New Insights into the Comprehensive System of Thermodynamic Sensors and Electronic Nose and Its Practical Applications in Dough Fermentation Monitoring.

This study focuses on an applicability of the device designed for monitoring dough fermentation. The device combines a complex system of thermodynamic sensors (TDSs) with an electronic nose (E-nose). The device's behavior was tested in experiments with dough samples. The configuration of the sensors in the thermodynamic system was explored and their response to various positions of the heat source was investigated. When the distance of the heat source and its intensity from two thermodynamic sensors changes, the output signal of the thermodynamic system changes as well. Thus, as the distance of the heat source decreases or the intensity increases, there is a higher change in the output signal of the system. The linear trend of this change reaches an R2 value of 0.936. Characteristics of the doughs prepared from traditional and non-traditional flours were successfully detected using the electronic nose. To validate findings, the results of the measurements were compared with signals from the rheofermentometer Rheo F4, and the correlation between the output signals was closely monitored. The data after statistical evaluation show that the measurements using thermodynamic sensors and electronic nose directly correlate the most with the measured values of the fermenting dough volume. Pearson's correlation coefficient for TDSs and rheofermentometer reaches up to 0.932. The E-nose signals also correlate well with dough volume development, up to 0.973. The data and their analysis provided by this study declare that the used system configuration and methods are fully usable for this type of food analysis and also could be usable in other types of food based on the controlled fermentation. The system configuration, based on the result, will be also used in future studies.

Removal of proteins and lipids affects structure, in vitro digestion and physicochemical properties of rice flour modified by heat-moisture treatment.

BACKGROUND: The objective of this experiment was to investigate the role of endogenous proteins and lipids in the structural and physicochemical properties of starch in heat-moisture treatment (HMT) rice flour and to reveal their effect on starch digestibility under heat. RESULTS: The findings indicate that, in the absence of endogenous proteins and lipids acting as a physical barrier, especially proteins, the interaction between rice flour and endogenous proteins and lipids diminished. This reduction led to fewer starch-protein inclusion complexes and starch-lipid complexes, altering the granule aggregation structure of rice flour. It resulted in a decrease in particle size, an increase in agglomeration between starch granules, and more surface cracking on rice granules. Under HMT conditions with a moisture content of 30%, slight gelatinization of the starch granules occurred, contributing to an increased starch hydrolysis rate. In addition, the elevated thermal energy effect of HMT enhanced interactions between starch molecular chains. These resulted in a decrease in crystallinity, short-range ordering, and the content of double-helix structure within starch granules. These structural transformations led to higher pasting temperatures, improved hot and cold paste stability, and a decrease in peak viscosity, breakdown, setback, and enthalpy of pasting of the starch granules. CONCLUSION: The combined analysis of microstructure, physicochemical properties, and in vitro digestion characteristics has enabled us to further enhance our understanding of the interaction mechanisms between endogenous proteins, lipids, and starches during HMT. © 2024 Society of Chemical Industry.

Potential of Rice-Flour Jelly Made from High-Amylose Rice as a Dysphagia Diet: Evaluation of Pharyngeal Residue by FEES.

Dysphagia diets are recommended to prevent choking and aspiration in people with dysphagia; however, rice-porridge and mashed rice-porridge, which are used as staple foods for people with dysphagia in Japan, are time-consuming to prepare. The National Agriculture and Food Research Organization has found jelly-like food products made from high-amylose rice-flour (rice-flour jelly) to be easy to prepare with a texture suitable for dysphagia diets. To investigate the potential of rice-flour jelly for the dysphagia diet, we evaluated the amount of pharyngeal residue after swallowing rice-flour jelly using fiberoptic endoscopic evaluation of swallowing and compared it with those of rice-porridge, mashed rice-porridge, and fruit jelly. We enrolled 70 participants (43 males and 27 females, aged 32-96 years, median 74.5 years) and evaluated their pharyngeal residue using the Yale Pharyngeal Residue Severity Rating Scale which includes five levels from I (none) to V (severe). Statistical analysis showed that level I was more common in fruit jelly for vallecula residue and pyriform sinus residue, and level III (mild) was more common in rice-porridge for vallecula residue (p < 0.05). No differences of pharyngeal residue were found in rice-flour jelly or mashed rice-porridge. No significant difference was observed in the number of participants with laryngeal penetration or aspiration. Therefore, rice-flour jelly is a suitable alternative to rice-porridge as a staple food for people with dysphagia in terms of food texture.

