Andreas Kiermeier

South Australian Research and Development Institute, Tarndarnya, South Australia, Australia

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Publications (33)70.37 Total impact

  • Andreas Kiermeier · John Sumner · Ian Jenson
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    ABSTRACT: Australia exports about 150,000 to 200,000 tons of manufacturing beef to the United States annually. Each lot is tested for Escherichia coli O157 using the N-60 sampling protocol, where 60 small pieces of surface meat from each lot of production are tested. A risk assessment of E. coli O157 illness from the consumption of hamburgers made from Australian manufacturing meat formed the basis to evaluate the effect of sample size and amount on the number of illnesses predicted. The sampling plans evaluated included no sampling (resulting in an estimated 55.2 illnesses per annum), the current N-60 plan (50.2 illnesses), N-90 (49.6 illnesses), N-120 (48.4 illnesses), and a more stringent N-60 sampling plan taking five 25-g samples from each of 12 cartons (47.4 illnesses per annum). While sampling may detect some highly contaminated lots, it does not guarantee that all such lots are removed from commerce. It is concluded that increasing the sample size or sample amount from the current N-60 plan would have a very small public health effect.
    Journal of food protection 07/2015; 78(7):1370-1374. DOI:10.4315/0362-028X.JFP-14-558 · 1.80 Impact Factor
  • Felicity Brake · Tom Ross · Geoffrey Holds · Andreas Kiermeier · Catherine McLeod
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    ABSTRACT: Impending international policies for norovirus in oysters and the lack of Australian data suggested there was a need to undertake a national survey of norovirus in oysters. Two geographically distinct oyster-growing areas from each of three Australian states were sampled on 4 occasions during 2010 and 2011. The sites selected were considered by state shellfish authorities to be the most compromised with respect to the potential for human faecal contamination as identified by shoreline surveys. The oysters were tested for norovirus GI, GII and Escherichia coli. Norovirus GII was detected in two of 120 (1.7%) samples and norovirus GI was not detected. One of the norovirus positive samples was cloned and sequenced as GII.3. Five of 120 (4.2%) samples were found to have more than the guidance concentration of 230 E. coli per 100 g of shellfish but these samples did not contain detectable concentrations of norovirus. The apparently low prevalence of norovirus in oysters from Australian growing areas supports epidemiological data that suggests norovirus contamination of Australian oysters is rare. The results from this study emphasise the need for future norovirus control measures for shellfish to be commensurate with the risk associated with the growing area.
    Food Microbiology 12/2014; 44:264–270. DOI:10.1016/j.fm.2014.06.012 · 3.37 Impact Factor
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    ABSTRACT: Given the scarcity of comprehensive nutritional data for Australia’s >400 commercially produced seafood species a pilot study was undertaken to collect and analyse 22 species of wild and aquaculture seafood in order to develop a model for future comprehensive surveys. The species analysed were: Atlantic salmon, Australian sardine, prawn (six species), barramundi, abalone (three species), blue sprat, burrowing blackfish, gummy shark, oyster (four species), ocean trout and yellowtail kingfish. The analyses undertaken in this pilot study were: moisture, protein, total fat, cholesterol, fatty acids, vitamin C, vitamins A and D, and 21 mineral elements (including total mercury and methyl mercury). The data reported here are for vitamin D and mercury only. Comprehensive data have already been published elsewhere. Issues identified that should be addressed prior to undertaking a more extensive and representative study of the remaining major edible commercial Australian seafood species include: choice of samples and nutrients for analysis, facilities for sample handling and storage, data management and scrutiny, and laboratory quality control.
