Sensory Evaluation of Regina Freestone Peaches Treated with Low Doses of Gamma Radiation

regina freestone peaches from california were given low postharvest doses of gamma radiation (65-75 krads) and were compared with non-irradiated controls approximately one month after harvest. Practiced judges were used, with a technique of minimal cross-sensory interference, as an analytical tool to guide subsequent instrumental analysis. Strong differences were found in odor and components of taste not associated with sweetness. Lesser trends were noted for firmness and appearance. Untrained subjects also detected gross sensory differences.     

High hydrostatic pressure modification of whey protein concentrate for improved functional properties

Whey protein concentrate (WPC) has many applications in the food industry. Previous research demonstrated that treatment of whey proteins with high hydrostatic pressure (HHP) can enhance solubility and foaming properties of whey proteins. The objective of this study was to use HHP to improve functional properties of fresh WPC, compared with functional properties of reconstituted commercial whey protein concentrate 35 (WPC 35) powder. Fluid whey was ultrafiltered to concentrate proteins and reconstituted to equivalent total solids (8.23%) as reconstituted commercial WPC 35 powder. Solutions of WPC were treated with 300 and 400 MPa (0- and 15-min holding time) and 600 MPa (0-min holding time) pressure. After HHP, the solubility of the WPC was determined at both pH 4.6 and 7.0 using UDY and BioRad protein assay methods. Overrun and foam stability were determined after protein dispersions were whipped for 15 min. The protein solubility was greater at pH 7.0 than at pH 4.6, but there were no significant differences at different HHP treatment conditions. The maintenance of protein solubility after HHP indicates that HHP-treated WPC might be appropriate for applications to food systems. Untreated WPC exhibited the smallest overrun percentage, whereas the largest percentage for overrun and foam stability was obtained for WPC treated at 300 MPa for 15 min. Additionally, HHP-WPC treated at 300 MPa for 15 min acquired larger overrun than commercial WPC 35. The HHP treatment of 300 MPa for 0 min did not improve foam stability of WPC. However, WPC treated at 300 or 400 MPa for 15 min and 600 MPa for 0 min exhibited significantly greater foam stability than commercial WPC 35. The HHP treatment was beneficial to enhance overrun and foam stability of WPC, showing promise for ice cream and whipping cream applications.     

Rapid CO2 Evolution Method for Determining Shelf Life of Refrigerated Catfish

The feasibility of a CO₂ evolution method using an IR analyzer to evaluate the shelf life of refrigerated (4deg;C) catfish was investigated. Aerobic plate count (APC), and isoelectric focusing (IEF) of samples were compared with the CO₂ evolution rate (CER) determinations. The increase in CER (25.78 to 195.63 Lg^?1h^?1) for farm raised catfish stored from 0 to 10 days correlated highly with APCs (4.32 to 10.24 log CFU g^?1). The IEF data also confirmed the APC and CER results. Catfish spoilage was evident after 6 days at 4°C. Direct measurement of CER is a rapid and effective method to determine the microbial quality of catfish.     

Real-time imaging of tunable adenosine 5-triphosphate release from an MCM-41-type mesoporous silica nanosphere-based delivery system

We studied a mesoporous silica nanosphere (MSN) material with tunable release capability for drug delivery applications. We employed luciferase chemiluminescence imaging to investigate the kinetics and mechanism of the adenosine 5-triphosphate (ATP) release with various disulfide-reducing agents as uncapping triggers. ATP molecules were encapsulated within the MSNs by immersing dry nanospheres in aqueous solutions of ATP followed by capping of the mesopores with chemically removable caps, such as cadmium sulfide (CdS) nanoparticles and poly(amido amine) dendrimers (PAMAM), via a disulfide linkage. By varying the chemical nature of the 'cap' and 'trigger' molecules in our MSN system, we discovered that the release profiles could indeed be regulated in a controllable fashion.     

Functional mesoporous silica nanoparticles for the selective sequestration of free fatty acids from microalgal oil

A series of 2d-hexagonally packed mesoporous silica nanoparticle material with 10 nm pore diameter (MSN-10) covalently functionalized with organic surface modifiers have been synthesized via a post-synthesis grafting method. The material structure has been characterized by powder X-ray diffraction, electron microscopy, and nitrogen sorption analyses, and the free fatty acid (FFA) sequestration capacity and selectivity was investigated and quantified by thermogravimetric and GC/MS analysis. We discovered that aminopropyl functionalized 10 nm pore mesoporous silica nanoparticle material (AP-MSN-10) sequestered all available FFAs and left nearly all other molecules in solution from a simulated microalgal extract containing FFAs, sterols, terpenes, and triacylglycerides. We also demonstrated selective FFA sequestration from commercially available microalgal oil.     

