Thomas H. Roberts

Knowledge of the influence of particle size, blending, and processing temperature on flour functionality is critical for the utilisation of emerging grains. This study investigated the flour pasting behaviour of four Australian native grains—Button Grass, Curly Mitchell Grass, Native Millet, and Weeping Grass—in relation to particle size, wheat flour substitution at various levels (0–30%), and elevated RVA temperatures (95–140 °C). The pasting properties of flour fractions (fine, medium, and wholegrain) were analysed using a Rapid Visco Analyser, and water absorption capacity was also determined. Particle size effects were species-specific. Native Millet and wheat had higher viscosity in the finer fractions, whereas Weeping Grass exhibited maximum viscosity in the medium fraction. Button Grass and Curly Mitchell Grass showed limited sensitivity to particle size, indicating a stronger influence of intrinsic structure. Increasing substitution with native flours generally reduced viscosity, except for Weeping Grass, which was less affected and maintained stable viscosity. High-temperature rapid visco analysis revealed distinct thermal responses: most grains showed reduced final viscosity at elevated temperatures, whereas Weeping Grass maintained relatively high final viscosity across most temperatures. These findings demonstrate the diverse functional behaviour of Australian native grains and provide insights into their potential application in gluten-free and composite flour systems.

Why was the work done?: Gluten-free (GF) beers typically exhibit poorer foam stability than conventional barley malt-based beers, yet the molecular basis underlying this difference remains poorly understood. This study aimed to investigate protein-level factors associated with foam stability in GF and barley beers. How was the work done?: Three commercially produced GF beers, comprising two lagers brewed from rice or sorghum, and one pale ale brewed from a millet-buckwheat-rice blend, were compared with two commercially produced barley-malt beers, comprising a lager and a pale ale. Soluble protein was isolated from freeze-dried beer powder using TCA-acetone. Protein profiles were examined using SDS-PAGE, and proteomes were characterised and compared using label-free quantitative LC-MS/MS. What are the main findings?: GF beers showed lower soluble protein concentrations and significantly lower foam stability than the barley beers. SDS-PAGE revealed fewer and weaker protein bands in GF beers compared with barley beers. Proteomic analysis showed that barley beers were enriched in known foam-active proteins, particularly lipid transfer protein 1 (LTP1) and Protein Z (serpin family members), whereas these proteins were not detected or were detected only at very low levels in GF beers.

Summary: Leaf rust, caused by Puccinia hordei , is a major barley disease worldwide. Despite repeated shifts in virulence, contrasting reproductive histories, and emerging fungicide insensitivity, the genomic basis of its diversification and adaptation remains poorly understood. In this study, we generated haplotype‐resolved, chromosome‐level genome assemblies for two isolates with contrasting virulence and analyzed 41 Australian isolates collected over 54 yr (1966–2020), integrating comparative and population genomics, mating‐type gene phylogenies, chromosome‐specific k ‐mer profiling, genome‐wide copy‐number variation (CNV) analysis, and gene‐expression analysis. We identified a structurally dynamic chromosome characterized by repeat‐associated rearrangements, structural variation, and lineage‐associated CNV, representing the first evidence in a rust fungus of chromosome‐scale structural diversification of this extent. Population analyses distinguished clonally expanded lineages from recombination‐associated lineages, with mating‐type gene phylogenies providing further support for lineage differentiation. More recently collected isolates showed increased duplication‐associated variation, and CNV boundaries were associated with structural‐variant breakpoints. We also identified lineage‐associated amplification of Cyp51 , with increased copy number associated with higher transcript abundance, supporting a potential role in fungicide adaptation. Overall, our findings highlight structural variation, contrasting reproductive histories, and lineage‐associated CNV as important contributors to diversification in P. hordei , providing insights for future rust pathogen surveillance and management strategies.

Heatwaves during flowering and grain development threaten global wheat production, yet the extent to which developmental stage shapes molecular and phenotypic responses remains unclear. Here, we investigated whether heat stress (36/29°C for 48 h) imposed at closely spaced developmental stages surrounding anthesis generates stage-specific molecular responses that are associated with subsequent effects on grain properties. Heat exposure increased floret abortion most strongly when it was imposed at the trinucleate stage (TN; ∼48%) compared with the binucleate (BN) and early post-anthesis stages. Methylation levels were largely unaffected by prior heat treatments; however, heat induced stage- and locus-specific methylation changes, particularly at BN. Spatial RNA-seq revealed tissue-specific heat responses that were distinctively different in BN and TN. Integrated metabolomic analyses revealed stage-dependent metabolic reprogramming, including shifts towards stress-associated pathways. Despite heat stress at BN generating broader molecular reprogramming in developing grain, exposure at TN produced stronger effects on grain set and composition, revealing a decoupling between the magnitude of responses and phenotypic outcomes. Together, these findings demonstrate that subtle differences in developmental stage influence the complex molecular responses to heat and subsequent grain properties.

