Ultrapress process

The concept of producing clarified fruit juice by a single pass of enzyme-treated fruit puree through a tubular, metallic ultrafiltration membrane system was recently described by Thomas et al. (5, 6). The process is known commercially as the Ultrapress process, since pressing and ultrafiltration are accomplished simultaneously (7). The metallic membrane ultrafiltration system is composed of sintered stainless steel tubes of varying diameters with membranes formed-in-place within the porous matrix of the tubes by deposition of various metallic oxides. Metallic oxides in combination with polymers are also possible. 

The previous studies also suggested that the Ultrapress process offered the potential for higher quality juice by reducing process time and also the potential for microbiologically stable juice, which could also provide an improved product by eliminating... 

Although the peaks in Figures 1 and 2 were not identified, it was apparent that the Ultrapress process caused insignificant changes in the volatile composition of the apple, indicating that fruit juices with aroma profiles nearly identical to that of the fresh fruit can be obtained. 

Figure 2. Volatile profile of apple juice manufactured by the Ultrapress process using McIntosh apples.

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