Rice Flour Products Research Articles

Development and verification of crossing priming amplification on rapid detection of virulent and viable L. monocytogenes: In-depth analysis on the target and further application on food screening

Virulent Listeria monocytogenes is responsible for listeriosis, a highly fatal foodborne illness that impairs human health. One of the major causes of its pathogenicity is the carriage of virulence factor, listeriolysin O, encoded by hylA gene. Herein, the specificity and conservativity of hylA gene sequences were analyzed, with most conservative region selected. Then, a crossing priming amplification (CPA) assay targeting hylA conservative region was established under an isothermal condition (63 °C) to identify virulent L. monocytogenes within 60 min. Forty-four reference strains including two standard L. monocytogenes strains and forty-two strains of other species were selected to assess sensitivity and specificity. The CPA assay showed strong specificity and sensitivity (genomic DNA at 5.66 pg/μL). The practicality of the CPA assay was further confirmed in four artificially contaminated rice-flour products with limit of detection at 104 CFU/mL. In addition, a PMA-CPA assay was developed to direct detect L. monocytogenes viable cells with rice-flour products as a model system. In conclusion, the developed CPA method has advantages of high sensitivity, specificity and quick measurement in the detection of virulent L. monocytogenes, showing considerably feasible promise for future food safety.

Impact of flaxseed gum on the aggregate structure, pasting properties, and rheological behavior of waxy rice starch

This study examines the effects of flaxseed gum (FG) on the aggregate structure, pasting and rheological properties of waxy rice starch (WRS). Results display an increase in the ordered molecular structure (R1047/1024), relative crystallinity (RC), compactness (α), and microphase heterogeneity (ε, density degree of nanoaggregates, from 3.52 to 4.23) for WRS-FG complexes. These suggested FG facilitated the development of more organized molecular and crystalline structures of WRS, accompanied by the formation of ordered nanoaggregates with higher density (i.e., nano-aggregation structure). Also, FG addition resulted in the formation of enhanced gel network structure characterized by thicker layer walls and more uniform pores. These structural transformations contributed to a rise in gelatinization temperature (To, from 56.90 °C to 62.10 °C) and enthalpy (ΔH), as well as alterations in paste viscosities (PV, from 1285.00 mPa·s to 1734.00 mPa·s), and the rigidity of network structure (e.g., decreased loss tangent). These results indicate that FG could effectively regulate the techno-functional properties of WRS by rationally controlling the starch intrinsic structures of starch. And this study may improve the pasting and gelling properties of starch, thus driving the development of high-quality starchy foods and prolonging their shelf life, especially for glutinous rice flour products.

Evaluation of oxidative stability of rice oil from brown rice flour under thermal oxidation and light irradiation.

Effects of autoxidation and light irradiation on the oxidative stability were evaluated in rice oil from two brown rice flours including 'Baromi2' and 'Samkwang'. 'Baromi2' is a newly developed variety for rice flour production while 'Samkwang' is a typical rice variety as a control. Degree of oxidation and volatile profiles were evaluated in rice oil stored at 60°C or under fluorescent light at 25°C. The oil yields of 'Baromi2' and 'Samkang' were 2.63 and 1.78%, respectively whereas rice oil from'Baromi2' had lower degree of unsaturation than 'Samkang'. Rice oil from 'Samkwang' possessed higher volatile compounds and more oxidized products during autoxidation whereas rice oil from 'Baromi2' had more oxidation products under light irradiation. Hexanal and 2-heptenal were major headspace volatile from heated rice oil while 2-heptenal and 1-octene-3-ol were main volatiles from light irradiated rice oil, which implies the involvement of singlet oxygen in rice oil during photooxidation.

