Effects of initial albumen quality and mineral oil–chitosan emulsion coating on internal quality and shelf‐life of eggs during room temperature storage

Effects of mineral oil (MO) and mineral oil–chitosan emulsion (MO:CH = 25:75) as coatings on internal quality and shelf‐life of eggs were evaluated during 5‐week storage at 25 °C. Eggs with three different initial albumen qualities [Haugh unit (HU): H = 87.8, M = 75.6 and L = 70.9] were evaluated. As storage time increased, HU and yolk index values decreased whereas weight loss increased. Coating with MO and/or 25:75 MO:CH emulsion could preserve the internal quality for at least 4 more weeks for H‐eggs and at least 3 more weeks for M and/or L‐eggs, all with weight losses <0.92%. All coated eggs had >70% positive purchase intent, and their colour differences at week 0 could not be detected by naked human eye (ΔE^* < 3.0, noncoated eggs as reference). Consumers significantly differentiated freshly MO‐coated from noncoated eggs on overall surface appearance. This study demonstrated that MO and 25:75 MO:CH emulsion coatings could preserve internal quality and prolong shelf‐life of eggs.     

Oil‐in‐Water Emulsion Exhibits Bitterness‐Suppressing Effects in a Sensory Threshold Study

Little is known about how emulsion characteristics affect saltiness/bitterness perception. Sensory detection and recognition thresholds of NaCl, caffeine, and KCl in aqueous solution compared with oil‐in‐water emulsion systems were evaluated. For emulsions, NaCl, KCl, or caffeine were dissolved in water + emulsifier and mixed with canola oil (20% by weight). Two emulsions were prepared: emulsion 1 (viscosity = 257 cP) and emulsion 2 (viscosity = 59 cP). The forced‐choice ascending concentration series method of limits (ASTM E‐679‐04) was used to determine detection and/or recognition thresholds at 25 °C. Group best estimate threshold (GBET) geometric means were expressed as g/100 mL. Comparing NaCl with KCl, there were no significant differences in detection GBET values for all systems (0.0197 ‐ 0.0354). For saltiness recognition thresholds, KCl GBET values were higher compared with NaCl GBET (0.0822 ‐ 0.1070 compared with 0.0471 ‐ 0.0501). For NaCl and KCl, emulsion 1 and/or emulsion 2 did not significantly affect the saltiness recognition threshold compared with that of the aqueous solution. However, the bitterness recognition thresholds of caffeine and KCl in solution were significantly lower than in the emulsions (0.0242 ‐ 0.0586 compared with 0.0754 ‐ 0.1025). Gender generally had a marginal effect on threshold values. This study showed that, compared with the aqueous solutions, emulsions did not significantly affect the saltiness recognition threshold of NaCl and KCl, but exhibited bitterness‐suppressing effects on KCl and/or caffeine.     

The moderating effect of human resource management practices on the relationship between knowledge absorptive capacity and project performance in project-oriented companies

In response to recent calls for research on human resource management (HRM) in project management, this research investigates the links between HRM practices, the project team's knowledge absorptive capacity (ACAP) and project performance in project-oriented companies (POCs). Based on survey data from 198 projects in multinational companies (MNCs) in the Thai automotive industry, this research finds that HRM practices moderate the effects of a project team's knowledge ACAP on project performance, in particular of potential ACAP on long-run project performance. In addition, HRM practices covary with a project team's realized ACAP, the other dimension of ACAP, to affect short-run project performance. This research sheds light on the different roles that HRM practices play in a project, finding that HRM practices not only facilitate knowledge management from the current project to future projects but also strengthen the relationship between a project team's knowledge ACAP and long-term project performance. This research contributes to the understanding of HRM in the literature of project management.     