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    ABSTRACT: The first national survey of Australian wild-caught abalone was conducted between September 2012 and December 2013. The aim of the survey was to determine the presence of paralytic shellfish toxins (PSTs), amnesic shellfish toxins (ASTs), and diarrhetic shellfish toxins (DSTs) in wild-caught abalone at levels above the current Codex marine biotoxin limits during the 2013 fishing season. Abalone (n = 190) were collected from 68 abalone-fishing blocks for which the combined annual harvest accounts for 80 % of Australian production. Concurrent seawater samples were collected and enumerated for potentially toxic phytoplankton. The foot and viscera tissues of each abalone sample were analyzed separately for PSTs, ASTs, and DSTs. No samples (abalone foot or viscera) contained toxins at levels exceeding the marine biotoxin limits stipulated by Codex. The resulting prevalence estimate suggests that less than 1.6 % of the commercially caught wild abalone population in Australia were contaminated with marine biotoxins at levels above the regulatory limit during the survey period. ASTs were detected at very low (trace) levels in the foot and viscera tissue of four and three abalone samples, respectively. To our knowledge, this represents the first reported detection of domoic acid in Australian abalone. PSTs also were detected at very low levels in 17 samples of abalone foot tissue and 6 samples of abalone viscera. The association between the low levels of ASTs and PSTs detected in abalone and the presence of potential toxin-producing phytoplankton in seawater samples was weak. DSTs were not detected in any abalone despite the detection of very low levels of DST-producing phytoplankton in a small number (9 of 77) of seawater samples. The results of this survey should be useful for public health risk assessments and provide additional evidence that the prevalence of marine biotoxins in Australian wild-caught abalone is very low.
    Journal of food protection 11/2014; 77(11-11):1960-1967. DOI:10.4315/0362-028X.JFP-14-221 · 1.80 Impact Factor
  • Andreas Kiermeier · Ian Jenson · John Sumner
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    ABSTRACT: We analyze the risk of contracting illness due to the consumption in the United States of hamburgers contaminated with enterohemorrhagic Escherichia coli (EHEC) of serogroup O157 produced from manufacturing beef imported from Australia. We have used a novel approach for estimating risk by using the prevalence and concentration estimates of E. coli O157 in lots of beef that were withdrawn from the export chain following detection of the pathogen. For the purpose of the present assessment an assumption was that no product is removed from the supply chain following testing. This, together with a number of additional conservative assumptions, leads to an overestimation of E. coli O157-associated illness attributable to the consumption of ground beef patties manufactured only from Australian beef. We predict 49.6 illnesses (95%: 0.0–148.6) from the 2.46 billion hamburgers made from 155,000 t of Australian manufacturing beef exported to the United States in 2012. All these illness were due to undercooking in the home and less than one illness is predicted from consumption of hamburgers cooked to a temperature of 68 °C in quick-service restaurants.
    Risk Analysis 06/2014; 35(1). DOI:10.1111/risa.12248 · 1.97 Impact Factor
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    ABSTRACT: In Australia, Europe and the United States, eggs and egg products are frequently associated with Salmonella food poisoning outbreaks. Many of the egg-associated Salmonella outbreaks have been due to the products such as mayonnaise, ice-cream and cold desserts which are eaten without cooking following the addition of raw egg. The ability of four Salmonella isolates (one each of S. Singapore, S. Adelaide, S. Worthington and S. Livingstone) to penetrate washed and unwashed eggs using whole egg and agar egg penetration methods was investigated in the current study. The results of the agar penetration experiment indicated that all the isolates used in the present study have the capacity to penetrate the eggshell. Eggshell penetration by the S. Worthington isolate was higher but not significant (p=0.06) in washed eggs compared to unwashed eggs. However, for all other isolates (S. Singapore, S. Adelaide and S. Livingstone), there was no significant difference in penetration of washed and unwashed eggs. Statistical analysis indicated that cuticle score was a significant linear predictor of Salmonella eggshell penetration. Whole egg penetration results showed that all of the Salmonella isolates used in the present study were capable of surviving on the eggshell surface after 21days of incubation (at 20°C) following a high dose of inoculation (10(5)CFU/mL). The combined data of all isolates demonstrated that, the survival rate of Salmonella on eggshells (inoculated with 10(5)CFU/mL) was significantly higher (p=0.002) at 20°C as compared to 37°C. S. Singapore, S. Worthington, and S. Livingstone were not detected in egg internal contents whereas S. Adelaide was detected in one egg's internal contents.