3G extruded snacks enriched with catechin for high antioxidant capacity

Extrusion yields either an expanded product or a non-expanded pellet. Non-expanded pellets undergo subsequent indirect expansion in a separate thermal device, such as a microwave oven, resulting in a third-generation (3G) snack. The utilization of milder conditions, makes this an encouraging approach for functional food development. Currently, the effects of both processes on retaining functional ingredients and the evolution of their structure are not yet fully understood. Accordingly, this work aimed to analyze how extrusion temperature (110, 135, and 150 °C) and moisture content (27 and 31%) affect the physical characteristics of 3G expanded rice-flour products enriched with catechins, using a microstructural approach, to better understand the relationship between catechin retention, antioxidant capacity, and structure development. The results showed that products with catechin exhibited higher expansion and increased crispiness/crunchiness, with a relatively higher percentage of small pores, as revealed by X-ray microtomography. Additionally, there was a remarkable retention of catechin and antioxidant capacity (DPPH) in the expanded products, reaching nearly 100%. The preservation of antioxidant capacity in the expanded products may be attributed to the high-temperature-short-time process, which favors catechin stability, along with the dense glassy structure of the extruded pellets obtained, protecting them through encapsulation until their subsequent expansion.

Effect of Rice Bran and Retrograded Time on the Qualities of Brown Rice Noodles: Edible Quality, Microstructure, and Moisture Migration.

Brown rice, as a kind of whole-grain food, has attracted significant attention due to its health benefits. This paper aimed to investigate the effect of rice bran content and retrograded time on the physicochemical properties and culinary qualities of brown rice noodles (BRNs). The results indicated that the addition of rice bran altered the pasting properties, gel properties, and texture of the brown rice flours (BRFs). The optimal cooking time and water absorption of BRNs were reduced after the incorporation of rice bran to 14.9% and 41.9%, respectively, while the breaking rate increased from 2.2% to 23.3%. The color of BRNs became darker and yellower, and the overall acceptability by the consumer decreased. The addition of rice bran also led to a decrease in hardness, chewiness and crystallinity. The binding water inside the BRNs decreased, while the free water increased, resulting in a looser structure. This study revealed that the retrograded time of the BRNs also affected its quality. When the retrograded time was 7 h, the cooked BRNs had a lower breaking rate, good hardness, cohesiveness, chewiness, and better overall acceptability by consumers. The structure was compact, the internal binding water content of BRN was higher, and the free water content was lower. This study provides insights into developing nutritionally healthy, high-quality novel rice flour products, and offers a theoretical basis for the industrial production of BRNs.

Characterization of flo4-6, a Novel cyOsPPDKB Allele Conferring Floury Endosperm Characteristics Suitable for Dry-Milled Rice Flour Production

Rice cultivars with floury endosperm provide a useful raw material for producing dry-milled rice flour, helping to enhance the processed rice food industry. To expand the genetic resources for breeding floury endosperm rice cultivars, we developed Samkwang(SA)-flo3 (SK-flo3), a floury endosperm mutant line derived from the chemical mutagenesis of Samkwang, an elite Korean japonica rice cultivar. Compared with Samkwang, SK-flo3 showed significantly lower grain hardness, which is suitable for producing dry-milled flour without the soaking and drying processes required in regular wet rice milling. The dry-milled flour of SK-flo3 exhibited excellent physicochemical properties with less damaged starch and finer flour particles relative to Samkwang. Genetic analyses revealed a G-to-A point mutation in exon 7 of cyOsPPDKB, substituting glycine with aspartic acid as a causative mutation for the floury endosperm of SK-flo3. We named this allele flo4-6 and developed a molecular marker to efficiently transfer it to commercial rice cultivars. Our results provide useful genetic resources and information for developing specialty rice cultivars for high-quality rice flour production with reduced milling costs.

Effect of Shearing and Heat Milling Treatment Temperature on the Crystallinity, Thermal Properties, and Molecular Structure of Rice Starch.

