Spray Dried Protein-Stabilized Emulsions as Vitamin Matrix Carriers: Contribution of Protein Aggregates and Lipid Nano- and Micro-Structures to Vitamin Long-Term Protection

Abstract

Nano and microstructured bioactive matrix carriers have gained increased interest to food industry. In this study we compared the degradation behavior of vitamin-loaded particles based on protein-stabilised emulsions before (E300 and E1200) and after (PE300 and PE1200) spray drying, and protein aggregates (A300 and A1200) subjected to 300 or 1200 bar, respectively. Efficacy of vitamin encapsulation (EVE) was close to 69 % for A300, A1200 and PE300, 78 % for PE1200, 85 % for E1200, and 97 % for E300. Their kinetics of vitamin degradation seemed to follow first-order reaction mechanisms for long-time storage (15 to 60 days). The constant rate of vitamin degradation (VD) was five times higher for E300 and A300 than E1200 and A1200, but lower by~70 % for PE300 and~5 % for PE1200, attesting to opposite effects on EVE and VD caused by increased treatment intensity in liquid formulations. For spray dried emulsions, EVE and VD differences were explained on the basis of physical structural data as observed by light and small angle X-ray scattering and differential scanning calorimetry. Comparing PE1200 and PE300 samples, PE1200 contained lower size particles (larger surface exchange), presented less crystalline fat (lower enthalpy of fat melting, and absence of Bragg's peak in X-ray profile). More or less ability of spray dried protein-stabilized emulsions for long-term vitamin protection appeared to be related to matrix structure-forming properties and, particularly to absence or presence of high energy crystals capable of vitamin expelling from the core of lipid droplets to their external phase.

Nanostructuring Biopolymers for Improved Food Quality and Safety

“…Although WAXS evidenced that a high degree of MMT intercalation within the chitosan/xanthan gum blend was achieved, SAXS showed that the incorporation of MMT reduced the structural changes undergone by the hydrogels when the pH of the medium was modified. The encapsulation of a vitamin into spray-dried protein-stabilized emulsions was evaluated and the vitamin stability was linked to structural changes by combining light scattering and differential scanning calorimetry with SAXS characterization (Relkin et al, 2014). The formation of lamellar structures as a result of the packing of the fatty phase, evidenced by the presence of a Bragg peak in the SAXS patterns, was seen to reduce the vitamin degradation.…”

Monitoring the formation of oil–water emulsions with a fast spatially resolved NMR spectroscopy method

“…Emulsions are metastable colloids made out of two immiscible fluids, one being dispersed in the other, in the presence of surface active agents. Due to advantages in enhancing the solubility and bioactivity of lipophilic ingredients, O/W emulsions have been widely used in various fields, including food, [1][2][3] cosmetics, [4][5][6] and pharmaceutical industries. [7][8][9] The knowledge of the formation mechanism of emulsions has great significance in understanding the stability of emulsions and phase separation progress.…”