Investigation of some quality characteristics of pekmez obtained from carob by determination of ultrasonic assisted extraction parameters

The most important step in making carob molasses is the stage of obtaining must. It is quite difficult to replace the 60% total sugar content in carob to the must due to the fibrous structure of carob. Traditionally, the must could be obtained by extraction method from 12 hours to 3 days. Ultrasonic assisted extraction process, which is one of the current extraction methods, was used to pass the components in carob into the cider in more amounts and in a shorter time. For the ultrasonically assisted extraction process, a pattern was created according to the Box-Benkhen method using the response surface method. The effects of extraction time, temperature, fruit/solvent ratio and ultrasonic power were independent variables, while total soluble dry matter, yield, antioxidant capacity and total amount of phenolic substances were responses in the optimization. According to the results, optimum conditions were found as 40˚C, 21min, 1/9 ratio and 84% ultrasonic power. In the optimum conditions determinated, carob juice was produced with ultrasonic extraction and three different molasses was produced in different conditions. In order to observe the differences between the traditional method and ultrasonic extraction method, three different molasses was produced by traditional and ultrasonic extraction method and analyzed. The molasses was produced in different conditions as traditional boiler, under vacuum at 70˚C and under vacuum at 80˚C. There is no significant differences in chemical composition, color, total antioxidant capacity and total amount of phenolic compounds between the carob molasses that produced using traditional production and ultrasonic production. It was found that in ultrasonic method HMF leves were partially higer, but the results were less than the acceptable level. According to the sugar distribution of molasses, it was found that in ultrasonic method; the amount of glucose decreased, the amount of sucrose increased and there was no significant difference in the amount of fructose. In terms of phenolic compound distribution, was determined that the amount of catechin and vanillin increased in ultrasonic method, whereas the amount of rutin decreased. In terms of gallic acid, protocatehuic acid, chlorogenic acid and trans-p-qumaric acid, there was no difference between the ultrasonic method and traditional method. It was also observed that vanillin and rutin are degraded by cooking in traditional boiler. Carob molasses is traditionally and commercially produced at very different extraction temperatures (between 50˚C and 90˚C) and times (from 4 h to 12 h or even 3 days). It can be seen that with the ultrasonic extraction applied in our study, the duration can be reduced to 21 minutes and the temperature to 40˚C. It is thought that ultrasonic assisted extraction can be used in the molasses production methods at the extraction stage.