Rice flour is produced by various methods for use in the food industry, but little is known about how the structure of starch is affected during rice flour production. In this study, the crystallinity, thermal properties, and structure of starch in rice flour were investigated after treatment with a shearing and heat milling machine (SHMM) at different temperatures (10-150 °C). Both the crystallinity and gelatinization enthalpy of starch showed an inverse relationship with the treatment temperature; rice flour treated with the SHMM at higher temperatures showed lower crystallinity and gelatinization enthalpy than that treated at lower temperatures. Next, the structure of undegraded starch in the SHMM-treated rice flour was analyzed by gel permeation chromatography. A significant reduction in the molecular weight of amylopectin was observed at high treatment temperatures. Chain length distribution analysis showed that the proportion of long chains (degree of polymerization (DP) > 30) in rice flour decreased at temperatures ≥ 30 °C. By contrast, the molecular weight of amylose did not decrease. In summary, the SHMM treatment of rice flour at high temperatures resulted in starch gelatinization, and the amylopectin molecular weight decreased independently, due to the cleavage of amorphous regions connecting the amylopectin clusters.

Factors affecting the properties of rice flour: a review

Rice (Oryza sativa L.) is a global essential food. Rice flour production had a significant upsurge, leading to various development in rice-based food products. The properties of starch within rice flour are generally affected by different factors, resulting in rice flour with various physicochemical and functional properties. This article summarized the several factors that affect rice flour properties, including environmental conditions in terms of temperature extreme and soil conditions, milling methods, amylose and amylopectin composition, and endogenous protein and lipid. Overall, environmental conditions in extreme temperatures can influence the amylose content, altering the amylopectin chain length and functional and thermal properties, to be specific gelatinization temperature and pasting properties. As for soil conditions like water deficiency and salinity stress could affect the pasting properties, reduce amylose content, increase the swelling rate, and pasting properties due to the alteration of protein endosperm level in rice flour, respectively. Factors such as the milling method are capable of influencing the starch characteristics within rice flour, and wet-milled rice flour is more applicable in the development of gluten-free rice bread than dry-milled rice flour. Amylose and amylopectin composition were found to affect the texture of final products and the physicochemical properties of rice flour, such as swelling capacity, gelatinization temperature and pasting properties. Whereas endogenous protein and lipid can influence the swelling properties, water solubility index, gelatinization temperature and retrogradation rate by the formation of complexes with amylose, called amylose-protein and amylose-lipid. In general, different factors could lead to vast properties of rice flour that can affect its performance of flour.

EXTRACTION OF Al3+, Pb2+, Cd2+ AND Sr2+ IONS WITH A PHOSPHORUS-CONTAINING PRODUCT FROM RICE FLOUR

Materials of natural origin can serve as raw materials for the production of environmentally friendly inexpensive polyfunctional materials with a wide range of applications. Agricultural waste from rice production (rice husks, straw and flour) can serve as a source of such substances. In this work, the process and conditions for the extraction of aluminum, lead, strontium and cadmium ions from aqueous solutions by an organophosphorus product (derivative of inositol hexaphosphoric, phytic acid) obtained from rice flour production waste are studied. Phytic acid and its derivatives are highly effective ligands capable of chelating metal cations, which allows them to be considered as a natural material suitable for removing heavy metal ions from aqueous solutions. The degree of extraction of aluminum ions reaches 97%, lead and strontium – 89%, and cadmium – 93%. It is shown that the absorption decreases in the series Cr3+ > Al3+ > Bi3+ (from 13.0 mg/g to 4.9 mg/g) and Cd2+ > Pb2+ > Sr2+ (from 8.9 mg/g to 7.5 mg/g). These studies allow us to offer a fundamental possibility of using a natural phosphorus-containing compound as an environmentally friendly sorbent.

Residue changes of five pesticides during the production and storage of rice flour

ABSTRACT The residue changes of five pesticides in samples from different steps of rice flour production and accelerated storage were systematically investigated. Rice flour was produced both by the extrusion process and the drying on roller process. The change of pesticide residues varied in different processing steps and storage time. The water adjusting step had little influence on the pesticide residues. The pesticide residues were decreased significantly in the extruding, soaking, and grinding steps with reduction from 21% to 76%. The drying step increased or decreased the pesticide residues in varying degrees through concentration due to water evaporation and thermal evaporation or thermal degradation. All the pesticide residues decreased during the accelerated storage, especially for methidathion and chlorpyrifos, neither was detected after accelerated stored for 14 days. The processing factors (PFs) for imidacloprid and isocarbophos in the drying step were greater than 1, and the others were all less than 1. The whole drying on roller process had lower PFs than the whole extrusion process, indicated that the drying on roller process had a greater effect on pesticide residues. The PFs of accelerated storage for five pesticides were all below 1. Overall, this study provides important references for monitoring pesticide residues in the processing and storage of rice flour. Moreover, the PFs obtained in this study could be useful in the dietary exposure and risk assessment of pesticides in rice flour.

