Pectolytic and Cellulytic Enzymes for improvement of Date sugar

Date is a middle stoned fruit from the Palmaceae family. Dates have higher caloric content and more essential minerals and vitamins as compared to other fruits. According to the data from the Food and Agriculture Organization (FAO), Iran was ranked third in the production of dates in year 2003. Though a wide area is cultivated for date palms, unfortunately, only 11 – 12 percent of this amount is processed and packaged. In such a situation, improvement of the process for the production of date concentrate and liquid date sugar is important in order to increase the production of these products and thus reviving the national economical status. In this research we studied the enzymatic treatment of grade III date of the Mazafati variety with pectolytic and cellulytic enzymes on improvement of sugar extraction. The following indicators were measured in the raw material: pH, weight percentage of the stone, humidity, total sugar, reducing sugars, ash, fiber and pectin. In order to provide for the best condition for the function of pectolytic and celulolytic enzymes and their combination we used the Taguchi and Response Surface methods (R.S.M) to design the experiments and predict the results. After defining the optimal functioning situation for the above-mentioned enzymes, the effect of pectolytic and cellulolytic enzymes and their combinations was compared on the total sugar, reducing sugars, transparency, soluble solid materials and the productivity of sugar extraction of date. Results showed that using the combination of pectolytic and cellulolytic enzymes with a ratio of 2:1 with a concentration of 0.017 percent (v/v) in 62ºC, pH 5.75, significantly affected the total sugar, reducing sugars, soluble solid material and production ratio compared to each enzyme individually and to the control sample. There was no significant change in transparency. Results showed that with enzymatic treatment total sugar in date juice increased 3.33% and reducing sugars, soluble solid materials and production ratio increased in 3.22%, 3.6% and 15.05% respectively. In-house sensory evaluators confirmed that the product of the combined enzyme process was sweeter than the control sample. According to the results obtained in this study, enzymatic treatment in the process of producing date syrup and date liquid sugar is recommended under the above-mentioned conditions.