Mixing operations, food industry

Rheology is of major importance in processing operations in industry. The rheological behavior of process streams and dispersions determines the pumping and transportation costs, the ease of mixing operations in reactors, and the quality of the final product in many cases. What we do not often realize is that it is also one of the factors that determine the esthetic and sensual appeal of certain products, especially in the case of food products and cosmetics Differences in the fed of a face lotion or a skin cream or the consistency of a ketchup can make or break the market for the product ... 

Muro et al. [80] showed the beneficial effects of hybrid processes in wastewater treatment in the food industry. These mixed systems included traditional techniques as centrifugation, cartridge filtration, disinfection, and different membrane techniques resulting in a cascade design, which could be applied in a variety of the applications. They argued that the risk of membrane damage due to the contact with particles, salt conglomerates, chemicals, or others substances must be minimized to prevent short membrane life. Operation... 

The selection of mixed cultures with a high capacity for PHA accumulation occurs naturally because of reactor operation conditions and, consequently, there is no need to sterilize the system. On the other hand, having mixed cultures facilitates the use of complex substrates made from organie residues, such as food industry effluent, and the microbial population continuously adapts to substrate changes. Therefore, it is possible to minimize costs by using mixed cultures and selected substrates. The cost of PHAs produced by mixed cultures may decrease to around half of the cost of those produced by pure cultures, due to lower substrate and investment costs. 

Fluid mixing is a unit operation carried out to homogenize fluids in terms of concentration of components, physical properties, and temperature, and create dispersions of mutually insoluble phases. It is frequently encountered in the process industry using various physical operations and mass-transfer/reaction systems (Table 1). These industries include petroleum (qv), chemical, food, pharmaceutical, paper (qv), and mining. The fundamental mechanism of this most common industrial operation involves physical movement of material between various parts of the whole mass (see Supplement). This is achieved by transmitting mechanical energy to force the fluid motion. 

Screw extruders are also used, however, to produce pelleted materials, either as a final product or for further processing, in the food, ceramics, chemical and other industries. Many orifices in a die plate form a multiplicity of extruded rods which are cut into pellets by rotary cutter blades. The extrusion operation is frequently the final step in a sequence of processes which may include binder/lubricant addition, mixing, heating, cooling or vacuum degassing. 

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