Gas-producing and spoilage potential of Enterobacteriaceae and lactic acid bacteria isolated from chilled vacuum-packaged beef

This study aimed to enumerate and identify lactic acid bacteria and Enterobacteriaceae from spoiled and nonspoiled chilled vacuum-packaged beef and determine their potential to cause blown pack spoilage. These microbial groups were also enumerated in nonspoiled samples and detected in abattoir samples. The potential of isolates to cause blown pack spoilage of vacuum-packaged beef stored at chilled temperature (4 degrees C) and abuse temperature (15 degrees C) was investigated. Populations of lactic acid bacteria in exudate of spoiled and nonspoiled samples were not significantly different (P > 0.05), whereas the number of lactic acid bacteria on the surface was significantly higher (P < 0.05) in spoiled samples as compared to nonspoiled samples. The population of Enterobacteriaceae species in exudate and on the surface of samples were significantly higher (P < 0.05) in spoiled packs in comparison with nonspoiled packs. Results of the deterioration potential showed that blown pack spoilage was noticeable after 7 days at 15 degrees C and after 6 weeks at 4 degrees C for samples inoculated with Hafnia alvei.

Influence of different shrinking temperatures and vacuum conditions on the ability of psychrotrophic Clostridium to cause 'blown pack' spoilage in chilled vacuum-packaged beef

This study determined the ability of psychrotrophic Clostridium strains isolated from vacuum-packaged beefs and abattoir environments to cause 'blown-pack' spoilage of vacuum-packaged beef stored at 2 and 15 degrees C. The influence of shrinking temperatures (83, 84 and 87 degrees C) and vacuum pressure (6 and 9 mbar) on the occurrence of such spoilage as well as the effects of simulated transportation (500 km) on the integrity of packages was determined. At 15 degrees C and 2 degrees C, twelve and six strains caused 'blown-pack' spoilage, respectively. The combination of vacuum pressure (9 mbar) combined with shrinking temperature (87 degrees C) retarded the occurrence of spoilage. The simulated transportation under the experimental conditions did not affect the integrity of packages. More studies that assess the factors that may contribute for the occurrence of 'blown-pack' spoilage should be performed to avoid the occurrence of such spoilage during its shelf-life. (C) 2012 Elsevier Ltd. All rights reserved.

Gases and volatile compounds associated with micro-organisms in blown pack spoilage of Brazilian vacuum-packed beef

This study correlated the composition of the spoilage bacterial flora with the main gaseous and volatile organic compounds (VOCs) found in the package headspace of spoiled, chilled, vacuum-packed meat. Fifteen chilled, vacuum-packed beef samples, suffering from blown pack spoilage, were studied using 16S rRNA clone sequencing. More than 50% of the bacteria were identified as lactic acid bacteria (LAB), followed by clostridia and enterobacteria. Fifty-one volatile compounds were detected in the spoiled samples. Although the major spoilage compounds were identified as alcohols and aldehydes, CO2 was identified as the major gas in the spoiled samples by headspace technique. Different species of bacteria contribute to different volatile compounds during meat spoilage. LAB played an important role in blown pack deterioration of the Brazilian beef studied.