    International Journal of Food Microbiology 05/2014; 182-183C:18-25. DOI:10.1016/j.ijfoodmicro.2014.04.030 · 3.16 Impact Factor
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    ABSTRACT: This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters.
    Food Microbiology 04/2014; 38:219-27. DOI:10.1016/j.fm.2013.09.005 · 3.37 Impact Factor
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    ABSTRACT: Salmonella is an important foodborne pathogen, causing an estimated 11,992 cases of infection in Australia per year. Egg or egg product related salmonellosis is a major concern for the egg industry. Worldwide, S. Typhimurium is one of the most common serovars identified in Salmonella food poisoning cases. The current study investigated the ability of five S. Typhimurium strains to penetrate washed and unwashed eggs using whole egg and agar egg penetration methods. All S. Typhimurium strains were able to penetrate eggshells and survive in egg albumen (at 20°C) according to whole egg penetration results. Polymerase Chain Reaction results demonstrated that S. Typhimurium strain 2 (103 and 105 CFU/mL), and strain 5 (103 and 105 CFU/mL) egg penetration was significantly higher (p<0.05) in washed eggs when compared to unwashed eggs. Statistical analysis of the agar penetration experiment indicated that S. Typhimurium was able to penetrate washed eggs at a significantly higher rate when compared to unwashed eggs (p<0.05). When compared to unwashed eggs, washed eggs also had significantly damaged cuticles. Statistical analysis also indicated that eggshell penetration by S. Typhimurium was related to various eggshell ultrastructural features such as cap quality, alignment, erosion, confluence, Type B bodies and cuticle cover.
    PLoS ONE 03/2014; 9(3):e90987. DOI:10.1371/journal.pone.0090987 · 3.23 Impact Factor
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    ABSTRACT: In Australia, Europe and the United States, eggs and egg products are frequently associated with Salmonella food poisoning outbreaks. Many of the egg-associated Salmonella outbreaks have been due to the products such as mayonnaise, ice-cream and cold desserts which are eaten without cooking following the addition of raw egg. The ability of four Salmonella isolates (one each of S. Singapore, S. Adelaide, S. Worthington and S. Livingstone) to penetrate washed and unwashed eggs using whole egg and agar egg penetration methods was investigated in the current study. The results of the agar penetration experiment indicated that all the isolates used in the present study have the capacity to penetrate the eggshell. Eggshell penetration by the S. Worthington isolate was higher but not significant (p = 0.06) in washed eggs compared to unwashed eggs. However, for all other isolates (S. Singapore, S. Adelaide and S. Livingstone), there was no significant difference in penetration of washed and unwashed eggs. Statistical analysis indicated that cuticle score was a significant linear predictor of Salmonella eggshell penetration. Whole egg penetration results showed that all of the Salmonella isolates used in the present study were capable of surviving on the eggshell surface after 21 days of incubation (at 20 °C) following a high dose of inoculation (105 CFU/mL). The combined data of all isolates demonstrated that, the survival rate of Salmonella on eggshells (inoculated with 105 CFU/mL) was significantly higher (p = 0.002) at 20 °C as compared to 37 °C. S. Singapore, S. Worthington, and S. Livingstone were not detected in egg internal contents whereas S. Adelaide was detected in one egg's internal contents.