Increasing Protein Content of Rice Flour with Maintained Processability by Using Granular Starch Hydrolyzing Enzyme.

Rice flour (RF) has become a promising food material. In the present study, RF with higher protein content was prepared using a granular starch hydrolyzing enzyme (GSHE). Particle size, morphology, crystallinity, and molecular structures of RF and rice starch (RS) were characterized to establish a hydrolytic mechanism; thermal, pasting, and rheological properties were determined to evaluate processability using differential scanning calorimetry (DSC), rapid viscosity analysis (RVA), and rheometer, respectively. The GSHE treatment resulted in pinholes, pits, and surface erosion through sequential hydrolysis of crystalline and amorphous areas on the starch granule surface. The amylose content decreased with hydrolysis time, while the very short chains (DP < 6) increased rapidly at 3 h but decreased slightly later. After hydrolysis for 24 h, the protein content in RF increased from 8.52% to 13.17%. However, the processability of RF was properly maintained. Specifically, the data from DSC showed that the conclusion temperature and endothermic enthalpy of RS barely changed. The result of rapid RVA and rheological measurement indicated that RF paste viscosity and viscoelastic properties dropped rapidly after 1 h hydrolysis and thereafter recovered slightly. This study provided a new RF raw material useful for improving and developing RF-based foods.

[Determination of beauvercin and enniatins in rice flour and wheat flour by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To develop a method for the determination of beauvercin(BEA), enniatin A(ENNA), enniatin A1(ENNA1), enniatin B(ENNB) and enniatin B1(ENNB1) in rice flour and wheat flour by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: Samples were extracted by acetonitrile-water, purified by Oasis Prime HLB solid-phase extraction column. The sample solution was separated by waters BEH C_(18) column(2.1 mm×100 mm, 1.8 µm). The detection was performed in the electrospray positive ionization(ESI+) under multiple reaction monitoring(MRM) mode. The internal standard method and the matrix-matched calibrations were used for quantification. RESULTS: The linear relationships of BEA and 4 kinds of enniatins(ENNs) were good in the range of 0.1-50.0 ng/mL(r>0.999). The average recoveries of BEA and ENNs in rice flour and wheat flour were 96.4%-105.4% and 99.1%-109.2%, with the relative standard deviations(RSD) of 1.01%-7.42% and 1.09%-9.69%(n=6). The detection limits(LOD) of BEA and ENNs were 0.03 µg/kg. The quantitative limits(LOQ) of BEA and ENNs were 0.1µg/kg. The matrix induced suppression or enhancement effect were 72.7%-99.3% and 60.8%-100.4%, respectively. The levels of emerging BEA and ENNs in wheat flour were higher than rice flour. The detection rate of enniatin B was highest in wheat flour and rice flour, the contents were 0.03-9.57 µg/kg and 0.03-0.56 µg/kg, the positive percentage were 98.5% and 36.4%. CONCLUSION: The method is quick, easy, accurate and sensitive, which is suitable for the determination of BEA and 4 kinds of ENNs in rice flour and wheat flour.

Study on physicochemical characteristics of local colored rice varieties (black, red, brown, and white) fermented with lactic acid bacteria (SBM.4A).

In this study, the physicochemical properties of local colored rice flour were studied after modification through fermentation with lactic acid bacteria (LAB) SBM.4A. SBM.4A was LAB isolated from the rice washing water and was in the cladogram of the Pediococcus pentosaceus strain SRCM102739 CP028266.1 and Pediococcus pentosaceus strain SRCM102738 CP028264.1. The studied rice varieties were wakacinda (white rice), wakawondu (red rice), warumbia (brown rice), and wakaombe (black rice). Characterizations of both fermented and native rice flour included chemical composition, FTIR profile, crystallinity, morphology, and pasting properties. Fermentation did not introduce new chemical functional groups to the flour and only slightly increased crystallinity from approximately 22.5% to 25.05%. In contrast, fermentation greatly affected the chemical composition and pasting properties of rice flour. Protein content of the fermented flour increased up to 214% relative to the native rice flour. Effect of fermentation on pasting properties varied between rice varieties. Increase in peak and final viscosities was observed in red, brown, and black rice. The opposite effect was found in white rice. However, fermentation improved the stability of flour to retrogradation for all rice varieties. These showed that the fermentation improved the properties of the local-colored rice flour and may widen their application as food ingredients.

