting features were used as a machine learning dataset for classification, the support vector machine classifier was the most effective in correctly classifying the rice flour varieties by showing a high accuracy and F1-score, followed by the decision tree and stochastic gradient descent. In addition, the integration of pasting features with machine learning analysis showed the potential to predict the amylose content of rice flours. These prediction performances were confirmed by validating the models with independent datasets.

Effects of Heat-Moisture-Treated High-Amylose Rice Flour on Body Weight, Lipid Metabolism, and Gut Microbiome Composition in Obese Rats.

The rising prevalence of lifestyle diseases, such as type 2 diabetes, cardiovascular diseases, and metabolic syndrome, has increased the need for effective dietary interventions. This study aimed to evaluate the effects of heat-moisture-treated high-amylose rice (HA-HMT) on body weight, lipid metabolism, and gut microbiome composition in a rat model of obesity. Starch digestibility-specifically, resistant starch-has been shown to provide various health benefits, including improved metabolic health and gut microbiome composition. We employed a sequential approach: firstly, utilizing diet-induced obesity rat models fed with HMT-processed and HMT-non-processed low- or high-amylose rice to investigate the potential of amylose content or HMT to alter phenotypic characteristics and lipid metabolism; and secondly, using the optimal rice flour identified in the previous step to explore the underlying mechanisms. Our findings indicate that heat-moisture treatment, rather than the level of the amylose content of the rice, contributes to the observed anti-obesity and cholesterol-lowering effects. We identified candidate genes contributing to the cholesterol-regulating potential and demonstrated that HMT rice flour could influence the gut microbiome, particularly the Ruminococcus taxa. This study provides valuable insights into the health benefits of HA-HMT rice and supports its potential as a functional food ingredient in the management of obesity and cholesterol-related disorders.

Development of low glycemic index instant Phirni (pudding) mix-its visco-thermal, morphological and rheological characterization

High amylose rice (HAR) and carboxymethyl cellulose (CMC) are the preferred choices for enhancement of resistant starch content and lowering of glycemic index in dairy desserts. The effects of different levels of skimmed milk powder (SMP): HAR flour (45:55 to 75:25) and CMC (0.1 to 1%) were investigated on physical characteristics of dry-mix and on texture profile parameters, resistant starch (RS), predicted glycemic index (pGI), glycemic load (GL) and overall acceptability of phirni (a traditional milk pudding). Design expert predicted SMP (70): HAR (30) and CMC (0.8%) as optimum levels for reducing the pGI and maximizing the RS content and other quality characteristics in phirni. RS content of phirni (4.38%) prepared from optimized dry-mix (ODM) was higher while pGI (48.12) and GL (7.50) were lower as compared to phirni prepared from market dry-mix (MDM). The visco-thermal properties of ODM and MDM also showed significant variations. Storage modulus (Gʹ) and loss modulus (Gʹʹ) indicated that ODM phirni was less solid than MDM phirni. Scanning electron micrographs showed fused structures in ODM, while coarse sheet like structures were observed across the surface of MDM. Thus, ODM can be a promising substitute for the available milk desserts for diabetic patients.

The impact of heat moisture treatment on the physicochemical properties and in vitro glycemic index of rice flour with different amylose contents and associated effects on rice dumpling quality

This study investigated the effects of heat moisture treatment (HMT) on the in vitro glycemic index and physicochemical properties of rice flour from two cultivars with different amylose contents. HMT decreased glycemic index and pasting viscosity, but increased pasting temperature and onset temperature relative to non-treated rice flour. High-amylose rice flour exhibited significantly higher pasting temperature and lower glycemic index than that with low amylose content. Rice flour dumplings prepared with 0, 40, 50, or 60% w/w HMT flour demonstrated differing texture profiles and sensory characteristics. Pearson's correlation showed that the amylose content of the rice flour used to make the dumplings was positively correlated (p < 0.01) with their hardness and negatively correlated (p < 0.01) with their adhesiveness, cohesiveness, and overall acceptance score. In addition, the glycemic index decreased with increasing HMT flour proportion. It was therefore concluded that HMT of rice flour could be used to achieve product acceptance with a lower glycemic index by compromising between physicochemical properties and sensory quality.