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    ABSTRACT: Packaging fresh lamb in a vacuum (VAC) versus a 100% CO2 modified atmosphere (MAP) may influence product shelf-life and the bacterial communities. While VAC is a common packing method and 100% CO2 MAP is used in some countries, there is little information about how these different techniques affect the growth of spoilage bacteria and sensory attributes of lamb. The aim of this study was to assess changes in microbiological and organoleptic properties, and determine differences in microbial communities by terminal restriction fragment length polymorphism (TRFLP) and 454 pyrosequencing, in bone-in (BI) and bone-out (BO) MAP- and VAC-packed lamb shoulders stored at -0.3 °C over 12 wk. VAC and MAP lamb shoulders were acceptable in sensory test scores over 12 wk of storage at -0.3 °C, despite total viable count (TVC) and lactic acid bacteria (LAB) levels increasing to 8 log10 CFU/cm(2) for VAC lamb and 4-6 log10 CFU/cm(2) for MAP lamb. Similar to the sensory results, there were no significant differences in microbial communities between BI and BO product. However, types of bacteria were different between VAC and MAP packaging. Specifically, while VAC shoulder became dominated by Carnobacterium spp. in the middle of the storage period, the MAP shoulder microbial population remained similar from the start until later storage times.
    Food Microbiology 12/2013; 36(2):305-15. DOI:10.1016/j.fm.2013.06.016 · 3.37 Impact Factor
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    ABSTRACT: BACKGROUND: Developing sampling strategies to target biological pests such as insects in stored grain is inherently difficult due to species biology and behavioural characteristics. The design of robust sampling programmes should be based on an underlying statistical distribution which is sufficiently flexible to capture variations in the spatial distribution of the target species. RESULTS: We compare the accuracy of four probability of detection sampling models - the negative binomial model,(1) the Poisson model, (1) the double logarithmic model (2) and the compound model (3) - to detect insects over a broad range of insect densities. Although the double log and negative binomial models performed well under specific conditions, we show that of the four models examined the compound model performed the best over a broad range of insect spatial distributions and densities. In particular, this model predicted well the number of samples required when insect density was high and clumped within experimental storages. CONCLUSIONS: This paper reinforces the need for effective sampling programs that are designed to detect insects over a broad range of spatial distributions. The compound model is robust over a broad range of insect densities and leads to substantial improvement of detection probabilities within highly variable systems such as grain storage.
    Pest Management Science 09/2013; 69(9). DOI:10.1002/ps.3469 · 2.74 Impact Factor
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    ABSTRACT: This study aimed to assess the feasibility of the use of instrumental methods such as digital image analysis (DIA) and near-infrared reflectance spectroscopy (NIRS) to objectively characterise changes in freshness (shelf-life) of half shell Pacific oysters, Crassostrea gigas. Oysters were stored in air under PVC film for five days at 4 degrees C. On a daily basis, oysters were photographed with a digital camera, spectra were collected using a Fourier transform NIR spectrometer in reflectance mode and odour analysed by a sensory panel. Calibrations based on NIRS were successfully developed for days of storage (R-2 = 0.8, RER = 5.37) and odour (R-2 = 0.77, RER = 7.77) with the latter being influenced by wavelengths typically associated with aromatic compounds. However, colour (derived from digital images) was found to be a poor indicator of freshness. This work has demonstrated the feasibility of NIRS as an objective measure of oyster freshness. Industrial relevance: This manuscript describes a feasibility study that assesses the use of digital image analysis and near-infrared spectroscopy to objectively define the freshness of half shell oysters. Successful near-infrared calibrations were developed for days of refrigerated storage and also for odour. We have also demonstrated the potential for use this applications in food processors and retailers to rapidly evaluate freshness and quality of products. The proposed method shows promise for at-line analysis.