Ultrasound Treatment Enhanced Semidry-Milled Rice Flour Properties and Gluten-Free Rice Bread Quality.

The structural and functional properties of physical modified rice flour, including ultrasound treated rice flour (US), microwave treated rice flour (MW) and hydrothermal treated rice flour (HT) were investigated with wet-milled rice flour (WF) used as a positive control. The results showed the presence of small dents and pores on the rice flour granules of US and MW while more fragments and cracks were showed in HT. XRD and FTIR revealed that moderate ultrasonic treatment promoted the orderly arrangement of starch while hydrothermal treatment destroyed the crystalline structure of rice flour. In addition, the significant decrease of gelatinization enthalpy and the narrowing gelatinization temperature were observed in US. Compared to that of SF, adding physical modified rice flour led to a batter with higher viscoelasticity and lower tan δ. However, the batter added HT exhibited highest G' and G″ values and lowest tan δ, which led to a harder texture of bread. Texture analysis demonstrated that physical modified rice flour (except HT) reduced the hardness, cohesion, and gumminess of rice bread. Especially, the specific volume of bread with US increased by 15.6% and the hardness decreased by 17.6%. This study suggested that ultrasound treatment of rice flour could improve texture properties and appearance of rice bread.

Effect of rice flour incorporation on some physicochemical, color, rheological, bioactive and sensory properties of a new pestil formulation: one factor design approach and optimization.

Pestil is a special and a traditional food produced with wheat flour or a starch, water and molasses. In this study, a new pestil formulation was developed using different concentrations of rice flour (0-12%). One factor design (Response surface methodology) approach was used to determine the some physicochemical, rheological, bioactive, color and sensory properties of newly formulated pestil products. Also, an optimization study was performed to reveal the most-liked samples using the sensory analysis results. Dry matter levels ranged between 86.87 and 96.55 g/100g while the protein contents were in the range of 4.18-5.91 g/100g. Maximum and minimum total phenolic and antioxidant activity levels of the samples were observed for the samples coded as R4 and R5 with 1471.93-887.91 mg GAE/kg and 17701.65-12684.09 mg AAE/kg, respectively. The dynamic rheological properties of the pestil samples were significantly affected by the rice flour addition (p < 0.05). The optimization results showed that the best pestil formulation can be produced by incorporating 0.44 g/100g rice flour. In conclusion, the rice flour could be assisted to pestil production in the formulation for better pestil production.

Evaluation of solid state of rice flours produced by different milling processes using ATR-FTIR spectroscopy.

This study evaluated the influence of the milling process on solid state of rice flours according to water activity using ATR-FTIR. A band at 1740 cm-1 attributed to the C=O stretching of lipids was detected for crystalline samples, and it disappeared at a high aw range. The CH band at 2930 cm-1 of crystalline samples gradually shifted to a higher wavenumber with aw. This band of the α-formed and wet-milled samples shifted to higher wavenumbers above 0.8aw. A band due to OH stretching mode in the 3500-3000 cm-1 region did not shift with aw. The result obtained from IR spectra suggests that the parameter K calculated by Guggenheim-Anderson-de Boar model reflected not only the interaction between water molecules but also the changes of state in solids. Consequently, the results from this study provide insights about the adsorption properties of nonideal solids such as rice flour.

Effects of milling methods on the properties of glutinous rice flour and sweet dumplings.

