Characterization Of Grains Research Articles

Laser ultrasonic characterization of grains in titanium alloy by the inversion method

Abstract The polycrystalline materials have been usually described by the average grain size (AGS). This paper provides a nondestructive method for determination of the AGS in titanium alloy from an inversion of experimental ultrasonic attenuation spectrum (UAS). The detailed analyses of the inverse algorithm and sensitivity of UAS to the AGS are presented, and the sensitivity is identified as a criterion for selecting the experimental data of UAS used in inversion. An example of the inverse method and experimental measurement for UAS comparison was given for the titanium alloy specimen with the AGS of 26 μm. The relative error between the AGS determined by the inversion and scanning electron microscope (SEM) observation was found to be about 1.5 %. The provided method demonstrates the feasibility of laser ultrasonic technology used for the non-destructive evaluation of AGS in polycrystalline materials.

Impedance and Dielectric Analysis of Nickel Ferrites: Revealing the Role of the Constant Phase Element and Yttrium Doping

This paper presents the analysis of electrical and dielectric properties of the yttrium-doped nickel ferrite nano-powders synthesized using the co-precipitation method. Impedance and dielectric measurements have been carried out as a function of frequency at different temperatures from 200 to 25 °C in the range of 0.1 kHz–1 MHz. In order to investigate the conduction mechanism and highlight the role of yttrium doping in different concentrations, impedance spectroscopy was employed. The obtained data were analyzed in terms of equivalent circuits made of resistor and capacitor components describing the contributions from different electrical active regions in a material. Further, this study highlights the importance of a single constant phase element (CPE) in the description of dispersion behavior of the impedance response of the investigated samples in the given frequency range. The use of this technique enabled the characterization of grain and grain boundaries contribution in overall conductivity mechanism. The dielectric dispersion nature of all investigated materials is reflected in this study. Very high values of the real part of permittivity at low frequencies are assigned to space-charge polarization. The dependence of the real part of dielectric permittivity values of the yttrium content was also discussed. Doping with yttrium in different concentrations that reflects in different electric and dielectric responses is concluded in this study. The greatest change is noticed for the sample with the minimum dopant content for a x = 0.05 atomic percent share of yttrium. To reveal the potential role of more than one ion contribution to the overall relaxation process in investigated compounds, a modified Debye’s equation was utilized.

Characteristic of grain and rice quality from five superior varieties support food sustainability

Rice is the main food crop consumed by no less than 270 million of Indonesians. The provision of the main food (rice) in the future the challenge is getting heavier. Research on the characterization of grain and rice quality of five superior varieties of rice, namely Inpari 32, Inpari 42, Inpari 45, Inpari Nutrizinc, and Pamelen. Research was conducted from August until October 2021 in post-harvest laboratory AIAT East Java Malang, using a group design with 5 replicates. Grain quality anaysis includes weight, moisture content, rice yield, density, length/width ratio, and colour. While rice quality includes thick, length/width ratio, yield, whole grains, head grain, broken grain, damaged grain, and rice organoleptic test. Grain and rice quality analysis based on SNI. Result shown that Inpari 32, Inpari 45, and Pamelen grains weight greater than others. Inpari 42, Nutrizinc, and Pamelen varieties slimmer than others. However, Inpari 32 showed the highest rice yield, which was 70.13%, while the lowest rice was shown by the Inpari Nutrizinc variety at 64.87%. Based on the precentage of broken grain, 5 rice varieties can be catagorized as medium grade 1, 2, and 3. Based on organoleptic test of five varieties by panelist with an average score of 5.

Tensile Properties and Deformation of AISI 316L Additively Manufactured with Various Energy Densities.

Additive manufacturing (AM) is an emerging fabrication technology that offers unprecedented potential for manufacturing end-to-end complex shape customized products. However, building products with high performance by AM presents a technological challenge. Inadequate processing parameters, fabrication environment or changes in powder properties may lead to high defect density in the part and poor mechanical properties. Microstructure, defect structure, and mechanical properties of AISI 316L stainless steel pieces, additively manufactured by the laser powder bed fusion method using three different volume energy densities (VEDs), were investigated and compared with those of a commercial wrought AISI 316L sheet. Scanning and transmission electron microscopies were employed for characterization of grain and defect structures, and mechanical properties were determined by tensile testing. It was found that the number of defects such as pores and lack of fusion in AM specimens did not affect the strength, but they impaired the post-uniform elongation, more significantly when processed with the low VED. Twinning was found to be an active deformation mechanism in the medium and high VED specimens and in the commercially wrought material in the later stage of straining, but it was suppressed in the low VED specimens presumably because the presence of large voids limited the strain attained in the matrix.

