Reduction of verotoxigenic Escherichia coli in production of fermented sausages

After a number of foodborne outbreaks of verotoxigenic Escherichia coli involving fermented sausages, some countries have imposed regulations on sausage production. For example, the US Food Safety and Inspection Service requires a 5 log(10) reduction of E. coli in fermented products. Such regulations have led to a number of studies on the inactivation of E. coli in fermented sausages by changing processing and post-processing conditions. Several factors influence the survival of E. coli such as pre-treatment of the meat, amount of NaCl, nitrite and lactic acid, water activity, pH, choice of starter cultures and addition of antimicrobial compounds. Also process variables like fermentation temperature and storage time play important roles. Though a large variety of different production processes of sausages exist, generally the reduction of E. coli caused by production is in the range 1-2 log(10). In many cases this may not be enough to ensure microbial food safety. By optimising ingredients and process parameters it is possible to increase E. coli reduction to some extent, but in some cases still other post process treatments may be required. Such treatments may be storage at ambient temperatures, specific heat treatments, high pressure processing or irradiation. HACCP analyses have identified the quality of the raw materials, low temperature in the batter when preparing the sausages and a rapid pH drop during fermentation as critical control points in sausage production. This review summarises the literature on the reduction verotoxigenic E. coli in production of fermented sausages.     

An educational tool for artificial neural networks

Artificial neural networks are some kind of data processing systems, which try to simulate features of the human brain and its learning process. So, they are widely used by researchers to solve different problems in optimization, classification, pattern recognition, associative memory and control. In this paper, an educational tool, which can be used to work on different kinds of neural network models and learn fundamentals of the artificial neural network, is described. At this point, the whole tool environment provides an advanced system to ensure mentioned functions. The developed system supports using MLP, LVQ and SOM models and related learning algorithms. It employs some visual, interactive tools, which enable users to compose their own neural networks and work on the developed networks easily. By using these tools, users can also understand and learn working mechanism of a typical artificial neural network, using features of different models and related learning algorithms.     

Production of bacterial cellulose in static conditions by a simple fed-batch cultivation strategy

The current study investigated fed-batch cultivation for the increased productivity of bacterial cellulose (BC) sheets by Gluconacetobacter hansenii PJK in static conditions using chemically defined medium and waste from beer fermentation broth. Fermentations were carried out in a 3 L jar fermenter without any impeller for 30 days. In the proposed fed-batch cultivation, 500 mL of the medium was initially inoculated with pre-culture in a jar fermenter while a fresh medium was fed periodically. BC production was also done by using batch cultivation which was used as a control for comparison. The results obtained revealed an overall of 2–3 times increase in BC production in fed-batch cultivation compared to batch cultivation after 30 days of cultivation. During these experiments, it was found that waste from beer fermentation broth is a superior medium for the BC production using fed-batch cultivation. The production of water soluble oligosaccharides as useful by-products was also monitored during these investigations. Fed-batch cultivation and waste from beer fermentation was also found superior for the production of these by-products. According to literature search and to the best of our knowledge, it is the first report of using fed-batch cultivation for BC production in static conditions.     

3-D ultrasound imaging using a forward-looking CMUT ring array for intravascular/intracardiac applications

Forward-viewing ring arrays can enable new applications in intravascular and intracardiac ultrasound. This work presents compelling, full-synthetic, phased-array volumetric images from a forward-viewing capacitive micromachined ultrasonic transducer (CMUT) ring array wire bonded to a custom integrated circuit front end. The CMUT ring array has a diameter of 2 mm and 64 elements each 100 microm x 100 microm in size. In conventional mode, echo signals received from a plane reflector at 5 mm had 70% fractional bandwidth around a center frequency of 8.3 MHz. In collapse mode, 69% fractional bandwidth is measured around 19 MHz. Measured signal-to-noise ratio (SNR) of the echo averaged 16 times was 29 dB for conventional operation and 35 dB for collapse mode. B-scans were generated of a target consisting of steel wires 0.3 mm in diameter to determine resolution performance. The 6 dB axial and lateral resolutions for the B-scan of the wire target are 189 microm and 0.112 radians for 8 MHz, and 78 microm and 0.051 radians for 19 MHz. A reduced firing set suitable for real-time, intravascular applications was generated and shown to produce acceptable images. Rendered three-dimensional (3-D) images of a Palmaz-Schatz stent also are shown, demonstrating that the imaging quality is sufficient for practical applications.     

