Removal of polyphenols and recovery of proteins from alfalfa white proteinconcentrate by ultrafiltration and adsorbent resin separations

The peptides remaining after phenol removal from a co-product of the alfalf a industry have various applications: in the food industry (as an additive) , in therapeutic nutrition (high-value protein, peptides with opioid or imm unostimulant activities. etc.), and in cosmetics. Hydrolysis of alfalfa whi te protein concentrate (AWPC) by an industrial enzyme (Delvolase) improved its solubility and nutritional properties, But, colored peptidic hydrolysat e was observed. This color change was due to phenolic oxidation at alkaline pH. A combined ultrafiltration process and sorption technique was investig ated. A ZrO2 Carbosep membrane (nominal molecular weight cutoff of 10,000 D a) allowed a 51% color reduction and a 96% peptide transmission, The colore d peptide fraction in the permeate had a known and reproducible molecular-w eight distribution. Permeate polyphenol removal was performed by a sorption technique. A polystyrene resin, Amberlite IRA900Cl, packed in a column, al lowed a 92-95% phenol extraction while: preserving peptide fractions.