Applications of ultrasound in analysis, processing and quality control of food: A review

Over the last forty years many computer simulations of water have been performed using rigid non-polarizable models. Since these models describe water interactions in an approximate way it is evident that they cannot reproduce all of the properties of water. By now many properties for these kinds of models have been determined and it seems useful to compile some of these results and provide a critical view of the successes and failures. In this paper a test is proposed in which 17 properties of water, from the vapour and liquid to the solid phases, are taken into account to evaluate the performance of a water model. A certain number of points between zero (bad agreement) and ten (good agreement) are given for the predictions of each model and property. We applied the test to five rigid non-polarizable models, TIP3P, TIP5P, TIP4P, SPC/E and TIP4P/2005, obtaining an average score of 2.7, 3.7, 4.7, 5.1, and 7.2 respectively. Thus although no model reproduces all properties, some models perform better than others. It is clear that there are limitations for rigid non-polarizable models. Neglecting polarizability prevents an accurate description of virial coefficients, vapour pressures, critical pressure and dielectric constant. Neglecting nuclear quantum effects prevents an accurate description of the structure, the properties of water below 120 K and the heat capacity. It is likely that for rigid non-polarizable models it may not be possible to increase the score in the test proposed here beyond 7.6. To get closer to experiment, incorporating polarization and nuclear quantum effects is absolutely required even though a substantial increase in computer time should be expected. The test proposed here, being quantitative and selecting properties from all phases of water can be useful in the future to identify progress in the modelling of water.

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Simulating water with rigid non-polarizable models: a general perspective

Consumers increasingly demand convenience foods of the highest quality in terms of natural flavor and taste, and which are free from additives and preservatives. This demand has triggered the need for the development of a number of nonthermal approaches to food processing, of which high-pressure technology has proven to be very valuable. A number of recent publications have demonstrated novel and diverse uses of this technology. Its novel features, which include destruction of microorganisms at room temperature or lower, have made the technology commercially attractive. Enzymes and even spore forming bacteria can be inactivated by the application of pressure-thermal combinations, This review aims to identify the opportunities and challenges associated with this technology. In addition to discussing the effects of high pressure on food components, this review covers the combined effects of high pressure processing with: gamma irradiation, alternating current, ultrasound, and carbon dioxide or anti-microbial treatment. Further, the applications of this technology in various sectors— fruits and vegetables, dairy, and meat processing—have been dealt with extensively. The integration of high-pressure with other matured processing operations such as blanching, dehydration, osmotic dehydration, rehydration, frying, freezing / thawing and solid-liquid extraction has been shown to open up new processing options. The key challenges identified include: heat transfer problems and resulting non-uniformity in processing, obtaining reliable and reproducible data for process validation, lack of detailed knowledge about the interaction between high pressure, and a number of food constituents, packaging and statutory issues.

/pdf/opportunities-and-challenges-in-high-pressure-processing-of-3p4mjmljox.pdf

Opportunities and Challenges in High Pressure Processing of Foods

Effects of high pressure on meat: A review.

Rheological Properties of Foods, H. Dogan and J. L. Kokini Reaction Kinetics in Food Systems, R. Villota and J. G. Hawkes Phase Transitions and Transformations in Food Systems, Y. H. Roos Transport and Storage of Food Products, M.A. Rao Heating and Cooling Processes for Foods, R. P. Singh Food Freezing, D. R. Heldman Mass Transfer in Foods, B. Hallstroem, V. Gekas, I. Sjoeholm, and A. M. Romulus Evaporation and Freeze, K. R. Morison and R. W. Hartel Membrane Concentration of Liquid Foods, M. Cheryan Food Dehydration, M. R. Okos, O. Campanella, G. Narsimhan, R. K. Singh, and A. C. Weitnauer Thermal Processing of Canned Foods, A. Teixeira Extrusion Processes, L. Levine and R. C. Miller Food Packaging, J. M. Krochta Cleaning and Sanitation, E. A. Plett and A. Grasshoff Appendix Index

Handbook of food engineering

Pressure depresses the freezing point of water and the melting point of ice, as well as enabling various high-density forms of ice to be obtained. These effects of pressure on the solid-liquid phase diagram of water have several potential applications in food technology, including pressure-assisted freezing, pressure-assisted thawing and non-frozen storage at low temperature (under pressure). Studies that have been published in these and in related areas are reviewed, and the potential applications and limitations are highlighted.

Potential food applications of high-pressure effects on ice-water transitions

Temperature changes during pressure-shift freezing (400 MPa) of potato cubes and its effects on the drip loss (weight and conductivity), texture (shear and compression tests), colour (L, a, b values), drying behaviour, rehydration properties (water uptake, texture after rehydration) and visible cell damage after thawing (micrographs) were investigated and compared with conventional freezing (0.1 MPa, -30°C), subsequent frozen storage (-18 °C) or pressure treatment (400 MPa) at +15°C. Pressure-shift freezing resulted in increased crystallization rates compared to conventional freezing at -30°C. Crystallization and cooling to -8°C took 2.5 min during and after pressure release versus 17 rain at atmospheric pressure. Drip loss was reduced from 12.0 to 10.8 g/100 g. Water uptake during 10 min of rehydration (93.9 g/100 g compared to 77.4 g/100 g and incomplete rehydration) and texture values were improved. Browning after thawing or after fluidized bed drying was reduced (increased a value, lower L value), suggesting partial enzyme inactivation during pressure treatment. Differences in colour and texture to the untreated controls were smaller after pressure-shift freezing than after conventional freezing. Cooling to -30°C after pressure-shift freezing did not significantly affect the results, whereas subsequent frozen storage at -18°C resulted in quality deterioration, as observed after frozen storage of conventionally frozen samples. The improved preservation of cell structure was demonstrated using scanning electron microscopy.

M. T. Kalichevsky

Papers

Potential food applications of high-pressure effects on ice-water transitions

Pressure‐shift freezing and its influence on texture, colour, microstructure and rehydration behaviour of potato cubes