Effect of Microwave Concentration on the Quality of Dibs

Dates are a major fruit crop in Saudi Arabia and its dibs product represents one of the most important products. Local date dibs are produced in some Saudi regions using traditional method which results in products with darker color and a highly turbid. This study aimed at improving the quality of date dibs from two common varieties of data palm (Sufri and Silage). The experiment was designed to optimize extraction, clarification and concentration of date juice using microwave oven at 40, 70 and 100% Power Level (PL). Extraction, clarifying with active charcoal and concentration date juice with microwave at 40 or 70% PL improved the color of date dibs compared to local dibs. Also, the obtained dibs were characterized with its higher viscosity and TSS; and contained higher percentage of glucose and fructose. Storage time and temperature (25 and 45°C) had a little effect on the glucose and fructose levels; variation in viscosity and significant decrease in pH. Also, storage had a significant effect on the browning status of date dibs, the highest (55.34) browning values were found in local dibs. The total bacterial count of microwave concentrated dibs decreased during storage at 25 or 45°C to reach the lowest count after 6 months. The study concluded that, using microwave at 70% PL was able to improve physicochemical and microbiological properties of date dibs.