Concentration of Polyphenolic Antioxidants in Apple Juice and Extract Using Ultrafiltration

Abstract

The aim of the present work was to study the potential of ultrafiltration with three polyacrylonitrile membranes (1, 10, and 25 kDa) to concentrate polyphenolic antioxidants in apple juice and extract. The permeate flux, total polyphenols, polyphenolic profile, phenolic acid content, and total antioxidant capacity were determined using the FRAP and DPPH tests, the content of water-soluble proteins during ultrafiltration was established, and the concentration factors and rejections were determined. The permeate flux decreased by increasing the volume reduction ratio and decreasing the molecular weight cut-off of the membranes. The concentration factor and rejection of polyphenolics increased with the increase in the volume reduction ratio (VRR) for all membranes and both liquids. The concentration and rejection effectiveness of the 1 kDa membrane was higher than those observed for 10 and 25 kDa during the ultrafiltration of the apple extract, while these values were comparable for 1 and 10 kDa during the ultrafiltration of the apple juice. The concentration factors and rejections of total polyphenols were higher in the extract than in the juice. Chlorogenic acid was the main compound in the polyphenol profile of apple juice. The total content of phenolic acids, determined by using HPLC, increased by 15–20% as a result of the membrane concentration, but the separation process did not significantly change the ratio between the individual compounds.

Influence of Centrifugation and Transmembrane Treatment on Determination of Polyphenols and Antioxidant Ability for Sea Buckthorn Juice

“…It was originally for the detection of tyrosine [ 36 ] and was later developed to measure the TPC [ 37 ]. Some fruit juices and their products were reported to need to be centrifuged or filtered before the determination of TPC, such as yellow peach wines that were centrifuged at 8000× g for 5 min before determination [ 38 ], sea buckthorn pulp that was centrifuged at 4000× r/min for 10 min [ 27 ], apple juice extraction that was filtered through a paper filter [ 8 ], mixed juice with blue honeysuckle juice and fermented goat milk that was centrifuged at 5000× g for 10 min [ 39 ], five kinds of smoothies including fruit and vegetables that were centrifuged at 5000× g for 5 min [ 40 ], fresh or fermented noni juice extracts that were filtered through a Nylon filter (0.22 µm, 25 mm) [ 41 ]. It is necessary to study the influence of centrifugation and filtration on the determination of polyphenols.…”

“…The detection of plant polyphenols is very extensive, and the accuracy of the detection method is very important. Methods for the determination of polyphenolic compounds include spectrophotometry [ 7 ], high performance liquid chromatography (HPLC) [ 8 , 9 ], high performance liquid chromatography-mass spectrometry [ 10 ], gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS) [ 11 , 12 ]. Among them, spectrophotometry is the most commonly used method for the determination of TPC, including the Folin-Ciocalteu (F-C) assay, the Prussian Blue (P-B) assay, and the Ferrous Tartrate (F-T) assay.…”

A New Ultrafiltration-Based Process for Green Recovery of Polyphenols from Rose Petal By-Product

“…where A = 0.125 m 2 is the membrane surface area in the module [9]. Rejection (R, %) and concentration factor (CF) were calculated using the following formulas:…”

“…The total polyphenolic content (TPP) was established by the method of Singleton and Rossi [10] with modifications described in previous our work [9].…”

Artemisia abrotanum and Symphytum officinale Polyphenolic Compounds-Rich Extracts with Potential Application in Diabetes Management

“…Processing is performed at mild temperatures, maintaining the original characteristics of the products processed, with minimal loss of vitamins, polyphenols, proteins, and other thermolabile compounds [ 22 , 23 , 24 ]. Recent studies demonstrated the efficiency of ultrafiltration and nanofiltration for the concentration of bioactive compounds, such as anthocyanins, flavonoids, oligosaccharides, and phenolic compounds from vegetable extracts [ 25 , 26 , 27 ].…”