Sorghum consumption has potential health-promoting effects for consumers. This study identified sorghum-containing grain-based food products available in major supermarkets in China and Australia. A total of 1,692 products were audited in Shenzhen, China and Illawarra, Australia, in 2023/24. Breakfast cereals and snack bars were evaluated in both countries, while flours, pastas, and noodles were evaluated only in Australia. Information on ingredients, including the presence of sorghum, food format, brand, product name, wholegrain/gluten-free labelling was recorded. In China, sorghum was found in 4.3% (12/279) of breakfast cereals, with only 1/12 sorghum-containing breakfast cereals listed sorghum in the first position of the ingredient list. Sorghum was found in 2.0% (9/458) of snack bars and was listed as either ‘sorghum’ (n = 3) or ‘sorghum flour’ (n = 6). In Australia, sorghum was found in 22/356 (6.2%) breakfast cereals, 9/285 (3.2%) snack bars, and was absent from all flours, pastas, and noodles. Most sorghum-containing cereals were extruded (36.4%) and labelled gluten-free (16/22, 73%) or wholegrain (14/22, 64%). Sorghum-containing snack bars, notably oat-bake and muesli bars, were mostly made from sorghum flour and flakes. Sorghum appeared in the first position in the ingredient list in 2/22 (9.1%) of breakfast cereals, and in the third or higher position for all snack bars. Among the breakfast cereal and snack bar subcategories analyzed, there were no significant differences in sorghum utilization between China and Australia (Fisher’s Exact Tests, p < 0.05), except for oat bake snack bars (higher in China, p = 0.0265). Overall, the audit data suggests that sorghum is not widely incorporated as an ingredient in common grain-based food products available to consumers in major Chinese and Australian supermarkets. Greater awareness of its potential consumer health benefits is needed to drive utilization of sorghum grain in foods across different markets.

Sorghum consumption has potential health-promoting effects for consumers. This study identified and compared sorghum-containing grain-based food products available in major supermarkets in China and Australia. A total of 1,692 products were audited in Shenzhen, China and Illawarra, Australia, in 2023/24. Breakfast cereals, snack bars, flours, pastas, and noodles were evaluated. Information on ingredients, including the presence of sorghum, food format, brand, product name, wholegrain/gluten-free labelling was recorded. In China, sorghum was found in 4.3% (12/279) of breakfast cereals, with only 1/12 sorghum-containing breakfast cereals listed sorghum in the first position of the ingredient list. Sorghum was found in 2.0% (9/458) of snack bars and was listed as either ‘sorghum’ (n=3) or ‘sorghum flour’ (n=6). In Australia, sorghum was found in 22/356 (6.2%) breakfast cereals, 9/285 (3.2%) snack bars, and was absent from all flours, pastas, and noodles. Most sorghum-containing cereals were extruded (36.4%) and labelled gluten-free (16/22, 73%) or wholegrain (14/22, 64%). Sorghum-containing snack bars, notably oat-bake and muesli bars, were mostly made from sorghum flour and flakes. Sorghum appeared in the first position in the ingredient list in 2/22 (9.1%) of breakfast cereals, and in the third or higher position for all snack bars. Among the breakfast cereal and snack bar subcategories analyzed, there were no significant differences in sorghum utilization between China and Australia (Fisher’s Exact Tests, p < 0.05), except for oat bake snack bars (higher in China, p = 0.0265). Overall, the audit data supported the conclusion that sorghum is underutilized as an ingredient in common grain-based food products available to consumers in major Chinese and Australian supermarkets. Greater awareness of its potential consumer health benefits is needed to drive utilization of sorghum grain in foods across different markets.

