Mathematical modelling and validation of oil migration on a model chocolate system using magnetic resonance imaging (MRI)

Oil migration is a common problem in chocolate confectionery products leading to quality defects, particularly fat bloom. Magnetic resonance imaging (MRI) is among the most novel techniques as being a non-destructive method to monitor and quantify migration. The main objective of this study was to model oil migration of peanut butter over dark chocolate layer system stored at 30°C with the predictions of a Fickian-based mathematical model. For this purpose, signal intensity (SI) values of chocolate layers containing migrated oil through peanut butter were obtained by using MRI over a time frame of 18 days. Although there are similar studies, different chocolate formulations and peanut butter were used in this study. Experimental data were fitted to a Fickian-based mathematical model. Parameters (C0, b) belonging to time varying boundary conditions and diffusion coefficients (D) were estimated using MATLAB program. Dimensionless equilibrium interface concentrations (C0) were found between 0.70 and 3.53 over time. Time constant (b) was obtained as 0.14 day-1. During storage, D values varied from 8.09×10-11 to 5.42×10-10 m2 s-1. Higher D values were obtained at day 1 indicating faster migration rate

New 3-hydroxyflavone derivatives for probing hydrophobic sites in microheterogeneous systems.

International audienc

Development of pH Sensitive Alginate/Gum Tragacanth Based Hydrogels for Oral Insulin Delivery

Insulin entrapped alginate-gum tragacanth (ALG-GT) hydrogels at different ALG replacement ratios (100, 75, 50, 25) were prepared through an ionotropic gelation method, followed by chitosan (CH) polyelectrolyte complexation. A mild gelation process without the use of harsh chemicals was proposed to improve insulin efficiency. Retention of almost the full amount of entrapped insulin in a simulated gastric environment and sustained insulin release in simulated intestinal buffer indicated the pH sensitivity of the gels. Insulin release from hydrogels with different formulations showed significant differences (p < 0.05). Time domain (TD) NMR relaxometry experiments also showed the differences for different formulations, and the presence of CH revealed that ALG-GT gel formulation could be used as an oral insulin carrier at optimum concentrations. The hydrogels formulated from biodegradable, biocompatible, and nontoxic natural polymers were seen as promising devices for potential oral insulin delivery

New 3-hydroxyflavone derivatives for probing hydrophobic sites in microheterogeneous systems

Nine new 3-hydroxyflavone derivatives as fluorescent molecular sensors having two well-separated emission bands were synthesized. These sensors can occupy well-determined locations and orientations in macromolecular ensembles, such as micelles due to their finely-tuned designs. These polarity-sensitive dyes can incorporate into the anhydrous hydrophobic core of aqueous micelles. (C) 2007 Published by Elsevier Ltd

A Cross-cultural exploration of problematic Internet use, pathological personality traits, defense mechanisms, coping strategies, and self-esteem in 14 countries

Objectives: The primary objective of this study was to compare the estimates of Problematic Internet Use (PIU) from 14 countries around the world, considering gender. The second objective was to explore the relationships between PIU and personality-related variables (pathological personality traits, defense mechanisms, coping strategies, and self-esteem). Materials and methods: Our total sample consisted of 7726 participants (30.8% male, n = 2378), aged between 18 and 86 years old (M = 25.55; SD = 9.8). Recruited online, they completed several scales about their Internet use, defense mechanisms and coping strategies, self-esteem, and pathological personality traits. Results: The PIU accounted for between 20.5% and 75% of participants using the PIUQ-9, while “self-perception” of PIU with a single item revealed estimates from 2% to 60.1%, with gender differences. Systematically, PIU significantly correlated with two variables: borderline personality traits (from .09 at P &lt; .05 to .42 at P &lt; .01) and immature defense mechanisms (from .13 to .42 at P &lt; .01). Dependent, avoidant, narcissistic, histrionic, and antisocial personality traits were positive predictors of PIU and self-esteem, paranoid and schizoid personalities were negative predictors. Conclusions: This research highlights the many cross-cultural differences. Its design also allows for a better understanding of gender differences