Leuconostoc spoilage of refrigerated, packaged foods

Leuconostoc spp. are lactic acid bacteria (LAB) implicated in food spoilage, especially on refrigerated, modified atmosphere packaged (MAP) meats. The overall aim of this thesis was to learn more about Leuconostoc spp. as food spoilage organisms with a focus on commercial products where LAB spoilage is considered a problem and the main factor limiting shelf-life. Therefore, we aimed to identify Leuconostoc spp. involved in food spoilage, as well as to characterise the spoilage reactions they caused and their contamination sources during poultry meat processing. In addition, we examined the distribution of strains of Leuconostoc gasicomitatum in different food commodities. Finally, we analysed the genome content of L. gasicomitatum LMG 18811 with a special focus on metabolic pathways related to food spoilage. The findings show that Leuconostoc gelidum and L.gasicomitatum were responsible for the discoloration and off-odours developed in beef steaks. Together with Leuconostoc mesenteroides, these Leuconostoc spp., also cause spoilage of vegetable sausages. In contrast, we showed that Leuconostoc spp. are not important for the shelf-life or quality of non-marinated broiler products although, in marinated broiler fillet products, Leuconostoc spp., L.gasicomitatum in particular, are considered spoilage organisms. Furthermore, the findings of the contamination survey we carried out in a poultry processing plant indicated that spoilage Leuconostoc spp. are derived from the processing environment rather than from the broilers, and that air movement distributes psychrotrophic spoilage LAB, including leuconostocs, and has an important role in meat contamination during poultry processing. Pulsed-field gel electrophoresis (PFGE) based genotyping of L. gasicomitatum strains demonstrated that certain genotypes are common in various meat products. In contrast, genotypes associated with meat were not recovered in vegetable-based sources. This suggests that these two food categories either become contaminated with, or favour the growth of different genotypes. Furthermore, the results indicated that the meat processing environment contributes to L. gasicomitatum contamination as certain genotypes were repeatedly identified from products of the same processing plant. Finally, the sequenced and annotated genome of L.gasicomitatum LMG 18811 allowed us to identify the metabolic pathways and reactions resulting in food spoilage.

Identification of meat spoilage by FTIR spectroscopy and neural networks

Freshness and safety of muscle foods are generally considered as the most important parameters for the food industry. To address the rapid determination of meat spoilage, Fourier transform infrared (FTIR) spectroscopy technique, with the help of advanced learning-based methods, was attempted in this work. FTIR spectra were obtained from the surface of beef samples during aerobic storage at various temperatures, while a microbiological analysis had identified the population of Total viable counts. A fuzzy principal component algorithm has been also developed to reduce the dimensionality of the spectral data. The results confirmed the superiority of the adopted scheme compared to the partial least squares technique, currently used in food microbiology.

A Fuzzy-Wavelet Neural Network Model for the Detection of Meat Spoilage using an Electronic Nose

Food product safety is one of the most promising areas for the application of electronic noses. The performance of a portable electronic nose has been evaluated in monitoring the spoilage of beef fillet stored aerobically at different storage temperatures (0, 4, 8, 12, 16 and 20°C). This paper proposes a fuzzy-wavelet neural network model which incorporates a clustering pre-processing stage for the definition of fuzzy rules. The dual purpose of the proposed modeling approach is not only to classify beef samples in the respective quality class (i.e. fresh, semi-fresh and spoiled), but also to predict their associated microbiological population directly from volatile compounds fingerprints. Comparison results indicated that the proposed modeling scheme could be considered as a valuable detection methodology in food microbiology

A Rapid Detection of Meat Spoilage using an Electronic Nose and Fuzzy-Wavelet systems

Freshness and safety of muscle foods are generally considered as the most important parameters for the food industry. To address the rapid detection of meat spoilage microorganisms during aerobic or modified atmosphere storage, an electronic nose with the aid of fuzzy wavelet network has been considered in this research. The proposed model incorporates a clustering pre-processing stage for the definition of fuzzy rules. The dual purpose of the proposed modelling approach is not only to classify beef samples in the respective quality class (i.e. fresh, semi-fresh and spoiled), but also to predict their associated microbiological population directly from volatile compounds fingerprints. Comparison results against neural networks and neurofuzzy systems indicated that the proposed modelling scheme could be considered as a valuable detection methodology in food microbiology

Neuro-Fuzzy based Identification of Meat Spoilage using an Electronic Nose

Freshness and safety of muscle foods are generally considered as the most important parameters for the food industry. The performance of a portable electronic nose has been evaluated in monitoring the spoilage of beef fillet stored aerobically at different storage temperatures (0, 4, 8, 12, 16 and 20°C). An adaptive fuzzy logic system model that utilizes a prototype defuzzification scheme has been developed to classify beef samples in their respective quality class and to predict their associated microbiological population directly from volatile compounds fingerprints. Results confirmed the superiority of the adopted methodology and indicated that volatile information in combination with an efficient choice of a modeling scheme could be considered as an alternative methodology for the accurate evaluation of meat spoilage