Soy sauce odour induces and enhances saltiness perception

Developing products with reduced sodium content is one alternative for consumers interested in reducing their daily sodium intake. In this research, we determined whether soy sauce odour could induce and enhance salty taste perception in salt solution models. The sensory threshold technique (ASTM E679‐04, the ascending forced choice method of limits) was used to determine thresholds at 25 °C. Group best estimate threshold geometric means of soy sauce odour were expressed as parts‐per‐billion (ppb, v/v). At 28.45 ppb (recognition threshold), soy sauce odour could induce salty taste in 0.03 mm NaCl solution (in which salty taste was undetectable without soy sauce odour) and at 122.71 ppb (difference threshold), it enhanced salty taste (i.e. saltier) perception in 20 mm NaCl solution. Through the odour–taste interaction concept, this study demonstrated that the soy sauce odour could induce and enhance salty taste perception, which could be applied in the development of reduced‐sodium foods.     

The split plot with repeated randomised complete block design can reduce psychological biases in consumer acceptance testing

A randomised complete block design (RCBD) has been extensively used in consumer testing; however, it is ineffective in preventing sample presentation biases. This study demonstrated a more efficient experimental design [i.e. split plot with repeated randomised complete block design (SPRRCBD)] to help minimise positional and first serving‐order (FSO) biases in consumer tests. Results suggested that positional biases were strongly pronounced for the poor‐quality sample. Comparing between RCBD and RCBD without FSO experiments, there were significant differences in overall liking (OL) scores of the same sample served at the same position. Hence, omitting the first sample score from data analysis was not recommended. The mean‐squared error (MSE) of SPRRCBD was lower than RCBD and RCBD without FSO (2.28, 2.72 and 2.60, respectively), indicating a more powerful design to explain variations in mean hedonic differences. SPRRCBD extracted more explained variances, resulting in a decreased Type‐II error in the model.     

Preparation and characterization of ultrafine electrospun polyacrylonitrile fibers and their subsequent pyrolysis to carbon fibers

The present contribution reports the fabrication and characterization of ultrafine polyacrylonitrile (PAN) fibers by electrospinning and further development of the as‐spun PAN fibers into ultrafine carbon fibers. The effects of solution conditions (i.e., solution concentration, viscosity, conductivity, and surface tension) and process parameters (i.e., applied electrostatic field strength, emitting electrode polarity, nozzle diameter, and take‐up speed of a rotating‐drum collector) on morphological appearance and average diameter of the as‐spun PAN fibers were investigated by optical scanning (OS) and scanning electron microscopy (SEM). The concentration, and hence the viscosity, of the spinning solutions significantly affected the morphology and diameters of the as‐spun PAN fibers. The applied electrostatic field strength and nozzle diameter slightly affected the diameters of the as‐spun fibers, while the emitting electrode polarity did not show any influence over the morphology and size of the as‐spun fibers. Utilization of the rotating‐drum collector enhanced the alignment of the as‐spun fibers. Within the investigated concentration range, the average diameter of the fibers ranged between 80 and 725 nm. Finally, heat treatment of the as‐spun fibers with their average diameter of about 450 nm was carried out at 230 and 1000 °C, respectively. Various characterization techniques revealed successful conversion into carbon fibers with an average diameter of about 250 nm. Copyright © 2006 Society of Chemical Industry     

Antimicrobia activity of garlic (Allium sativum L.) and holy basil (Ocimum sanctum L.) essential oils applied by liquid vs. vapour phases

Antimicrobial activity of garlic (Allium sativum L.) and holy basil (Ocimum sanctum L.) essential oils (GEO and HBEO, respectively) was evaluated in liquid vs. vapour phases. Diallyl disulphide and diallyl trisulphide in GEO while eugenol, caryophyllene and methyl eugenol in HBEO were predominant active compounds. Individually, GEO was highly effective in the vapour phase, showing the greatest antimicrobial activity (P ≤ 0.05) against Bacillus cereus and Staphylococcus aureus with complete inhibition, followed by Salmonella typhimurium and Pseudomonas fluorescens, but had no effect on Escherichia coli, Lactobacillus plantarum or Listeria monocytogenes. The combined GEO:HBEO (a 1:1 ratio) at 30 μL demonstrated inhibitive activity against all bacteria tested with complete inhibition against B. cereus and S. aureus. Minimum bactericidal concentration (MBC) of the combined oil was <0.4% v/v, except for P. fluorescens requiring a higher MBC (1.5%, v/v). This study demonstrated potential of the combined GEO:HBEO to be used for food preservation applications.