15D-12 |
Influence of processing parameters on lycopene changes during extrusion of tomato-based food products |
C. MORARU and T. C. Lee. Dept. of Food Science/Center for Advanced Food Technology, Rutgers, The State Univ. of New Jersey, 65 Dudley Rd., New Brunswick, NJ 08901 Tomato is a major agricultural commodity and enjoys worldwide acceptance. Its appealing red color is given by lycopene, the major carotenoid in tomato. Lycopene also acts as an important antioxidant, protecting against oxidative and photo-oxidative damage, and contributes to the health status of humans. However, long or intense heating causes significant lycopene loss, amplified by oxygen or light exposure. This may be important when tomatoes are used for processing. The lycopene changes occurring during tomato-based foods manufactured by extrusion are not well documented, because of the inability to discriminate between degradation and geometric isomerization. This study aims to determine the extent of lycopene changes in innovative extruded tomato-based foods and to relate it to the extrusion parameters. Tomato puree and rice flour were used to manufacture noodles and snacks, in a lab scale twin-screw extruder. Different lycopene concentrations and various extrusion parameters were evaluated. An HPLC quantification method was used to evaluate the extent of lycopene change occurring due to processing. A mathematical model relating the lycopene change to the processing conditions was developed. Our results indicate various extents of lycopene retention (60-75%) in the processed tomato-based products manufactured by extrusion. Further analysis showed that correlations exist between lycopene changes and the extrusion parameters (temperature, screw speed, die pressure). This study yielded a quantification of lycopene changes in extruded tomato-based products and confirmed the major influence of extrusion methods and parameters on lycopene retention in such products. The correlations found between lycopene changes and the extrusion parameters could be of potential interest for choosing processing parameters able to give optimal lycopene retention. The model may help to predict the effects of changing parameters on lycopene retention.
Session 15D, Food Engineering: Processing Technologies
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