Impact of folic acid on beta-lactoglobulin and fabrication of nanocomplexes at neutral pH

OSCAR E. PEREZ; ELINA KESELMAN; URI LESMES

Montpellier

Congreso; 2012 EFFoST Annual Meeting; 2012

INRA (Institut National de la Recherche Agronomique) and The European Federation of Food Science & Technology

Nowadays there is a growing interest in the specific reactions and interactions which can facilitate the delivery of bioactive compounds in foods. To this end, food delivery systems offer the possibility of protecting and delivering liable and technologically challenging substances. Out of various potential delivery vehicles, milk proteins are receiving increasing attention. This study focused on the interactions of â-Lactoglobulin (beta-lg), a well-studied whey protein, with folic acid (FA) which is an essential and liable vitamin. Our main aim was to promote beta-lg and FA complexation and the characterization on the complexes nanostructure. Initial experiments were conducted to elucidate and optimize the conditions for such complexation to occur. Practically, solutions of beta-lg 0.2% (w/w) were mixed with increasing levels of FA (0.01-0.2% ( wt), pH 7) and measurements of Z-potential, particle size distribution and turbidity were conducted by dynamic light scattering, DLS (NanoZS, Malvern, Worcestershire, UK. ) and spectrophotometer. Selected beta-lg-FA complexes were then studied by intermittent atomic force microscopy (NanoWizard 2, JPK, Germany) under intermittent contact mode using butanol to obtain high resolution morphological information. Also, we will provide evidence on the impact of beta-lg-FA complexation on the in vitro proteolysis of beta-lg under simulated gastric conditions. Overall, data obtained demonstrates that the complexation with FA alter beta-lg pH responsiveness as well as its assemblies in solution and their morphological organization. Also, we will provide evidence into the implications to beta-lg gastric proteolysis. This information is important for future attempts to combine FA in beta-lg containing products and to ascertain whether they may impact protein digestibility which could have ramifications to human health and well-being.