Presence Of Crust Research Articles

Optical and portable equipment for characterizing soil roughness

Knowledge of surface roughness with the consequent presence of crust in the soil is important information for the rational management of environmental resources. Soil surface roughness can be determined by contact and noncontact methods. Contact methods have lower values and precision than noncontact methods. Therefore, the objective of this study was to develop low-cost, portable and robust optical equipment to characterize the roughness and presence of crust in the soil through an illumination system with a line laser and monocular vision. The mean roughness was calculated by the difference in height between a point and its neighbours and the presence of crust was determined by a semivariogram. The developed equipment was used in different experimental areas: an eroded area and a compost barn. For the validation of the results, the surface roughness of the same areas analysed by the equipment was also analysed by existing techniques: for the area with erosion, a noncontact technique, i.e., structure from motion (SfM), and for the compost barn, a contact technique, i.e., a pin meter. From the results, it was found that the optical equipment developed to characterize the soil surface roughness and the presence of crust in the soil proved to be valid and provided reliable results.

Visualization of Crust in Metallic Piping Through Real-Time Neutron Radiography Obtained with Low Intensity Thermal Neutron Flux

Abstract The presence of crust on the inner walls of metallic ducts impairs transportation because crust completely or partially hinders the passage of fluid to the processing unit and causes damage to equipment connected to the production line. Its localization is crucial. With the development of the electronic imaging system installed at the Argonauta/Nuclear Engineering Institute (IEN)/National Nuclear Energy Commission (CNEN) reactor, it became possible to visualize crust in the interior of metallic piping of small diameter using real-time neutron radiography images obtained with a low neutron flux. The obtained images showed the resistance offered by crust on the passage of water inside the pipe. No discrepancy of the flow profile at the bottom of the pipe, before the crust region, was registered. However, after the passage of liquid through the pipe, images of the disturbances of the flow were clear and discrepancies in the flow profile were steep. This shows that this technique added the assembled apparatus was efficient for the visualization of the crust and of the two-phase flows.

Fecal excretion of Maillard reaction products and the gut microbiota composition of rats fed with bread crust or bread crumb.

A comparison between the impacts of advanced (Nε-carboxymethyllysine - CML) and terminal (melanoidins) Maillard reaction products from bread on gut microbiota was carried out in this study. Gut microbiota composition as well as fecal excretion of CML from both bread crust and bread crumb, and of melanoidins from bread crust were assessed on a rodent model. Rats were fed with pellets supplemented or not with 13% of bread crust, bread crumb, a fiber-free bread crust model (glucose, starch and gluten heated together) or a fiber-free-melanoidin-free bread model (glucose-starch and gluten heated separately) for four weeks. These model systems were developed to limit the presence of wheat-native dietary fibers such as cellulose, hemicelluloses and lignin. CML and melanoidins in pellets and feces were evaluated by LC/MS-MS and HPLC/fluorescence respectively, and gut microbiota composition was determined by cultivation and molecular approaches. Diets supplemented with crumb or the fiber-free-melanoidin-free model contained respectively 17% and 64% less melanoidins than their respective controls. A higher excretion of melanoidins was observed for rats fed with crust or bread crust model compared to their controls, confirming that melanoidins are in contact with gut microbiota. No impact of diets was observed on Firmicutes, Bacteroidetes and lactic flora. A decrease of enterobacteria was only observed for rats fed with the diet supplemented with the fiber-free bread crust model. Moreover, a significant increase of bifidobacteria numbers in the presence of crust, crumb and both bread models was observed, showing that this bifidogenic effect of bread is not due to the presence of melanoidins or wheat-native dietary fibers.

Respective impact of bread structure and oral processing on dynamic texture perceptions through statistical multiblock analysis

Texture perception is a multidimensional and dynamic phenomenon resulting from both the initial structure of food and its breakdown during oral processing. The aim of this study is to identify the respective contribution of food and bolus properties to temporal changes in texture perceptions during bread consumption. For this purpose, the perception dynamics of three French baguettes with dif\\ferent structures were assessed through Temporal Dominance of Sensations and Progressive Profiling. Samples of crumb with and without crust were tasted by trained panelists. The intensities of nine texture attributes were evaluated at three key stages of oral processing (10%, 40% and 100% of individual swallowing time) using the Progressive Profiling method. Six of them were related with a Multiblock Partial Least Squares (MB-PLS) regression to the initial bread properties and to some bolus properties measured at these three stages. The evolution during oral processing of some attributes such as “soft”, “dry”, “doughy” and “sticky” was more influenced by modifications of bolus properties than by the initial characteristics of the breads. Among bolus properties, the MB-PLS highlighted that the hydration and texture properties of the bolus had a greater impact on texture perceptions than bolus structure. The “aerated” perception was more affected by the crumb structure, while the “heterogeneousness” and the “crispiness” were more affected by the presence of crust. This study thus contributes to improving our understanding of dynamic texture perceptions through a statistical model that takes the physical properties of bread and bolus during oral processing into account.

Determination of the sensory attributes of a Spanish dry-cured sausage

A lexicon for describing the sensory attributes of a Spanish dry-cured sausage (salchichón) was developed in order to characterise this product. A highly trained, descriptive sensory panel generated, defined, selected and referenced the main sensory characteristic of commercial salchichón elaborated from meat of white pig. This language was not only descriptive but also discriminative. Panellists initially produced a vocabulary of 108 terms that were later modified to 15 attributes: four for appearance (luminance, presence of crust, fat/lean connection and exudate); four for odour (black pepper, lactic acid, mould and other spices); two for texture (hardness and initial juiciness) and five for flavour (black pepper aroma, mould aroma, other spices aroma, acid taste and salty taste). The Kruskal–Wallis test showed that all attributes were significantly different between samples ( p < 0.001). Three different groups of Salchichones were separated by principal component analyses: group I was characterised by strong other spices smell and aroma and higher juiciness than the other groups. Salchichones from group II had a high mould smell and aroma, a notable fat/lean connection and exhibited a great amount of exudate. Salchichones from group III were characterised by an acid and salty taste.