Polyols and chocolate technology: recent developments and advances

Reducing the sugar level in chocolate and developing low-calorie products are important for meeting consumer expectations, supporting public health and adapting to current consumption trends. However, the identification of bulking agents to be used for this aim is a critical factor. The most commonly used sugar alternatives for this aim are polyols. In this study, recent advances and developments for using possibilities of polyols in chocolate technology were discussed and future perspectives were highlighted. Partially and/or complete replacing of sugar with polyols can provide a low-calorie product. In addition, the use of mixtures consisting of more than one polyol is an approach that can be used in chocolate sugar substitution. Optimization of refining, conching and tempering processes by considering polyol type and content may contribute to the development of chocolate with improved quality properties and shelf life. However, polyol and bioactive compounds interactions and possible effects on bioaccesibility, bioavalibility and stability of these compounds in chocolate composition and pre- and post-digestion periods should be deeply investigated. In addition, the conching methods and conditions used is another factor to be considered in the use of polyols.     

Multi-objective optimization of transporting blood products by routing UAVs: the case of Istanbul

Since the blood is necessary for surgical operations, disease treatments, chronic disorders, and traumatic accidents, it is staminal to manage the flow in the supply chain of blood products from donors to patients that can save lives. Therefore, this paper focuses on transporting blood products from distribution centers to hospitals in cities by routing unmanned aerial vehicles (UAVs). The problem includes two objective functions as minimizing the used number of UAVs and their total travel distances, simultaneously by considering range, payload weight, and payload volume of UAVs. The problem also covers the blood product demands of hospitals and the supply capacities of distribution centers. A multi-objective integer programming (MOIP) model and three multi-objective metaheuristics are designed to solve the defined problem. To test the effectiveness of the proposed methods, real-life blood product demands of hospitals in Istanbul for the year 2019 are obtained from the Turkish Red Crescent and several scenarios are created as the case study. In scenarios, two types of vertical take-off and landing UAVs are considered, the MOIP is developed by using ILOG, solved via CPLEX, and the metaheuristics are coded in MATLAB. The results reveal that the proposed methods can find good solutions for the problem in acceptable CPU times.     

GSH-Activated Porphyrin Sonosensitizer Prodrug for Fluorescence Imaging-Guided Cancer Sonodynamic Therapy

Sonodynamic therapy (SDT), which uses ultrasound to trigger a sonosensitizer to generate reactive oxygen species (ROS), is a promising form of cancer therapy with outstanding tissue penetration depth. However, the sonosensitizer may inevitably spread to surrounding healthy tissue beyond the tumor, resulting in undesired side effects under an ultrasound stimulus. Herein, as glutathione (GSH) is overexpressed in the tumor microenvironment, a GSH-activatable sonosensitizer prodrug is designed by attaching a quencher to tetraphydroxy porphyrin for tumor therapy. The prodrug exhibits poor fluorescence and low ROS generation capacity under ultrasound irradiation, but it also showed that it can be activated by GSH to simultaneously switch on fluorescence emission and ROS generation capability at the tumor site. Compared with the non-quenched sonosensitizer, the designed prodrug exhibits significantly higher tumor/healthy organ fluorescence ratios, due to the specific fluorescence and ROS activation by overexpressed GSH in the tumor. Finally, the prodrug exhibits efficient tumor growth inhibition under ultrasound irradiation, further demonstrating its promise as a GSH-activated sonosensitizer prodrug for highly effective cancer treatment.     

Physico-chemical and sensory properties of chips produced using different lupin (Lupinus albus L.) flour formulations and cooking methods

Development of novel snack foods is an important area of research, and different ingredients are being tested to develop and process new formulations. In this study, lupin chips prepared using different formulations (hulled lupin, whole lupin, wheat and corn flours) were cooked using baking and frying, and changes in the sensory and colour parameters, acrylamide contents, fat absorption, peroxide number and p-anisidine values of the final products were studied. Lupin flour significantly changed p-anisidine value of chips. Addition of lupin flour and cooking methods affected the colour, fat absorption and peroxide values. Significant differences in chemical properties of chips made from whole and hulled lupin flours were also observed. Acrylamide was not detected in all the formulations studied. The lupin chips have increased brightness (L*), no acrylamides, reduced peroxide and p-anisidine values and acceptable sensory quality; hence, this ingredient is recommendable for use in snack foods.     

Assessing Software Quality Using the Markov Decision Processes

Quality of software is one of the most critical concerns in software system development, and many products fail to meet the quality objectives when constructed initially. Software quality is highly affected by the development process's actual dynamics. This article proposes the use of the Markov decision process (MDP) for the assessment of software quality because MDP is a useful technique to abstract the model of dynamics of the development process and to test its impact on quality. Additionally, the MDP modeling of the dynamics leads to early prediction of the quality, from the design phases all the way through the different stages of development. The proposed approach is based on the stochastic nature of the software development process, including project architecture, construction strategy of Software Quality Assurance system, its qualification actions, and team assignment strategy. It accepts these factors as inputs, generating a relative quality degree as an output. The proposed approach has been demonstrated for the design phase with a case study taken from the literature. The results prove its robustness and capability to identify appropriate policies in terms of quality, cost, and time. © 2011 Wiley Periodicals, Inc.