ORCID Profile
0000-0003-0799-5525
Current Organisation
Federation University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: MDPI AG
Date: 21-02-2022
Abstract: The objective of this study was to develop an alternative novel process technology for enhancing the rheological and functional properties of Greek-style yogurt (GSY). The GSY was formulated and prepared in the lab using micellar casein concentrate as a source of protein to achieve a protein content of 10% (w/w). The changes in physicochemical, microstructural, rheological, and functional properties of control (C-GSY) and micro- and nano-bubbles-treated GSY (MNB-GSY) were studied and compared before and after storage for 1, 2, 3, and 4 weeks. Before storage, the apparent viscosity at 100 s−1 (η100) was 1.09 Pa·s for C-GSY and 0.71 Pa·s for MNB-GSY. Incorporation of MNBs into GSY significantly (p 0.05) decreased the η100 by 30% on 1 week of storage. Additionally, the η100 of MNB-GSY was lesser than C-GSY on week 2, 3, and 4 of storage. Notable microstructural changes and significant rheological differences were observed between the C-GSY and MNB-GSY s les. Differences were also noticed in syneresis, which was lower for the MNB-GSY compared with the control. Overall, the incorporation of MNBs into GSY showed considerable improvements in rheological and functional properties. Additionally, it’s a simple, cost-effective process to implement in existing GSY production plants.
Publisher: Walter de Gruyter GmbH
Date: 17-11-2008
Abstract: In this paper, two acetylcholinesterase (AChE) immobilization methods on the surface of a glassy carbon electrode (GCE) were compared. AChE-employed homogenate from chicken brain was home-made in the laboratory. The immobilization methods employed a cross-linking method with glutaraldehyde as a cross-linking agent, bovine serum albumin (BSA) as a protectant, and sol-gel method with tetraethoxysilane (TEOS). AChE was immobilized on chitosan membranes by these two immobilization methods. Then the enzyme membrane was fixed on the surface of GCE to prepare an AChE-GCE erometric biosensor for the detection of organophosphorus pesticide. Measuring the activity of immobilization AChE by the oxidation current of thiocholine (TCh), produced by hydrolysis of the acetylthiocholine iodide (ATChI) substrate, the results showed that the activity of AChE-employed sol-gel method with TEOS was higher than the cross-linking method with glutaraldehyde. Biosensor sensitivity and reproducibility were statistically evaluated for the different immobilization methods and the most suitable immobilization procedure was selected.
Publisher: American Chemical Society (ACS)
Date: 17-02-2014
DOI: 10.1021/LA404569H
Abstract: Nanoparticles are finding increasing application because of their unusual optical properties. Processing these materials would be drastically simplified if they could be routinely dispersed into a wide variety of polar and nonpolar solvents. We report the synthesis of a new bidentate thiol ligand, (Z)-octadec-9-en-1-yl-5-(1,2-dithiolan-3-yl)pentanoate, and demonstrate its ability to phase transfer gold nanospheres (5-70 nm), nanorods, and silver nanoparticles efficiently from water into various organic solvents. The protocol obviates the need for solid-phase steps or polymeric ligands. Electronic spectra and electron micrographs demonstrate that the particles are fully dispersed in a variety of organic solvents after transfer.
Publisher: Walter de Gruyter GmbH
Date: 24-08-2009
Abstract: The package headspace composition, in terms of O2 and CO2 concentrations, in modified atmosphere packaging (MAP) of Agaricus bisporus at 2, 4, 8 and 20°C were respectively monitored within 15h by a gas chromatograph. The respiration rate of Agaricus bisporus under modified atmosphere packaging at any instant of time were calculated by a C program based on permeable system. The dependence of respiration rate on gas composition was well described by a Michaelis-Menten type enzyme kinetic equation with uncompetitive CO2 inhibition. The model parameters were estimated by fitting the model to the experimental data by non-linear regression using Excel. The relationship between maximum rate Vm and temperature was well described by the Arrhenius equation. The results suggest that, the respiration rate of Agaricus bisporus as well as Vm increased with temperature, and it has a linear relationship between lnVm and T-1. Results of the study can be applied to the MAP design for Agaricus bisporus.
