Estudo da concentração de licopeno por ultrafiltração a partir de suco de melancia (Citrullus vulgaris Schard). / Study of the concentration of lycopene for ultrafiltration from watermelon juice (Citrullus vulgaris Schard).




The aim of this work was to study lycopene concentration in watermelon juice using ultrafiltration. Watermelon has a greater lycopene concentration than tomato, which is considered as the reference. For the ultrafiltration 4 ceramic membrane modules were used, with a total surface area of 200cm² and a pore diameter of 0,01um. A batch process was used with 11 experiments, according to a complete experimental design (22). The frequency of the pump was adjusting to reach 1500rpm giving a concentration factor of 2. The independent variables were: process temperature (25-45°C) and transmembrane pre ssure (TMP) (1.5-3.5bar); the responses were: fouling effect, lycopene concentration in the retentate and initial permeate flow rate. It was observed that the fouling effect was only influenced by the linear form of TMP, in the range studied. The lycopene concentration, relative to the initial juice concentration, varied from 78 to 88%, increasing with TMP in a linear way and with temperature in a linear and quadratic way. The initial permeate flow rate increased with TMP and a smaller increase was observed with increase in temperature. Fouling affected the reduction in flow rate. The smallest values for final permeate flow rate were in tests 5 (25°C/2.5bar) (68.80kg/h·m²) and 7 (35°C/1.5bar) (57.19kg/h·m²). In the other tests, this value varied from 86.04 to 103.00kg/h.m². The permeate showed an acceptable microbiological condition. The presence of peroxidase was detected in all the fractions. The retentate was acidified to pH4.3 and pasteurized (83°C/45s) for application in the products, in this case, gum candies. In the preliminary development of phase, these gums were evaluated by sensory analysis. The scores obtained in the sensory analysis ranged from 6.14 to 7.58, on a scale from 1 to 9 for the attributes: odor, taste, color, texture and overall impression. A total of 48% of the consumers would probably buy the product. In the triangular test, a difference was detected, 95% significance, between the two treatments with the same TMP (2.5bar) and different temperatures (35 and 40°C). The retentate was acidified and pasteurized before the sensory tests. It was also observed that centrifugation could be used as an additional treatment to ultrafiltration, resulting in a higher lycopene concentration in the precipitate.


watermelon membranas lycopene carotenoides ultrafiltration licopeno membranes carotenoids melancia ultrafiltração

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