The objective of this study was to investigate the optimal formulation of mulberry fruit leather product when varying the weight ratio of mulberry fruit: water as 70:30 60:4050:50 40:60 and 30:70. Three factors were then determined by simplex centroid design; sugar (0-100% or 0-50 grams) citric acid (0-100% or 0-5 grams) and pectin (0-100% or 0-3 grams) which the sum of them equivalent to 100% while other ingredients remained constant. Analysis of the data was performed using ANOVA and Mixture Response Surface Models. The results indicated that the highest adhesiveness force and gumminess of mulberry fruit leather product were founded when the weight ratio of mulberry fruit to water was 70:30. The amount of sugar acid and pectin had effects on water activity (Aw) texture profile and sensory score of overall liking of product. From contour plot the predictive models were obtained by plottin g the contour line of all sensory attributes with acceptable score greater than 5.5 and thus the optimization area was selected. After overlapping contour plots an optimal formulation obtained was composed of 40-70% sugar 0-5% citric acid and 30-55% pectin. The sensory score of overall liking of product using a 9-point hedonic scale was 6.3. The water activity (Aw)adhesiveness force cohesiveness and gumminess of the prototype mulberry fruit leather product was 4.9 945.11 g. sec. 0.85 N and 452.12 N. respectively.

The optimum conditions of extracting pectin from vegetables and fruits are apples grapefruit lemons and bananas were studied. It was found that pectin from grapefruit peel gave good physical property white and has a relatively highest yield. Therefore in this study was interested to choose grapefruit peel as raw materials to optimum the conditions of pectin extraction. In the process of pectin extraction the temperatures of the extraction were studied at various 50 60 70 80 and 90 ?C by using hydrochloric acid for 24 hours. It was found that when the temperature increased the pectin extract was increased while at 80 and 90 ?C have a similar effect. After that pH conditions of the extraction were studied by various acids such as hydrochloric acid nitric acid and acetic acid at the same concentration of 1.0 molar at 80 C for 24 hours (1440 minutes). The results found that hydrochloric acid gave maximum pectin extracted yield. Finally the extraction times were studied at 30 60 90 120 and 1440 minutes using 1.0 M hydrochloric acid. From this work can optimized the pectin extraction condition as of 80 C and the extraction time was 90 minutes that gave maximum yield of pectin. At the otherwise the times of extraction have no effect to the amount of pectin. The potential from this study had satisfactory results can be used to improve the extraction of pectin system.