Characterization of tofu produced with different soybean cultivars/ Caracterização de tofu produzido com diferentes cultivares de soja

Soybean has good properties for industrial application, including tofu production. Cultivar is one of the major factors that influence food product making potential of soybeans. This study aimed to perform the physicochemical characterization of grains, tofu and okara, as well as the sensory analysis of tofu produced from seven different experimental lines of soybean. CAC TNS showed the lowest 100 grain mass, which was equal to 12.43 g. The protein content of the cultivars showed no significant difference, which ranged from 27.77 % to 36.82 %. For tofu yield, there was no significant difference between all cultivars. Tofu of CP-09, CP-27 and CAC TNS cultivars showed the highest protein concentration and were equal to 12.76 %, 11.58 % e 11.20 %, respectively. Tofu from CP-02, CP-09, CP-12, CAC TN and CAC TNS cultivars had the highest scores for the flavor parameter. However, only tofu from CAC TN and CAC TNS had higher scores for the aroma parameter. Regarding the texture, the tofu from CP-09, CAC TN and CAC TNS showed the highest scores. Thus, CAC TNS cultivar is the most suitable to produce tofu for providing a product with better sensorial acceptance and high nutritional value. The okara obtained from the different cultivars showed considerable amounts of proteins, lipids, minerals and carbohydrates, constituting a potential residue for human consumption. These results could be used as auxiliary guide of tofu manufacturers during raw material selection with characteristics more acceptable by consumers.

Morphology and texture characterization of grains in laser welding of aluminum alloys

Grain morphology and texture of welds significantly affect the properties of the corresponding joint. It is very important to determine how heat and grain growth during welding correlate. Our studies involved both experiments and multi-scale numerical modeling. The laser welding temperature distribution was studied by the macroscopic finite element method. The grain growth and morphology evolution under different heat input conditions were calculated by the Monte Carlo method at the mesoscale. The relationship between heat flow distribution and grain orientation was established. Results of electron backscattered diffraction (EBSD) were compared to those obtained by numerical modeling. The welding heat input affected the heat flow distribution and the shape of the molten pool, which, in turn, influenced grain morphology and crystal orientation.

Characterization of Grain Boundary‐Engineered Aluminum–Magnesium Alloys

Herein, the effect of sputtering rate on the fraction of special grain boundaries in 5xxx series Al–Mg alloys is explored. Samples are synthesized via interrupted direct current (DC) magnetron sputtering with varying deposition rates, and the grain size and grain boundary character are evaluated with electron backscatter diffraction (EBSD). The highest sputtering rate (7 nm s−1) leads to an increase in the total number of special grain boundaries, ≈1.5× greater than that of the lower rates. Increased thermal energy and enhanced stress relaxation during film growth promote the formation of Σ3 and Σ7 boundaries.

Caracterização da qualidade físico-química em grãos de soja de municípios da região centro-oeste do Brasil

Objetivou-se caracterizar a qualidade físico-química em grãos de soja provenientes de unidades armazenadoras em municípios da região Centro-Oeste. Os grãos de soja foram coletados em oito unidades armazenadoras de grãos distribuídas em diferentes municípios da Região Centro-Oeste do Brasil. Realizou-se a caracterização dos grãos por meio do teor de água, condutividade elétrica, cor, massa específica aparente, massa de mil grãos, pH, composição proximal e os índices de acidez, peróxido e iodo do óleo. A caracterização física se apresentou com médias de 127,15 µS cm-1 g-1 para condutividade elétrica, 7,50 para pH, 55,74 para L*, 10,41 a* e 31,46 para b*, 33,15 para croma e 71,70 para h*, 163,91 g massa de mil grãos e 701,00 kg m-3 massa específica aparente. A composição proximal se deu com valores médios de, 11,30% para teor de água, 32,11% proteína, 7,76% fibra, 4,68% cinza, 20,62% carboidratos e 23,62% para teor de óleo. A caracterização dos índices de qualidade do óleo mostrou-se com valores de 0,08 mg KOH g óleo-1 para acidez, 1,18 meq O2 kg óleo-1 para peróxido, 30,72 g I2 100 g óleo-1 para iodo. Conclui-se que os grãos de soja dos municípios da região Centro-oeste quanto a qualidade físico-química dos grãos está dentro do padrão de qualidade segundo a legislação e literaturas pesquisadas e a qualidade do óleo com exceção do iodo com valores abaixo do padrão, está na faixa que garantem sua qualidade.