    Innovative Food Science & Emerging Technologies 07/2013; 19:204-209. DOI:10.1016/j.ifset.2013.04.005 · 3.27 Impact Factor
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    Samiullah · K K Chousalkar · J R Roberts · M Sexton · D May · A Kiermeier
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    ABSTRACT: The vast majority of eggs in Australia are washed prior to packing to remove dirt and fecal material and to reduce the microbial contamination of the egg shell. The egg contents can be an ideal growth medium for microorganisms which can result in human illness if eggs are stored improperly and eaten raw or undercooked, and it is estimated that egg-related salmonellosis is costing Australia $44million per year. Egg shell characteristics such as shell thickness, amount of cuticle present, and thickness of individual egg shell layers can affect the ease with which bacteria can penetrate the egg shell and washing could partially or completely remove the cuticle layer. The current study was conducted to investigate the effects of egg washing on cuticle cover and effects of egg shell quality and cuticle cover on Salmonella Infantis penetration of the egg shell. A higher incidence of unfavorable ultrastructural variables of the mammillary layer such as late fusion, type B bodies, type A bodies, poor cap quality, alignment, depression, erosion and cubics were recorded in Salmonella penetrated areas of egg shells. The influence of egg washing on the ability of Salmonella Infantis on the egg shell surface to enter the egg internal contents was also investigated using culture-based agar egg penetration and real-time qPCR based experiments. The results from the current study indicate that washing affected cuticle cover. There were no significant differences in Salmonella Infantis penetration of washed or unwashed eggs. Egg shell translucency may have effects on Salmonella Infantis penetration of the egg shell. The qPCR assay was more sensitive for detection of Salmonella Infantis from egg shell wash and internal contents than traditional microbiological methods. The agar egg and whole egg inoculation experiments indicated that Salmonella Infantis penetrated the egg shells. Egg washing not only can be highly effective at removing Salmonella Infantis from the egg shell surface, but also allows subsequent trans-shell and trans-membrane penetration into the egg. Consequently, it is important to prevent recontamination of the egg after washing.
    International journal of food microbiology 05/2013; 165(2):77-83. DOI:10.1016/j.ijfoodmicro.2013.05.002 · 3.16 Impact Factor
  • Alison Holdhus Small · Ian Jenson · Andreas Kiermeier · John Sumner
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    ABSTRACT: When vacuum-packed striploins and cube rolls processed by six Australian establishments were stored at 2 0.5°C to determine their shelf life, all product was acceptable organoleptically for at least 26 weeks. The aerobic plate counts and counts of lactic acid bacteria over the storage period did not accord with those established by previous studies, i.e., stationary phase attained at 7 to 8 log CFU/cm(2) after 5 to 8 weeks followed by the development of negative sensory characteristics around 12 to 16 weeks. Rather, counts rarely progressed to 7 log CFU/cm(2) even after 30 weeks. It is believed that the combined effects of meat pH, temperature, and CO(2) concentration may combine to create conditions in which little or no growth occurs.
    Journal of food protection 08/2012; 75(8):1524-7. DOI:10.4315/0362-028X.JFP-12-042 · 1.80 Impact Factor
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    Andreas Kiermeier · Arūnas P Verbyla · Richard G Jarrett
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    ABSTRACT: Pharmaceutical companies and manufacturers of food products are legally required to label the product's shelf-life on the packaging. For pharmaceutical products the requirements for how to determine the shelf-life are highly regulated. However, the regulatory documents do not specifically define the shelf-life. Instead, the definition is implied through the estimation procedure. In this paper, the focus is on the situation where multiple batches are used to determine a label shelf-life that is applicable to all future batches. Consequently, the short-comings of existing estimation approaches are discussed. These are then addressed by proposing a new definition of shelf-life and label shelf-life, where greater emphasis is placed on within and between batch variability. Furthermore, an estimation approach is developed and the properties of this approach are illustrated using a simulation study. Finally, the approach is applied to real data.
