Effects of spray drying conditions on the physicochemical and antioxidant properties of the Gac (Momordica cochinchinensis) fruit aril powder

Gac fruit aril has an attractive orange red colour and very high level of carotenoids, giving it exceptional antioxidant properties. However, spray drying of this material has not been successful and malto dextrin is considered as a suitable drying aid to preserve its colour and antioxidant properties. This paper reports the effects of inlet drying air temperature (120, 140, 160, 180 and 200 °C) and maltodextrin addition (10%, 20% and 30%) on the physicochemical and antioxidant properties of the Gac aril powder. Moisture content and bulk density, colour characteristics, total carotenoid content (TCC), encapsulation efficiency and total antioxidant activity (TAA) were significantly affected by maltodextrin concentration and the inlet air temperatures. However, pH, a_w and water solubility index were not significantly influenced by the spray drying conditions. Overall, a good quality Gac powder in terms of colour, TCC and TAA can be produced by spray-drying at inlet temperature of 120 °C and adding maltodextrin concentration at 10% w/v.     

Role of acidic sphingomyelinase in thymol‐mediated dendritic cell death

Scope : Thymol is a component of several plants with antimicrobial activity. Little is known about the effects of thymol on immune cells of the host. This study addressed the effects of thymol on dendritic cells (DCs), regulators of innate and adaptive immunity. Methods and results : Immunohistochemistry, Western blotting and fluorescence‐activated cell sorting analysis were performed in bone marrow‐derived DCs either from wild‐type mice or from mice lacking acid sphingomyelinase (ASM^?/?) treated and untreated for 24 h with thymol (2–100 μg/mL). Thymol treatment resulted in activation of ASM, stimulation of ceramide formation, downregulation of anti‐apoptotic Bcl‐2 and Bcl‐xL proteins, activation of caspase 3 and caspase 8, DNA fragmentation as well as cell membrane scrambling. The effects were dependent on the presence of ASM and were lacking in ASM^?/? mice or in wild‐type DCs treated with sphingomyelinase inhibitor amitriptyline. Conclusion : Thymol triggers suicidal DC death, an effect mediated by and requiring activation of ASM.     

Evaluating the impact of thermal and pressure treatment in preserving textural quality of selected foods

A study was conducted to evaluate the efficacy of various combinations of pressure and thermal treatments in preserving textural quality of selected foods. Carrot, zucchini, apricot, red radish, and jicama were used as test samples. Pressure-assisted thermal processing (PATP; 600 MPa, 105 °C), high-pressure processing (HPP; 600 MPa, 25 °C), and thermal processing (TP; 105 °C, 0.1 MPa) experiments were conducted. Role of pressure (600 MPa) in preserving product quality while simultaneously (PATP) or sequentially (HPP-TP) exposed to elevated process temperature (105 °C) was also compared. Instrumental puncture, shear force, color and sensory analyses were utilized to compare the influence of the various process treatments. A crunchiness index (CI), relating product puncture force and stiffness, was able to characterize the severity of the process treatments on various products tested. Among the treatments, TP was the worst at retaining texture, but HPP-TP improved texture retention. In comparison to TP alone, PATP better retained texture and color. Jicama was least influenced by the treatments as compared to products tested. Process treatments investigated degraded the textural quality of zucchini and apricot. Instrumental CI results were also in agreement with the sensory data of carrot, red radish and jicama samples.     

Microorganisms in landfill bioreactors for accelerated stabilization of solid wastes

Landfill bioreactors (LBRs) with management of leachate and biogas have presented numerous advantages such as accelerated stabilization of solid wastes, reduced amount of leachate, and in situ leachate treatment. Such advantages have minimized environmental risks, have allowed extension of the useful life of the landfill site, and have fostered cost reduction. LBRs of three types have been developed using both anaerobic and aerobic modes: anaerobic, aerobic, and hybrid. Microorganisms in landfills cause various reactions related with organic fractions and heavy metals. Such functions have been stimulated in LBRs by recirculation of leachate with or without aeration. To date, most studies of microorganisms in LBRs have analyzed bacteria and archaea based on 16S rRNA genes and have analyzed fungi based on 18S rRNA genes from a taxonomical viewpoint. Indicator genes for specific functions in LBRs such as nitrification, denitrification, and methane production have also been monitored. The population dynamics of microorganisms in LBRs have been partially clarified, but the obtained data remain limited because of highly heterogeneous features of solid wastes inside LBRs. Systematic monitoring of microorganisms should be established to improve LBR performance.     

Influence of salt concentration on the salting kinetics of cod loin (Gadus morhua) during brine salting

The influence of different salt concentrations of 6%, 15%, 18% and 24% (w/w) on mass transfer of water and salt during brine salting of cod loins was studied. An increase in salt concentration accelerated water exudation and salt diffusion in the cod loins. Weight gain of the cod loins increased with decreasing salt concentration and the cod loins in the 6% brine had the highest process yield. The salting kinetic parameter values for total and water weight changes decreased with increasing salt concentration. Inversely, higher salting kinetic parameter values for salt weight changes were observed for higher brine concentrations. The samples brined at 18% and 24% had identical effective diffusion coefficients and the highest effective diffusion value was found in the cod loins brined at 15%.     

Initiation of cationic polymerization with alcohol/Lewis acid systems

Alcohols in conjunction with BCl₃ have been found to be efficient initiating systems for the polymerization of isobutylene in CH₂Cl₂ solvent. The following alcohols exhibited high initiating activity: tert.-butanol, 1,1-diphenyl ethanol, 2-phenyl-2-propanol, benzhydrol. The organic moiety of the alcohol becomes the head-group of the polyisobutylene formed. The tailgroup of the polymer is a tertiary chlorine most likely because termination is by chlorination by the BCl₃OH^Θ counter anion.     

Digital image processing of combined SEM and EDX signals

Due to the complexity of biological tissue and man-made materials, the limits of light microscopy in quantitative image analysis are often reached. The scanning electron microscope provides a much higher resolution in such situations, especially when using the low noise secondary electrons signal. However, secondary electrons are sensitive to topography rather than to the elements constituting the specimen. This effect usually makes discrimination of distinct phases or objects by simple grey value thresholding difficult or even impossible. The additional information given by an energy dispersive X-ray system is the step to overcome this problem. The combination of both signals—grey level and energy dispersive information—leads to a masking procedure which eliminates image sections, not belonging to the phase under investigation, from the evaluation.     

Effects of pretreatment and air drying temperature on Noni fruit powder

Food Science and Biotechnology - The plant Morinda citrifolia L. (Noni) has been the subject of several recent research due to its positive impact on the treatment and prevention of a variety of...