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Abstract: A new structural method was developed to characterise texture of colour meat images. Structural primitives or region-primitives were constructed using a region-growing method with a global and automatically calculated threshold. A total of eight textural features under the consideration of size, orientation, and contrast, which are the primary factors of human perception of texture pattern, were obtained from the region-primitives. An experiment was set up to classify the texture pattern of a set of 60 cooked meat colour images consisting of 20 beef images, 20 lamb images, and 20 pork images using texture features obtained from the proposed region-primitive method and run-length matrix method, respectively. The proposed region-primitive method (error rate: 18.3%) was found to perform better than the run-length matrix method (error rate: 35.0%). Results also indicated that the texture features obtained by the proposed method carried adequate texture information for classification and that the proposed region-primitive method could be potentially used for the characterisation of irregular textural pattern in cooked meat images, which was inapproachable by conventional structural texture analysis techniques. [Copyright &y& Elsevier]

Abstract: The principle of vacuum cooling is based on rapid evaporation of part of the moisture of the product under vacuum. Vacuum cooling can be used to shorten processing time, extend product shelf life, and improve product quality and safety. Traditionally, vacuum cooling is used in the agricultural industry to pre-cool leafy vegetables and mushroom in order to rapidly remove field heats. Recently, vacuum cooling has been applied to cool viscous food products and bakery products in the food industry, and tuna in the fish industry. Food safety concern has driven cooked meat manufacturers to explore new method to reduce cooling time, which has consequently led to a comprehensive research study of vacuum cooling of large cooked meat joints in the past few years including mathematical modelling of the vacuum cooling process using finite element method and computational fluid dynamics (CFD), especially thorough research work has been carried out by the Food Refrigeration and Computerised Food Technology (FRCFT) Research Group in National University of Ireland. Currently, research studies on vacuum cooling of ready meal components have also been conducted in FRCFT Research Group. This paper first discusses the principles and equipment of vacuum cooling and critically analyses the advantages and disadvantages of this technique. Much effort is then spent on reviewing the development of this technology for the agri-food industry, in particularly, the latest research results from the FRCFT Research Group, which have carried out extensive research work since 1997 funded by the Non-Commissioned Food Research Programme and the Food Institutional Research Measures administered by the Irish Government Department of Agriculture and Food. Future prospects of research and development of vacuum cooling technology is finally addressed. [Copyright &y& Elsevier]

The performance of slow air, air blast and water immersion cooling methods in the cooked meat industry was evaluated by a validated finite element model. The cooked meat joints in commercial and controlled geometries were cooled by these three traditional cooling methods under different operating conditions. Simulations showed that it is difficult for traditional cooling methods to cool the large commercial cooked meat joints because the poor thermal conductivity of meat controls the cooling rate. It takes about 8.5, 6.5 and 3.5 h for air blast cooling with an air velocity of 3 m/s and an air temperature of 0°C to reduce the cooked meat joints in a typical ellipsoid shape with the weights of 8, 5 and 2 kg from the core temperature of 74–10°C, respectively. For water immersion cooling with water velocity of 0.15 m/s and water temperature of 0°C, the cooling times can be reduced to 7, 5 and 2.8 h, respectively. A rapid cooling can be achieved by controlling the shortest dimension. For cooling a cooked meat joint with the weight more than 5 kg by air blast cooling to meet the cooling requirements specified in cook-chill guidelines, the infinite slab shape with the shortest dimension of 5 cm and an infinite cylinder with the diameter of 10 cm was chosen. For water immersion cooling, the shortest dimension of the brick-shaped meat joints could be increased to near 10 cm. [Copyright &y& Elsevier]

The three-dimensional transient heat transfer of roasted meat during air blast cooling process was modelled by the finite element method for evaluating the cooling performance. Moisture loss rate was considered in the model to account for the weight loss during air blast cooling. The model includes the variations in physical properties of the roasted meat and in operating conditions during the air blast cooling process. A user-friendly computer program developed in visual C++ by the authors was used to solve the model. The model was validated by comparing the numerical solutions with the experimental results. The comparison showed that the maximum deviation between the predicted and experimental core temperatures was within 2.4°C. The deviation between the predicted and experimental total weight loss was 2.5%. The model and software can also be used to analyse other thermal processing procedures of foods with some modifications. [Copyright &y& Elsevier]