Evaluation of Food Safety of Commercial Baby Foods according to Legal Regulations

It has recently been recognized that some commercial infant formulae have, due to spoilage and pathogen microorganisms, which are detected risks to health, been recalled and reported in the Rapid Alert System for Food and Feed on notification lists. The risk of microbial contamination from the environment or from the addition of ingredients to cereal-based follow-on formulae (FOF) and powdered infant foods (PIF) products could occur under poor hygienic conditions. This project was designed to evaluate the associated risks of Cronobacter sakazakii, Salmonella, Total Coliform, E. coli, E. coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus and Ochratoxin-A in PIF, FOF and rice flour products marketed in Turkey. Seventy-four baby formulae and thirteen rice flour trademarks obtained in 2018 randomly from different markets in Samsun, Kars, and Adana in Turkey. Salmonella, C. sakazakii, Coliform, S. aureus, L. monocytogenes and Bacillus cereus were analyzed using the ISO 6579:2002, ISO/TS 22964:2006, MPN, FDA (2001), FDA (1998) and FDA (2012) methods, respectively. C. sakazakii was isolated from 7/74 FOF products and 4/13 rice flour products, yielding 12.64% prevalence. Salmonella, S. aureus and L. monocytogenes were not detected in any of the samples. The FOF products, including cereals of different origins and one rice flour sample (7.69%), were found to be contaminated with B. cereus (6.76%) and B. subtilis (5.41%). OTA values were found to be above the legal limits in 4.05% (3/74) FOF products. These results suggest that routine quality controls and hazard and risk analysis for infant foods have to be much more rigorous in terms of the potential risk of microbiological contamination.

Industrial applications of selected JFS articles

Industrial applications of selected <i>JFS</i> articles

Phenomenological analysis on whipping behavior of rice flour batter.

In this study, the bubbles in rice flour batter were investigated under a constant temperature, because the bubble size distribution is important for the control of food texture. We obtained experimental data using a hand mixer and compared the properties of doughs prepared using six rice flours; each flour was prepared through a different milling process. We also added the size effect of the rice flour particles as the Bond number. Furthermore, we performed a dynamic wettability test to estimate the wettability of the rice flour surface. The results of this test were described well by the Washburn equation, and dccosθ/dp was calculated as a wettability parameter (where, dc = effective diameter of a capillary in a powder bed, cosθ = the contact angle, dp = mean particle diameter of rice flour). If bubble sizes depend mainly on the inertial force, viscous force, surface tension, and gravity, then the normalized mean bubble diameter should be a function of the Reynolds number, Weber number, and Froude number. The mean bubble diameter (dbm) generated by whipping was expected to be affected by the thickness (d) of the rod of the mixer, its movement speed, and physical properties of the material. Therefore, dimensionless mean diameter (dbm/d) was expressed based on a dimensionless equation. In the three‐phase dispersion, different empirical equations were obtained depending on the amount of rice flour added, and the bubble diameter could be predicted using dimensionless parameters. In addition, the equations were generally applicable to the various materials selected for this study.Practical ApplicationThe powder properties of rice flour were investigated, and dimensionless parameters were analyzed to construct an appropriate process control system for rice flour‐based food products. Although the process method optimized for flour products is also used for rice flour products in practical situations, the comprehensive evaluation based on dimensionless parameters leads to optimization of the process for rice‐flour based products. Moreover, this optimization might strongly support the creation of a new texture, and thus, the potential for market expansion of rice‐flour based products is considerable.

