Flash-desolventizing systems

Of obvious concern in any DT application is the potential for overtoasting the meal and adversely affecting the water solubility of the protein, often expressed in terms of the protein dispersion index, or PDl. For certain edible flour and other applications demanding a high PDI, the DTDC process may be replaced with a flash desolventizing system. These systems, which typically use superheated solvent to evaporate volatiles present in the freshly extracted white flakes, maintain the high PDI while desolventizing the feedstock. 

A relatively recent alternative to traditional flash-desolventizing systems is the down-draft desolventizer (DDD system). The DDD system incorporates a low-temperature, low-pressure desolventizer to reduce the hexane content to 2500 ppm in the first stage, followed by a high-vacuum stripper to produce white flakes with a residual... 

Despite much research to demonstrate new uses, only about 3% of the available soybean meal is processed into edible flours and protein concentrates (>65% protein) and isolates (>90% protein). The flash desolventizer was developed to reduce protein denaturation and produce highly soluble protein food ingredients from soybeans (Fig. 11.17). Integrating these desolventizing systems with subsequent cooking systems produces edible protein flours with a broad spectrum of protein dispersibility characteristics. The system includes a desolventizing tube, a flake separator, a circulating... 

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