Glutinous rice flour (GRF) was prepared using three milling process (wet milling, low temperature impact milling (dry milling), and roller milling (dry milling)) to investigate their effects on the physicochemical properties of glutinous rice flour and sweet dumplings prepared with that flour. Results revealed that a method of grinding used in the milling process had a significant (P < 0.05) effect on the properties of GRF and the resulting sweet dumplings. Dry milling (low temperature impact milling and roller milling) resulted in higher damaged starch content and coarser particle size than wet milling. Dry-milled flour exhibited a significantly lower hunter whiter value, apparent viscosity, pasting temperature, enthalpy value, and degree of crystalline compared to the wet-milling method. Dry milling significantly decreased the smoothness of the surface, whiteness value, transmittance of soup, resilience of dumplings, as well as increased the cracking rate and water loss during the fast-freeze. The obtained results could be used as reference for improving sweet dumpling made from dry-milled GRF.

Use of almond flour and stevia in rice-based gluten-free cookie production.

ABSTRACT: The gluten-free cookies were produced by replacing rice flour (RF) and sucrose content with almond flour (AF) and stevia. Supplementation of AF caused to decrease the moisture content of the gluten-free cookies; while ash, total protein, total fat and total dietary fiber content increased. Regarding of total phenolics; extractable, hydrolyzable and bioaccessible fractions of gluten-free cookie samples that were produced with 30% of AF supplementation, were increased by 43.69-73% compared with the control group that was prepared with 100% RF (p ≤ 0.01). Gluten was detected in the cookies with neither RF nor AF. No cross-contamination was detected during the production, too. Quality characteristics of the gluten-free cookies reached the acceptable level while AF and stevia contents were increased. Protein and dietary fiber contents of the cookie with AF and stevia were enriched to 82 and 96%, while the total carbohydrate amount decreased 19% (p ≤ 0.01). The contents of TEACABTS and TEACFRAP of gluten-free cookies with AF and stevia were 5.72 ± 0.07 and 26.08 ± 0.49 µmol Trolox/g and higher than the control (100% RF + sucrose). It has found that physicochemical, nutrition and sensorial properties of gluten-free cookies that were produced with AF + stevia supplementation provided to produce more acceptable products.

CRM rapid response approach for the certification of arsenic species and toxic trace elements in baby cereal coarse rice flour certified reference material BARI-1.

With recently legislated maximum levels of inorganic arsenic (iAs) in white and brown rice in Canada, the regulatory bodies are evaluating the need for regulation of As levels in infant food products. Rice is a major part of infants' diet, and therefore, the presence of As in this staple food causes concerns. So far, the scientific community was lacking suitable certified reference material (CRM) which could be used to assess the accuracy of developed analytical methods for As speciation in infants' food products. As a result, we have developed BARI-1, a baby cereal coarse rice flour reference material which was certified for total arsenic (0.248 ± 0.018 mg kg-1), cadmium (0.0134 ± 0.0014 mg kg-1), mercury (0.0026 ± 0.0003 mg kg-1), lead (0.0064 ± 0.0016 mg kg-1), inorganic As (0.113 ± 0.016 mg kg-1) and dimethylarsinic acid (DMA) (0.115 ± 0.010 mg kg-1), and reference value for monomethylarsonic acid (MMA) (0.0045 ± 0.0008 mg kg-1) was reported. We also observed trace amounts of an unknown As compound, with chromatographic retention time close to DMA. Participating laboratories were allowed to use their in-house-validated extraction and/or digestion methods, and the detection of total metals was done by ICP-MS whereas HPLC-ICP-MS was used for As speciation. Despite the diversity in sample preparation and quantitation methods, reported values were in good agreement. For iAs measurement, the comparison between hydride generation ICP-MS and HPLC-ICP-MS found iAs overestimation with the former method, possibly due to interference from DMA. The certification was accomplished with a CRM rapid response approach in collaborative, focused effort completing the CRM development in few months instead of the typical multiyear project. This approach allowed to respond to measurement needs in a timely fashion. Graphical abstract.

Rapid DNA template preparation directly from a rice sample without purification for loop-mediated isothermal amplification (LAMP) of rice genes.

Rapid DNA template preparation directly from a single rice (Oryza sativa) grain or rice flour of its equivalent weight was developed for loop-mediated isothermal amplification (LAMP). LAMP efficiency using DNA extract obtained from consecutive addition of alkaline lysis reagent (25 mM NaOH, 0.2 mM EDTA) and neutralizing reagent (40 mM Tris-HCl [pH 5]) was comparable to that using an equivalent amount of purified DNA as template. The stability of the prepared DNA extract was confirmed for up to six-day storage at room temperature. Without using any special laboratory devices, the developed method enabled a rapid, simple, and low-cost DNA template preparation method for reliable LAMP testing to detect rice genes.