Optimization of High-Protein Glutinous Rice Flour Production Using Response Surface Method

A response surface method was employed to study the effect of α-amylase concentration, hydrolysis temperature and time on the production of high protein glutinous rice flour (HPGRF). The suspension of glutinous rice flour (15%) that contained 6.52% protein was gelatinized and subsequently hydrolyzed by thermostable α-amylase. The hydrolysis yielded 0.144–0.222g/g HPGRF with 29.4%–45.4% protein content. Hydrolysis time exerted a significant effect, while enzyme concentration and hydrolysis temperature showed insignificant effect on the protein content and production yield of HPGRF. The result of response surface method showed that the optimum condition for the production of HPGRF that contained at least 36% protein was treating gelatinized 15% glutinous rice flour suspension with 0.90 Kilo Novo α-amylase Unit (KNU)/g α-amylase at 80°C for 99min. By carrying out the predicted hydrolysis condition, HPGRF with 35.9% protein and 61.8% carbohydrates was resulted. The process yielded 0.172g/g HPGRF. HPGRF contained higher amount of essential amino acids compared to glutinous rice flour. HPGRF had higher solubility and lower swelling power, and also showed no pasting peak compared with glutinous rice flour.

Determination of thiourea based on the reversion of fluorescence quenching of nitrogen doped carbon dots by Hg2.

Herein, a facile and quick strategy to detect thiourea was conducted based on the reversion of fluorescence quenching of nitrogen doped carbon dots (NCDs) by Hg2+. The NCDs with good water solubility and 17% of quantum yield was synthesized by one-step hydrothermal method, using ammonium citrate and dextrin as carbon source and nitrogen source, respectively. The fluorescence of NCDs was obviously quenched by Hg2+ and can be recovered, due to stronger interaction between thiourea and Hg2+. There was a good linear relationship between the recovered fluorescence and the concentration of thiourea within range of 0.90-10.0 μM and the detection limit for thiourea detection was 0.15 μM. The as-prepared NCDs can be used for determination of thiourea in tap water, lake water and rice flour products, and the spike recoveries were between 91.6 and 108%.

Aflatoxin contamination of baby food flour sold on Haitian markets

Mycotoxins (Mox) are secondary metabolites produced by filamentous moulds. Among Mox, aflatoxins (AFs) are noted as the most preoccupant carcinogen substances known. AFs contaminate several food materials and derived products such as flour. The present investigation aimed at evaluating the AF contaminations of maize, cassava, moringa and rice flour products utilized as baby food in Haiti. Twenty five samples were collected in South Haiti (from street’s vendors and, Les Cayes markets and supermarkets). Those products were tested for AFs content using and following Reveal® Q+ aflatoxin test (Neogen® ) supply instruction. Results reveal that AF contaminations of substrates range from 2.7 and 119 ppb. Cereal products were more AF contaminated compared to tuber and moringa. Maize flour samples were more AF contaminated than rice. AF contaminations of maize seem to depend on provenance (p&lt; 0.05). AF contaminations of maize from Iron and Relais markets were respectively 5.2 and 32.1 ppb. Moreover, AF contaminations of maize collected from street vendors represented almost seven times of that from Les Cayes supermarkets. Similar results suggest necessity to perform and develop programs for managing AF contaminations on baby food in Haiti. Keywords: Aflatoxin, flour, maize, cassava, moringa, rice.

Influence of Different Transplanting Dates on Amylopectin Branch-chain-length and Pasting Properties of Rice Flour Varieties

This study was conducted to examine the influence of different transplanting dates on rice quality and starch properties (morphology and pasting properties) of rice varieties that may be used for the production of rice flour. Three rice flour varieties, ‘Seolgaeng’, ‘Hangaru’, and ‘Milyang317’, were transplanted on May 20, May 30, June 10, and June 20. The peak viscosity decreased with a delay in the transplanting date. However, the amylose content increased with a delay in the transplanting date, whereas that of protein decreased. Amylopectin short-branch chain content increased in the rice varieties that were transplanted on May 30. The morphology of the starch granule of the varieties was determined by SEM. No apparent external difference in the starch granules was observed for the different transplanting dates. These results indicate that the transplanting date influenced the amylopectin structure and pasting properties, which led to changes in the physicochemical characteristics of rice starch.