Operating characteristics of aqueous magnetite electrochemical capacitors

Operating characteristics, including capacitance, leakage current, operating potential range, cycling stability and open-circuit self-discharge behaviours, of the magnetite (Fe₃O₄) supercapacitor, containing 10 wt % carbon black as conductive additive, in aqueous electrolytes of Na₂SO₃, KOH and Na₂SO₄ were investigated. Although the capacitance of the oxide was found to depend heavily on electrolyte composition, the self-discharge mechanism in these electrolytes appeared to be the same. Reduction in the dissolved oxygen content (DOC) of the electrolyte reduced the leakage current and profoundly improved the cycling stability. In particular, Na₂SO_3(aq) gives the highest capacitance, nearly 30 F (g-Fe₃O₄)^–1 or 80 F cm^–2 of actual surface area, with an operation range of 1.1 V based on a leakage current less than 0.1 mA F^–1, and the electrode showed no deterioration after 10⁴ cycles under a DOC < 0.1 ppm.     

A Chinese Text Input Brain–Computer Interface Based on the P300 Speller

In this article the results of a usability study of CONTACT, an application that supports negotiation strategy training via video modeling for enhancing the conflict resolution of adolescents with autism spectrum disorder (ASD), are presented. This application was modified from the NoProblem! prototype based on feedback from two focus groups of typically developing adolescents and therapists and teachers of adolescents with ASD. It has been designed to address social competencies through video modeling and complies with the principles of constructivist learning theory. Twenty-one adolescents with ASD, 12 to 18 years of age, and 27 age- and gender-matched typically developing adolescents participated in this study. The outcome measure used was the Intrinsic Motivation Inventory. Both adolescents with ASD and typically developing adolescents perceived the application to be interesting and enjoyable; they claimed that it did not generate feelings of pressure or tension and that they had independent choices. The results also showed that adolescents with ASD felt significantly more competent than typically developing adolescents when using this application. The findings of this study emphasize the important role that the usability process has when designing and developing new technologies for educational purposes for adolescents with and without ASD.     

Combined effect of aqueous chlorine dioxide and modified atmosphere packaging on inhibiting Salmonella Typhimurium and Listeria monocytogenes in mungbean sprouts

This study was conducted to investigate the effect of chlorine dioxide (ClO2) combined with modified atmosphere packaging (MAP) on inhibiting total mesophilic microorganisms, Salmonella Typhimurium, and Listeria monocytogenes in mungbean sprouts during refrigerated storage. Mungbean sprouts were packaged using 4 different methods (air, vacuum, CO2 gas, and N2 gas) following treatment with water or 100 ppm ClO2 for 5 min and stored at 5 +/- 2 degrees C. The population of total mesophilic microorganisms in mungbean sprouts was about 8.4-log(10) CFU/g and this level was not significantly reduced by treatment with water or ClO2 (P > 0.05). However, when samples were packaged under vacuum, N2 gas, or CO2 gas following treatment with ClO2, the populations of total mesophilic microorganisms were significantly reduced during storage (P < 0.05). Levels of S. Typhimurium and L. monocytogenes in mungbean sprouts following inoculation were 4.6- and 5.6-log(10) CFU/g and treatment with water followed by different packaging conditions (air, vacuum, N2 gas, and CO2 gas) had no significant effect on population reduction (P > 0.05). However, treatment with ClO2 significantly reduced populations of S. Typhimurium and L. monocytogenes by 3.0- and 1.5-log CFU/g, respectively (P < 0.05), and these reduced cell levels were maintained or decreased in samples packaged under vacuum or in N2 or CO2 gas during storage. These results suggest that the combination of ClO2 treatment and MAP such as CO2 gas packaging may be useful for inhibiting microbial contamination and maintaining quality in mungbean sprouts during storage.     

Hydrophobic interfacing layers for improvement of corrosion protection by polymeric coatings

Water sorption of coating materials is the main cause of coating deterioration, adhesion loss and substrate corrosion. By introducing alkanethiol self-assembled monolayers (SAMs), a hydrophobic interfacing layer between coating and substrate metal can be constructed. The effect of the hydrophobic SAMs interfacing layer on the corrosion protection of epoxy coatings was evaluated using electrochemical techniques including Tafel polarization, electrochemical impedance spectroscopy and impedance–time transition measurement. It was found that the SAMs interfacing layer improved the corrosion protection of the coating significantly. The improvement was attributed to the strong interaction between SAMs and the metal substrate, the compact structure and low water affinity of the SAMs interfacing layer, which prevent water absorbed by the coating from reaching the coating–metal interface and spreading along the interface.     

Microwave techniques for diagnostic laboratories

Microwaves (MWs) were first introduced as a method of fixation just over 20 years ago. In recent years their use has extended far beyond that of a safe, clean, and rapid method of fixation of tissue blocks and large specimens, including brains. MWs accelerate the action of cross-linking fixatives and can greatly accelerate the various stages of tissue processing to produce a paraffin block in 30 min. An extensive range of ultrafast MW-stimulated special stains has been developed, and immunohistochemical procedures can be completed in 20 min by employing MWs. Cellular antigens are distinctly better preserved in tissues fixed by MWs than by conventional cross-linking fixatives. Also, the cytomorphology of cryostat sections irradiated in Wolman's solution is clearly improved. MWs can similarly be applied for fixation and staining of preparations for transmission and scanning electron microscopy, and they also greatly accelerate polymerisation of resins. In the current climate of cost containment, this wide range of applications makes the MW oven an invaluable addition to the diagnostic laboratory.