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Functional attributes of pea protein isolates prepared using different extraction methods and cultivars
- Andrea K. Stone, Anna Karalash, Robert T. Tyler, Thomas D. Warkentin, Michael T. Nickerson
- Food research international 2015 v.76 pp. 31-38
- alkali treatment, binding properties, chemical precipitation, cultivars, emulsions, foaming, foaming properties, foams, food industry, hydrophobicity, meat, oils, pea protein, peas, protein isolates, protein solubility, water holding capacity
- Protein isolates prepared from three pea cultivars by alkali extraction/isoelectric precipitation (AE-IP), salt extraction-dialysis (SE) and micellar precipitation (MP) were assessed for their surface (charge, hydrophobicity) and functional (water/oil holding capacity, solubility, foaming and emulsion capacities/stabilities) properties. Isolate yield was greatest for SE, followed by AE-IP and then MP. Salt extraction and AE-IP (~70%) resulted in higher protein recoveries then MP (~31%). Surface charge was similar for all isolates whereas hydrophobicity was greatest for AE-IP isolates. Overall, differences in functionality between cultivars for a particular extraction method were minimal. Salt-extracted isolates exhibited the highest protein solubility (~89%) and MP isolates the lowest (~46%). Salt-extracted isolates had the highest oil holding capacities (5.3g/g) and the lowest water holding capacities (0.3–2.6g/g). Foaming properties were affected by both extraction method and cultivar, however, in general SE isolates tended to have better foaming capacities whereas AE-IP isolates produced more stable foams. Emulsion capacity was greater for SE isolates than AE-IP isolates. All isolates displayed high emulsion stability (~98%). The prepared protein isolates show potential as a plant protein alternative to soy for the food industry, with the exception of possibly meat applications due to the isolates' poor water binding properties relative to soy.