Development of instant phirni mix (a traditional dairy dessert) from high amylose rice, skim milk powder and carboxymethyl cellulose-resistant starch, predicted glycemic index and stability during storage

High amylose rice (HAR) and carboxymethyl cellulose (CMC) are ideal choices to enhance the resistant starch and reduce the glycemic index of dairy desserts. Therefore, the effect of ingredient composition (i.e., skim milk powder: high amylose rice flour -SMP: HAR, and carboxymethyl cellulose- CMC) on physical characteristics of phirni dry mix were investigated in the present study. Variation in SMP: HAR flour and CMC concentration significantly (p < 0.05) affected the insolubility index, wettability, Hausner ratio, luminosity (L*), and yellowness (b*) of different phirni dry mix samples. Design expert predicted SMP (70%), HAR (30%) and CMC concentration of 0.85% as desirable conditions for preparation of phirni dry mix. A typical A-type diffraction pattern and absorption bands representative of proteins, lactose and starch were detected in optimized phirni dry-mix (OPDM). Irrespective of packaging material and storage condition, resistant starch (RS) increased significantly (p < 0.05) while predicted glycemic index (pGI) showed significant (p < 0.05) decrease during storage. However, maximum RS content (7.57%) and minimum pGI (44.95) were recorded in LDPE packed samples (LDPE-PS) on 90th day of storage under accelerated conditions. At the same time, moisture content, water activity, free fatty acids, and peroxide value increased significantly (p < 0.05), while overall acceptability showed a significant (p < 0.05) decrease in LDPE-PS. The inference drawn from the present study was that irrespective of packaging material and storage condition, the OPDM was safe to consume up to 90 days, however, aluminum laminated package and ambient storage condition could be better options to retain the quality of OPDM with better consumer acceptability.

Exploring high amylose rice in combination with carboxymethyl cellulose for preparation of low glycemic index gluten-free shelf-stable cookies

PurposeLow glycemic index gluten-free cookies from high amylose rice flour were prepared by modifying baking conditions and ingredient composition.Design/methodology/approachBaking temperature, baking time, and concentration of carboxymethyl cellulose (CMC) were varied between 170 and 190° C, 12–25 min, and 0.2–1%, respectively, using central composite rotatable design. The developed cookies were packed in metalized polyester pouches and stored under ambient conditions for a period of 90 days.FindingsWidth and bulk density of cookies increased significantly (p &lt; 0.05) with an increase in baking temperature, while thickness, baking loss and yield decreased with an increase in baking temperature. Puffiness increased predominantly with the increase in the concentration of CMC. Design expert predicted baking temperature of 185° C, baking time of 22 min, and 0.8% concentration of CMC as desirable conditions for the development of gluten-free cookies from rice flour. Cookies developed after following optimized conditions recorded dietary fiber of 4.66%, resistant starch (RS) content of 7.20% and predicted glycemic index (pGI) of 44.60. RS, pGI, moisture, water activity, free fatty acids and peroxide value increased significantly, whereas hardness and overall acceptability decreased during storage.RPractical implicationsGluten-free (GF) foods are in high demand globally due to the prevalence of celiac disease. Rice lacks gluten protein, and thus, can serve as a potential raw material for the development of GF cookies. In the present study, the ingredient modification and freezing interventions during baking were found to be crucial if the development of low GI gluten-free cookies having good RS content is targeted. Optimized GF cookies prepared via technological intervention and packed in metalized polyester were shelf stable for up to 3 months under ambient conditions. Furthermore, resistant starch content was enhanced while the predicted glycemic index was decreased during storage. Adoption of baking conditions and CMC level optimized in the present study can help to develop shelf-stable GF bakery products for people suffering from comorbidities like celiac disease and diabetes.Originality/valueResistant starch content was enhanced while predicted glycemic index was decreased during storage of gluten-free cookies prepared from high amylose rice flour. The developed cookies can be a complementary diet to people suffering from comorbidities like celiac disease and diabetes.

