Discharged filtrate movement in food materials under application of electrokinetics. (1st May 2018)

• Record Type: Journal Article
• Authors: Iessa, H.; Christensen, K.; Hall, J.A.; Seal, C.J.
• Is Part Of: Food chemistry. Volume 247(2018)
• Page Start: 1
• Page End: 7
• Publication Date: 2018-05-01
• Subjects: Electrokinetics -- Dewatering -- Food drying -- Discharged filtrate; A/C ratio anolyte to catholyte ratio -- EK electrokinetic -- IEP isoelectric point -- LCP lowest conductivity point -- OJ orange juice -- ME malt extract -- NEC net electrical charge -- WPD water profile direction; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2017.12.007
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Dewatering of foods by electrokinetics is investigated. Water flow direction is determined by pH and lowest conductivity point (LCP). In acidic foods (e.g. orange juice), pH/LCP < 1; water moves to the anode. In alkaline foods (e.g. malt extract), pH/LCP > 1; water moves to the cathode. Controlling pH and electrode orientation maximises dewatering efficiency. Abstract: Orange juice (OJ) and malt extract (ME) samples were treated using an electrokinetic (EK) application to investigate the impact of the pH/Lowest conductivity point (LCP) ratio of experimental materials on the water profile direction and the anolyte to catholyte filtrate ratio. After applying the electric field through samples between two electrodes, filtrate was discharged mainly towards the anode in OJ samples (acidic medium, pH/LCP < 1) and towards the cathode in ME samples (alkaline medium, pH/LCP > 1). Adjusting the orientation of electrodes depending on the results maximised dewatering efficiency under EK by 7.8% in OJ and 11.8% in ME. Changing the pH/LCP ratio by adjusting the starting pH improved dewatering efficiency under EK by 25.7%. The results are used to develop theoretical guidelines to help determine the water profile direction and filtrate outlets for different food materials based on their pH and LCP values. EK is an effective method for dewatering food materials.