    Australian &amp New Zealand Journal of Statistics 08/2012; 54(3):343-358. DOI:10.1111/j.1467-842X.2012.00685.x · 0.42 Impact Factor
  • A. Pointon · A. Kiermeier · N. Fegan
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    ABSTRACT: Withholding of feed prior to transport (feed curfew) is practiced to reduce soiling during transport and optimise hide/fleece cleanliness at slaughter. However, as this represents only a portion of the time off feed before slaughter, the scope of this food safety and carcase hygiene review covers mustering-to-slaughter to enable the likely impact of the entire feed withholding period, and other related factors contributing to carcase contamination, to be evaluated. The review examines the ecology of major contaminants of carcases and whether the practice of on-farm feed curfew is likely to be effective in minimising contamination. The significance of withholding feed before slaughter is twofold. Firstly, it leads to an increase in rumen pH, due to reduced volatile fatty acids which in turn favours the multiplication and growth of undesirable enteric bacteria (Salmonella and Escherichia coli). This causes an increase in microbial hazard prevalence and counts in both rumen contents and faeces as time off feed increases. Secondly, withholding feed reduces visible contamination of the surface of the animals and facilitates hygienic dressing. Putting these points together, faecal contamination is less likely to occur if animals have been adequately fasted, but when protracted, the bacterial load is likely to be more hazardous placing great emphasis on avoiding ingesta spillage and effective between carcase hygiene measures. For pathogenic Shiga Toxin producing E. coli (STEC) that have a different ecology in livestock where feed withholding may not exert such a dramatic effect on shedding, the need to minimise hide/fleece soiling with faeces remains paramount. Consequently, the conclusion drawn is that animals should be fasted before loading only enough to allow sufficient faecal expulsion i.e. ≤24 h to maintain ‘clean’ livestock after transport. Adverse food borne microbial growth can be minimised by not exceeding 48 h for time off feed before slaughter.
    Food Control 08/2012; 26(2):313–321. DOI:10.1016/j.foodcont.2012.01.034 · 2.82 Impact Factor
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    ABSTRACT: The effect of sample homogenisation and storage on the near-infrared spectra of Pacific Oysters (Crassostrea gigas) has been assessed. On each day of storage (Days 0, 3 and 5), spectra were collected using a Fourier transform near-infrared reflectance spectrometer in reflectance mode between 833 and 2,630 nm from whole (n = 20) and homogenised oysters (n = 20). The raw spectra were dominated by water- and fatty-acid-associated bands. Linear regression analysis of the water-associated absorbance bands occurring at 1,942 nm indicated that a physical or chemical interaction may be taking place within the oysters at or near Day 3, likely associated with transfer of liquids to and from oyster tissues. One-way analysis of variance of principal component scores and extended multiplicative scatter correction highlighted the water regions (O–H bonds) in whole oysters and the importance of N–H-related compounds in homogenised oysters throughout storage. These findings indicate the potential usefulness of near-infrared reflectance spectroscopy to monitor and evaluate degradation of oysters over time.
    Food Analytical Methods 10/2011; 5(5). DOI:10.1007/s12161-011-9329-7 · 1.80 Impact Factor
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    ABSTRACT: Farmed greenlip abalone Haliotis laevigata were fed commercial seaweed-based food pellets or feed pellets supplemented with 8 × 10⁵ Alexandrium minutum dinoflagellate cells g⁻¹ (containing 12 ± 3.0 μg STX-equivalent 100 g⁻¹, which was mainly GTX-1,4) every second day for 50 days. Exposure of abalone to PST supplemented feed for 50 days did not affect behaviour or survival but saw accumulation of up to 1.6 μg STX-equivalent 100 g⁻¹ in the abalone foot tissue (muscle, mouth without oesophagus and epipodial fringe), which is ∼50 times lower than the maximum permissible limit (80 μg 100 g⁻¹ tissue) for PSTs in molluscan shellfish. The PST levels in the foot were reduced to 0.48 μg STX-equivalent 100 g⁻¹ after scrubbing and removal of the pigment surrounding the epithelium of the epipodial fringe (confirmed by both HPLC and LC-MS/MS). Thus, scrubbing the epipodial fringe, a common procedure during commercial abalone canning, reduced PST levels by ∼70%. Only trace levels of PSTs were detected in the viscera (stomach, gut, heart, gonad, gills and mantle) of the abalone. A toxin reduction of approximately 73% was observed in STX-contaminated abalone held in clean water and fed uncontaminated food over 50 days. The low level of PST uptake when abalone were exposed to high numbers of A. minutum cells over a prolonged period may indicate a low risk of PSP poisoning to humans from the consumption of H. laevigata that has been exposed to a bloom of potentially toxic A. minutum in Australia. Further research is required to establish if non-dietary accumulation can result in significant levels of PSTs in abalone.