Effect of carboxymethyl cellulose and baking conditions on in-vitro starch digestibility and physico-textural characteristics of low glycemic index gluten-free rice cookies

In this study, we aimed to formulate low glycemic index gluten-free cookies from high amylose rice flour by modifying baking conditions and ingredient composition. Baking temperature, baking time, and concentration of carboxymethyl cellulose were varied between 170 and 190 °C, 12–25 min, and 0.2–1%, respectively, using central composite rotatable design. Among the physical quality attributes, spread ratio and hardness of cookies increased predominantly with the increase in baking temperature. Resistant starch content and overall acceptability of cookies increased prominently, whereas predicted glycemic index and glycemic load decreased with the increase in the concentration of carboxymethyl cellulose. Design expert predicted baking temperature of 185 °C, baking time of 22 min, and 0.8% concentration of carboxymethyl cellulose as desirable conditions for the development of gluten-free low-glycemic index cookies from rice flour. Dietary fiber content of developed cookies was recorded as 4.66%. In-vitro starch digestibility results confirmed that resistant starch increased from 2.85% in rice flour to 7.20% in cookies, whereas predicted glycemic index and glycemic load decreased from 50.12 to 30.07 in rice flour to 44.60 to 17.51 in cookies, respectively. Overall acceptability of cookies was recorded as 8.90 on a 9-point hedonic scale.

Screening of Local Rice Varieties Grown in Khyber Pakhtunkhwa; Blending High Amylose Rice Flour Modified Functional and Pasting Profile of Low Amylose Rice Flour

Screening of Local Rice Varieties Grown in Khyber Pakhtunkhwa; Blending High Amylose Rice Flour Modified Functional and Pasting Profile of Low Amylose Rice Flour

Quality of gluten-free cookies made with rice flour of different levels of amylose and cowpea beans

PurposeThe objective of this study was to evaluate the effects of rice flour obtained from rice grains with different levels of amylose on technological, nutritional and sensory properties of cookies made with a blend of rice and cowpea flour.Design/methodology/approachThe cookies preparation was set at a ratio of rice flour and cowpea beans 70:30. The studied formulations were: LA: low amylose rice flour; MA: medium-amylose rice flour; HA: high amylose rice flour. The quality of the obtained cookies was analyzed for proximate composition, in vitro protein digestibility, thickness, diameter, dispersion factor, texture, color, amino acid profile and sensory properties.FindingsProximate composition and in vitro protein digestibility showed no differences between the three studied formulations. The medium and low amylose rice flour cookies showed the lowest hardness values. The combination of rice and beans allowed a good balance of essential amino acids. The cookies formulated with high amylose rice flour presented lighter coloration, low hardness and greater sensory preference.Originality/valueRice and cowpea flours are an alternative source for the preparation of gluten-free bakery products, such as cookies. The high amylose content of rice flour has less negative interference in the texture characteristics of the cookies. The combination of rice and beans flour provides a balance of essential amino acids.

Effect of amylose content in rice flour on batter rheology and bread baking quality

The effect of amylose content in rice batter without wheat on the baking quality and rheological property of rice bread was assessed. Bread was made with waxy and non‐waxy rice flours of similar amylopectin structure at various mixing ratios. The quality of rice bread was evaluated by the expansion ratio. The use of rice flours with similar amylopectin structure controls for the effect of differences in amylopectin structure caused by mixing different rice types. The expansion ratio of bread increased in a rice flour amylose content‐dependent manner. Rheological data showed that high viscosity batters maintained the foam structure generated during proofing, which was related to the high amylose content of the rice flour. An iodine coloration experiment confirmed that the origin of the high viscosity of high amylose rice batters was the elution of amylose into the water surrounding the rice particles in the batter. PRACTICAL APPLICATIONS: In this study, rice bread was made without additives. The batter was made by mixing waxy and non‐waxy rice flours. Storage modulus of the batter was affected by alterations in the mixing ratio of rice flours. Storage modulus of the batter showed a tendency to increase as the ratio of non‐waxy rice increased. The use of high amylose rice flours allowed for the rice batter to be proofed and processed as bread. Practical application of this study is the development of various gluten‐free foods such as bread, pasta, and pizza using rice flour without wheat.

Effect of Waxy Rice Starch on Processing Quality of High Amylose Rice Flour

Effect of Waxy Rice Starch on Processing Quality of High Amylose Rice Flour

Texture of Gel Made from High-amylose Rice Flour

Texture of Gel Made from High-amylose Rice Flour

Particle size effect of rice flour in a rice-zein noodle system for gluten-free noodles slit from sheeted doughs

