Wäetamisest ja wäetusainetest Eestis

Digiteeritud Euroopa Regionaalarengu Fondi rahastusel, projekti "Eesti teadus- ja õppekirjandus" (2014-2020.12.03.21-0848) raames.https://www.ester.ee/record=b1324736*es

A comprehensive investigation of gluten free bread dough rheology, proving and baking performance and bread qualities by response surface design and principal component analysis

Contribution of methylcellulose (MC), psyllium seed husk powder (PSY), and water addition level to gluten free bread quality and correlations between dough rheological properties and bread qualities were investigated by response surface design and principal component analysis. The generalised Maxwell model was applied to estimate the relaxation frequency of gluten free doughs. The addition of PSY has a complex influence on pasting viscosity at high temperature and an additional peak was observed. MC significantly influenced dough extensibility and work of adhesion, which are good predictors of bread volume and textural properties. Other rheological responses are less significantly correlated to specific volume, but they are sensitive to formulation variations, reflect dough structures and stability, related to proving behaviours, and correlated to loaf concavity. An inappropriate combination of water and hydrocolloids might lead to problems such as low stability of doughs, overexpansion, and weak crumb structure at high water addition levels, or, in contrast, high rigidity of dough, a trap of excessive air during mixing, and restrained gas cell expansion with high hydrocolloid addition and low water addition

The development of an objective measure of achievement in swimming at the advanced level for college women

The study was conducted for the purpose of developing an objective measure of achievement in swimming at the advanced level for college women. A secondary purpose was to establish tentative norms. The subjects were volunteers from the undergraduate classes at the University of North Carolina at Greensboro. All subjects participating in the study were enrolled in or had been members of one of the following groups at the University: (1) advanced swimming class; (2) water safety instructor's course; or (3) physical education major's course. Ten students enrolled in an advanced swimming class served as subjects in a pilot study group. Thirty-seven students participated as subjects in a regular testing program

Cellulose fibrillation and interaction with psyllium seed husk heteroxylan

© 2020 Elsevier Ltd Fibrillated cellulose (FC) and its mixture with psyllium seed husk powder (PSY) were investigated to broaden the applications of these two materials by a novel combination. Purified cellulose was processed by a colloid mill and relatively stable suspensions were obtained. An FC suspension shows localised concentrations appearing as flocculates, which can be promoted by heating or centrifugation. The structures of unheated mixtures of FC and PSY appear to be binary phase dispersions while, after heat treatment, FC fibres were incorporated into PSY gels and form composites. Fibrillation on the FC surface does not influence the structure and rheological property of the composite mixtures while fibre disintegration contributes to a denser structure and higher moduli. Fluorescent images show the attachment of PSY heteroxylan aggregates on cellulose and fibrillated cellulose fibres. The interaction is weak and time-dependent because G’ during cooling was higher than that during heating, and declined back to the same value as the start of heating during an isothermal test at 20 °C. PSY was fractionated according to temperature and only F60 (fraction at 60 °C) clearly associates with the unfibrillated cellulose fibres, possibly via long arabinan sidechains (similar to hairy pectin) or/and backbone (via interaction with helical domains or/and conformational compatibility). The interaction was promoted by fibrillation, potentially trapping PSY heteroxylan aggregates within the cellulose dispersion. With further fibrillation, smaller FC fibres were generated and form interpenetrating particles with whole PSY or PSY fractions. Highly fibrillated cellulose has a higher surface area and smaller fibrils, which significantly increased the interaction resulting in a clumped structure

Starch replacement in gluten free bread by cellulose and fibrillated cellulose

© 2020 Elsevier Ltd This study investigated starch reduction and replacement by purified cellulose (FC0) and fibrillated cellulose (FC60) which included a comprehensive investigation on dough properties, proofing behaviours, cooking performance, and bread qualities. Replacing flour with FC0 and FC60 was found to strength the doughs without, however, altering the extension of the structural network according to the weak gel model. The relaxation time calculated by the generalised Maxwell model was found to be shorter than the deformation rate during proofing which suggests that the doughs behave like fluids during proofing. The relaxation time was less influenced by the additions of FC0 and FC60. Although the initial stage of proofing was less influenced, the later stage was significantly affected by the additions of FC0 and FC60 which increased dough rigidity and restrained the volume growth. The pasting properties were significantly influenced by the competition for water and volume between FC0/FC60 and flour. The bread qualities were characterised in terms of loaf volume and crumb properties. Loaves containing FC0 and FC60 had smaller specific volume and harder crumb. However, the addition of FC0 and FC60 is beneficial to the generation of a finer crumb structure. Fibrillation process is detrimental to maximise the addition of fibres. However, a small amount of fibrillated cellulose is beneficial to workability and crumb structure

Lack of a Hyperkalemic Response in Emergency Department Patients Receiving Succinylcholine

Objective: To determine whether serum potassium (K) levels increase significantly following succinylcholine (SCh)-assisted intubation in ED patients. Methods: A prospective. noncontrolled, consecutive case series design was used to evaluate the change in serum K levels in ED patients who received SCh for emergency intubation. The study was performed at an academic medical center staffed by board-certified emergency physicians. The subjects were 100 consecutive prescreened ED patients with various diagnoses who received SCh for intubation. The eligible subjects had serum K levels determined prior to and 5 minutes after administration of a 1.0–1.5-mg/kg IV dose of SCh. Serum K levels were measured by the ionselective electrode assay method. Results: The mean change in serum K levels was -0.04 mmol/L (95% CI -0.14 to 0.06). The maximum increase was 1.10 mmol/L. The serum K level rose in 46 cases, decreased in 46 cases, and was unchanged in eight cases. No instance of SCh-induced cardiac arrest was identified. Conclusion: Changes in serum K levels following SCh administration in prescreened ED patients were minimal. A hyperkalemic response is uncommon in ED patients who undergo SCh-assisted intubation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75073/1/j.1553-2712.1995.tb03124.x.pd

