Short- and long-term movement patterns in the freshwater whipray (Himantura dalyensis) determined by the signal processing of passive acoustic telemetry data.

Patterns of movement in aquatic animals reflect ecologically important behaviours. Cyclical changes in the abiotic environment influence these movements, but when multiple processes occur simultaneously, identifying which is responsible for the observed movement can be complex. Here we used acoustic telemetry and signal processing to define the abiotic processes responsible for movement patterns in freshwater whiprays (Himantura dalyensis). Acoustic transmitters were implanted into the whiprays and their movements detected over 12 months by an array of passive acoustic receivers, deployed throughout 64 km of the Wenlock River, Qld, Australia. The time of an individual's arrival and departure from each receiver detection field was used to estimate whipray location continuously throughout the study. This created a linear-movement-waveform for each whipray and signal processing revealed periodic components within the waveform. Correlation of movement periodograms with those from abiotic processes categorically illustrated that the diel cycle dominated the pattern of whipray movement during the wet season, whereas tidal and lunar cycles dominated during the dry season. The study methodology represents a valuable tool for objectively defining the relationship between abiotic processes and the movement patterns of free-ranging aquatic animals and is particularly expedient when periods of no detection exist within the animal location data.

Processing small diameter logs from sub-tropical species

Small spindleless veneer lathe technology was used to produce veneer sheets as an alternative processing option to optimise the use of small log plantation resource. Thinned (300 spha) and unthinned control (1000 spha) plantings of 10.5-year-old Corymbia citriodora ssp. variegata (CCV) and E. dunnii (Dunn’s white gum) grown in two contrasting sites from climatic regions with large annual rainfall differences were studied. Overall veneer gross recoveries ranged from 50% to 70%, which were up to 3 times higher than typical sawn green-off saw recoveries from small plantation hardwood logs of similar diameter. Major limiting factors preventing veneer from meeting higher grades were the presence of kino defects and encased knots. Splits in E. dunnii veneer also contributed to reduced grade quality. Differences between two thinning treatments for veneer properties and grade recovery were generally small. There was significant evidence of site and species differences on veneer quality. The good quality site with higher rainfall in northern New South Wales produced denser and stiffer veneers with higher grade recoveries. CCV is a superior structural veneer species with high wood density and hardness as well as very good veneer stiffness exceeding 15,000 MPa but Dunn’s white gum has also demonstrated good potential as a useful structural plywood resource. Results indicate that relatively high veneer recoveries were achieved for the sub-tropical plantation hardwoods combined with very superior mechanical properties which suggest that veneer production have suitable attributes for a range of engineered wood products including plywood and laminated veneer lumber.

Processing Tomato Production in the Burdekin: Opportunities and Risks for Growers

The research undertaken here was in response to a decision by a major food producer in about 2009 to consider establishing processing tomato production in northern Australia. This was in response to a lack of water availability in the Goulburn Valley region following the extensive drought that continued until 2011. The high price of water and the uncertainty that went with it was important in making the decision to look at sites within Queensland. This presented an opportunity to develop a tomato production model for the varieties used in the processing industry and to use this as a case study along with rice and cotton production. Following some unsuccessful early trials and difficulties associated with the Global Financial Crisis, large scale studies by the food producer were abandoned. This report uses the data that was collected prior to this decision and contrasts the use of crop modelling with simpler climatic analyses that can be undertaken to investigate the impact of climate change on production systems. Crop modelling can make a significant contribution to our understanding of the impacts of climate variability and climate change because it harnesses the detailed understanding of physiology of the crop in a way that statistical or other analytical approaches cannot do. There is a high overhead, but given that trials are being conducted for a wide range of crops for a variety of purposes, breeding, fertiliser trials etc., it would appear to be profitable to link researchers with modelling expertise with those undertaking field trials. There are few more cost-effective approaches than modelling that can provide a pathway to understanding future climates and their impact on food production.

Vegetables containing phytochemicals with potential anti-obesity properties: A review

The incidence of obesity is rising worldwide at an alarming rate and is becoming a major public health concern with incalculable social and economic costs. Studies have exposed the relationship between the adiposity, inflammation and the development of other metabolic disorders, so dietary factors that influence some or all of these are of interest. Dietary phytochemicals appear to be able to target different stages of the adipocyte (fat cell) lifecycle. For example, several classes of polyphenols have been implicated in suppressing the growth of adipose tissue through modifying the adipocyte lifecycle. Many dietary phytochemicals also have strong anti-inflammatory activity, but the amount present in plants varies and may be affected by processing. In this review we summarise the likely mechanisms of action of plant phytochemicals. We highlight the major vegetable sources of polyphenols, including those with possible synergistic attributes, discuss the variation in polyphenol levels and their distribution in cultivars and outline the effects of food processing. The identification and characterisation of the anti-obesogenic properties of phytochemicals in vegetables, as well as an appreciation of the effect of cooking on phytochemical content provide significant new information supporting dietary guidelines that encourage vegetable consumption for the prevention and management of lifestyle related disease.

