Synergistic effects of PEF treatment and lactic acid fermentation on protein digestibility and texture in a blended oat and pea yogurt alternative

Abstract

The use of pulsed electric field (PEF) to improve functional and nutritional aspects of a plant-based yogurt alternative (PBYA) was explored for the first time. A blended oat and pea protein dispersion was subjected to mild preheating (30–40 °C, 24 s) and PEF at various conditions (0–217 kJ/L, 10 kV/cm). A drastic increase in net surface charge as indicated by a significant decrease in ζ-potential, was observed and suggested that PEF (≥77 kJ/L) led to protein structural changes that render a stabilizing effect to the oat-pea dispersion. Following lactic acid fermentation ( Lactiplantibacillus plantarum 299v, 35 °C, 10 h), PEF-treated oat-pea dispersion (≥162 kJ/L) developed a semi-solid, brittle gel texture, characterized by increased hardness, decreased cohesiveness, and the emergence of fracture peaks. Moreover, combining PEF (205 kJ/L at 40 °C) and fermentation led to a complementary reduction in antinutrients (phytic acid and trypsin inhibitors) and a subsequent increase in the in vitro digestibility of oat-pea protein by up to 16.1%, estimated based on an applied fractional conversion first-order kinetic model. Combined PEF and fermentation allowed protein gelation to occur and promoted protein digestibility of the resulting oat-pea yogurt alternative. This study demonstrates a promising application of PEF in modifying the texture and digestive properties of protein-rich PBYA products. • PEF with preheating was used as a pasteurization alternative for PBYA. • PEF stabilized oat-pea dispersions indicating protein structural changes. • PEF induced the formation of semi-solid textures during fermentation. • Combined PEF and lactic acid fermentation improved protein digestibility by 16%.

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