Development of a separated-dough method and flour/starch replacement in gluten free crackers by cellulose and fibrillated cellulose

Two strategies were combined and applied in this study to achieve a desired structure and texture of gluten free crackers and to reduce the calorie content. The first strategy is increasing structural heterogeneity of crackers and doughs and a separated-dough method was developed. A butter dough and a water dough were prepared separately and mixed together and the influence of mixing time was investigated. In the second strategy, which is the incorporation of a structuring material, powdered cellulose and fibrillated cellulose were incorporated in formulation to replace flour and pregelatinised starch with enhanced health benefits of low calorie and high fibre. Powdered cellulose played the role of the skeleton of the gluten free crackers. A laminar structure was observed in crackers when powdered cellulose was initially added to the butter dough. The crackers exhibit high thickness, hardness and fracturability and sharp sound emission which are typically observed in wheat crackers. Pregelatinised starch can be replaced by fibrillated cellulose at a lower addition level

Individual differences in oral tactile sensitivity and gustatory fatty acid sensitivity and their relationship with fungiform papillae density, mouth behaviour and texture perception of a food model varying in fat

Fat provides multimodal stimulation, particularly through mouthfeel and as a taste stimulant via free fatty acids. Individuals vary in perception of both mouthfeel and taste sensations from fat. Papillae number on the tongue can influence oral tactile and taste sensitivity. In addition, mouth behaviour (how foods are manipulated in the mouth during eating before swallowing) varies between individuals, and may influence mouthfeel perception. Limited research has explored the relationships between these factors. Fatty acid (FA) taste sensitivity was measured at two levels of oleic acid. Oral tactile sensitivity was measured using von Frey filaments. Fungiform papillae density (FPD) was measured on the tongue anterior. Mouth behaviour (MB) was measured by Graphic Jeltema/Beckley Mouth Behaviour (JBMB) classification tool. Mouthfeel perception (hardness, crunchiness, and greasiness) in a biscuit model was measured to examine the influence of FPD, tactile sensitivity and MB on mouthfeel perception. Higher FPD was significantly related to higher taste sensitivity to fatty acid and to higher oral tactile sensitivity. FPD and oral tactile sensitivity both significantly influenced mouthfeel perception of biscuits. The results demonstrate the need to characterise individual differences in oral sensory perception by more than one method, and suggest oral tactile sensitivity can be used as a marker of FPD. Further studies are required to understand the impact of MB on sensory perception. The BMI of participants in this study was negatively related to oral tactile sensitivity and the perception of greasiness

Temperature fractionation, physicochemical and rheological analysis of psyllium seed husk heteroxylan

© 2020 Elsevier Ltd Psyllium husk is a source of natural dietary fibre with marked water absorbability and gelling properties, which makes it an attractive functional ingredient for applications in the food industry, such as gluten free bread and breakfast cereals. The main functional component of psyllium husk is a complex branched heteroxylan. In this study, a straightforward sequential fractionation of hydrated psyllium seed husk powder based on temperature-dependent behaviours was applied. The F20 (20 °C fraction) showed the highest yield followed by F60 while 13.5% of the husk is unextractable (residue). The obtained fractions showed unique rheological properties as analysed using small amplitude oscillatory shear rheometry and the time-temperature superposition (TTS) technique. The results indicate that: 1) only F20 was influenced by heat treatment, 2) high temperature fractions showed stronger gel properties, 3) a three-step softening/melting was observed, 4) F60 has longest relaxation time as shown in TTS master curves. The four fractions were also characterised using the monosaccharide analysis, FTIR and 13C NMR. The arabinose/xylose ratio was found to increase with the increase in fractionation temperature. FTIR and 13C NMR spectra supported that low temperature fraction is less branched. Two hypotheses were therefore proposed: The first one based on models by Haque, Richardson, Morris, and Dea (1993) and Yu et al. (2019) focusing on chemical and structural properties of the molecules. The second hypothesis highlights differences in hierarchical molecular conformations of polysaccharides which is proposed by Diener et al. (2019). Sidechain substitution and composition and length of sidechains are critical and significantly influence the properties of each fraction

Effects of processing conditions on the release of sodium chloride from fat crystal ‘shell’ stabilised water-in-oil emulsions

Over the last two decades, water-in-oil fat crystal stabilised Pickering emulsions have been increasingly studied for the controllable release of encapsulated (water-soluble) species. The stability inherent to Pickering emulsions has been shown to be enhanced by sintering to form an interfacial lipid 'shell' around the droplets, which improves the retention and prolongs the delivery of the enclosed species. Using a scraped surface heat exchanger/pin stirrer setup, the present work shows that processing conditions used to produced W/O emulsions with dispersed droplets enclosed in lipid shells, have a significant impact upon the subsequent release of NaCl enclosed within them. The best performing emulsion structure produced here is reported to retain about 98% of its initial salt load over a period of 100 days. NaCl release profiles were also used to calculate the interfacial rate constants for the transferal of salt across the lipid shells. Interfacial rate constants ranged from 5.5 to 3593.2×10−3 nm2/s and were significantly (up to three orders of magnitude) lower than those reported in literature for similar systems. Analysis revealed that depending on the specific conditions employed, the processing environment can enhance or compromise lipid shell integrity. Overall, the current study offers significant direction in terms of the optimum processing requirements that are necessary to produce fat-continuous emulsion microstructures that can successfully regulate the release of NaCl, paving the way for the successful development of food formulations of controlled salt-perception