Development and evaluation of extruded ready-to-eat snack from optimized rice, kersting's groundnut and lemon pomace composite flours.

Composite flour comprising rice, kersting's groundnut and lemon pomace were produced. The percentage blends of the composite flours based on the proximate composition and functional properties were optimized using optimal mixture design of response surface methodology (RSM). The optimum blends were subjected to further analyses (pasting properties and Mixolab). The overall best blend was selected for extrusion. The extrusion process was optimized using central composite design of RSM. The variables were moisture content, screw speed and temperature while the dependent variables were lateral expansion, residence time, throughputs, water absorption index and water solubility index. The microbial analysis as well as the sensory evaluation of the extrudates was also evaluated. The result showed that addition of kersting's groundnut had positive effect on the protein content while lemon pomace had positive effect on both fibre and protein contents. Blend with highest rice flour had the best pasting properties. The Mixolab results had C1 stage similar to wheat flour while it had no C2-C5 stages. The optimum blend for extrusion was 97 °C barrel temperature 12% moisture and 90 rpm screw speed which present the best lateral expansion, water absorption index and water solubility index. All the snacks had high general acceptability.

Combining Fourier Transform Mid-Infrared Spectroscopy with Chemometric Methods to Detect Adulterations in Milk Powder.

Adulteration is one of the major concerns among all the quality problems of milk powder. Soybean flour and rice flour are harmless adulterations in the milk powder. In this study, mid-infrared spectroscopy was used to detect the milk powder adulterated with rice flour or soybean flour and simultaneously determine the adulterations content. Partial least squares (PLS), support vector machine (SVM) and extreme learning machine (ELM) were used to establish classification and regression models using full spectra and optimal wavenumbers. ELM models using the optimal wavenumbers selected by principal component analysis (PCA) loadings obtained good results with all the sensitivity and specificity over 90%. Regression models using the full spectra and the optimal wavenumbers selected by successive projections algorithm (SPA) obtained good results, with coefficient of determination (R2) of calibration and prediction all over 0.9 and the predictive residual deviation (RPD) over 3. The classification results of ELM models and the determination results of adulterations content indicated that the mid-infrared spectroscopy was an effective technique to detect the rice flour and soybean flour adulteration in the milk powder. This study would help to apply mid-infrared spectroscopy to the detection of adulterations such as rice flour and soybean flour in real-world conditions.

Utilization of flour from rice brokens in wheat flour chapatti: evaluation of dough rheology, starch digestibility, glycemic index and retrogradation behavior.

Broken rice, a byproduct of the rice milling industry was utilized at different levels to evaluate unleavened flat bread (chapatti) making properties of whole wheat flour. Chapattis were prepared by replacing whole wheat flour with broken rice flour up to 50% level. Mixolab studies revealed that incorporation of rice flour lowered dough development time and dough stability of whole wheat flour up to 23.49% and 78.33%, respectively. Lower retrogradation was observed in whole wheat rice flour blends as revealed from soluble starch/amylose. A positive correlation of mixolab retrogradation was observed with soluble starch and soluble amylose. Whole wheat flour chapatti (fresh and retrograded) containing different level of rice flour were also evaluated for glycemic index (GI), rapidly digestible starch (RDS) and slowly digestible starch (SDS). Chapattis containing rice flour demonstrated higher GI and RDS but lower SDS. RDS correlated positively with GI. Chapattis from the whole wheat rice flour blends had good consumer acceptability.

Influence of honey types and heating treatment on the rheological properties of glutinous rice flour gels.

