Koen Dewettinck

Linking leadership empowerment behavior to employee attitudes and behavioral intentions: testing the mediating role of psychological empowerment

To improve their overall flexibility and efficiency, many organisations have replaced traditional hierarchical management structures with empowered (semi-autonomous or self-managing) work teams. Managers, once charged with directing and controlling work, are now asked to take on a new set of roles and responsibilities in order to lead these teams (Lawler, 1992). Arnold and colleagues (2000) identified five categories of empowering leadership behavior and constructed and validated a scale for measuring those behaviors. We build on their work by investigating how these behaviors relate to employee attitudes and behavioral intentions. We do so by developing a model in which psychological empowerment (Spreitzer, 1995, 1996; Thomas & Velthouse, 1990) mediates the relationship between empowering leadership behavior and employee job satisfaction and affective organizational commitment. We also modeled the relationship between these employee attitudes and intention to stay as a final outcome variable. Based on a sample of 381 service employees from four companies, we empirically tested this model using structural equation modeling in AMOS. Our results show that psychological empowerment is partially mediating the relationship between perceived empowering leadership behavior and employee job satisfaction and affective commitment. This indicates that perceived leadership behavior does relate toe employee attitudes through its impact on employee motivation. However, leadership behavior also shows to be directly related to employee attitudes, which in turn are strongly related to an employees intention to stay working for the organisation. Implications for theory and managerial practice are discussed.

The professional career on the right track: A study on the interaction between career self-management and organizational career management in explaining employee outcomes

This article explores the relationship between organizational career management and career self-management and addresses the impact on employee outcomes. Within six large organizations, a sample of 491 employees reported on their career self-management initiatives, on their expectations towards organizational career support, and on their commitment and career success. This was complemented by information from their supervisors on career management support offered by HR and line management to these employees. Results show that individuals who take more initiatives to manage their career expect more career support from their employer. Career self-management positively impacts affective commitment and perceived career success, while organizational career management is positively related with affective commitment and career progress. Career self-management moderates the relationship of organizational career management with affective commitment and subjective career success.

Edible oil structuring: an overview and recent updates

In recent years, research dealing with edible oil structuring has received considerable interest from scientific community working in the area of food formulation. Much of this interest is linked to the possibility of using structured oil in development of newer product formats with improved nutritional profile (trans fat-free, low in saturated fats and high in mono and/or poly unsaturated fatty acids). In addition to the obvious industrial need of finding the alternative formulation approach, the interesting properties of structured systems (particularly, oleogels) also makes them a fascinating subject for fundamental studies. In this paper, we attempt to give a comprehensive and concise overview of the field of oil structuring with special emphasis on the updates from recent years. Specifically, several categories of food-grade oleogelators and their potential food applications are summarized with typical examples along with a discussion on the general principles and unresolved challenges related to this emerging area.

Preparation and rheological characterization of shellac oleogels and oleogel-based emulsions.

We report the preparation and rheological characterization of oleogels and oleogel-based emulsions prepared using shellac as a structurant. Shellac showed excellent oleogelation properties, resulting in liquid oil gelation at a concentration as low as 2 wt%. Microscopic evaluation of these oleogels indicated that the oil gelation was a result of physical entrapment of liquid oil in crystal networks of shellac formed by cooling the hot oil dispersions of shellac to room temperature. The rheological behaviour of shellac oleogels to varying deformation (% strain) was comparable to oleogels prepared using a commercial crystal starter. The cooling and shear rate showed a significant effects on the rheological properties of formed oleogels. The thermo-reversible, hysteresis, thixotropic and shear thinning properties of oleogels were evaluated by comparing rheological data obtained from rotational and oscillatory measurements. Shellac oleogels were further used as continuous phases to generate emulsifier-free w/o emulsions which surprisingly showed good stability over 4 months of storage. Microscopy and rheological evaluations of these emulsions were carried out to obtain more insight into its microstructures.

Biopolymer-based structuring of liquid oil into soft solids and oleogels using water-continuous emulsions as templates.

Physical trapping of a hydrophobic liquid oil in a matrix of water-soluble biopolymers was achieved using a facile two-step process by first formulating a surfactant-free oil-in-water emulsion stabilized by biopolymers (a protein and a polysaccharide) followed by complete removal of the water phase (by either high- or low-temperature drying of the emulsion) resulting in structured solid systems containing a high concentration of liquid oil (above 97 wt %). The microstructure of these systems was revealed by confocal and cryo-scanning electron microscopy, and the effect of biopolymer concentrations on the consistency of emulsions as well as the dried product was evaluated using a combination of small-amplitude oscillatory shear rheometry and large deformation fracture studies. The oleogel prepared by shearing the dried product showed a high gel strength as well as a certain degree of thixotropic recovery even at high temperatures. Moreover, the reversibility of the process was demonstrated by shearing the dried product in the presence of water to obtain reconstituted emulsions with rheological properties comparable to those of the fresh emulsion.