Study of microstructure and mechanical properties of aluminium alloy (AA-6351-T6) using friction stir welding

The current study investigates the effect of welding speed on the mechanical and microstructural properties in similar friction stir welding of Aluminium Alloy (AA-6351-T6). The contribution of intense plastic deformation and high-temperature exposure within the stirred zone during friction stir welding results in recrystallization and development of texture within the stirred zone and precipitate dissolution and coarsening within and around the stirred zone. Based on micro-structural characterization of grains and precipitates, three distinct zones, stirred (nugget) zone, thermo-mechanically affected zone (TMAZ), and heat-affected zone (HAZ).The micro-structural changes in various zones have significant effect on post weld mechanical properties.

Calidad pozolera en poblaciones de maíz Cacahuacintle de los Valles Altos de Puebla, México


 
 
 La raza de maíz Cacahuacintle (MC) está confinada en nichos ecológicos específicos y ha sido mínimamente estudiada a nivel intra-racial en sus aspectos de calidad para pozole, no obstante que su uso culinario específico en la gastronomía mexicana lo ubica como una opción agrícola rentable para los agricultores de los Valles Altos de México. El objetivo del estudio fue identificar poblaciones sobresalientes en calidad para pozole (CPP) en colectas de maíz Cacahuacintle de Valles Altos de Puebla (MCVAP). Se utilizaron poblaciones de MCVAP, poblaciones de MC del Estado de México, y como testigos para calidad, una población de maíz Cónico y otra de maíz Ancho. La caracterización morfológica y física de grano se aplicó en todas las poblaciones; la evaluación de la calidad para pozole, contenido de amilosa y propiedades de formación de pasta (PFP) sólo en poblaciones seleccionadas por forma de grano y en los testigos. La forma de grano predominante fue redondeada globosa (86%), que es la típica del maíz Cacahuacintle. Los valores promedio de las variables físicas del grano en las poblaciones de MC fueron: peso de mil granos de 540.6 g, peso hectolítrico de 60.5 kg hL-1, y color de grano con 83.8% de ref lectancia. El grupo formado por las poblaciones CPue-00473,00 474,00477 y 00487 se consideró como de mejor calidad para pozole, por presentar equilibrio en las variables de calidad consideradas. El contenido de amilosa no mostró correlación significativa con ninguna de las variables tecnológicas analizadas. Sin embargo, el perfil viscoamilográfico mostró una clara diferencia entre los maíces Cacahuacintle y el maíz Ancho.
 
 

Adaptation of the quantitative PCR method for the detection of the main representatives of cereal grain mycobiota

ABSTRACT The content of fungal DNA and mycotoxins in cereal crops (31 varieties of wheat, oats, and barley) was quantitatively determined and used for the comparative characterization of grains. The quantitative PCR has been adapted for the analysis of the target DNA of Alternaria spp., Bipolaris sorokiniana (B. sorokiniana), Fusarium graminearum (F. graminearum), F. culmorum, and F. sporotrichioides fungi, which are often present in the mycobiota of small grain cereals. The content of the DNA of the aggressive pathogen B. sorokiniana was determined using quantitative PCR for the first time. The DNA of Alternaria fungi was found abundantly in all grain samples, but its content in the oat was significantly higher compared to barley and wheat (5 and 9 times higher, respectively). In barley grain, the content of B. sorokiniana DNA was on average significantly higher than in the grains of oats and wheat. All of the analyzed grain samples contained the DNA of F. graminearum while F. culmorum DNA was found in 70% of the oat samples and in all of the samples of barley and wheat. Mycotoxin deoxynivalenol (DON) produced by these fungi was detected in all the analyzed cereal grains in a range from 77 to 4,133 μg/kg. The DNA of F. sporotrichioides was detected in 70% of oats and 50% of barley samples but was not found in wheat. The T-2 toxin produced by this fungus was detected in 45% of all samples within a range from 2 to 89 μg/kg. The statistically significant positive correlation with the Pearson correlation coefficient (r) equal to 0.49 (p<0.05) was observed between the content of F. graminearum DNA and the amount of DON in the grain samples. Another significant positive correlation (r=0.72, p<0.01) was found between the DNA contents of Alternaria fungi and F. sporotrichioides in the grain samples. This leads to the suggestion that conditions for the growth of these fungi in grain substrates are similar.