Comparative effects of thermal and high pressure processing on phenolic phytochemicals in different strawberry cultivars

Abstract It is widely considered that high pressure processing (HPP) results in better retention of micronutrients and phytochemicals compared to thermal pasteurization (TP), although some studies indicate that this may not be true in all cases. The aims of this study were (1) to objectively compare the effects of HPP under commercial processing conditions with thermal pasteurization (TP) on the stability of phenolic antioxidants in strawberries following processing and during storage and (2) to evaluate the influence of varietal differences and hence differences in biochemical composition of strawberries on the stability of phenolic antioxidants. Strawberry puree samples from cultivars Camarosa, Rubygem, and Festival were subjected to HPP (600 MPa/20 °C/5 min) and TP (88 °C/2 min). The activities of oxidative enzymes were evaluated before and after processing. Furthermore, the antioxidant capacity (total phenolic content (TPC), oxygen radical absorbance capacity (ORAC), and ferric reducing antioxidant power (FRAP)) and individual anthocyanins (by HPLC) were determined prior to and following processing and after three months of refrigerated storage (4 °C). Depending on the cultivar, HPP caused 15–38% and 20–33% inactivation of polyphenol oxidase and peroxidase, respectively, compared to almost complete inactivation of these enzymes by TP. Significant decreases (p < 0.05) in ORAC, FRAP, TPC and anthocyanin contents were observed during processing and storage of both HPP and TP samples. Anthocyanins were the most affected with only 19–25% retention after three months of refrigerated storage (4 °C). Slightly higher (p < 0.05) loss of TPC and antioxidant capacity were observed during storage of HPP samples compared to TP. Industrial Relevance: The results of the study demonstrated that both high pressure processing and thermal pasteurization result in high retention of phenolic phytochemicals in strawberry products. Under the conditions investigated, high pressure processing did not result in a better retention of phenolic phytochemicals compared to thermal pasteurization. In fact, a slightly higher loss of total polyphenol content and antioxidant capacity were observed during refrigerated storage of HPP processed samples. Our results showed that, high pressure processing may not always be a better alternative to thermal processing for strawberry puree processing if the main objective is better retention of phenolic antioxidants. However, it should be noted that other quality attributes such as sensory properties, where distinct advantages of HPP are expected, were outside the scope of this study.

Japanese plums (Prunus salicina Lindl.) and phytochemicals – breeding, horticultural practice, post-harvest storage, processing and bioactivity

Previous reviews of plum phytochemical content and health benefits have concentrated on the European plum, Prunus domestica L.. However, the potential bioactivity of red and dark red fleshed Japanese plum, Prunus salicina Lindl., so called blood plums, appears to warrant a significant increase in exposure as indicated in a recent review of the whole Prunus genus. Furthermore, Japanese plums are the predominate plum produced on an international basis. In this review the nutrient and phytochemical content, breeding programs, horticultural practice, post harvest treatment and processing as well as bioactivity (emphasizing in vivo studies) of Japanese plum are considered with a focus on the anthocyanin content that distinguishes the blood plums.

Harvesting, packing, postharvest technology, transport and processing

This chapter provides updated information on avocado fruit quality parameters, sensory perception and maturity, production and postharvest factors affecting quality defects, disinfestation and storage (including pre-conditioning), predicting outturn quality and processing.

Quantitative effects of in-line operations on Campylobacter and Escherichia coli through two Australian broiler processing plants

Campylobacter is an important food borne pathogen, mainly associated with poultry. A lack of through-chain quantitative Campylobacter data has been highlighted within quantitative risk assessments. The aim of this study was to quantitatively and qualitatively measure Campylobacter and Escherichia coli concentration on chicken carcasses through poultry slaughter. Chickens (n = 240) were sampled from each of four flocks along the processing chain, before scald, after scald, before chill, after chill, after packaging and from individual caeca. The overall prevalence of Campylobacter after packaging was 83% with a median concentration of 0.8 log10 CFU/mL. The processing points of scalding and chilling had significant mean reductions of both Campylobacter (1.8 and 2.9 log10 CFU/carcase) and E. coli (1.3 and 2.5 log10 CFU/carcase). The concentration of E. coli and Campylobacter was significantly correlated throughout processing indicating that E. coli may be a useful indicator organism for reductions in Campylobacter concentration. The carriage of species varied between flocks, with two flocks dominated by Campylobacter coli and two flocks dominated by Campylobacter jejuni. Current processing practices can lead to significant reductions in the concentration of Campylobacter on carcasses. Further understanding of the variable effect of processing on Campylobacter and the survival of specific genotypes may enable more targeted interventions to reduce the concentration of this poultry associated pathogen.