Effect of washing conditions on the recovery of milk fat globule membrane proteins during the isolation of milk fat globule membrane from milk

During the isolation of milk fat globule membrane (MFGM) from milk, washing is considered the most critical stage in which loss of MFGM components occurs. In this study, using a cream separator, the influence of washing on the recovery of MFGM proteins was investigated. The residue of non-MFGM proteins in the MFGM material obtained after washing was quantitatively determined using densitometric analysis of one-dimensional sodium dodecyl sulfate-PAGE after silver staining of the gel. Using deionized water as the washing solution did not increase the loss of MFGM proteins compared with other common salt solutions in terms of recovery of MFGM proteins and contamination with non-MFGM proteins. The increase in wash temperature from 38 to 46 degrees C did not show a significant decrease in yield of MFGM proteins because of variation between the experimental replicates. Coalescence of fat globules occurs during isolation. To increase MFGM purity while maintaining a high MFGM protein recovery, using larger volumes of wash solution is more advisable rather than increasing the number of washings from 2 to 3.

Probabilistic intake assessment and body burden estimation of dioxin-like substances in background conditions and during a short food contamination episode.

The objective was to perform a dioxin body burden estimate based on a probabilistic intake assessment of PCDDs, PCDFs and dioxin-like PCBs because of the so-called 1999 ‘Belgian dioxin incident’. Monte Carlo simulation techniques were used to combine detailed 7-day food intake data on the individual level from a sample of 14–18-year-old adolescents with ‘background’ and ‘incident-related’ food contamination data. In background conditions, 3% of the adolescents had an intake <1 pg TEQ kg-1 bw day-1, while 85% had <4 pg TEQ kg-1 bw day-1. Milk and other dairy products were the basic source of dioxin-like contaminants, while fish constituted the main source at the higher percentiles of intake. During the dioxin incident, the estimated median dioxin intake showed a moderate increase. At the 99th percentile, the highest intake level, and the 95% upper bound uncertainty level, peak body burden—23.73 ng TEQ kg-1 bw—remained below body burdens that in the experimental animal or in man are accompanied by a population-based observable increase in the incidence of adverse effects. The 1999 Belgian dioxin incident most likely did not affect public health in Belgium in a measurable way, although exceptions remain possible on the individual level.

Comparative evaluation of structured oil systems : shellac oleogel, HPMC oleogel, and HIPE gel

In lipid-based food products, fat crystals are used as building blocks for creating a crystalline network that can trap liquid oil into a 3D gel-like structure which in turn is responsible for the desirable mouth feel and texture properties of the food products. However, the recent ban on the use of trans-fat in the US, coupled with the increasing concerns about the negative health effects of saturated fat consumption, has resulted in an increased interest in the area of identifying alternative ways of structuring edible oils using non-fat-based building blocks. In this paper, we give a brief account of three alternative approaches where oil structuring was carried out using wax crystals (shellac), polymer strands (hydrophilic cellulose derivative), and emulsion droplets as structurants. These building blocks resulted in three different types of oleogels that showed distinct rheological properties and temperature functionalities. The three approaches are compared in terms of the preparation process (ease of processing), properties of the formed systems (microstructure, rheological gel strength, temperature response, effect of water incorporation, and thixotropic recovery), functionality, and associated limitations of the structured systems. The comparative evaluation is made such that the new researchers starting their work in the area of oil structuring can use this discussion as a general guideline. Practical applications Various aspects of oil binding for three different building blocks were studied in this work. The practical significance of this study includes (i) information on the preparation process and the concentrations of structuring agents required for efficient gelation and (ii) information on the behavior of oleogels to temperature, applied shear, and presence of water. This information can be very useful for selecting the type of structuring agents keeping the final applications in mind. For detailed information on the actual edible applications (bakery, chocolate, and spreads) which are based on the oleogel systems described in this manuscript, the readers are advised to refer our recent papers published elsewhere. (Food & Function 2014, 5, 645–652 and Food & Function 2014, 5, 2833–2841).

Improved solvent extraction procedure and high-performance liquid chromatography-evaporative light-scattering detector method for analysis of polar lipids from dairy materials

A normal-phase high-performance liquid chromatography-evaporative light-scattering detector method employing dichloromethane, methanol, and acetic acid/triethylamine buffer as the mobile phase was developed for analysis of polar lipids (PLs). This method was applicable for analysis of PLs from both dairy materials and soy lecithin. All of the PLs of interest such as glycolipids, phospholipids, and sphingomyelin were well separated with a total run time of 22.5 min and without necessitating the removal of neutral lipids beforehand. Peak retention times were stable, and the method was reproducible. In this study, a modified method of using solvents for extraction of PLs from dairy matrices was also investigated. The modified method offered higher extraction efficiency, consumed less time, and in some cases saved solvent use.

Fumed silica-based organogels and ‘aqueous-organic’ bigels

We report the use of fumed silica (hydrophilic colloidal silica particles) to generate triglyceride solvent-based soft matter systems (organogels and bigels). Interestingly, the bigels showed a better gel strength compared to organogels while showing a comparatively weaker thixotropic recovery. Electron microscopy and energy dispersive X-ray spectroscopy were used to understand the microstructure of these new thixotropic molecular gel systems with respect to the fractal-like aggregation of silica particles as well as the percolating network of organic-aqueous phases.