A plant protein-based fat texturizer: Enzymatic bioproduction and application in non-fat yogurt

The growing demand for low-fat or non-fat food products highlights the need for fat texturizers that replicate the mouthfeel and texture of fat. This study investigates the enzymatic modification of lentil protein isolates (LPI) to generate amphiphilic polypeptides for fat replacement in non-fat foods, exemplified by yogurt. LPI was hydrolyzed using Alcalase at varying enzyme-to-substrate ratios (1:100-1:2000) and hydrolysis times (2-240 min). Enzymatic hydrolysis significantly modified LPI, with partially hydrolyzed proteins (LPP5-10, <50 kDa) exhibiting balanced functional properties, including surface hydrophobicity (207 A.U.) comparable to lecithin (199 A.U.), high solubility across pH 2-12, and substantially higher oil-holding capacity (752%) than native LPI (174%). Adding 0.05% LPP5-10 to non-fat milk enhanced yogurt gelation, storage modulus, and yield stress, achieving textures comparable to whole-milk yogurt. These findings demonstrate that enzymatically produced lentil polypeptides are effective plant-protein fat texturizers for restoring the texture and structure of low-fat food products.