Адаптация метода количественной ПЦР для выявления представителей микобиоты зерновых культур

Проведена сравнительная оценка содержания ДНК грибов и микотоксинов в зерне 31 сорта пшеницы, овса и ячменя. Метод количественной ПЦР был адаптирован для выявления ДНК грибов, часто встречающихся в микобиоте зерновых культур: Alternaria spp., Bipolaris sorokiniana (B. sorokiniana), Fusarium graminearum (F. graminearum), F. culmorum и F. sporotrichioides. Количественное выявление в зерне ДНК гриба B. sorokiniana проведено впервые. ДНК грибов Alternaria выявлена во всех образцах в диапазоне от 184×10-4 до 11160×10-4 пг/нг общей ДНК, но в зерне овса, по сравнению с зерном ячменя и пшеницы, ее количества были больше в 5 и 9 раз соответственно. ДНК B. sorokiniana выявлена во всех образцах зерна ячменя и овса, а также в 56% образцов пшеницы. В зерне ячменя содержание ДНК B. sorokiniana в среднем было существенно выше (402×10-4 пг/нг), чем в зерне овса (51×10-4 пг/нг) и пшеницы (10×10-4 пг/нг). Присутствие ДНК гриба F. graminearum установлено в зерне всех анализированных образцов в диапазоне от 14×10-4 до 1110×10-4 пг/нг, ДНК F. culmorum выявлена в 70% образцов овса и в 100% образцов ячменя и пшеницы в количестве от 8×10-4 до 90×10-4 пг/нг. Микотоксин дезоксиниваленол (ДОН), продуцируемый грибами F. graminearum и F. culmorum, выявлен в зерне всех образцов в диапазоне от 77 до 4133 мкг/кг. ДНК F. sporotrichioides, продуцирующего Т-2 токсин, обнаружена в 70% образцов овса и 50% образцов ячменя в количестве от 5×10-4 до 47×10-4 пг/нг и не выявлена в зерне пшеницы. Количество T-2 токсина, обнаруженного в 45% образцов, не превышало 89 мкг/кг. Установлена достоверная положительная связь между количествами ДНК F. graminearum и ДОН в зерне. Коэффициент корреляции Пирсона (r) составил 0.49 (p <0.05). Также выявлена положительная связь (r = 0.72, p <0.01) между количе-ствами ДНК Alternaria spp. и F. sporotrichioides, что предполагает сходство условий для развития этих грибов на зерновом субстрате.

Pyroelectric Properties and Local Piezoelectric Response of Lithium Niobate Thin Films

In this paper, comprehensive investigation of the pyroelectric properties and local piezoelectric response in ferroelectric film heterostructures is presented. The pyroelectric effect is determined by the dynamic method and the pyroelectric response is recorded for further analysis. It is shown that such studies are effective to analyze the self‐polarization phenomena, the stability of the polarized state, the determination of the ferroelectric phase fraction in the film structures, the characterization of grains with in‐plane and out‐of‐plane polarization and others. For example, thin film samples of ferroelectric LiNbO3 deposited by magnetron sputtering on silicon substrates are considered. The measurement results show that a part of the crystal grains (about 30%) in these films possessed the out‐of‐plane polarization directed from the free surface to the substrate and determined the peculiarities of the pyroelectric response and the vertical component of the local piezoelectric response.

Quality assessment and molecular characterization of rice genotypes using DNA markers

ABSTRACT : Genetic relatedness among rice varieties were assessed using ten RAPD, two SSR and two STS markers. The 56 rice genotypes studied included improved varieties and landraces collected from different parts of India. The number of alleles per RAPD locus ranged from 3 to 7, averaging 4.7 alleles per locus. Polymorphism information content (PIC) values ranged from 0.474 to 0.811, with an average of 0.665. The number of alleles per SSR locus ranged from 2 to 4, averaging 2 alleles per locus and PIC values ranged from 0.069 to 0.278, with an average of 0.017. The band size for a given SSR locus varied between 170 bp and 180 bp and for STS markers the band size varied between 175bp to 180bp with an average pic value of 0.299. Characterization of the genotypes was also done for important quality parameters including amylose content, gel consistancyn and gelatinization temperature. Cluster analyses were used to group cultivars by constructing dendrograms based on DNA marker analysis and physicochemical characterization of grains. The dendrogram based on molecular marker analysis grouped the 56 rice cultivars into different diverse groups. Clustering of these varieties according to their genotypes as well as phenotypes revealed the possible linkage or pleiotropic effects of the genomic regions associated with some grain quality traits. Information generated through cluster analysis based on phenotypic and genotypic data could be efficiently used in breeding rice varieties harboring grain quality traits. Pure-line selection can be made using farmer varieties that are characterized morphologically and phenotypically in the study.

