Effect of Thermal Processing on the Degradation, Isomerization, and Bioaccessibility of Lycopene in Tomato Pulp

Abstract

Thermal processing affects the nutritional value of food products. The nutritional value is not only determined by the content but also by the bioaccessibility of nutrients. The present study was performed to gain detailed insight into the influence of thermal processing on the degradation, isomerization, and bioaccessibility of lycopene isomers in tomato pulp, without adding any other ingredient. The bioaccessibility, which is defined as the fraction of the nutrient that can be released from the food matrix, was measured using an in vitro method. The results demonstrated the rather high thermal stability of lycopene. Although a treatment at 140 °C induced isomerization, the contribution of cis-lycopene to the total lycopene content remained small. Results also confirmed that thermal processing as such can improve the in vitro bioaccessibility of lycopene in tomato pulp, but the improvement was only significant upon treatments at temperatures of 130 and 140 °C. At such intense process conditions, one should be aware of the negative effect on other quality and nutrient parameters. Possibilities of thermal processing as such to improve the nutritional value of tomato pulp (without the addition of other ingredients) thus looks rather limited.

Current Food Classifications in Epidemiological Studies Do Not Enable Solid Nutritional Recommendations for Preventing Diet-Related Chronic Diseases: The Impact of Food Processing

“…Indeed, even if the process degrades labile molecules, some molecules may become more bioaccessible to enzymes within the digestive tract after processing (7). This effect has been largely demonstrated for carotenoids in the vegetable matrix (52)(53)(54). Therefore, 2 different original raw products may be processed in the same manner, but their nutritional content, which is modified by the process in opposite ways, may be entirely different.…”

Antioxidant Activity from Various Tomato Processing

“…It could damage the cell walls structure and release out antioxidants in tomatoes (Colle, et al, 2010a(Colle, et al, : 2010b. Based on the results of the research on total antioxidant capacity and antioxidant activity, the TCA value of tomatoes in steamed tomato was higher than all processing groups.…”

Lycopene in chemoprevetion of breast cancer

“…Stwierdzono, że forma 5-cis jako jedyna jest termodynamicznie bardziej stabilna od wszystkich izomerów trans [7]. Badania dowodzą, że likopen jest stosunkowo stabilny termicznie [8]. Dla przykładu retencja likopenu w pulpie pomidorowej ogrzewanej do temperatury 140 o C przez 30 minut wynosi aż 75%, ponadto stwierdzono w tej temperaturze ograniczenie izomeryzacji likopenu [8].…”

“…Badania dowodzą, że likopen jest stosunkowo stabilny termicznie [8]. Dla przykładu retencja likopenu w pulpie pomidorowej ogrzewanej do temperatury 140 o C przez 30 minut wynosi aż 75%, ponadto stwierdzono w tej temperaturze ograniczenie izomeryzacji likopenu [8]. Zawartość wszystkich izomerów trans likopenu wynosiła 84%, natomiast resztę stanowiły formy cis [9].…”

“…Na zwięk-szoną wartość biologiczną likopenu wpływają również inne procesy technologiczne z zastosowaniem wysokiej Tabela I. Zawartość likopenu w wybranych produktach spożywczych [8] …”