Production of protein nanovehicles by heat treatment of industrial egg white in a batch reactor

Abstract

A process to obtain protein nanovehicles to carry lipophilic bioactive compounds (LBC) was developed by heat treatment of industrial liquid egg white (EW) in a batch reactor (1.0 L). It was noted an increase in particle size with heating temperature, nevertheless, a clear relationship with heating time was not observed. In all cases, particle sizes were lower than 100 nm. Moreover, surface hydrophobicity and linoleic acid (LA) binding capacity showed a similar trend with heating temperature and time. Hence, LA binding capacity would be explained by the exposition of hydrophobic amino acid residues and the generation of new surface binding sites. From these results, heating conditions were selected to produce EW protein nanovehicles (EWPn) and to evaluate reproducibility through four replicates (n = 4) of the whole process. Thus, EWPn with an average hydrodynamic diameter (Zav) of 87 ± 2 nm and LA loading capacity of 0.35 ± 0.08 g LA/g EWPn were obtained by heat treatment at 85 °C, 5 min of the 5% EW protein solution, pH 11.4. The results indicated that this batch process would be reproducible in terms of particle size and binding ability. Hence, information presented in this work could be relevant to scale up the production of protein nanovehicles using industrial liquid EW.