EFFECTS OF DIFFERENT GRINDING METHODS ON MORPHOLOGICAL, TEXTURAL PROPERTIES AND PASTING PROFILES OF MR220 RICE FLOUR

Three different grinding techniques (dry, semi-wet, and wet) were employed in rice flour production. Investigation on the effects of the grinding techniques on starch damage percentage, particle size distribution, pasting profiles, morphological and textural properties of rice flours produced were evaluated. Wet grinding resulted in significantly (p< 0.05) has lower percentage of damaged starch (3.24 %) than other grinding methods. Morphological studies (microscopy and particle size analysis) have reflected significant differences among rice flours granule shapes. The granules displaying different shapes of polygonal, round and angular forms, with some as an individual granule while others tend to attached together. Wet grinding technique also yielded flour that exhibit significantly (p< 0.05) with higher gel hardness (16.62 g). Pasting profiles showed that pasting temperature for rice flour produce using these three grinding methods varied between 80.15 – 80.42 °C. Results revealed that the three grinding techniques clearly affected the physicochemical properties of rice flour. The results from this study play an important role in the selection criteria of rice flour with desirable pasting and textural properties for manufacturing rice-based product.

Characteristics of Rice Flour Suitable for the Production of Rice Flour Bread Containing Gluten and Methods of Reducing the Cost of Producing Rice Flour

3 Niigata Agricultural Research Institute Food Research Center (Kamo, Niigata 959-1381, Japan) Abstractproduction of various rice flour-based food products such as bread, noodles, and cakes is expect- ed to increase the consumption of rice and the utilization of rice paddies in Japan. This paper reviews studies conducted on the characteristics of rice flour and the rice cultivars suitable for the production of rice flour bread containing gluten. The challenges of reducing the cost of producing rice bread are also reviewed. The production of rice flour bread containing gluten of a highly specific loaf volume requires the use of rice flour with a low damaged starch content that can be produced by jet milling wet rice after water or enzyme treatment. The amylose content of rice flour affects the quality of bread, including its shape and hardness. Rice flour with an amylose content of 16% to 20% forms a chewy and moderately soft bread. When rice flour with a low damaged starch content (less than 5%) and a desirable amylose content (16% to 20%) is used, the production of rice flour bread containing gluten is easy without being different from how wheat flour bread is made. In order to reduce the cost of producing rice flour, high-yielding cultivars or a pin milling system using floury rice cultivars should be employed; high-yielding cultivars are now being used for the production of rice flour. With the pin milling system, rice flour belonging to the floury rice cultivar has a low damaged starch content. However, there is a need to develop a high-yield floury rice with reduced weight loss during polishing, as well as new polishing processes. Furthermore, the production of brown rice flour con- tributes to reducing the cost of producing rice flour because no polishing process is required. Brown rice flour with a low damaged starch content can be produced using a jet mill after soaking for more than 12 h. And given its favorable high nutritional properties, bread made from brown rice flour will prove appealing to consumers. Despite expectations of increasing of the consumption of rice through the use of rice flour as in the production of rice flour bread, the cost reduction of rice flour produc- tion and the development of delicious rice flour bread desired by consumers are still insufficient. By understanding the requirements of bread-making companies and obtaining a deeper knowledge about the quality characteristics of rice flour, such as amylose content and protein composition, the produc- tion of rice flour bread appealing to consumers can be expected.

Effects of Different Grinding Methods on Chemical and Functional Properties of MR211 Rice Flour

Investigation on chemical and functional properties as affected by different grinding techniques was carried out during the milling process of rice grains into rice flour production. Proximate analysis revealed that dry ground flour had significantly (p<0.05) highest protein, lipid, ash and carbohydrate contents. Wet grinding technique yielded flour that exhibit significantly finest average particle size distribution (9.32μm), with significantly lowest damaged starch (4.08%) and highest L* value (93.55). Water absorption index, flour swelling volume and solubility were significantly highest in dry ground flour as compared to others. Results indicated that different grinding methods significantly affected chemical and functional properties of starch and data generated provide additional opportunities of exploiting rice flour utilization and hence boost its value-addition potentials for product development. 