Journal of Cereal Science最新文献

Based on sensory evaluation and texture characteristics, the improving effect of soaking temperature adjustment in an electric cooker on the palatability of cooked aged indica rice was investigated. The water content and distribution, starch gelatinization, and crystal structure of aged rice grains were analyzed at different soaking temperatures. The results demonstrated that soaking aged indica rice at low temperatures (25 °C and 40 °C) and high temperature (70 °C) increased hardness and reduced viscoelasticity, which were not conducive to achieving desirable sensory qualities. Conversely, soaking treatment at 50 °C positively impacts the palatability of aged indica rice. This treatment increased the proportion of structural water in aged rice grains to 6.38% and reduced starch crystallinity to 22.61%, thereby facilitating starch gelatinization and promoting the formation of desirable taste during subsequent cooking stages. Microstructural analysis revealed that soaked aged indica rice exhibited increased water absorption rates and more uniform distribution of moisture. These findings provided valuable insights for optimizing the cooking process of aged indica rice using the electric cooker.

Bread is a food of high consumption worldwide the thermal processing causes the formation of Maillard Reaction Products (MRP). Despite the beneficial sensorial impact, MRP are implicated in harmful effects on human health. This study aimed to review data on critical preparation factors and their influence on specific MRP contents in different types of bread and identify ways to mitigate the formation of these compounds in breadmaking. Acrylamide (AA) and hydroxymethylfurfural (HMF) stood out with the highest frequency of quantification in bread. In thermal processing, the highest AA contents are related to the increase in temperature depending on the exposure time; the highest HMF contents are exclusively related to the increase in temperature (regardless of time); and FUR levels decrease depending on temperature intensity and longer exposure time. A temperature of up to 220 °C tends to form less MRP for up to 60 min of roasting. The evolution of MRP in bread is affected by the weight of the baked dough; type, composition, and refinement of flour; type of yeast/leaven; modified atmosphere equipment and technologies during baking, and essentially, thermal exposure (time x temperature). These factors can contribute to good manufacturing practice criteria for mitigating MRP in bread.

In view of the advantage of heat-moisture treatment (HMT) in modifying the properties of starchy materials, the purpose of this study was to explore the effects of directly applying HMT during the drying process on the properties of dried rice noodles. As attained to prescribed moisture content (20%–35%), the rice noodles were subjected to HMT at 110 °C for 2 h. By HMT, the dried rice noodles exhibited greater structural orderliness and thermal resistance. The relative crystallinity increased from 8.73% to 11.50% and the short-range order (the absorbance ratio of 1047 cm⁻¹/1022 cm⁻¹) increased from 0.57 to 0.72. On the contrary, the lamellar thickness, the radius of gyration, and the mass fractal dimension and pasting viscosities were lowered. Then, HMT induced dried rice noodles with restricted starch leaching during rehydration and reduced cooking loss. HMT increased microstructure homogeneity and texture properties of the cooked rice noodles. Notably, the heat-moisture treated rice noodles at 20% moisture content showed a significant higher cooking yield, about threefold of extensibility, and 1.68 folds of chewiness than the control. Our findings, if generally applicable to the processing of rice noodles, could offer a streamlined approach to increasing the quality of dried rice noodles.

Gluten quality is an important characteristic of wheat. Gluten is a viscoelastic protein network that is formed after hydrating and mixing wheat flour. This protein network is mainly composed of glutenins (High and Low Molecular Weight Glutenins (HMW-GS and LMW-GS, respectively)) and gliadins. HMW-GS are codified by the loci GLU-A1, GLU-B1 and GLU-D1 in common wheat. For the GLU-A1 locus, many alleles have been described and collected in the Wheat Gene Catalogue (WGC). Many of those alleles have not been compared in conjunction and it is not possible to know if the current GLU-A1 variability described is real or it is overestimated. This study has focused on collecting all the germplasm associated with GLU-A1 variability, to verify the GLU-A1 allele of each accession and if the current variability described in the WGC is real. It was possible to collect and compare by SDS-PAGE most of the germplasm described in the WGC. The identity of many alleles was confirmed while there are other cases that should be reviewed in more detail. This study contributes to the correct classification of the GLU-A1 diversity and will promote the use of different alleles in future breeding programs aiming to improve gluten quality.

Different salts were added to gluten to investigate the effects of different cations on a fully developed gluten network. The chloride salts KCl, NaCl, MgCl₂, CaCl₂ were mixed with pre-isolated wet gluten in a low and high dose, and the gluten was dried at 40 °C and 80 °C to yield vital gluten. The impact of the individual cations on the gluten protein composition and functionality was determined by analysis of chemical and rheological properties of vital and wet gluten. All cations influenced the gluten protein composition and the rheological behaviour. While the observed changes could not be attributed to the order of the Hofmeister series, monovalent, kosmotropic cations K⁺ and Na⁺ and divalent, chaotropic cations Mg²⁺ and Ca²⁺ showed similar behaviour in terms of protein composition and functional properties. Salts therefore have an influence on the gluten protein composition of a fully developed gluten network and gluten protein composition and functionality can be altered by an after-treatment process in a targeted way.

