GC-MS metabolite profiling of Pseudocercospora fijiensis isolates resistant to thiabendazole.

Black Sigatoka is the most widespread banana disease worldwide. It is caused by Pseudocercospora fijiensis, a fungal pathogen known for developing resistance to fungicides such as thiabendazole. Despite the increasing costs associated with the use of chemicals to control this disease, the pathogen's mechanisms for fungicide resistance are not fully understood.

Stabilization of galactose oxidase by high hydrostatic pressure: Insights on the role of cavities size.

High hydrostatic pressure stabilized galactose oxidase (GaOx) at 70.0-80.0°C against thermal inactivation.

Increased activity of alcohol oxidase at high hydrostatic pressure.

Alcohol oxidase (AOx) from P. pastoris has potential applications in the production of carbonyl compounds and for the detection and quantification of alcohols. However, AOx's poor stability and low activity have hindered its practical application.

Pectinmethylesterase affects the flow behavior of orange pulp.

In the orange juice industry, pulp (ruptured juice sacs) is separated from the juice after extraction and pasteurized separately before blending back with juice or sold for other food applications. However, pulp is not always pasteurized immediately after extraction and the flow behavior is affected by endogenous pectinmethylesterase (PME). This is particularly important because of the high power required to pump orange pulp in industrial pasteurizers.

FEAST of biosensors: Food, environmental and agricultural sensing technologies (FEAST) in North America.

We review the challenges and opportunities for biosensor research in North America aimed to accelerate translational research. We call for platform approaches based on: i) tools that can support interoperability between food, environment and agriculture, ii) open-source tools for analytics, iii) algorithms used for data and information arbitrage, and iv) use-inspired sensor design. We summarize select mobile devices and phone-based biosensors that couple analytical systems with biosensors for improving decision support.

Combined rotational and capillary rheomtery to determine slip coefficients and other rheological properties of orange pulp.

The characterization of the rheological properties of orange pulp under typical processing temperatures is needed for the design and optimization of orange pulp processing systems. The flow of orange pulp produced slip at shear rates at ∼1 to 5 s . Rotational rheometry revealed that the flow behavior of orange pulp before slip occurrence followed the Power Law model for concentrations of ∼500 to 800 g/L at 4 to 80 °C.

Continuous flow system for biofilm formation using controlled concentrations of from chicken carcass and coupled to electrochemical impedance detection.

Most studies dealing with monitoring the dynamics of biofilm formation use microbial suspensions at high concentrations. These conditions do not always represent food or water distribution systems. A continuous flow system capable of controlling the concentration of the microbial suspension stream from 10 to 10 CFU ml is reported.

Catalytic activity and stabilization of phenyl-modified glucose oxidase at high hydrostatic pressure.

Glucose oxidase (GOx) was modified by attaching phenyl groups to either carboxyl or amino side chains on the enzyme. High hydrostatic pressure (HHP) stabilized the aniline-, and benzoate-modified GOx at 69.1-80 °C compared to atmospheric pressure.

Increased thermal stability of a glucose oxidase biosensor under high hydrostatic pressure.

We report the effects of high hydrostatic pressure (HHP), immobilization in electrochemically generated poly-o-phenylenediamine nano-films, and reticulation with glutaraldehyde on the thermal stability of glucose oxidase (GOx). The pseudo-first-order rate constant of inactivation of immobilized GOx inactivated at 70 °C and atmospheric pressure was 20.6 times smaller than that of GOx in solution under the same conditions.

GC-MS study of changes in polar/mid-polar and volatile compounds in Persian lime (Citrus latifolia) during fruit growth.

Background: Citrus fruits possess a high content of bioactive compounds whose changes during fruit maturation have not been studied in depth. Fruits were sampled from week 1, after fruit onset (7 days after flowering), to week 14. Volatile compounds isolated by headspace-solid-phase microextraction and polar extracts from all samples were analyzed by gas chromatography-mass spectrometry.

Stability and Stabilization of Enzyme Biosensors: The Key to Successful Application and Commercialization.

Fifty-five years have passed and more than 100,000 articles have been published since the first report of an electrochemical enzyme biosensor. However, very few biosensors have reached practical application and commercialization. The bulk of the research effort has been on increasing sensitivity and selectivity.

Effects of high hydrostatic pressure or hydrophobic modification on thermal stability of xanthine oxidase.

The effect of high hydrostatic pressure (HHP) on the kinetics of thermal inactivation of xanthine oxidase (XOx) from bovine milk was studied. Inactivation of XOx followed pseudo-first-order kinetics at 0.1-300MPa and 55.

Glucose oxidase stabilization against thermal inactivation using high hydrostatic pressure and hydrophobic modification.

High hydrostatic pressure (HHP) stabilized glucose oxidase (GOx) against thermal inactivation. The apparent first-order kinetics of inactivation of GOx were investigated at 0.1-300 MPa and 58.

Nonthermal inactivation of soy (Glycine max Sp.) lipoxygenase by pulsed ultraviolet light.

