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Protein-starch matrix plays a key role in enzymic digestion of high-amylose wheat noodle
No full textWheat flour, consisting of a complex matrix of starch and protein, is used as a representative model of whole food here to investigate the binary interaction in relation to amylose level and hydrothermal treatment in noodles as a food exemplar. Noodle made of high-amylose wheat (HAW) flour showed an eight-fold higher resistant starch content, compared to the wild type. Protein removal under simulated intestinal digestion conditions resulted in higher starch digestion rate coefficients in raw and cooked flours. In cooked flours, the substrate becomes similarly accessible to digestive enzymes regardless of protein removal. The results indicate that the increased protein content in native HAW flour and thermal stability of starch in HAW noodles lead to higher food integrity and consequently enhance the resistance against α-amylase digestion. Overall, the study suggests that a diversity of starch-protein interactions in wheat-based food products underlies the nutritional value of natural whole foods
A sensitive and high-throughput fluorescent method for determination of oxidase activities in human, bovine, goat and camel milk
No full textMilk oxidases are an integral part of milk immune system, and good indicators for milk thermal history. Current assay methods for milk oxidases are either insensitive, tedious or not cost-effective. In this study, a high-throughput fluorescence assay method for determination of xanthine oxidase (XO) and polyamine oxidase (PAO) activities in milk samples was developed. The hydrogen peroxide generated by XO catalysed oxidation of hypoxanthine, and PAO catalysed oxidation of spermine, was coupled to horseradish peroxidase conversion of Amplex® Red (1-(3,7-dihydroxyphenoxazin-10-yl)ethanone) to the fluorescent product resorufin. The assay was highly sensitive, with limits of detection of activity in milk being 3 × 10 and 7 × 10 U/mL for XO and PAO, respectively. Intra-run and inter-run results showed good assay repeatability and reproducibility. The assay was successfully applied to survey the XO and PAO activities in human, bovine, goat and camel milk samples, and it can be readily adapted for measurements of other oxidase activities
Reinventing library research support services at Griffith University
No full textGriffith University provides advice and services to researchers around research grants, ethics and integrity, research performance, and publications and outputs. A broad-based researcher education and development program helps inform and upskill researchers and research students. From 2019, Griffith University Library has developed new services to support data-driven, data-intensive research and assist researchers through the entire research lifecycle. This chapter describes the staffing structure and the ideas underpinning a new service catalogue based around key areas, such as data management, open scholarship, and data wrangling. Methods to achieve this included a collaboratively developed knowledge base, the development of new workshops, mapping of research environments and referral pathways, and developing support for researchers for whom there is no established tool for the kinds of research they want to do. A push to establish the library as a vital and valued partner in research projects was a key driver for change
Effect of different types and concentrations of fat on the physico-chemical properties of soy protein isolate gel
No full textThe effect of different types of fat (anhydrous milk fat, palm stearin, soybean oil) and concentrations (0.5, 1, and 2%) in soy protein isolate (SPI) gel on their gelation behaviour (acidification, cooling, annealing and heating step), tribological, microstructure and textural properties were investigated. SPI gels made from soy protein isolate added with different fat types showed different gelation behaviour compared to control (without fat) by modulating the acidification time. Among all the gels, incorporating anhydrous milk fat into soy protein produced stronger and firmer gels (0.66–0.73 N) followed by palm stearin (0.64–0.68 N) and soybean oil (0.60–0.62 N). The apparent viscosity for all samples showed a shear thinning behaviour. The lowest coefficient of friction were observed from SPI gels added with 2% of anhydrous milk fat which indicating better lubrication properties. The gel particle sizes of all the samples were also not significantly different, although from microscopic images the soy protein with soybean oil showed smaller fat globules and more compact protein network. These results demonstrated that the presence of fats as a filler affects the firmness and gelling properties of SPI gel. The highest G′ (~1.4 kPa) and the lowest friction coefficient (0.24) of SPI gel obtained from 2% of anhydrous milk fat addition suggested the potential of incorporating anhydrous milk fat to provide desirable texture and pleasant mouthfeel in SPI gel
Self-templated fabrication of hierarchical hollow manganese-cobalt phosphide yolk-shell spheres for enhanced oxygen evolution reaction
No full textHierarchical nanostructures with hollow architectures can provide rich active sites, improved transport of ions, and highly robust structure for electrochemical applications. In this work, we report the self-templated fabrication of hierarchical manganese-cobalt phosphide (Mn-Co phosphide) yolk-shell spheres using highly uniform cobalt glycerate spheres as sacrificial templates. Through a simple exchange reaction with the manganese precursor solution at room temperature, these cobalt glycerate spheres are readily converted to hierarchical Mn-Co LDH yolk-shell spheres, which can be further phosphidized at 350 °C under inert atmosphere to generate hierarchical Mn-Co phosphide with distinct yolk-shell morphology. When tested as an electrocatalyst for oxygen evolution reaction (OER), the hierarchical Mn-Co phosphide yolk-shell spheres exhibit an overpotential of 330 mV at a current density of 10 mA cm and a Tafel slope of 59.0 mV dec, which are higher than those of Mn-Co oxide yolk-shell spheres (480 mV and 113 mV dec) and hierarchical cobalt phosphide spheres (410 mV and 61.3 mV dec). Post-OER analysis by XPS reveals that the high activity of the hierarchical Mn-Co phosphide yolk-shell catalyst originates from the existence of Mn/Mn and Co/Co redox couples and the formation of active metal oxyhydroxide species on its surface. The proposed self-sacrificial templating strategy will provide useful guidance for future construction of hollow inorganic metal nanostructures with yolk-shell morphology for energy storage and conversion applications