In this research, changes in microbial shelf-life and quality characteristics of fresh wet noodles (FWNs) were analyzed under acid and different mild heat treatment conditions. Acid combined with heat treatment at 50 °C for 30 min extended the shelf-life of FWNs by 30–40 d and effectively delayed the color deterioration of FWNs. The water absorption of FWNs was reduced by the mild heat treatment. Meanwhile, the cooking loss of the noodles and hardness significantly (p < 0.05) increased. Differential scanning calorimetry (DSC) analysis showed that the gelatinization enthalpy of the starch in FWNs decreased and the gelatinization temperature increased. The X-ray diffraction (XRD) results showed that the crystallinity of the starch decreased from 27.51% to 24.2% after mild heat treatment. In addition, it was observed by confocal laser scanning microscope that the mild heat treatment made the gluten networks more continuous. The free sulfhydryl content of noodles showed a decreasing trend, while the sodium dodecyl sulfate-extractable protein (SDS-EP) value was also significantly (p < 0.05) reduced. Overall, the combination of mild heat treatment with acid extended the shelf-life of FWNs and had less impact on their quality.

In this study, the use of an electrostatic field on a Teflon surface to separate free bran from bulgur during processing was investigated. The results suggest that this method could be an effective solution to the problem of free bran, which can negatively impact the appearance and quality of bulgur in bulgur processing and packaged products. Unlike traditional methods, a novel technology was used with the device having flat and folded Teflon surfaces (flat and folded inclined channels). The device was designed with the widths of 4, 5 and 6 cm, the lengths of 20, 40 and 60 cm and the angles of 30, 35 and 40°. The flat Teflon system produced the best results overall. In addition, the design parameters of 4 and 5 cm width, 20 and 40 cm length, and 35 and 40° inclination were suitable for separating bran from bulgur using an electrostatic system. As a result, a fine bulgur mixture containing 5 g of bran per 1000 g of bulgur was passed through the system at a flow rate of 0.89 g/s, resulting in a reduction of bran in bulgur from 5 to around 2 g (around 60% reduction).

Rice cultivation in Karst regions shows significant variations in both yield and quality due to temperature and light. Herein, 241 varieties including 198 indica rice and 43 japonica rice were planted in three ecological regions to investigate responses of rice qualities to meteorological factors. Results showed that in regions with higher average temperature (25.43 °C) and less daily sunshine hour (2.53 h/day), the appearance qualities (chalkiness degree, chalkiness rate and size) and processing qualities (brown rice percentage, head rice and milled rice percentages) were significantly reduced (p < 0.05). A total of 723 samples in three ecological environments were grouped into 4 clusters, arranged in descending order of cluster scores. In high-scoring cluster, the processing quality, appearance quality, protein content, hot paste viscosity, consistence viscosity, and setback viscosity were negatively correlated with temperatures (average temperature, temperature difference, effective accumulated temperature, maximum and minimum temperatures) from heading to mature stages, but positively correlated with sunshine hours. Apparent amylose contents were negatively correlated with temperatures but not significantly correlated with sunshine hours. In low-scoring cluster, only the processing quality had significant correlations with meteorological factors. These findings revealed the interaction between temperature and light for the formation of rice quality.

In this study, a total of 33 key differential metabolites related to phenolic synthesis were obtained in the fresh-eating and maturity stages by LC-MS analysis using UNIFY with a self-constructed database. Based on KEGG pathway analysis, three pathways related to phenolic metabolite synthesis were identified. The differential genes selected from the transcriptome and the differential metabolites selected from the target metabolism were correlated in the analysis, revealing the existence of 7 enzymes involved in the synthesis of phenolic compounds in secondary metabolism. Among which the fresh-eating stage promotes phenolics synthesis by up-regulation of the activities of the two enzymes, CCoAOMT and 4CL, and the enzymes, DFR, C3H, DFR, CHI, REF1 and F3H were expressed at higher levels during the maturity stage than fresh-eating stage, thus improving the tolerance and stress resistance of the plant itself and its ability to respond to the external environment, which has an important impact on the regulation of phenolic accumulation.

This study investigated the role of water in the high-pressure treatment (300–600 MPa/15 min) of buckwheat (Fagopyrum esculentum) flour and property changes in post-process samples. DSC and XRD measurements demonstrated complete gelatinization of buckwheat starch occurred at 600 MPa. The particle size of flour decreased above 450 MPa. HP-treatment successfully transformed the crystalline A-type structure of hydrated samples into a B-type structure. Dry samples did not gelatinize or exhibit any structural change, even at 600 MPa. The progress of gelatinization and gel rigidity of post-process samples were measured on a rheometer. The thermal transition captured in rheometer and DSC differs significantly. The impact of further heating on the pressurized samples resulted in a significant improvement in their mechanical rigidity. Overall, this study confirmed that an optimum flour-to-water ratio should be maintained during HP treatment to achieve the desired changes in buckwheat flour so that it could be used in food formulation.