Storage stability of lycopene in tomato juice subjected to combined pressure-heat treatments.

A study was conducted to characterize the storage stability of lycopene in hot-break tomato juice prepared from two different cultivars and processed by various pressure-heat combinations. Samples were subjected to pressure assisted thermal processing (PATP; 600 MPa, 100 degrees C, 10 min), high pressure processing (HPP; 700 MPa, 45 degrees C, 10 min), and thermal processing (TP; 0.1 MPa, 100 degrees C, 35 min). Processed samples were stored at 4, 25, and 37 degrees C for upto 52 weeks. HPP and PATP treatments significantly improved the extractability of lycopene over TP and control. All-trans lycopene was found to be fairly stable to isomerization during processing, and the cis isomer content of the control and processed juice did not differ significantly. During storage, lycopene degradation varied as a function of the cultivar, processing method, storage temperature, and time. This study shows that combined pressure-temperature treatments could be an attractive alternative to thermal sterilization for preserving tomato juice quality.