Downstream processing of reverse osmosis brine: Characterisation of potential scaling compounds

Reverse osmosis (RO) brine produced at a full-scale coal seam gas (CSG) water treatment facility was characterized with spectroscopic and other analytical techniques. A number of potential scalants including silica, calcium, magnesium, sulphates and carbonates, all of which were present in dissolved and non-dissolved forms, were characterized. The presence of spherical particles with a size range of 10–1000 nm and aggregates of 1–10 microns was confirmed by transmission electron microscopy (TEM). Those particulates contained the following metals in decreasing order: K, Si, Sr, Ca, B, Ba, Mg, P, and S. Characterization showed that nearly one-third of the total silicon in the brine was present in the particulates. Further, analysis of the RO brine suggested supersaturation and precipitation of metal carbonates and sulphates during the RO process should take place and could be responsible for subsequently capturing silica in the solid phase. However, the precipitation of crystalline carbonates and sulphates are complex. X-ray diffraction analysis did not confirm the presence of common calcium carbonates or sulphates but instead showed the presence of a suite of complex minerals, to which amorphous silica and/or silica rich compounds could have adhered. A filtration study showed that majority of the siliceous particles were less than 220 nm in size, but could still be potentially captured using a low molecular weight ultrafiltration membrane.

Mapping the carriage of flaA-restriction fragment length polymorphism Campylobacter genotypes on poultry carcasses through the processing chain and comparison to clinical isolates

Poultry are considered a major source for campylobacteriosis in humans. A total of 1866 Campylobacter spp. isolates collected through the poultry processing chain were typed using flaA-restriction fragment length polymorphism to measure the impact of processing on the genotypes present. Temporally related human clinical isolates (n = 497) were also typed. Isolates were obtained from whole chicken carcass rinses of chickens collected before scalding, after scalding, before immersion chilling, after immersion chilling and after packaging as well as from individual caecal samples. A total of 32 genotypes comprising at least four isolates each were recognised. Simpson's Index of Diversity (D) was calculated for each sampling site within each flock, for each flock as a whole and for the clinical isolates. From caecal collection to after packaging samples the D value did not change in two flocks, decreased in one flock and increased in the fourth flock. Dominant genotypes occurred in each flock but their constitutive percentages changed through processing. There were 23 overlapping genotypes between clinical and chicken isolates. The diversity of Campylobacter is flock dependant and may alter through processing. This study confirms that poultry are a source of campylobacteriosis in the Australian population although other sources may contribute.

Benzyl isothiocyanate: maximising production in papaya tissue extracts

Abstract: Although mainly grown for its sweet flavoured fruit, papaya (Carica papaya) has also been used for pharmacological purposes for many years. The reasons for use are varied with one of the best known being its anti-fungal action. Benzyl isothiocyanate (BITC) is the constituent most often implicated in this activity. Isothiocyanates are formed when the enzyme myrosinase catalyses the hydrolysis of the non-bioactive glucosinolates. This occurs when cellular contents come into contact through chewing, cutting or during extraction processes in the laboratory. While this is common in Brassica vegetables, the glucosinolate-myrosinase system is rare in fruit, papaya being a notable exception. It contains benzyl glucosinolate (BG), the glucosinolate precursor of BITC, in significant quantities. Parameters that determine the amount of BITC formed are duration of hydrolysis, presence/absence of nitrile-specifier proteins and BG content of different cultivars and tissues. We experimented with differing BITC extraction solvents, with the intention of developing a low cost, natural anti-fungal extract based on under-utilised papaya tissues. The findings suggest that papaya seeds, particularly from quarter-ripe fruit, have the potential to produce the highest levels of BITC necessary. Furthermore, they compare well with the nitrile-specifier protein-containing garden cress seeds (Lepidium sativum). To utilise the papaya seeds as a BITC source, an organic solvent such as ethanol is required to extract the largely water-insoluble BITC from the hydrolysed papaya seed mixture.

Natural Hendra Virus Infection in Flying-Foxes - Tissue Tropism and Risk Factors

Hendra virus (HeV) is a lethal zoonotic agent that emerged in 1994 in Australia. Pteropid bats (flying-foxes) are the natural reservoir. To date, HeV has spilled over from flying-foxes to horses on 51 known occasions, and from infected horses to close-contact humans on seven occasions. We undertook screening of archived bat tissues for HeV by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Tissues were tested from 310 bats including 295 Pteropodiformes and 15 Vespertilioniformes. HeV was detected in 20 individual flying-foxes (6.4%) from various tissues including spleen, kidney, liver, lung, placenta and blood components. Detection was significantly higher in Pteropus Alecto and Pconspicillatus, identifying species as a risk factor for infection. Further, our findings indicate that HeV has a predilection for the spleen, suggesting this organ plays an important role in HeV infection. The lack of detections in the foetal tissues of HeV-positive females suggests that vertical transmission is not a regular mode of transmission in naturally infected flying-foxes, and that placental and foetal tissues are not a major source of infection for horses. A better understanding of HeV tissue tropism will strengthen management of the risk of spillover from flying-foxes to horses and ultimately humans.