Present study compared the rheological properties of glutinous rice flour (GRF) gel (33.3%, w/v) added with raw bee honey (RBH) or stingless bee honey (SBH) with/without heating treatment. RBH (diatase activity: 12.14 Schade) and SBH (1.53 Schade) significantly reduced the network of GRF gel by lowering the gel viscosity, with RBH having the highest rate of viscosity decrease (- 2.74 × 10-5 Pa). As the addition of heated-SBH or heated-RBH did not reduce gel viscosity, it was hypothesised that active diastase played a major role to weaken gel network. This was further supported by the significant and the lowest storage modulus (G') value of RBH-GRF gel (5.99 ± 0.02 Pa), as compared to SBH-GRF (6.27 ± 0.04 Pa) and control (6.33 ± 0.04 Pa). A detail of rheological behaviour of the gels was further explained using power law. Overall, this GRF gel model has successfully demonstrated the potential of honey diastase in weakening network of starch-based food.

Milling and thermal treatment induced changes on phenolic components and antioxidant activities of pigmented rice flours.

Processing methods involved in value addition to pigmented broken rice, a milling by-product may affect the nutraceutical qualities. Hence the effect of pulverisation and toasting on nutraceutical content in brown rice flours of red and black rice varieties were studied. Plate milling reduced soluble, bound and total polyphenols in red, but increased in black; increased insoluble polyphenols and oryzanol, and reduced anthocyanin in both varieties; antioxidant activity is reduced in red, but increased in black. Toasting caused reduction of soluble, insoluble and total polyphenol, anthocyanin and antioxidant activity in both varieties with an increase in bound polyphenols, and retention of flavonoids and oryzanol. HPLC characterization of phenolics showed changes on processing in content of catechin, caffeic, vanillic, protocatechuic and ferulic acid. It can be concluded that processing impacts the phenolic components of pigmented broken brown rice flour and this information is useful for functional food industry.

Production of innovative gluten-free breakfast cereals based on red and black rice by extrusion processing technology.

The transformation of black and red, broken or not, whole rice grains, into breakfast cereals is an interesting way to add value to these snacks for some reasons. Firstly, broken kernels hardly achieve a high market value; whole rice is healthy not only for their nutrient contents but also for their phytochemical profile, rich in phenolic compounds; breakfast cereals from pigmented rice are colored by themselves, and any additional colorant is unneeded; finally, rice is naturally gluten-free and suitable for those with conditions like celiac disease or gluten sensitivity. The objective of this study was to optimize some extrusion parameters that account for the physicochemical properties of extrudates by using response surface methodology. Feed moisture between 15 and 21% and the 4th barrel zone temperature between 110 and 160 °C were the independent variables. Specific features such as color, texture, water solubility and absorption, cold viscosity, expansion, specific volume, and compression force were evaluated. The trials have shown that moisture had a higher impact on the extrusion process than temperature. Less expanded, denser, harder, and darker products were obtained at higher moisture levels. The optimum points were defined at 15.5% and 16.0% of feed moisture and 159 °C and 150 °C of temperature for black and red rice extrudates, respectively. These conditions resulted in cereal breakfast balls with optimal water solubility, volume, texture, and good color. Additionally, cold viscosities and a low compression led to products with a potential high approval by consumers.

Reaction-diffusion approach to modeling water diffusion in glutinous rice flour particles during dynamic vapor adsorption.

Dynamic vapor sorption (DVS) method is now widely adopted to determine water diffusion properties in food materials using a sheet or bulk particles as test samples. The Fickian second law with an instant equilibrium boundary condition, although commonly used, can not accurately model the water adsorption kinetics during DVS tests. Dynamic water adsorption of glutinous rice flour was measured at 30 °C and eleven relative humidity steps, and modeled using the Fickian second law with three kinds of boundary condition. Results indicated that the boundary conditions had great impacts on the predicted values especially for the initial section in the DVS curves, and that modifying boundary conditions could not improve the fitness of the final section which characterized a continuing slight increase of water concentration. A reaction-diffusion model, which assumes two diffusible water populations and describes water transport as a competition between diffusion and reversible adsorption on solid matrix, was developed and found to be able to capture the features of water diffusion in the whole adsorption duration. Implementation of the reaction-diffusion approach to glutinous rice flour indicated that diffusion of the Langmuir water became very slow when its adsorption reached equilibrium, while the diffusion of the non-Langmuir water slowed down when water clustering occurred, at the same time the rates of the surface adsorption and bulk adsorption began to decrease. The model developed in this work would help to deepen our mechanistic understanding of water diffusion during a isothermal adsorption.