Enzymatic hydrolysis improves the stability of UHT treated faba bean protein emulsions

Abstract

As an alternative to bovine milk, plant-based milks are gaining popularity in the global food market. However, industry faces various technological hurdles such as colloidal instability and sedimentation of these plant-based milk alternatives. Colloidal stability of UHT legume-based milk alternatives made from native and partially hydrolysed faba bean protein concentrate (FBPC) was investigated. FBPC was hydrolysed with alcalase for 5−90 min. Hydrolysates were assessed for physicochemical properties viz., degree of hydrolysis (DH), protein solubility, ζ-potential, and surface hydrophobicity. Extended enzymatic hydrolysis resulted in increased DH, protein solubility, higher electronegativity, and reduced surface hydrophobicity. Subsequently, oil-in-water emulsions (protein 5%) were prepared using either native FBPC or hydrolysates (DH 0–35%), 1% sunflower oil and 0.2% sunflower lecithin. These emulsions were homogenised and UHT treated, and then assessed for physicochemical properties. The findings revealed that emulsions stabilised by FBPC hydrolysates viz., 9 and 16% DH had better colloidal stability than native FBPC and other hydrolysates viz., 0–2, 30 and 35% DH, as indicated by droplet size, polydispersity index, flocculation index, coalescence index, surface charge and surface hydrophobicity. Overall, study showed that partial enzymatic hydrolysis of legume proteins may promote the colloidal stability of plant-based dairy alternative drinks.