Embedded Files
Benjamin Steiner, Viral Shukla,...Gabriel Davidov Pardo
Abstract
Ternary complexes of Maillard Conjugates (MC) comprised of proteins, polysaccharides and polyphenols can be used as emulsifiers to stabilize emulsions and prevent their oxidation. The objective was to investigate the effect of the molecular weight (MW) of dextran (polysaccharide) on the formation of MC with sodium caseinate (NaC) and the capacity of the MC to bind resveratrol and stabilize nanoemulsions. To form the MC, samples containing NaC and dextran 12, 40, and 250 kDa were submitted to dry heat. Conjugation efficiency (CE) and conjugation yield (CY) were measured to determine the optimal dextran molecular weight as well as conjugation time. Polyphenol-binding capacity and antioxidant activity were also measured to determine the impact of adding resveratrol (polyphenol) to the MC. NaC with dextran 12 and 40 kDa yielded the greatest CE. CY after 24 h was 100% for both 12 and 40 kDa dextrans. Dextran 40 kDa was selected to test the stabilization of nanoemulsions and the polyphenol-binding capacity. The diameter of the nanoemulsions formed with the MC at the Isoelectric point remained monomodal at 134±0.015 nm, while the diameter of the nanoemulsion made with the non-conjugated protein completely destabilized. The addition of up to 500 µm/mL of resveratrol showed a polyphenol-binding capacity of 100%, which showed greater antioxidant activity than the MC alone. MC and resveratrol form stable complexes that can be used to physically stabilized nanoemulsions to deliver hydrophobic compounds sensitive to oxidation.
Maillard Conjugation with the use of Pea Protein and Dextran for the Stabalization of Multilayered Nanoemulsions
Viral Shukla, Gabriel Davidov-Pardo
Abstract
An emulsion is a dispersion of two immiscible liquids, these mixtures are unstable and will separate unless surfactants are used to coat the dispersed phase. Many common foods are emulsions, usually made of oil and water (e.g. salad dressings, margarine, gravies, etc.). Proteins are a viable alternative to artificial surfactants to create emulsions. The main drawback of using proteins as emulsifiers is their precipitation at certain pHs. When reaching the pH of the isoelectric point, proteins lose their electrostatic charge and coagulate. Through Maillard reactions, proteins combined with polysaccharides create conjugates that prevent their coagulation. In recent years pulse proteins have gained interest in the food industry for their sustainability and high biological value. The objective of this work was to determine if pulses are a suitable replacement for typical protein sources for creation of Maillard conjugates. Maillard conjugates were created by mixing protein and saccharides in a 1:1 w/w ratio, freeze-drying, then placing them in a climactic chamber at 60°C and 77.5% relative humidity for 72 hours with samples removed at 24 hour intervals for testing. The initial proteins and saccharides consisted of pea protein and sodium caseinate (control) in conjunction with various molecular weights of dextran (12, 40, 150, and 250KD). To determine conjugation yield, Lowry assays were conducted to assess the stability of the proteins at the isoelectric point. To determine efficiency of conjugation O-phtaldehyde assays were conducted to determine the amount of free amino groups remaining. Current results show that at 24h the pea protein with dextran (40KD) had the greatest yield of 81%, meaning 81% of the protein remained in solution at the isoelectric point, though yield decreased over 48h and 72h samples. The same sample had an efficiency of 22% reduction of total amino groups. In casein samples, the conjugation yield under same conditions reached 97% and the conjugation efficiency 9%. We proved that is possible to stabilize pea proteins through Maillard conjugation. In future research we hope to combine these conjugates with polyphenols and lutein to form stable lutein enriched multilayered emulsions for functional products.
Google Sites
Report abuse