Liquid Sugar Extraction from Date Palm (Phoenix dactylifera L.) Fruits

Abstract

In date syrup manufacturing, date fruits (Phoenix dactylifera L.) are mixed with a suitable amount of water with heating at a temperature greater than 70°C for about 1 h. These conditions are not satisfactory for extraction greater amount of liquid sugar (date syrup). In addition, overheating for an extended period could damage nutritious materials and changes product’s color. In this study, pectinase/cellulase enzymes and sonication processes were used to achieve maximum syrup extraction from a date variety (Reziz) compared with classical method. The following variables were examined: fruit/water ratio, mixture of enzymes percent and ultrasonic power. Enzymes and Ultrasound were applied for improving the quantity and quality of extracted syrup. Date extract was filtered with filter system (Novox 200, filtrox) which could result entirely a clear syrup and then concentrated by a rotary evaporator until about 75% total solids to produce higher quality syrup. Physicochemical properties of each collected sample during process were evaluated. Results showed that sonication power 25% at ratio 1/3 D/W could lead to a higher extraction of RSS (Recovery of Soluble Solids) (74.30%) in a shorter time with a better physicochemical quality of syrup in comparison to mixture of enzymes 1.0% (66.70%) and classical methods of extraction (58.45%). Data indicated the possibility of employing ultrasound (25%) or enzymes processes (pectinase/ cellulase 0.1%) for producing greater syrup amount highly desirable for use in food product development.