Emulsification of chemical and enzymatic hydrolysates of β-lactoglobulin: characterization of the peptides adsorbed at the interface

Abstract

Bovine beta-Lactoglobulin (BLG) was cleaved by BNPS-skatole (2-(2'-nitrophenylsulfenyl)-3-methyl-3'-bromoindolenine), trypsin, or pepsin in 40% ethanol before emulsification with hexadecane in order to characterize the peptides active at the interfaces. The total digests and the different phases obtained after emulsification were analyzed by RP-HPLC to separate the peptides according to their gradual order on a hydrophilicity-to-hydrophobicity scale. In each case, hydrophobic peptides were recovered in the creamed phase and characterized by mass spectrometry and sequencing. After tryptic hydrolysis, short peptides were identified at the interfacial layer as fragments S21-L32, V41-L57, V41-K60, and W61-K70 linked to L149-I162 by a C66-C160 bond. It indicates that the hydrophilic/hydrophobic distribution of the amino acids in the sequence of the fragments is more relevant to adsorption than the length of the peptide. BNPS-skatole and peptic hydrolysis produced larger hydrophobic peptides which were also recovered in the creamed phase of the emulsion and characterized.

Functional properties of protein hydrolysates from Riceberry rice bran

“…Thus, poorer stability of CBH‐stabilised emulsion compared to RBH could be due to the smaller size peptides as well as the type of peptides produced. It should be noted, however, that other studies have reported that specific peptides rather than the molecular weight distribution play an important role in emulsifying activity and emulsion stability (Rahali et al ., ). In addition to protein and peptides, the presence of phenolic compounds could play a role in emulsion formation and stability.…”

Antioxidant activities and functional properties of grass carp (Ctenopharyngodon idellus) protein hydrolysates

“…The EAI of both HA and HP decreased with increasing DH. According to Rahali et al ,40 in order to exhibit good emulsifying activity, the protein and/or peptides must be able to migrate rapidly to the water/oil interface and then unfold and rearrange rapidly at the interface. Additionally, although the peptides with low molecular weight can migrate rapidly to the interface, the hydrophobic/hydrophilic balance of these small peptides is not good enough to exhibit good emulsifying activity.…”

Effect of Blanching Plus Fermentation on Selected Functional Properties of Mealworm (Tenebrio molitor) Powders

“…As the molecular sizes of the soluble proteins decreased, it was clear that also the protein structure was modified by the fermentation process, which in turn led to changes in techno-functional properties. Rahali et al [40] and Razali et al [41] reported that the surface hydrophobicity of the proteins is more important than the peptide length in emulsion and foaming properties. Most often, high surface hydrophobicity is needed to allow the formation of stable emulsions and foams.…”