Zein was incorporated at 5% (w/w) to high amylose rice flours with different particle sizes (80–100, 100–140, and 140–250 μm) and the rice flour-zein composites were utilized to generate gluten-free noodles slit from sheeted doughs. Rice flours with smaller particle size showed higher starch damage whereas they had greater water hydration properties and higher pasting parameters. In addition, the fine particle size contributed to the elastic properties of the rice-zein composites. The ability of zein to generate a viscoelastic protein network at above its glass transition temperature, successfully produced gluten-free rice sheeted doughs regardless of particle size that could be slit into long and thin noodle strands without gluten. The rice-zein noodles with larger particle sizes had a rough surface while the noodle surface became smooth and flat at decreasing particle sizes. The noodle samples with rice flour having an intermediate particle size (100–140 μm) showed the highest values of maximum resistance and extensibility to extension that consequently contributed to the decreased cooking loss. This study provided a new opportunity for food manufacturers to improve the qualities of gluten-free rice noodles made from sheeted doughs by controlling particle size.

Physico-chemical Properties of High and Low Amylose Rice Flour

Physico-chemical Properties of High and Low Amylose Rice Flour

Combined speed and duration of milling affect the physicochemical properties of rice flour

The properties of flour from polished rice that had been subjected to various milling conditions were investigated. Waxy, low- and high-amylose rice were milled at different speeds (1050, 950, and 750 r/min) for different durations (20, 40 and 60 s). The swelling power was increased with milling duration and speed compared to brown rice flour. The solubility of milled waxy rice flour was substantially lower than for brown rice flour, but for milled low- and high-amylose rice flour, it was unchanged or slightly reduced. The peak viscosity of low- and high-amylose rice flour was more affected by milling duration, whereas the final viscosity was more affected by milling speed. Total milling revolutions led to greater effect on pasting properties of WRF than LARF and HARF. Milling duration was a greater determinant of thermal properties than was milling speed. Milling conditions had different effects on the digestibility of different rice flours. Milling speed had less effect on digestibility than did milling duration for waxy rice flour, but speed had a greater effect on the digestibility of low- and high-amylose rice flour. This study showed that both milling duration and speed impacted the physicochemical and digestibility properties of different rice flours, but to different extents.

Preparation of gluten-free rice spaghetti with soy protein isolate using twin-screw extrusion.

The objective of this study was to investigate the effect of soy protein isolate on functional properties and consumer acceptance of gluten-free rice spaghetti (GFRS) made from rice flour. Dry-milled high-amylose (Chai Nat 1) rice flour was premixed with dry-milled waxy (RD 6) rice flour at a ratio of 90:10 (w/w) with the soy protein isolate (SPI) concentration varying between 0, 2.5, 5.0, 7.5, 10.0%, db. The GFRS formulation was processed using a co-rotating twin-screw extruder up to 95°C with a screw speed of 220rpm, 32% moisture content, and then dried at 40°C. The GFRS samples were analyzed by differential scanning calorimetry (DSC), X-ray diffraction, scanning electron microscopy (SEM) and texture parameters. Increasing SPI decreased the starch retrogradation of GFRS, whereas the enthalpy change of the amylose-lipid complex increased and crystallinity decreased. SEM revealed that the surface of GFRS containing SPI was much more porous than that of GFRS without SPI. The cooked GFRS containing 5.0% SPI showed the best eating quality with increased firmness and tensile strength, and decrease stickiness. The GFRS samples were evaluated on the bases of cooking qualities and sensory evaluation. The results showed that the GFRS containing 5.0% SPI decrease the cooking time from 17.6 to 13.7min and cooking loss from 25.4 to 17.0%. Overall acceptability of cooked GFRS containing 5.0% SPI was the highest among all GFRS samples.

Physicochemical characterization and in-vitro digestibility of extruded rice noodles with different amylose contents based on rheological approaches

The physicochemical properties and in-vitro digestibility of extruded rice noodles with different amylose contents were characterized from a rheological point of view. Thermo-mechanical measurements showed that the rice flour with higher amylose contents exhibited greater stability to dual-mixing and higher degrees of starch gelatinization and retrogradation. In addition, greater elastic properties were clearly observed in the high amylose rice samples. The use of high amylose rice flour produced noodles with a harder texture, consequently contributing to reduced cooking loss. Furthermore, the rheological changes of extruded rice noodles were monitored in real time during the in-vitro starch digestion. The rice noodle digesta with higher amylose contents exhibited greater viscosities throughout the simulated oral-gastric-intestinal digestion steps. The flow behaviors of the rice noodle digesta consisted of the Power-law region and infinite shear plateau that were satisfactorily characterized by the Sisko model (R2 > 0.99).

