Influence of Spray-Drying Conditions on Physical and Morphological Characteristics of Microencapsulated Benzoic Acid

Benzoic acid is widely used as a preservative in the food and feed industry, and microencapsulation is important in the application of this ingredient in various food products. The objective of this work was to evaluate the effect of benzoic acid concentration and drying air temperature on the physical characteristics of powders produced by spray drying, using maltodextrin and modified starch as the wall materials. A rotatable central composite design was used; the independent variables were inlet air temperature (145–180 °C) and benzoic acid concentration (2–10 %, m/m). Maximum yield was obtained when higher concentrations of benzoic acid and higher inlet air temperatures were applied. The highest microencapsulation efficiency was reached at intermediate temperatures (160 °C) and low concentration of benzoic acid. The particles size (D _[4,3]) ranged from 24.99 to 29.52 μm and, in general, presented amorphous structure, spherical shape with rough surfaces and had no cracks The optimum condition, considering all the response variables together, was drying air temperature 169 °C and benzoic acid concentration 6 % (m/m). Under these conditions, the particles presented solubility of 75.96 g/100 g and wettability of 56.8 s/g. Moreover, the process showed microencapsulation efficiency of 76.77 g/100 g and yield of 40.1 %. Spray drying was considered a potential process to provide microencapsulated benzoic acid.     

Chemical composition and antibacterial activity of Laurus nobilis essential oil towards foodborne pathogens and its application in fresh Tuscan sausage stored at 7 °C

The presence of foodborne pathogens in fresh Tuscan sausage has been reported and these contaminations pose a potential risk to consumers. The objective of the present study was to evaluate the antimicrobial activity of bay leaf essential oil (EO) in vitro and in fresh Tuscan sausage stored at 7 °C for 14 d. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against foodborne pathogens were determined in vitro. The lowest MIC and MBC were found for Escherichia coli (MIC = MBC = 2.5 g/L) and Yersinia enterocolitica (MIC = 1.25 g/L, MBC = 2.5 g/L). Fresh Tuscan sausages were treated with bay leaf EO at 0.05 g/100 g or 0.1 g/100 g and their shelf life was compared to a non-treated control. All groups presented low levels of rancidity (TBARS < 0.5 mg MDA/kg). The EO was able to reduce the population of total coliforms (2.8 log CFU/g) and to extend the product shelf life for two days. Although the presence of the EO affected the sensory characteristics of the sausage, it was considered acceptable by consumers at both concentrations tested. Overall, the results of this study indicate that bay leaf essential oil can be applied in fresh Tuscan sausage to improve its safety and shelf life.     

Uncertainty of air pollution cost estimates: to what extent does it matter?

How large is the social cost penalty if one makes the wrong choice because of uncertainties in the estimates of the costs and benefits of environmental policy measures? For discrete choices there is no general rule other than the recommendation to always carefully compare costs and benefits when introducing policies for environmental protection. For continuous choices (e.g., the ceiling for the total emissions of a pollutant by an entire sector or region), it is instructive to look at the cost penalty as a function of the error in the incremental damage cost estimate. Using abatement cost curves for NOx, SO2, dioxins, and CO2, this paper evaluates the cost penalty for errors in the following: national emission ceilings for NOx and SO2 in each of 12 countries of Europe, an emission ceiling for dioxins in the UK, and limits for the emission of CO2 in Europe. The cost penalty turns out to be remarkably insensitive to errors. An error by a factor of 3 due to uncertainties in the damage estimates for NOx and SO2 increases the total social cost by at most 20% and in most cases much less. For dioxins, the total social cost is increased by at most 10%. For CO2, several different possible cost curves are examined: for some the sensitivity to uncertainties is greater than for the other pollutants, but even here the penalty is less than 30% and in most cases much less if the true damage costs are twice as high as the ones estimated. The paper also quantifies the benefit of improving the accuracy of damage cost estimates by further research.     

Society Supports Software Engineering PE Examination

The IEEE Computer Society, in conjunction with the IEEE-USA, recently announced its partnership with the National Council of Examiners for Engineering and Surveying in support of establishing a Principles and Practice of Engineering examination for the software engineering discipline. Other topics include the election of editors in chief for 2011-2013 terms and the appointment of four EICs for CS transactions