Evaluation of Physical‐Chemical, Pharmacodynamic and Pharmacological Attributes of Hot Air Dried and Swell Dried Jujube Powders

Abstract

AbstractThe main objective of this work is to study and compare the functional properties of jujube fruit (Zizyphus jujuba) powders obtained from two different drying processes: hot‐air drying and swell‐drying by combining Instant Controlled Pressure‐Drop (DIC) with conventional air drying process. For this purpose, we performed the convective drying kinetics of pitted whole fruit at an atmospheric pressure of 2 m/s, 85C, and 4% relative humidity. DIC treatment was carried out with 0.35 MPa saturated steam pressure for 15 s after eliminating a water content of 12.5 g H2O/100 g db (dry basis) through the first stage of ambient temperature convection drying. Under these experimental conditions, the effects of drying processes, the type of solvent and powder granulometry were studied. The results showed that swell‐dried compared to hot‐air dried powders had a higher availability of phenolic compounds (20.14 ± 0.07 against 13.28 ± 2.06 mg Gallic Acid Equivalent GAE/g dry basis db) and flavonoids (72.3 ± 7.1 against 17.5 ± 4.7 mg Quercetin Equivalent Querc. E/g db). The presence of several active compounds thanks to DIC texturing was observed in all the granule sizes. The biological activities of swell‐dried jujube flavonoids extracts showed the highest antimicrobial activity. The physical and pharmacological properties of jujube tablets were compared to Fumacur, which is known as an Algerian traditional drug used against anemia. In terms of metals, swell‐dried jujube powder contains a higher concentration of metals than that of Fumacur. This first approach greatly encourages the use of these natural pharmaceutical tablets as a very effective and economical drug to fight certain health problems.Practical ApplicationsThis research highlights the valorization of Zizyphus jujuba and its transformation into powder through swell‐drying process using “Instant controlled pressure drop” DIC as adequate texturing process coupled with conventional airflow drying. This study aims to reach possible industrial applications based on the functional quality of final products. The DIC swell‐drying process makes it possible to obtain a nutritional and functional powder with a high health benefit. A directly simple compression method has been efficient to transform the jujube powder into tablets. Based on the obtained results showing important chemical constituents, their biological activities and pharmacological properties, the swell‐dried jujube powder has exhibited a great potential for their use as pharmaceutical formulations and nutraceutical fields.