Correlation of pasting behaviors with total phenolic compounds and starch digestibility of indigenous pigmented rice grown in upper Northern Thailand

Background: Thailand has one of the most important rice genetic resources with white, light brown, brown, red, and purple rice bran colors. The latter believed to have potential for health benefits due to their phenolic content. Recently researchers have indicated that starch digestive enzymes, including salivary and pancreatic α-amylases and α-glucosidases, can be inhibited by phenolic compounds. Although pasting properties of rice flour are key determinants of quality significantly impacting the final product texture, there is no in-depth study on their correlation with phenolic compound and starch digestibility. Methods: Rice flour from twelve varieties, three from each of five bran colors (white, brown, red, and purple), were evaluated for pasting properties (RVA-3D), total phenolic compounds, amylose content, resistant starch and estimated glycemic index. Simple correlation coefficients were calculated for the relationships between pasting properties (final viscosity, breakdown, setback and pasting temperature) and total phenolic compounds, resistant starch and estimated glycemic index.Results: Within each rice variety, red and purple pigmented flours had higher total phenolic compounds (TPC) and more resistant starch than that of white flours. The TPC and resistant starch content of the flours ranged between 7.83- 47.3 mg/L and 2.44–10.50% respectively, and producing 60-80 of estimated glycemic index. Viscosity behavior showed that pigmented with low amylose rice had lower viscosity temperature than that of pigmented with high amylose rice flour, but higher in peak viscosity. Correlation coefficients of pasting temperature, final viscosity, break down and setback with TCP was observed to be inversely related to glycemic index. However, it was positively correlated to the resistant starch and amylose content. Conclusions: Pigmented rice flour is a better source of TPC and resistant starch which in turn provides low glycemic index. This could help reduce the onset of type 2 diabetes and other related chronic diseases. In addition, this study provides impact of pasting behavior – TPC- resistant starch of rice flour relationships, which have important implication for utilization in food industry.Keywords: total phenolic compounds, amylose content, resistant starch, glycemic index

Physicochemical Properties of High-amylose Rice Varieties

The objective of this study was to determine the physico-chemical properties in the high-amylose rice varieties. The rice flours were analyzed by RVA, DSC, HPAEC, resistant starch kit, SEM, spectrophotometer, etc. According to the RVA measurement of rice flours, the pasting temperature of Dodamssal was higher than those of the others. The proportion of amylopectin short chains (DP 6-12) of the Dodamssal was significantly lower than that of the others. The contents of amylose and resistant starch in the high-amylose rice flours ranged from 19.03% to 38.71% and from 0.6% to 12.39%, respectively. In SEM images, starch granules within Ilmibyeo, Mimyeon, Saegoami rice flours displayed polyhedrons different from those (relatively spherical morphology) of Dodamssal rice flour. According to the DSC results of rice flours, there were significant differences in the onset, peak temperatures of the endothermic peak. Gelatinization enthalpy was 4.52-6.3 J/g, with the lowest change in Dodamssal rice flour.

Effect of Heat Moisture Treatment Using Different Solvents and Incubation Times on Resistant Starch Formation of Rice Flour

The thermal and pasting properties and Resistant Starch (RS) formation of high amylose rice flour were investigated at 121°C using different solvents and storage times. The samples treated with water and lactic acid 10 mmol/L with storage times 0, 24, 48 and 72 h had the highest degree of gelatinization, ranging from 98.64 to 99.86%. The samples treated with ethanol and lactic acid 10 mmol/L (in ethanol) had degrees of gelatinization varying between 58.25 and 59.91%. For the study on the thermal properties, the onset temperature (To), peak temperature (Tp), conclusion temperature (Tc) and enthalpy (ΔH) of resistant starch preparation (retrograded rice flour) using water and lactic acid 10 mmol/L were not observed, but those of heated flour using ethanol and lactic acid in ethanol (10 mmol/L) were detected. The endothermic peaks of the amylose-lipid complex and resistant starch were also observed at higher temperatures from the Differential Scanning Calorimeter (DSC), with no effect of treatments on To, Tp and Tc. Rice flour heated in water and then stored for 24 h showed a favorable effect on formation of RS at 10.80%. Significant reductions were observed in all Rapid Visco Analyzer (RVA) viscosities of the retrograded rice flours.