Novel emulsifiers as products from internal Maillard reactions in okra hydrocolloid mucilage

Abstract

Maillard conjugates have been prepared in situ in okra mucilage from the existing populations of protein and polysaccharide. SEC–MALLS/UV and FTIR data suggest that an initial ensemble of polysaccharide and protein changes dramatically during heating at 100 °C for 6 h. While the raw extracts and the products of milder heat treatments are inefficient emulsifiers at neutral pH, the conjugates prepared from the above heat treatment are efficient emulsifiers for n-hexadecane–in–water emulsions, both in terms of initial average droplet size (d32) and the evolution of d32 and d43 over a week's stay at ambient conditions. The emulsifying ability of these products is superior to that of the more conventional Maillard products of the reaction between bovine serum albumin (BSA) and okra extract (experiments held in parallel). The emulsifying ability of the above materials is in complete agreement with the relevant measurements of the development of their interfacial tensions. The above suggest that the intrinsic components of natural extracts can lead to Maillard products of commercial interest, and form a solid basis for the possible exploitation of okra as an emulsifier, rather as a thickening agent.