Author: John Leo

When moisture is removed within the solid network of a food product during drying, a pressure unbalance is produced between the inner and external part of the food material, generating contracting stresses that lead to material shrinkage, changes in shape and sometimes product cracking (Mayor and Sereno, 2004). Visual appeal is affected too should severe shrinkage is experienced by the product. Typically, shrinkage increases proportionally with the volume of water removed during drying. Under ideal shrinkage condition the volume of water removed is equivalent to the reduction in sample volume. Sometimes, this could be untrue especially at low moisture…

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Scientific experiments are important in research laboratories of universities and also in the engineering laboratories of industries. Experiments in processing companies are often conducted in a series of trials or tests which produce quantifiable outcomes. For continuous improvement in product/process quality, it is fundamental to understand the process behavior, the amount of variability and its impact on processes (Mason et al., 2003). Quality and productivity with process economics are characteristic goals of industrial processes, which are expected to result in superior goods that are highly sought by consumers and that yields profit for firms that supply them. Recognition is now…

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It has long been realized that a relationship exists between diet and food on the one hand, and health and disease on the other. If our intake of the substances which provide energy is too low, the result will be under nutrition. Similarly, an inadequate intake of the vitamins and minerals required for regeneration and regulation is likely to lead to various deficiency diseases, some of which can be life-threatening. Current scientific insights however, suggest a more complex relationship between diet and health, particularly in terms of the so-called ‘lifestyle diseases’. A high energy intake with low energy expenditure is…

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Osmotic dehydration is relatively slow so acceleration of mass transfer would be advantageous. There are various methods to increase the mass transfer, such as application of ultrasound, high hydrostatic pressure, high electrical field pulses, vacuum and centrifugal force and microwave Application of ultrasound During osmotic dehydration Ultrasound in the food industry is relatively new and it has not been explored indepth until recently (De Gennaro et al., 1999). Ultrasound has been applied in the food industry to determine food properties due to low-frequency, high-energy ultrasound. It can travel through a solid medium; therefore, it can influence mass transfer. A phenomenon…

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In recent decades significant changes have occurred in the Dutch dietary pattern with regard to several important dietary factors. In the case of some factors, the diet has clearly become more healthy; for others, the reverse is true (see table 1). The main improvements are the decrease in the content of saturated and Trans fatty acids in foods, and the increase in the consumption of fish. Between 1988 and 1998, the consumption of Trans fatty acids decreased by over 60% as a result of modifications to the composition of margarines and cooking fats. The consumption of saturated fatty acids decreased…

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Calculated in terms of the quantity and composition of the nutrients and other healthpromoting constituents, is ‘optimal’ (in terms of health) according to current scientific insights. Maintaining a healthy eating pattern is therefore a question of eating neither too much nor too little (the energy intake must be in balance with energy expenditure), and that the dietary composition (in terms of the main nutrients) is in line with the recommended levels. You can download movie from khatrimaza The term ‘food’ is defined as the complete range of foods and edible products made available by the agricultural sector and the food…

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It was in 1985 that I suggested to Dr. Carl W. Hall, then Editor of Drying Technology – An International Journal and Deputy Director for Engineering at the National Science Foundation, Washington D.C., that since IDS had matured and developed its own momentum and recognition around the world, it was time to honor those who have made outstanding contributions to the field. Much to my delight Dr. Hall accepted the idea and went ahead to seek successfully sponsors for four major awards that were initiated at IDS’86 held on the august campus of MIT, Cambridge, MA. This program has now…

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The energy crisis of the early seventies gave real impetus to recognition of drying as a worthwhile R&D area by industry, especially in industries where drying was a key and costly operation e.g. in pulp and paper, wood, foods etc. This led me to develop and found the idea of providing a forum for exchange of ideas, research results as well as technology transfer between academia and industry. The idea was (and still is) to acquaint academics with industrial needs in the inter- and cross-disciplinary area and to familiarize the industry with current R&D. It also turned out to be…

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