This study investigated pulsed ultraviolet (PUV) illumination at different distances from the PUV source on soybean lipoxygenase (LOX) (0.4 mg/mL in 0.01 M Tris-HCl buffer, pH 9) activity.

An HPLC-MS characterization of the changes in sweet orange leaf metabolite profile following infection by the bacterial pathogen Candidatus Liberibacter asiaticus.

Huanglongbing (HLB) presumably caused by Candidatus Liberibacter asiaticus (CLas) threatens the commercial U.S. citrus crop of an annual value of $3 billion.

Further studies on the role of water in R67 dihydrofolate reductase.

Previous osmotic pressure studies of two nonhomologous dihydrofolate reductase (DHFR) enzymes found tighter binding of the nicotinamide adenine dinucleotide phosphate cofactor upon addition of neutral osmolytes. This result is consistent with water release accompanying binding. In contrast, osmotic stress studies found weaker binding of the dihydrofolate (DHF) substrate for both type I and type II DHFRs in the presence of osmolytes; this observation can be explained if dihydrofolate interacts with osmolytes and shifts the equilibrium from the enzyme-bound state toward the unbound substrate.

Metabolomics in food science.

Metabolomics, the newest member of the omics techniques, has become an important tool in agriculture, pharmacy, and environmental sciences. Advances in compound extraction, separation, detection, identification, and data analysis have allowed metabolomics applications in food sciences including food processing, quality, and safety. This chapter discusses recent advances and applications of metabolomics in food science.

GC-MS based metabolomics for rapid simultaneous detection of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Muenchen, and Salmonella Hartford in ground beef and chicken.

A metabolomic-based method for rapid detection of Escherichia coli O157:H7, Salmonella Hartford, Salmonella Typhimurium, and Salmonella Muenchen in nonselective media was developed. All pathogenic bacteria were grown in tryptic soy broth (TSB) at 37 °C followed by metabolite quantification at 2-h intervals for 24 h. Results were compared with the metabolite profiles similarly obtained with E.

Aroma characterization of tangerine hybrids by gas-chromatography-olfactometry and sensory evaluation.

Background: Tangerines have a distinct flavor among citrus fruit. However, information on tangerine volatiles remains limited. Volatile compounds from a breeding population of tangerines were earlier identified by gas chromatography-mass spectrometry.

GC-MS metabolomic differentiation of selected citrus varieties with different sensitivity to citrus huanglongbing.

Huanglongbing (HLB) is the most destructive disease of citrus worldwide. The rapid identification of tolerant varieties is considered a critical step towards controlling HLB. GC-MS metabolite profiles were used to differentiate HLB-tolerant citrus varieties 'Poncirus trifoliata' (TR) and 'Carrizo citrange' (CAR) from HLB-sensitive varieties 'Madam Vinous sweet orange' (MV) and 'Duncan' grapefruit (DG).

GC-MS analysis of headspace and liquid extracts for metabolomic differentiation of citrus Huanglongbing and zinc deficiency in leaves of 'Valencia' sweet orange from commercial groves.

Introduction: Citrus Huanglongbing (HLB) is considered the most destructive citrus disease worldwide. Symptoms-based detection of HLB is difficult due to similarities with zinc deficiency.

Objective: To find metabolic differences between leaves from HLB-infected, zinc-deficient, and healthy 'Valencia' orange trees by using GC-MS based metabolomics.

Kinetics of lipase catalyzed isoamyl acetate synthesis at high hydrostatic pressure in hexane.

Lipase-catalyzed synthesis of isoamyl acetate in hexane at 10-250 MPa at 80 degrees C and 1-100 MPa at 40 degrees C resulted in activation volumes of -12.9 +/- 1.7 and -21.

Untargeted metabolite analysis of healthy and Huanglongbing-infected orange leaves by CE-DAD.

Huanglongbing (HLB) is considered the most destructive bacterial citrus disease worldwide. Early detection of HLB is crucial for minimizing its spread. CE was used for the discovery of potential biomarkers for HLB.

Simultaneous determination of hydrolysis and mutarotation rates during the enzymatic hydrolysis of lactose.

An experiment is described in which a custom-made glucose electrode is used to directly monitor the enzymatic hydrolysis of lactose to glucose. The transient profile of beta- d-glucose can be used to simultaneously determine the rate constants for mutarotation and for enzymatic hydrolysis by applying a dynamic nonlinear regression routine. Due to differences in the mutarotation rate constants between lactose and glucose, the beta- d-glucose concentration "overshoots" equilibrium under certain conditions, which can be modeled mathematically.

Reduction of Salmonella enterica serovar enteritidis on the surface of raw shelled almonds by exposure to steam.

This study was conducted to investigate the effect of steam treatment on the reduction of Salmonella enterica serovar Enteritidis on the surface of raw almonds. Two cultivars, 'Nonpareil' and 'Mission', were studied. Salmonella Enteritidis was inoculated on the surface of raw almonds, which were then treated with steam (93 degrees C +/- 1 degrees C) for 5, 15, 25, 35, 45, 55, and 65 s.