Instant polysaccharide-based emulsions: impact of microstructure on lipolysis

The development of emulsion-based products through optimisation of ingredients, reduction in energy-input during manufacture, while fulfilling healthy attributes, are major objectives within the food industry. Instant emulsions can meet these features, but comprehensive studies are necessary to investigate the effect of the initial formulation on the final microstructure and, in turn, on the in vitro lipolysis, comprising the double aim of this work. The instant emulsion is formed within 1.5–3 min after pouring the aqueous phase into the oil phase which contains a mixture of emulsifier (Tween 20), swelling particles (Sephadex) and thickeners (hydroxypropylmethylcellulose, HPMC, and guar gum, GG) under mild shearing (180 rpm). The creation of oil-in-water emulsions is monitored in situ by viscosity analysis, the final microstructure visualised by microscopy and the release of free fatty acids under simulated intestinal conditions quantified by titration. Increasing the concentration and molecular weight (Mw) of GG leads to smaller emulsion droplets due to increased bulk viscosity upon shearing. This droplet size reduction is magnified when increasing the Mw of HPMC or swelling capacity of viscosifying particles. In addition, in the absence of the emulsifier Tween 20, the sole use of high-Mw HPMC is effective in emulsification due to combined increased bulk viscosity and interfacial activity. Hence, optimisation of the ingredient choice and usage level is possible when designing microstructures. Finally, emulsions with larger droplet size (>20 μm) display a slower rate and lower extent of lipolysis, while finer emulsions (droplet size ≤20 μm) exhibit maximum rate and extent profiles. This correlates with the extent of emulsion destabilisation observed under intestinal conditions

Characterization of polysaccharide -surfactant interaction

The hypocholesterolemic effect of certain polysaccharides has been attributed to their ability to bind bile acids. The purpose of this study was to better understand bile acid - polysaccharide interactions by systematically characterizing the interactions between selected polysaccharides (chitosan and pectin) and anionic surfactants (sodium dodecyl sulfate (SDS) and sodium taurocholic acid (NaTCA)) using isothermal titration calorimetry (ITC), surfactant selective electrode (SSE) and turbidity measurements. Initially, the influence of environmental conditions (pH, ionic strength and temperature) on the properties of SDS and NaTCA in buffer solutions was characterized. The CMC\u27s (critical micelle concentrations) were largely independent of temperature and pH, but decreased appreciably as the ionic strength increased. In general, the micellization behavior of NaTCA was different from that of SDS because of their different molecular structures. The influence of environmental conditions on the interactions between SDS and NaTCA with pectin and chitosan were then studied. SDS bound strongly to chitosan and formed insoluble complexes, which was attributed to electrostatic attraction. For SDS-chitosan interactions, temperature did not have a large affect on T1 (onset binding), T2 (surfactant concentration at polymer saturation) or CMC* (effective CMC in the presence of polymer). Strong binding only occurred at pH values where the chitosan was cationic (pH 3 and 5), but not when it was uncharged (pH 7). Salt (0 to 200 mM) decreased the CMC* because of the depression of the CMC of free SDS in solution. SDS bound weakly to pectin and formed soluble complexes, which was attributed to hydrophobic interactions. The general characteristics of NaTCA-chitosan interactions were fairly similar to those of SDS-chitosan interactions. The binding interaction was exothermic at all temperatures studied (10 to 50°C), suggesting that it was electrostatic in origin. The T1, T2 and CMC* values were influenced by salt and pH as described for SDS. In addition, only a weak binding interaction was observed between pectin and NaTCA. This study provides information that may lead to the rational design of polysaccharide-based food ingredients with beneficial nutritional and functional characteristics

การเขียนจำนวนเต็มในรูป x^2+ky^2-lz^2

Master of Science (Mathematics), 2022For positive integers k and l, we call l a k-special if every integer can be represented in the form x^2+ky^2-lz^2 where x, y, and z are non-zero integers. In this thesis, we find the necessary and sufficient conditions for 1-special and find the conditions for an odd positive integer l to be k-special.สำหรับจำนวนเต็มบวก k และ l เราจะเรียก l ว่า k-special ถ้าทุกจำนวนเต็ม n สามารถเขียนในรูป x^2+ky^2-lz^2 โดยที่ x, y และ z เป็นจำนวนเต็มที่ไม่เป็นศูนย์ ในการศึกษาครั้งนี้เราจะหาเงื่อนไขจำเป็นและเงื่อนไขเพียงพอสำหรับ 1-special และหาเงื่อนไขของจำนวนเต็มบวกคี่ l ที่จะเป็น k-special และ 2k-specia

Isothermal Titration Calorimetry Study of the Interactions Between Chitosan and a Bile Salt (Sodium Taurocholate)

