Progress towards the production of potatoes and cereals with low acrylamide-forming potential

The presence of acrylamide in foods derived from grains, tubers, storage roots, beans and other crop products has become a difficult problem for the food industry. Here we review how acrylamide is formed predominantly from free asparagine and reducing sugars, the relationship between precursor concentration and acrylamide formation, and the challenge of complying with increasingly stringent regulations. Progress made in reducing acrylamide levels in foods is assessed, along with the difficulty of dealing with a raw material that may be highly variable due to plant responses to nutrition, disease and cold storage. The potential for plant breeding and biotechnology to deliver low acrylamide varieties is assessed, in the context of a regulatory landscape covering acrylamide, crop biotechnology and crop protection

The sulphur response in wheat and its implications for acrylamide formation and food safety

Free (soluble, non-protein) asparagine concentration can increase many-fold in wheat grain in response to sulphur deficiency. This exacerbates a major food safety and regulatory compliance problem for the food industry because free asparagine may be converted to the carcinogenic contaminant, acrylamide, during baking and processing. Here we describe the predominant route for the conversion of asparagine to acrylamide in the Maillard reaction. The effect of sulphur deficiency and its interaction with nitrogen availability is reviewed, and we reiterate our advice that sulphur should be applied to wheat being grown for human consumption at a rate of 20 kg per hectare. We describe the genetic control of free asparagine accumulation, including genes that encode metabolic enzymes (asparagine synthetase, glutamine synthetase, glutamate synthetase and asparaginase), regulatory protein kinases (SnRK1 and GCN2) and bZIP transcription factors, and how this genetic control responds to sulphur, highlighting the importance of asparagine synthetase-2 (ASN2) expression in the embryo. We show that expression of glutamate-cysteine ligase is reduced in response to sulphur deficiency, probably compromising glutathione synthesis. Finally, we describe unexpected effects of sulphur deficiency on carbon metabolism in the endosperm, with large increases in expression of sucrose synthase-2 (SuSy2) and starch synthases

Baseline and greenhouse-gas emissions in extensive livestock enterprises, with a case study of feeding lipid to beef cattle

For accurate calculation of reductions in greenhouse-gas (GHG) emissions, methodologies under the Australian Government's Carbon Farming Initiative (CFI) depend on a valid assessment of the baseline and project emissions. Life-cycle assessments (LCAs) clearly show that enteric methane emitted from the rumen of cattle and sheep is the major source of GHG emissions from livestock enterprises. Where a historic baseline for a CFI methodology for livestock is required, the use of simulated data for cow-calf enterprises at six sites in southern Australia demonstrated that a 5-year rolling emission average will provide an acceptable trade off in terms of accuracy and stability, but this is a much shorter time period than typically used for LCA. For many CFI livestock methodologies, comparative or pair-wise baselines are potentially more appropriate than historic baselines. A case study of lipid supplementation of beef cows over winter is presented. The case study of a control herd of 250 cows used a comparative baseline derived from simple data on livestock numbers and class of livestock to quantify the emission abatement. Compared with the control herd, lipid supplementation to cows over winter increased livestock productivity, total livestock production and enterprise GHG emissions from 990 t CO2-e to 1022 t CO2-e. Energy embodied in the supplement and extra diesel used in transporting the supplement diminished the enteric-methane abatement benefit of lipid supplementation. Reducing the cow herd to 238 cows maintained the level of livestock production of the control herd and reduced enterprise emissions to 938 t CO2-e, but was not cost effective under the assumptions of this case study

Baseline and greenhouse-gas emissions in extensive livestock enterprises, with a case study of feeding lipid to beef cattle

For accurate calculation of reductions in greenhouse-gas (GHG) emissions, methodologies under the Australian Government's Carbon Farming Initiative (CFI) depend on a valid assessment of the baseline and project emissions. Life-cycle assessments (LCAs) clearly show that enteric methane emitted from the rumen of cattle and sheep is the major source of GHG emissions from livestock enterprises. Where a historic baseline for a CFI methodology for livestock is required, the use of simulated data for cow-calf enterprises at six sites in southern Australia demonstrated that a 5-year rolling emission average will provide an acceptable trade off in terms of accuracy and stability, but this is a much shorter time period than typically used for LCA. For many CFI livestock methodologies, comparative or pair-wise baselines are potentially more appropriate than historic baselines. A case study of lipid supplementation of beef cows over winter is presented. The case study of a control herd of 250 cows used a comparative baseline derived from simple data on livestock numbers and class of livestock to quantify the emission abatement. Compared with the control herd, lipid supplementation to cows over winter increased livestock productivity, total livestock production and enterprise GHG emissions from 990 t CO2-e to 1022 t CO2-e. Energy embodied in the supplement and extra diesel used in transporting the supplement diminished the enteric-methane abatement benefit of lipid supplementation. Reducing the cow herd to 238 cows maintained the level of livestock production of the control herd and reduced enterprise emissions to 938 t CO2-e, but was not cost effective under the assumptions of this case study

Caring for a marginalised community: the costs of engaging with culture and complexity