    Toxicon 07/2011; 58(1):101-11. DOI:10.1016/j.toxicon.2011.05.010 · 2.58 Impact Factor
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    ABSTRACT: Cassava (Manihot esculenta Crantz) is a widely consumed food in the tropics that naturally contains cyanogenic glycosides (cyanogens, mainly composed of linamarin, acetone cyanohydrin, and hydrocyanic acid). If cassava is not adequately processed to reduce the level of cyanogens prior to consumption, these compounds can lead to the formation of hydrocyanic acid in the gut. Exposure to hydrocyanic acid can cause symptoms ranging from vomiting and abdominal pain to coma and death. In 2008, a survey of ready-to-eat (RTE) cassava-based snack foods was undertaken to determine levels of cyanogens measured as total hydrocyanic acid. This survey was undertaken in response to the New South Wales Food Authority being alerted to the detection of elevated levels of cyanogens in an RTE cassava-based snack food. This survey took 374 samples of RTE cassava chips available in the Australian marketplace. Significant variation in the levels of total hydrocyanic acid were observed in the 317 samples testing positive for cyanogens, with levels ranging from 13 to 165 mg of HCN equivalents per kg (mean value, 64.2 mg of HCN eq/kg for positive samples). The results from this survey serve as a timely warning for manufacturers of RTE cassava chips and other cassava-based snack foods to ensure there is tight control over the levels of cyanogens in the cassava ingredient. Evidence from this survey contributed to an amendment to the Australia New Zealand Food Standards Code, which now prescribes a maximum level for hydrocyanic acid in RTE cassava chips of 10 mg of HCN eq/kg, which aligns with the Codex Alimentarius Commission international standard for edible cassava flour.
    Journal of food protection 06/2011; 74(6):980-5. DOI:10.4315/0362-028X.JFP-10-557 · 1.80 Impact Factor
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    Andreas Kiermeier · Glen Mellor · Robert Barlow · Ian Jenson
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    ABSTRACT: The aims of this work were to determine the distribution and concentration of Escherichia coli O157 in lots of beef destined for grinding (manufacturing beef) that failed to meet Australian requirements for export, to use these data to better understand the performance of sampling plans based on the binomial distribution, and to consider alternative approaches for evaluating sampling plans. For each of five lots from which E. coli O157 had been detected, 900 samples from the external carcass surface were tested. E. coli O157 was not detected in three lots, whereas in two lots E. coli O157 was detected in 2 and 74 samples. For lots in which E. coli O157 was not detected in the present study, the E. coli O157 level was estimated to be <12 cells per 27.2-kg carton. For the most contaminated carton, the total number of E. coli O157 cells was estimated to be 813. In the two lots in which E. coli O157 was detected, the pathogen was detected in 1 of 12 and 2 of 12 cartons. The use of acceptance sampling plans based on a binomial distribution can provide a falsely optimistic view of the value of sampling as a control measure when applied to assessment of E. coli O157 contamination in manufacturing beef. Alternative approaches to understanding sampling plans, which do not assume homogeneous contamination throughout the lot, appear more realistic. These results indicate that despite the application of stringent sampling plans, sampling and testing approaches are inefficient for controlling microbiological quality.
    Journal of food protection 04/2011; 74(4):539-44. DOI:10.4315/0362-028X.JFP-10-497 · 1.80 Impact Factor

Publication Stats

184 Citations
70.37 Total Impact Points

Institutions

  • 2006–2014
    • South Australian Research and Development Institute
      Tarndarnya, South Australia, Australia
  • 2012
    • Research Australia Development and Innovation Institute
      St Kilda West, Victoria, Australia
  • 2004–2006
    • University of Adelaide
      Tarndarnya, South Australia, Australia