Abstract #294

# 294
Development and characterization of novel bigel system.
M. Bollom*1, N. Acevedo1, S. Clark1, 1Iowa State University, Ames, IA.

Oleogels, typically made with plant-based oils and oleogelators, have limited application in dairy foods. Incorporation of whey protein concentrate (WPC) into oleogels, to create bigels, may change that. Bigels are semi-solid biphasic systems where each phase, an oleogel and hydrogel, is structured to give superior physical, mechanical, and stability properties. The novel bigel developed here is composed of a WPC hydrogel and an oleogel emulsion (soybean oil, soy lecithin, stearic acid, and water). There are many advantages to using a bigel over an individual oleogel or hydrogel, such as higher dairy content, higher protein content (on trend), improved drug delivery, potential to delay oxidation (due to the physical structure hindering prooxidant mobility), and improved consumer acceptance. Since bigels are so new, little is known about their microstructure and mechanical properties. Therefore, the purpose of this study was to better understand bigel structure and mechanical properties. Garnering a better understanding of structure and mechanical properties will allow optimization of bigel encapsulation abilities and incorporation into dairy foods. To understand bigel structure, 3 main techniques were used: small angle X-ray scattering, rheology, and fluorescence microscopy. Different ratios of oleogel emulsion:hydrogel were tested (0:10, 3:7, 5:5, 7:3, and 10:0), as well as 2 hydrogel protein contents (15% and 25%) and 2 oleogel emulsion moisture contents (10% and 20%). Higher WPC content yielded greater firmness (because of a stronger hydrogel) and higher moisture in the oleogel emulsion resulted in a less firm bigel. Pure oleogels and hydrogels had greater strength than the bigels. We hypothesize that this is due to each gel structure preventing the other from forming a cohesive, continuous structure. This research has shown that the functionality of an oleogel can be improved, through the addition of a WPC hydrogel, for addition into dairy products, while still retaining key stability features of the oleogel.

Key Words: bigel, whey protein concentrate (WPC)