Microwave sensing of quality attributes of agricultural and food products

Highly automated and computerized processes in agricultural and food industries require the development of sensors for continuous measurement and monitoring of quality attributes of agricultural and food products. Microwave dielectric-based sensors are well suited to fulfill such needs because water is a common component of these products, and water has a strong interaction with the electric field at microwave frequencies. Recent advances in calibration methods and availability of reliable and inexpensive microwave components offer an opportunity for the development of a new generation of low-cost microwave sensors for process monitoring and control that will result in significant labor and cost savings in addition to maintaining the desired quality and complying with safety regulations. This is even more relevant in a social and economic environment where consumer awareness is high and new rules and guidelines for labeling and safety standards are put in place. This paper discusses both the development of calibration methods for indirect determination of bulk density and moisture content from measurement of the dielectric properties at a single microwave frequency and development of inexpensive microwave meters for routine characterization of grain, seed, and in-shell peanuts in static and dynamic situations. Accuracy and savings associated with the use of such devices are also covered.

Improved Energy Storage Properties Accompanied by Enhanced Interface Polarization in Annealed Microwave‐Sintered BST

Microwave‐sintering (MWS) technique was employed to fabricate dense (Ba0.4Sr0.6)TiO3 (BST) ceramics. With respect to the high dielectric loss at room temperature, induced by the formation of oxygen defects during the MWS under vacuum atmosphere (−60 kPa), the as‐sintered samples were thermally annealed in air to reduce tanδ and recover the insulating performance. Accompanied by the decreased tanδ, the energy storage properties for annealed MWS BST were optimized, with increasing energy density (γ) from 0.77 to 1.15 J/cm3 and energy efficiency (η) from 60% to 82%. The lower oxygen vacancy concentrations were believed to account for the enhanced insulating characteristics of grain boundaries and contribute to the improved properties after annealing. Electrical characterization of grain and grain boundary by impedance spectroscopy demonstrated that the annealing preferentially modified the grain boundary. In addition, resistances extracted from the high temperature impedance analysis were found to be inadequate for evaluating the electrical characteristics of materials affected by extrinsic mechanisms, such as the interfacial polarization. For comparison, annealing effect on energy storage properties were also discussed for conventionally sintered BST.

Genetic Diversity Studies on Selected Rice (Oryza sativa L) Populations Based on Aroma and Cooked Kernel Elongation

Rice (Oryza sativa L.) is the main staple food for more than half of the world’s population. Improving cooking and eating quality of rice is one of the important objectives of many plant breeding programs. Aroma and cooked kernel elongation are two critical parameters that determine the market value, cooking and eating qualities of rice. The objective of this study was to evaluate the genetic diversity of thirteen (13) Oryza sativa L. populations from Kenyan and Tanzanian. Genetic diversity was determined using 8 simple sequence repeats (SSR) markers. Diversity data was analyzed using POWERMARKER version 3.25 and GENALEX v 6.5 software packages. The number of alleles per locus ranged from 2 to 4 alleles with an average of 3.12 across 8 loci. The polymorphic information content (pic) ranged from 0.2920 (RM 282) to 0.6409 (RM 339) in all loci with an average of 0.4821. Pair-wise genetic dissimilarity coefficients ranged from 0.1125 to 0.9003 with an average of 0.5312. The average gene diversity over all SSR loci for the 13 rice varieties was 0.6036, ranging from 0.3550 to 0.6391. Maximum genetic similarity was observed between Kilombero and Supa, BS 370 and BS 217. Minimum genetic similarity was observed between Kahogo and BS 217. Cluster analysis was used to group varieties by constructing dendrograms based on SSR data and morphological characterization of grains. The dendrogram based on SSR data formed two distinct clusters of the 13 rice varieties. RM 339 and RM 241 were the most informative markers and could be used for differentiating rice varieties from diverse geographical origins. Results obtained from this study demonstrated that use of trait specific SSR markers can be relied upon in diversity studies among diverse and closely related genotypes. RM 339 and RM 241 markers are recommended for use in diversity studies and in quality assurance for grading of rice varieties. Further analysis should be carried out using a larger number of samples and markers to come up a more conclusive report on the discriminating power of microsatellite markers based on rice grain quality traits.

