Effect of Mixing During Extraction on the Quality of Date Juice

Abstract: Juice of Siwi dates variety at tamr stage (semi-dry) was obtained using three different methods of extraction. In the first method, date was extracted with water at 25°Cfor 2.0 min (T1). In the second method, date residue of extraction (T1) was subjected to a second extraction at 75°C for 15 min (T2) and in the last method, date was extracted at 75°C for15 min (T3) at ratio 3:1 of water/date (wt/wt). Mixing of date with water was investigated using a paddle impeller. The flow behaviors of date juices were studied at 25°C, for treatment (T1) and 75°C for treatments (T2 and T3). The speed of spindle used is 20-200 rpm. Shear stress-Shear rate data indicate that the juice behaves as non-Newtonian pesudoplastic fluid. The impeller was connected to an Ammeter in order to predict the power of the mixer. Prediction of the power number, blend number and pumping number as a function of Reynolds number were plotted and this enabled an economic scale –up for non-Newtonian fluid. Excellent quality of date juice and minimal time were recorded for T2 and T3. It is also recommended to use the values 45-91 rpm for the mixer as scale-up value.

KEYWORDS: Extraction, date juice, mixing, flow behavior, Power consumption, Scale-up.
Publication year 2008
Pages 93-108
Availability location معهد بحوث تكنولوجيا الاغذية-9ش الجامعة-الجيزة
Availability number
Organization Name
City Cairo
serial title Journal of Engineering and Applied Scince
Author(s) from ARC
Agris Categories Food science and technology
AGROVOC
TERMS		 Dates. Extraction. Mixing. Quality.
Publication Type Journal
↑