Children overclaim more knowledge than adults do, but for different reasons
No full textOverclaiming is the phenomenon whereby people claim more knowledge of a topic than they actually have. In adults, this behavior is related to the extent to which they consider themselves an expert on that topic and may be related to impression management. We investigated the emergence of this phenomenon by developing a child-friendly overclaiming questionnaire (OCQ)—the Child-OCQ. We measured the tendency of children (5–10\ua0years of age old;\ua0N\ua0=\ua094) to claim knowledge of items that did not exist for a variety of topics (places, characters, animals, food, and musical instruments). We also examined the relationship between children’s overclaiming of knowledge and their self-perceived liking of, and expertise in, the topics. To validate our scale, an adult sample (N\ua0=\ua051) completed both the Child-OCQ and a standardized adult OCQ, the OCQ-150, showing similar overclaiming patterns on both measures. Although overclaiming behaviors decreased throughout childhood, even children as old as 10\ua0years were not adult-like and were more likely to overclaim knowledge than adults. In addition, we did not find strong evidence that children’s perceived expertise on a topic influenced their tendency to overclaim knowledge, suggesting that the mechanisms behind the overclaiming phenomenon are different in children and do not reflect impression management until later during adolescence or adulthood
Rapid fabrication of homogeneously distributed hyper-branched gold nanostructured electrode based electrochemical immunosensor for detection of protein biomarkers
No full textIn recent years, need for rapid, reliable, and low-cost protein biomarker screening has tremendously boosted research into the development of electrochemical immunosensors. In this line, here we report on rapid fabrication and proof-of-concept demonstration of a hyper-branched gold nanostructure (ns@gold) based electrochemical immunosensor for detection of protein biomarker at pg/mL level. We have optimized a simple direct electrochemical process to rapidly generate uniformly distributed high surface area ns@gold within 30 min. These 3D ns@gold show ∼ 8-times enhancement in conductivity and also a rapid surface functionalization via self-assembled monolayers (SAM) of mercaptoundecanoic acid within 45 min. Protein estimation data showed around 94 % immobilization efficiency on the ns@gold surface in comparison to 28.4 % on plain gold surface. A fast SAM formation and quick antibody immobilization steered the assay timing within 4 h. As a proof-of-concept, we used an antibody-antigen interaction for the detection of epithelial growth factor receptor (EGFR) protein. Voltammetric data for the target EGFR receptor resulted a linear working range of 10 pg/mL to 100 ng/mL with a low limit-of-detection of 6.9 pg/mL. High selectivity in detecting target proteins from a pool of non-target proteins using breast cancer cell lines was also demonstrated along with good stability and reusability
Influence mechanism and kinetic analysis of co-gasification of biomass char and semi-coke
No full textIn order to clarify the reaction mechanism of co-gasification of biomass char and semi-coke, the gasification properties of bamboo reed char (BR), semi-coke (SC) and their blends were systematically studied by the non-isothermal thermogravimetry. The physicochemical properties of BR and SC were characterized in detail, the main factors affecting the co-gasification reaction were studied, and the gasification kinetics under CO environment were further investigated. The results show that the gasification reactivity of SC is lower than BR, which is due to the higher order degree of carbonaceous structure and the lower alkali metal content in the ash, and the addition of BR can significantly improve the gasification reaction performance. Meanwhile, the synergistic effect between BR and SC was evidenced by the experimental and theoretical results. The gasification process of different chars was described with three typical kinetic models: unreacted core model (URCM), volumetric model (VM) and random pore model (RPM). The findings show that the performance of RPM is better than URCM and VM, and there is a significant kinetic compensation effect in the co-gasification reaction of BR and SC through kinetic fitting
Tailoring mechanical and electrical properties of graphene oxide film for structural dielectric capacitors
No full textGraphene oxide (GO) films can be used in structural dielectric capacitors (SDCs) as both primary structures and energy storage devices for large transportation equipment like aircraft. To meet the high requirements for aviation application, in this paper the mechanical and dielectric properties of GO films were optimized by concisely tailoring their carbon-to-oxygen (C/O) ratio. Our results show that both the mechanical and electrical conductivity of GO films increase with increasing the C/O ratio. This work also demonstrates that both mechanical and dielectric properties of GO films can be enhanced simultaneously through a mild reduction whilst retaining the electrical insulating nature of GO for SDC applications. The insights provided in this work would be beneficial not only for SDC applications but also for fundamental studies and developments of GO related materials
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