Three-dimensional visualization and quantitative characterization of grains in polycrystalline iron

Serial sectioning is employed to reconstruct the three-dimensional microstructure of polycrystalline iron for visualization and characterization of the three-dimensional geometry of α-iron grains. Full three-dimensional morphology of 1386 α-iron grains is investigated and compared with different theories with a particular emphasis on the investigation of the nearest neighbor grain effects in real three-dimensional polycrystalline systems. Different metric and topological parameters of three-dimensional grains are determined and their distributions and correlations are studied. Some important relationships between different parameters of grains are practically demonstrated by using visualization techniques for the first time. The results of certain distributions and parameter correlations revealed that, the non-random nearest-neighbor grain effects in polycrystalline systems are very important and play a vital role in the evolution of microstructure. By considering the effects of nearest-neighbor grains, the relationship between grain size and grain topology is studied and found an excellent linear relationship between these parameters, which verifies the validity of a recently proposed grain topology–size equation (Luan et al. EPL 99, 28001 (2012)). Whereas, the grain topology–size relationship investigated by neglecting the nearest-neighbor effects is represented by a curve concave downwards. Furthermore, the relationship between grain edge length and grain face number is also investigated by taking into account the nearest-neighbor effects and obtained a good linear relationship; while, these parameters are correlated by a curve slightly convex downwards when the relationship is studied by considering the grains in a mean field.

Diagnosis and Management of Grain-Induced Asthma

Grain-induced asthma is a frequent occupational allergic disease mainly caused by inhalation of cereal flour or powder. The main professions affected are bakers, confectioners, pastry factory workers, millers, farmers, and cereal handlers. This disorder is usually due to an IgE-mediated allergic response to inhalation of cereal flour proteins. The major causative allergens of grain-related asthma are proteins derived from wheat, rye and barley flour, although baking additives, such as fungal α-amylase are also important. This review deals with the current diagnosis and treatment of grain-induced asthma, emphasizing the role of cereal allergens as molecular tools to enhance diagnosis and management of this disorder. Asthma-like symptoms caused by endotoxin exposure among grain workers are beyond the scope of this review. Progress is being made in the characterization of grain and bakery allergens, particularly cereal-derived allergens, as well as in the standardization of allergy tests. Salt-soluble proteins (albumins plus globulins), particularly members of the α-amylase/trypsin inhibitor family, thioredoxins, peroxidase, lipid transfer protein and other soluble enzymes show the strongest IgE reactivities in wheat flour. In addition, prolamins (not extractable by salt solutions) have also been claimed as potential allergens. However, the large variability of IgE-binding patterns of cereal proteins among patients with grain-induced asthma, together with the great differences in the concentrations of potential allergens observed in commercial cereal extracts used for diagnosis, highlight the necessity to standardize and improve the diagnostic tools. Removal from exposure to the offending agents is the cornerstone of the management of grain-induced asthma. The availability of purified allergens should be very helpful for a more refined diagnosis, and new immunomodulatory treatments, including allergen immunotherapy and biological drugs, should aid in the management of patients with this disorder.

CHARACTERIZATION OF VISCOELASTIC PROPERTIES OF INDIVIDUAL RICE GRAIN BY MEASURING MECHANICAL IMPEDANCE

ABSTRACT The viscoelastic properties of individual rice grains were measured by using a novel oscillatory squeezing instrument. Specifically, rice grains at different moisture contents and cooking durations were chosen as the model grain, and their viscoelastic characteristics, namely viscous modulus and elastic modulus, were determined. During the measurement, the grains were squeezed between a rigid bottom plate and a top round element oscillating at random frequencies in the range of 10–30,000 rad/s. The mechanical impedance of the rice samples, defined as the ratio between the force applied to the samples and the oscillation velocity, was obtained and used to calculate viscoelastic parameters. Measurements with the grains having moisture content between 12.8 and 29.1% indicated that both viscous and elastic moduli of the samples decreased significantly with increasing moisture content. The measured mechanical impedances of the samples showed that changes in viscoelastic properties for various cooking periods can be also monitored using the proposed oscillatory squeezing method. PRACTICAL APPLICATIONSIn this study, a method for measuring viscoelastic properties of individual rice grain is presented. The technique is simple and easy to use. It can generate data for both elastic and viscous modulus properties for a single grain. There may be various practical applications for this instrument, such as textural characterization of grains having various chemical compositions and effect of cooking parameters on texture. The presented method can be also used to obtain textural differences between different varieties.