Study On The Extraction Of Lycopene From Tomato And Its Stability

Lycopene is an important natural carotenoids, it has the function of various health cares, such as resisting cancer, increasing the immunity and deferring decrepitude etc. As a potential functional natural colorant, more and more people pay attention to it. The present work focus on separation procedures and conditions by which oleoresin has been extracted from saponificated natural tomatoes. The physical and chemical properties of lycopene and its stability in different conditions have also been studied. The results are as follows:Alkaline saponification can increase the amount of oleoresin. The best conditions of tomato saponification are temperature, 40℃; concentration of NaOH, 0.6mol/L; and time, 45min. The dryness method after saponification is ethanol treating.Soxholet extraction and ultrasonically assisted extraction have been utilized to gain crude product from dry tomato powder with petroleum benzene. The factors such as temperature, time, ratio of liquid-solid, ultrasonic power, ultrasonic time will affect the yield of lycopene extraction . The result shows that the best conditions of soxholet extraction are temperature, 45℃; time, 6h; ratio of liquid-solid, 80:1. Under the above conditions, the yield of lycopene is 79.5%. Numerical results indicated the optimum yield of 0.863 at 60w of ultrasonic power, 15min of extraction time including 5 min of ultrasonic time and 35:1(v/w) of liquid-solid ratio.In this paper, the stability of lycopene oleoresin in different condition extracted by saponification was studied. The result showed that temperature influence the stability of lycopene and HCL damaged it greatly. Lycopene oleoresin was stable in alkaline condition. Lycopene was sensitive to sunlight, especially UV. However, it is not so sensitive to lamplight. Oxidant (H2O2) and reducing agent(Na2SO3) have no effect on the stability of lycopene. The Stability of lycopene is reduced when Fe 3+ or Cu2+ is added to its mediumwhereas other metal ions have no such effect on its stability.The lycopene-HP-β-cyclodextrin encapsulation complexes in various molar ratios (lycopene/ HP-β-cyclodextrin) were prepared by kneading method. The amounts of surface lycopene (extract from encapsulation complexes) and the total lycopene (extract from soluble encapsulation complexes) were measured by ultraviolet spectrophotometry. The results showed that the amount of surface menthol was the lowest when molar ratio was 0.53:1.