Charactrization of carotenoids (lyco-red) extracted from tomato peels and its uses as natural colorants and antioxidants of ice cream

摘要

The nine carotenoid pigment compounds of tomato peels were identified by HPLC analysis. The main component of carotenoids (lyco-red) extracted from tomato peels was lycopene, phytoene, phytofluene, β-carotene, cis -lycopene and lutein. Consequently, the higher stability of carotenoids (lyco-red) extracted from tomato peels was observed in alkaline pH ranging from 7 to 10 and temperature ranging from 40 to 70°C. Meanwhile, the degradation of carotenoids (lyco-red) extracted from tomato peel did not exceed than 16.20% of total pigments after 180min incubation at 100°C. On the other hand, the antioxidant activity of carotenoids (lyco-red) extracted from tomato peel was also studied by the Rancimat test at 110°C on sunflower oil by adding 50–200ppm of carotenoids (lyco-red) extracted from tomato peels. However, sunflower oil containing 50–200ppm recorded higher induction period than 200ppm BHT. Supplementing ice cream with carotenoids lyco-red extract increased the Radical Scavenging Activity RSA and Ferric Reducing Antioxidant Power (FRAP) in the ice cream by increasing the concentration of adding lyco-red extract. On the other hand, analysis of variance for sensory evaluation of prepared ice cream indicated that, ice cream containing 3% and 2% of carotenoids (lyco-red) extracted from tomato peels had the highest scores for flavor, body and texture, melting and color and the best mix compared with that prepared with 1%, 4% and 5% which recorded the lowest scores in all tested quality attributes.