Fermentation by lactic acid bacteria during pea protein isolation reduces undesirable flavors and changes techno-functional properties
Aleksei Kaleda, Navratan Sharma, Kadi Jakobson, Irina Stulova, Sirli Rosenvald
Abstract
Plant protein isolates often have undesirable flavors. The conventional protein isolation method involves alkaline solubilization and acidic precipitation. We investigated whether replacing chemical acidification with lactic acid fermentation could improve the sensory properties of pea protein isolate without compromising its techno-functional properties. We prepared two fermented isolates using different starter cultures and one conventional control. Both cultures grew in the protein solution, primarily consuming sucrose naturally present in peas, while producing lactic acid, lowering pH to 4.8 in 4-7 h. The protein yield was unaffected by fermentation, but undesirable flavors were reduced, and bitterness decreased threefold. Powder solubility decreased by 20 %, but water absorption and foaming capacity increased twofold. Oil holding capacity, emulsion activity, protein surface hydrophobicity, and in vitro protein digestibility showed minimal changes. Lactic acid fermentation during protein isolation appears to be a promising approach for improving the sensory properties of protein isolates.