Other Food Processing Applications

Protein recovery and concentration are other major applications for inorganic membranes in the food processing area. 

Protein recovery in Tish processing. A huge quantity of soluble proteins are carried in the effluents of fish products processing plants. This poses two issues. It represents a significant economic loss and at the same time raises the pollution level of the fish pulp washwater. Therefore, the recovery of soluble proteins is of practical interest 

Like all other membranes, dynamic membranes experience flux decline over time to low steady state values. The permeate flux can be restored to its initial high value by applying a 500 to 1,000 ppm of sodium hypochlorite solution to wash out the fouled dynamic membrane. Porous ceramic supports were used instead of organic polymer membranes due to their resistance to chemicals and heat during the cleaning cycle. 

Swafford [1987] has studied the use of ceramic membranes for processing the washwater of minced Alaska pollack. The membrane with a nominal MWCO of 10,000 daltons yields a membrane flux about 20 to 30% lower than that of a membrane with a MWCX) of 20,000 daltons. 

One of the most challenging issues in this application is the adsorption of proteins on both inorganic and organic membranes. This leads to fouling which in turn limits the membrane flux as shown in Table 6.3 [Quemeneur and Jaouen, 1991]. The hydraulic resistance due to the layer of the adsorbed protein, R, can be significant when compared 

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In considering heat transfer in gas-solid fluidization it is important to distinguish between, on the one hand, heat transfer between the bed and a heat transfer surface (be it heated bed walls or heat transfer coils in the bed) and, on the other hand, heat transfer between particles and the fluidizing gas. Much of the fluidization literature is concerned with the former because of its relevance to the use of fluidized beds as heterogeneous chemical reactors. Gas-particle heat transfer is rather more relevant to the food processing applications of fluidization such as drying, where the transfer of heat from the inlet gas to the wet food particle is crucial. 

The single most important food manufacturing application of NF membranes is desalting of whey permeate, as shown in Fig. 5, or other food processing water streams. 

Other organisms in the environment are just as vulnerable as humans to this danger. Because of these risks, radioactive materials are shipped in shielded containers. The risks for medical and food-processing applications that utilize radioactivity are known to be very small compared to the potential benefits, but this is considered by many to be a controversial topic. 

Several studies showed higher antimiCTobial activity of whole EOs present in plants compared to selective components and information on the effects of crude extracts of plant origin compounds against food-borne miaoorganisms is limited. Future studies are required to conduct a more in-depth review for individual, and in combination application of EOs with extracts from other parts of the plant, other effective EOs and other food-processing techniques. 

Another common device used in the rubber industry is the thin film evaporator. This device is very often used in the manufacture of ultra-low molecular weight elastomers that are used in sealant applications or specialty coatings, and as processing aids in conventional rubber compounding processes. The thin film evaporator described earlier, has found a multitude of other industry applications, including food processing operations. 

As will have become apparent, nickel and corrosion-resistant nickel alloys have wide ranges of application, particularly in industries where strongly acidic, strongly alkaline or strongly saline environments are encountered. Table 4.29 lists some of the more important applications in those industries where these conditions most frequently arise, i.e. in the chemical, petrochemical, oil and gas, nuclear and conventional power generating, textile, paper, marine, desalination and food processing industries. The list is by no means exhaustive and there are many other applications of a similar nature in these and other industries. The table should, nevertheless, serve... 

A disperse system is defined as a heterogenous, two-phase system in which the internal (dispersed, discontinuous) phase is distributed or dispersed within the continuous (external) phase or vehicle. Various pharmaceutical systems are included in this definition, the internal and external phases being gases, liquids, or solids. Disperse systems are also important in other fields of application, e.g., processing and manufacturing of household and industrial products such as cosmetics, foods, and paints. 

The most widespread biological application of three-phase fluidization at a commercial scale is in wastewater treatment. Several large scale applications exist for fermentation processes, as well, and, recently, applications in cell culture have been developed. Each of these areas have particular features that make three-phase fluidization particularly well-suited for them Wastewater Treatment. As can be seen in Tables 14a to 14d, numerous examples of the application of three-phase fluidization to waste-water treatment exist. Laboratory studies in the 1970 s were followed by large scale commercial units in the early 1980 s, with aerobic applications preceding anaerobic systems (Heijnen et al., 1989). The technique is well accepted as a viable tool for wastewater treatment for municipal sewage, food process waste streams, and other industrial effluents. Though pure cultures known to degrade a particular waste component are occasionally used (Sreekrishnan et al., 1991 Austermann-Haun et al., 1994 Lazarova et al., 1994), most applications use a mixed culture enriched from a similar waste stream or treatment facility or no inoculation at all (Sanz and Fdez-Polanco, 1990). 

Numerous other uses of microwaves have appeared in the recent years - essentially drying of different types of material (paper, rubber, tobacco, leather. ..), treatment of elastomers and vulcanization, extraction, polymerization, and many applications in the food-processing industry. 

The lack of adequate predictive models is an obstacle to industrial applications. The poor understanding of the fundamentals of mass transfer in biological cellular structures—a problem common even to other areas of food processing dealing with transport phenomena—is the main hindrance... 

Low levels of resistance have been reported for some populations of Indian meal moth, almond moth, and red flour beetle populations in stored peanuts in the southeastern United States (Zettler et al., 1989), but no assessments are available for phosphine resistance in insect populations in mills, warehouses, processing plants, and other structural facilities. Phosphine can be corrosive to metals, particularly copper, electrical wiring, and electronic equipment (Bond et al., 1984), which limits its application in food processing facilities and warehouses. A new formulation of phosphine, in which phosphine gas is combined with carbon dioxide and released from a cylinder, alleviates some but not all of the corrosive effects of phosphine and is labeled for use as a structural treatment. 

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