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Abstract: Rice is an important staple food, and often used in ready meals, which should be cooled rapidly after cooking. In the current research, cooked rice was cooled by vacuum cooling, air blast cooling, cold room cooling and plate cooling. It was found that vacuum cooling could chill the cooked rice with much shorter time but with higher weight loss than the other cooling methods. Vacuum cooling of the rice under different conditions could lead to changes of the cooling time and weight loss. If lower final pressure was used in the cooling process or less weight of cooked rice was vacuum cooled, shorter vacuum cooling time and lower weight loss could be obtained. If the rice was cooked for longer boiling time or was vacuum cooled with excess water, the cooled rice could have higher moisture content, but the cooling time would be prolonged significantly. Spraying water during vacuum cooling did not significantly prolong the cooling time, but increased the moisture content of cooled rice. On the other hand, longer boiling time, cooling with excess water and spraying water could reduce hardness of the cooled rice significantly. Only spraying of water could cause significant reduction in the adhesiveness of the rice. [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]

With increased expectations for food products of high quality and safety standards, the need for accurate, fast and objective quality determination of these characteristics in food products continues to grow. Computer vision provides one alternative for an automated, non-destructive and cost-effective technique to accomplish these requirements. This inspection approach based on image analysis and processing has found a variety of different applications in the food industry. Considerable research has highlighted its potential for the inspection and grading of fruits and vegetables. Computer vision has been successfully adopted for the quality analysis of meat and fish, pizza, cheese, and bread. Likewise grain quality and characteristics have been examined by this technique. This paper presents the significant elements of a computer vision system and emphasises the important aspects of the image processing technique coupled with a review of the most recent developments throughout the food industry. [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]

A computer vision system was used to evaluate the melting property of cheese. The method is suitable for both cheddar and mozzarella cheese. The effect of cooking time (0–20 min) and temperature (70–200°C) on the melting degree and melting rate of cheddar and mozzarella cheese was investigated and the melting property of both cheeses were compared. Both cheddar and mozzarella cheese melted rapidly at the initial stage of cooking and melting slowed down in about 3–4 min. Maximum melting degree and melting rate occurred at about 130–160°C. Extended cooking and cooking at high temperature may cause reduced melting. Cheddar cheese melted more rapidly and considerably than mozzarella cheese at all cooking temperatures. [Copyright &y& Elsevier]

This study aimed to develop an alternative technique for rapid, accurate and non-invasive determination of gross energy density values of salmon fillets based on hyperspectral imaging (900–1700 nm). Spectral data were extracted from the hyperspectral images with outlier pixels removed. Good performances were achieved with r P of 0.906 and 0.909, and normalized RMSEP of 6.768% and 7.064% for partial least squares regression (PLSR) and epsilon-support vector regression (epsilon-SVR) analysis, respectively. The optimized stepwise-PLS model built with four wavelengths (931, 1001, 1135 and 1168 nm) yielded good results with r P of 0.908 and normalized RMSEP of 6.871%. The distribution maps for visualizing energy density indices in all portions of the salmon fillet were subsequently generated. The overall results confirmed the successful development of a rapid and non-destructive technique using hyperspectral imaging for determining energy value of salmon fillets, and the provision of an alternative method for caloric density measurement for the food industry. [ABSTRACT FROM AUTHOR]

Abstract: Garlic powder with high allicin content was prepared using microwave–vacuum and vacuum drying as well as microencapsulation in order to protect alliinase activity throughout the human stomach and improve the ratio of alliin transforming into allicin. The results showed that the optimal microwave–vacuum drying condition was drying for 3min under the microwave output power 376.1W, then 282.1W for 3min, followed by 188.0W for 9min, and finally for 3min under the output power 94.0W. The thiosulfinates retention after drying was 90.2%. Following drying, garlic powder was microencapsulated by modified fluidized bed technique. Scanning electron microscope revealed good integrity and core materials that were embedded in microcapsules. Studies on the release kinetics of microencapsulated garlic granulates in vitro using simulated intestinal fluid indicated that release of garlic powder could be controlled in intestine by passing through human stomach conditions. [Copyright &y& Elsevier]

Abstract: As a consequence of market competition, the production and manufacture of cheese products are at the stage of innovative dynamics. Pasteurized cheese with vegetable ingredients is one of the new products that may be added to sandwiches, salads, sauce, toast and pizza. Since vegetable ingredients can improve the nutritive value and flavour of cheese, it will probably become more and more popular in the future. Such new products require new techniques for monitoring and evaluating their quality in order to satisfy the increased awareness and expectations of consumers. Computer vision methods have been used increasingly in the food industry for inspection and evaluation purposes as they provide a rapid, economical, consistent and objective assessment. The aim of this study was to develop a computer vision method for inspecting two major quality attributes of pasteurized cheese, i.e. the distribution and amount of ingredients. An image pre-processing algorithm was first developed to delete the border area of cheese. Next a three-step method for ingredient extraction was developed, comprising colour quantification, ingredient location, and mask operation. Finally, the distribution and amount of each ingredient was calculated automatically. Two kinds of pasteurized cheese were evaluated using the above method, i.e. (a) cheese with garlic and parsley and (b) cheese with a mixture of vegetables composed mainly of pepper and parsley. It was found that the distribution and amount of ingredients in the first set of samples were determined within an accuracy of over 88%, compared with the results of a sensory method. As for the second set of samples, accuracies of over 81% and over 71% were achieved for measuring the distribution and amount of ingredients, respectively. [Copyright &y& Elsevier]

Abstract: Recently, computational fluid dynamics (CFD) has been frequently applied in many fields relating to fluid flow, and it has been shown that CFD is useful in these fields. The cooling rate and quality of foodstuffs in a cold store are highly dependent on the temperature field which is closely related to flow field. However, the flow field designed by using traditional methods, using a lot of time and cost without reliable and repeatable results, is not good enough. In this paper, a two-dimensional mathematical model for the inside a minitype constructional cold store [4.5m (l)×3.3m (w)×2.5m (h)] was proposed and a related computer program with SIMPLE algorithm and crisscross girding technique were developed. The simulation results reflected the characteristics of airflow and temperature distribution. After that, several design parameters (corner baffle, the stack mode of foodstuffs, etc.) which would affect the flow field in the cold store were analyzed. The results of calculation indicated that all these design parameters especially the stack mode of foodstuffs influenced the flow and temperature fields inside the cold store greatly. It was demonstrated that CFD was a powerful tool for designing and optimizing the flow field in cold store. [Copyright &y& Elsevier]