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.FOODCHEM.2012.03.053
Abstract: Understanding the effect of evaporative concentration on casein micelle composition is of high importance for milk processing. Alterations to the hydration, composition and size of casein micelles were investigated in skimmed milk evaporated to concentrations of 12-45% total solids content. The size of casein micelles was determined by dynamic light scattering, and the water content and composition determined by analysis of supernatants and pellets obtained by ultracentrifugation. The mass balance and hydration results showed that during the evaporation process, while micelles were dehydrated, water was removed preferentially from the serum. The amount of soluble casein and calcium in the serum decreased as a function of increasing solids content, indicating a shift of these components to the micelles. The formation of a small proportion of micelle aggregates at high concentrations appeared dependent on the time kept at these concentrations. Upon redilution with water, casein micelles were immediately rehydrated and aggregates were broken up in a matter of minutes. Soluble calcium and pH returned to their original state over a number of hours however, only a small percentage of original soluble casein returned to the serum over the 5h period investigated. These results showed that casein micelles are significantly affected by evaporative concentration and that the alterations are not completely and rapidly reversible.
Publisher: American Dairy Science Association
Date: 04-2017
Abstract: Milk fouling and biofilms are common problems in the dairy industry across many types of processing equipment. One way to reduce milk fouling and biofilms is to modify the characteristics of milk contact surfaces. This study examines the viability of using Thermolon (Porcelain Industries Inc., Dickson, TN), a sol-gel-based surface modification of stainless steel, during thermal processing of milk. We used stainless steel 316L (control) and sol-gel-modified coupons in this study to evaluate fouling behavior and bacterial adhesion. The surface roughness as measured by an optical profiler indicated that the control coupons had a slightly smoother finish. Contact angle measurements showed that the modified surface led to a higher water contact angle, suggesting a more hydrophobic surface. The modified surface also had a lower surface energy (32.4 ± 1.4 mN/m) than the control surface (41.36 ± 2.7 mN/m). We evaluated the susceptibility of control and modified stainless steel coupons to fouling in a benchtop plate heat exchanger. We observed a significant reduction in the amount of fouled layer on modified surfaces. We found an average fouling weight of 19.21 mg/cm
Publisher: Walter de Gruyter GmbH
Date: 08-05-2008
Abstract: In this paper, four enzymes from different sources used for pesticide detection were tested and compared: homogenate from chicken liver, chicken brain and cyprinoids brain were made respectively in the laboratory and Acetylcholinesterase (AChE) was purchased from Musca domestica. The inhibition of AChE activity under different concentrations of omethoate, trichlorfon and dichlorvos were compared. The results showed that the AChE activity in chicken liver and cyprinoids brain were very low. The capacities of activity inhibition of other two kinds of AChE were better. Chicken brain-esterase's inhibition rate achieved 24.16%, 50.56%, and 54.1% for 100ug/L of omethoate, trichlorfon and dichlorvos respectively. Chicken brain-esterase has high specific activity, is low cost, and easy to prepare, and the inhibition of the sensitivity to three organophosphorus pesticides is significantly higher than enzymes from chicken liver and cyprinoids brain. So the chicken brain-esterase could be a good choice to use to detect pesticide residues in agricultural products.
Publisher: Springer Science and Business Media LLC
Date: 23-02-2014
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.FOODCHEM.2013.06.130
Abstract: Milk is a complex colloidal system that responds to changes in temperature imposed during processing. Whilst much has been learned about the effects of temperature on milk, little is known about the dynamic response of casein micelles to changes in temperature. In this study, a comprehensive physico-chemical study of casein micelles in skim milk was performed between 10 and 40 °C. When fully equilibrated, the amount of soluble casein, soluble calcium and the pH of skim milk all decreased as a function of increasing temperature, whilst the hydration and volume fraction of the casein micelles decreased. The effect of temperature on casein micelle size, as determined by dynamic light scattering and differential centrifugation, was less straightforward. Real-time measurements of turbidity and pH were used to investigate the dynamics of the system during warming and cooling of milk in the range 10-40 °C. Changes in pH are indicative of changes to the mineral system and the turbidity is a measure of alterations to the casein micelles. The pH and turbidity showed that alterations to both the casein micelles and the mineral system occurred very rapidly on warming. However, whilst mineral re-equilibration occurred very rapidly on cooling, changes to the casein micelle structure continued after 40 min of measurement, returning to equilibrium after 16 h equilibration. Casein micelle structure and the mineral system of milk were both dependent on temperature in the range 10-40 °C. The dynamic response of the mineral system to changes in temperature appeared almost instantaneous whereas equilibration of casein was considerably slower, particularly upon cooling.
Publisher: Elsevier BV
Date: 03-2014
No related grants have been discovered for Dylan Liu.