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.The Care and Prevention Programme (CPP) began in 1998. It is based on the philosophy of primary health care, and has improved health among homosexually active men, including about a third of HIV-positive South Australians. The CPP was assessed using financial analysis and qualitative methods. Participants wanted to access care where they could feel comfortable and safe to talk about issues of sexuality and lifestyle. The CPP model is "economically" sustainable, but not "financially" sustainable within the Medicare Benefits Schedule. It is vulnerable to changes in political environment. The financing model for the CPP has been adapted by including state funding. General practitioners have adapted by lowering their personal incomes (but not quality of care). These adaptations have achieved fragile financial viability. Facilitators of sustainability for the CPP included: It is part of the community that it serves; The creation of deeply integrated networks of diversity-competent service providers; and "Virtuous non-adaptability" of service providers in refusing to compromise care standards despite financial pressure to do so. Threats to sustainability included: Difficulty maintaining a diversity-competent workforce skilled in HIV medicine; Marginal financial viability; and Political vulnerability.Gary D Rogers, Christopher A Barton, Brita A Pekarsky, Ann C Lawless, Joy M Oddy, Rebecca Hepworth and Justin J Beilb

Stress, nutrients and genotype: understanding and managing asparagine accumulation in wheat grain

Plant stress and poor crop management strategies compromise the foundations of food security: crop yield, nutritional quality and food safety. Accumulation of high concentrations of the amino acid asparagine in its free (soluble, non-protein) form is an example of an undesirable outcome of stress for the nutritional quality and food safety of wheat because of its role as a precursor to acrylamide, a carcinogenic processing contaminant. In this review, we cover what is known about the mechanisms and functions of free asparagine accumulation in the grain during normal development and particularly during stress in wheat. Comparisons with other plant species, yeast, and mammals are drawn in order to gain deeper insight into the conserved biology underlying asparagine accumulation. Crop management strategies and practices are discussed in the context of managing asparagine accumulation, which must be balanced against other desirable goals, such as sustainability, protein content and yield

Heavy metals in suburban gardens and the implications of land-use change following a major earthquake

Numerous studies have shown that urban soils can contain elevated concentrations of heavy metals (HMs). Christchurch, New Zealand, is a relatively young city (150 years old) with a population of 390,000. Most soils in Christchurch are sub-urban, with food production in residential gardens a popular activity. Earthquakes in 2010 and 2011 have resulted in the re-zoning of 630 ha of Christchurch, with suggestions that some of this land could be used for community gardens. We aimed to determine the HM concentrations in a selection of suburban gardens in Christchurch as well as in soils identified as being at risk of HM contamination due to hazardous former land uses or nearby activities. Heavy metal concentrations in suburban Christchurch garden soils were higher than normal background soil concentrations. Some 46% of the urban garden samples had Pb concentrations higher than the residential land use national standard of 210 mg kg⁻¹, with the most contaminated soil containing 2615 mg kg⁻¹ Pb. Concentrations of As and Zn exceeded the residential land use national standards (20 mg kg⁻¹ As and 400 mg kg⁻¹ Zn) in 20% of the soils. Older neighbourhoods had significantly higher soil HM concentrations than younger neighbourhoods. Neighbourhoods developed pre-1950s had a mean Pb concentration of 282 mg kg⁻¹ in their garden soils. Soil HM concentrations should be key criteria when determining the future land use of former residential areas that have been demolished because of the earthquakes in 2010 and 2011. Redeveloping these areas as parklands or forests would result in less human HM exposure than agriculture or community gardens where food is produced and bare soil is exposed

Prospective associations between dietary patterns and cognitive performance during adolescence

Background: The aim of the study was to investigate prospective associations between dietary patterns and cognitive performance during adolescence .Methods: Participants were sourced from the Western Australian Pregnancy Cohort (Raine) Study that includes 2868 children born between 1989 and 1992 in Perth, Western Australia. When the children were 17 years old (2006–2009), cognitive performance was assessed using a computerized cognitive battery of tests (CogState) that included six tasks. Using a food frequency questionnaire administered when the children were 14 years old (2003–2006), ‘Healthy’ and ‘Western’ dietary patterns were identified by factor analysis. Associations between dietary patterns at 14 years of age and cognitive performance at 17 years of age were assessed prospectively using multivariate regression models.Results: Dietary and cognitive performance data were available for 602 participants. Following adjustment for the ‘Healthy’ dietary pattern, total energy intake, maternal education, family income, father's presence in the family, family functioning and gender, we found that a longer reaction time in the detection task (ß = .016; 95% CI: 0.004; 0.028; p = .009) and a higher number of total errors in the Groton Maze Learning Test – delayed recall task (ß = .060; 95% CI: 0.006; 0.114; p = .029) were significantly associated with higher scores on the ‘Western’ dietary pattern. The ‘Western’ dietary pattern was characterized by high intakes of take-away food, red and processed meat, soft drink, fried and refined food. We also found that within the dietary patterns, high intake of fried potato, crisps and red meat had negative associations, while increased fruit and leafy green vegetable intake had positive associations with some aspects of cognitive performance. Conclusion: Higher dietary intake of the ‘Western’ dietary pattern at age 14 is associated with diminished cognitive performance 3 years later, at 17 years