The binding of bile acids to dietary fibers in the small intestine has been proposed as a mechanism for the reduction of blood cholesterol levels. In this study, isothermal titration calorimetry (ITC) was used to characterize the binding of sodium taurocholate (NaTC) to a cationic biopolymer (chitosan). The influence of ionic strength (0–150 mM NaCl) and temperature (10–40 °C) on the binding interactions was examined (pH 3, acetate buffer). At 30 °C, NaTC bound strongly to chitosan to form an insoluble complex that contained about 4×10−3 mol of NaTC per 1 g of chitosan at saturation. The presence of salt (0–150 mM NaCl, pH 3) decreased the critical micelle concentration (CMC) of NaTC (in both the absence and presence of chitosan), increased the minimum NaTC concentration required for binding to be observed, but had little influence on the amount of NaTC bound to chitosan at saturation. The enthalpy changes associated with micelle dissociation went from exothermic at low-holding temperatures (10 °C) to endothermic at higher holding temperatures (40 °C). Conversely, the enthalpy changes associated with NaTC–chitosan binding went from endothermic at low-holding temperatures (10 °C) to exothermic at higher holding temperatures (40 °C). The temperature dependence of these processes indicated the importance of changes in hydrophobic interactions within the systems. This study provides information that may lead to the rational design of chitosan-based ingredients or products with improved cholesterol lowering ability

Effects of White Sorghum Flour Levels on Physicochemical and Sensory Characteristics of Gluten-Free Bread

This research studied the effects of white sorghum flour levels at 0, 10, 25, 40, 70, 85 and 100% in the matrix of rice and tapioca flours and corn starch on the properties of flour blends and the qualities of gluten-free (GF) bread. Single and composite flours were analyzed for moisture content, color and pasting properties. GF bread samples prepared from composite flours were analyzed for specific volume, moisture content, water activity, crumb color and instrumental texture. Sensory profiles of the breads were determined by nine trained descriptive panelists. The results show that increasing the sorghum flour content increased (p ≤ 0.05) color intensity, pasting temperature and setback viscosity, while it decreased (p ≤ 0.05) the peak and breakdown viscosities of flour blends. For GF bread, increasing white sorghum flour levels in the blends primarily affected specific volume, color, flavor and texture characteristics, leading to decreases (p ≤ 0.05) in specific volume, cohesiveness, springiness, chewiness and moistness, but increases (p ≤ 0.05) in color intensity, brown and nutty flavors, graininess and roughness. White sorghum flour could be used in the blends at the maximum level of 25% to get a good bread volume without sacrificing texture quality

Influence of pH, Ionic Strength, and Temperature on Self-Association and Interactions of Sodium Dodecyl Sulfate in the Absence and Presence of Chitosan

Chitosan is a cationic biopolymer that has many potential applications in the food industry because of its unique nutritional and physicochemical properties. Many of these properties depend on its ability to interact with anionic surface-active molecules, such as surfactants, phospholipids, and bile acids. The purpose of this study was to examine the influence of pH (3 and 7), ionic strength (0 - 200 mM NaCl), and temperature (10 - 50 °C) on the interactions between a model anionic surfactant (sodium dodecyl sulfate, SDS) and chitosan using isothermal titration calorimetry, selective surfactant electrode, and turbidity measurements. At pH 3 and 30 °C, SDS bound strongly to chitosan to form an insoluble complex that contained about 4 - 5 mmol of SDS/1 g of chitosan at saturation. When SDS and chitosan were mixed at pH 7 they did not interact strongly, presumably because the biopolymer had lost most of its positive charge at this pH. However, when SDS and chitosan were mixed at pH 3 and then the solution was adjusted to pH 7, the SDS remained bound to the chitosan. The presence of NaCl (0 - 200 mM) in the solutions decreased the critical micelle concentration (cmc) of SDS (in both the absence and the presence of chitosan) but had little influence on the amount of SDS bound to chitosan at saturation. The cmc of SDS and the amount of SDS bound to the chitosan at saturation were largely independent of the holding temperature (10 - 40 °C). Nevertheless, the enthalpy changes associated with micelle dissociation were highly temperature- dependent, indicating the importance of hydrophobic interactions, whereas the enthalpy changes associated with SDS - chitosan binding were almost temperature-independent, indicating the dominant contribution of electrostatic interactions. This study provides information that may lead to the rational design of chitosan- based ingredients or products with specific nutritional and functional characteristics, for example, cholesterol lowering

Ultrasound-assisted formation of chitosan-glucose Maillard reaction products to fabricate nanoparticles with enhanced antioxidant activity

10.1016/j.ultsonch.2023.106466Ultrasonics Sonochemistry97106466

RNA sequencing data of Notch ligand treated human dental pulp cells

Indirect immobilized ligand has been shown as an effective technique to activate Notch signalling in vitro. The data presented in this article are related to the published article entitled “Indirect immobilized Jagged1 suppresses cell cycle progression and induces odonto/osteogenic differentiation in human dental pulp cells” (Manokawinchoke et al. 2017) [1]. This data article describes gene expression in indirect immobilized Jagged1 treated human dental pulp cells (hDPs) using high throughput RNA sequencing technique. These data are valuable to analyze the regulation of Notch signalling in hDPs for understanding its molecular mechanism(s). Raw RNA sequencing data were deposited in the NCBI Sequence Read Archive (SRP100068) and NCBI Gene Expression Omnibus (GSE94989)