Multi-criteria assessment of innovative technology in the beef industry

In Australia rural research and development corporations and companies expended over $AUS500 million on agricultural research and development. A substantial proportion of this is invested in R&D in the beef industry. The Australian beef industry exports almost $AUS5billionof product annually and invest heavily in new product development to improve the beef quality and improve production efficiency. Review points are critical for effective new product development, yet many research and development bodies, particularly publicly funded ones, appear to ignore the importance of assessing products prior to their release. Significant sums of money are invested in developing technological innovations that have low levels and rates of adoption. The adoption rates could be improved if the developers were more focused on technology uptake and less focused on proving their technologies can be applied in practice. Several approaches have been put forward in an effort to improve rates of adoption into operational settings. This paper presents a study of key technological innovations in the Australian beef industry to assess the use of multiple criteria in evaluating the potential uptake of new technologies. Findings indicate that using multiple criteria to evaluate innovations before commercializing a technology enables researchers to better understand the issues that may inhibit adoption.

Beef carcasses with larger eye muscle areas, lower ossification scores and improved nutrition have a lower incidence of dark cutting

This study evaluated the effect of eye muscle area (EMA), ossification, carcass weight, marbling and rib fat depth on the incidence of dark cutting (pH u > 5.7) using routinely collected Meat Standards Australia (MSA) data. Data was obtained from 204,072 carcasses at a Western Australian processor between 2002 and 2008. Binomial data of pH u compliance was analysed using a logit model in a Bayesian framework. Increasing eye muscle area from 40 to 80 cm 2, increased pH u compliance by around 14% (P < 0.001) in carcasses less than 350 kg. As carcass weight increased from 150 kg to 220 kg, compliance increased by 13% (P < 0.001) and younger cattle with lower ossification were also 7% more compliant (P < 0.001). As rib fat depth increased from 0 to 20 mm, pH u compliance increased by around 10% (P < 0.001) yet marbling had no effect on dark cutting. Increasing musculature and growth combined with good nutrition will minimise dark cutting beef in Australia.

Improving communication and increasing adoption of innovations in the beef industry

Agriculture has adopted many scientific innovations that have improved productivity. The majority of innovations in agriculture have been communicated to end users through a simple diffusion and dissemination model. However, as the science underpinning the innovations becomes more complex, research and development organizations need to look at better ways to communicate their innovation to end users. This paper examines innovations in the beef industry in Australia and investigates how complex innovations are being communicated and identifies the nature and level of communication with end users and the role of intermediaries. The findings support the need for greater involvement of end users in the innovation development process and a more vibrant two-way communication process between scientists, intermediaries and end users. The results also suggest that the traditional diffusion processes are insufficient to ensure high levels of awareness and adoption.

A systemic view of innovation adoption in the Australian beef industry

Significant investments in developing technological innovations have been made in the Australian beef industry but with low adoption rates. By modelling the key variables and their interactions in the innovation adoption process, this research seeks to demonstrate the complexity and dynamics of the process. This research uses causal loop modelling and develops a holistic model of the current innovation adoption system in the Australian beef industry to show the complexity of dynamic interactions among multiple variables. It is suggested that innovation adoption is such an extremely complex issue, and we need to shift our views on this issue from a paradigm of linear thinking to systems thinking. Innovation adoption is more likely to be enhanced based on a full understanding of the complexity and dynamics of the system as a whole. The paper demonstrates to practitioners and developers of innovation the multiple variables and interactions impacting innovation adoption.

Productivism, culture and the challenges of sustainable beef production in Australia

Beef has become an important part of the South Korean diet. Rapid modernization and economic development since the 1960s has led to an increase in meat consumption, especially beef. Indeed, per capita beef consumption per year increased from 0.5kg in 1960 to 8.8kg in 2010, representing an 18-fold increase. The increasing demand for beef in Korea has been met by the development of intensive domestic meat production systems, along with a sharp increase in imports from meat exporting countries, most importantly Australia and the US.