Grains of Australian native grasses have been important components of traditional Aboriginal diets for millennia and have the potential for increased utilisation in contemporary food systems. This study assessed the macronutrient profiles of whole grains from Dactyloctenium radulans (Button Grass), Astrebla lappacea (Curly Mitchell Grass), Panicum decompositum (Native Millet), and Microlaena stipoides (Weeping Grass) compared to wheat, barley, and sorghum using proximate analysis, Osborne protein fractionation, gel electrophoresis, and carbohydrate assays. Key results were that Native Millet had high lipid content (8.0 g/100 g dry weight basis (db)), Curly Mitchell Grass had high protein (29.1 g/100 g db) and low carbohydrate content (64.0 g/100 g db), and there were substantial differences in prolamin and glutelin fractions across the species. All four native grains were gluten-free, and their starch amylose content ranged from 25.7% (Button Grass) to 41.2% (Curly Mitchell Grass), which affects starch properties. Button Grass had the highest dietary fibre content (21.9 g/100 g db), while Weeping Grass had the highest beta-glucan levels (8.6 g/100 g db), supporting functional food applications. Our findings highlight the potential for an expanded range of food applications for these grains and their contribution to human nutrition, together with implications for supporting Indigenous-led enterprises.

Large-scale cellular production systems offer a significant and diverse benefit impacting the therapeutic (stem cell and vaccine production) and cellular agriculture (lab-grown meat) sectors. Producing desired cells at mass can improve production yield whilst reducing the environmental and ethical burden associated with industrialised agriculture and production of therapeutic goods. Many existing large-scale cultivation strategies of adherent cells leverage the use of microcarriers (MCs) within bioreactors. However, currently commercial MCs are not dissolvable and lack specificity for different cell types and bioprocessing contexts. In this work, we validate the effectiveness of customisable, polymeric MCs engineered to enhance cell growth and productivity. These MCs, which can be adjusted in terms of stiffness, surface charge, and size, maintain their structural integrity while offering precise property modifications. Under specific bioprocessing conditions, the custom MCs demonstrated significant improvements in cell productivity and sustainability compared to other commercial options. Our study (1) highlights how tailored substrate properties, particularly stiffness, can significantly impact cell yield and outcomes, and (2) suggests additional optimisations in surface charge and size that could further enhance MC technology. These advancements have the potential to improve large-scale cell and virus production efficiency, ultimately reducing the cost of production.

Pulses are grown worldwide and provide agronomic benefits that contribute to the sustainability of cropping systems. Pulses are high in protein and provide a good source of carbohydrates, dietary fibre, vitamins, minerals, and bioactive constituents. Crops such as lupins, chickpeas, faba beans, field peas, lentils, and mung beans, and the diversity of varieties among them, provide enormous opportunities for processing protein ingredients for use in new and existing food formulations. This review highlights the nutritional properties of pulses, protein quality, functionality, and applications for pulse protein ingredients. Understanding the functionality of pulse proteins, and the unique properties between different pulses in terms of solubility, water- and oil-holding capacity, emulsification, gelation, and foaming properties, will help maximise their use in plant-based meat and dairy alternatives, beverages, bakery products, noodles, pasta, and nutritional supplements. In this review, researchers, food technologists, and food manufacturers are provided with a comprehensive resource on pulses, and the diverse applications for pulse protein ingredients within the context of food manufacturing and the constantly evolving food technology landscape.

Summary: The development of male gametes, vital to sexual reproduction in crops, requires meiosis followed by successive mitotic cell divisions of haploid cells. The formation of viable pollen is especially vulnerable to abiotic stress, with consequences both for yield and for grain quality. An understanding of key molecular responses when specific stages during pollen development are subjected to stress (e.g. heat) is possible only when sampling is carefully informed by developmental biology. Traditionally, morphological characteristics have been commonly used in cereals as ‘indicators’ of male reproductive stages. We argue that these morphological attributes are strongly influenced by genotype and genotype–environment interactions and cannot be used reliably to define developmental events during microsporogenesis and microgametogenesis. Furthermore, asynchronous development along the axis of a single inflorescence calls for selective sampling of individual florets to define specific reproductive stages accurately. We therefore propose guidelines to standardise the sampling of cells during male reproductive development, particularly when interrogating the impact of stress on susceptible meiosis. Improved knowledge of development will largely negate the variability imposed by genotype, environment and asynchronous development of florets. Highlighting the subtleties required for sampling and investigation of male reproductive stages will make the selection of abiotic stress‐tolerant cereal genotypes more reliable.