Novel Pickering High Internal Phase Emulsion Stabilized by Food Waste-Hen Egg Chalaza

Abstract

A massive amount of chalaza with nearly 400 metric tons is produced annually as waste in the liquid-egg industry. The present study aimed to look for ways to utilize chalaza as a natural emulsifier for high internal phase emulsions (HIPEs) at the optimal production conditions to expand the utilization of such abundant material. To the author’s knowledge, for the first time, we report the usage of hen egg chalaza particles as particulate emulsifiers for Pickering (HIPEs) development. The chalaza particles with partial wettability were fabricated at different pH or ionic strengths by freeze-drying. The surface electricity of the chalaza particles was neutralized when the pH was adjusted to 4, where the chalaza contained a particle size around 1500 nm and held the best capability to stabilize the emulsions. Similarly, the chalaza reaches proper electrical charging (−6 mv) and size (700 nm) after the ionic strength was modified to 0.6 M. Following the characterization of chalaza particles, we successfully generated stable Pickering HIPEs with up to 86% internal phase at proper particle concentrations (0.5–2%). The emulsion contained significant stability against coalescence and flocculation during long term storage due to the electrical hindrance raised by the chalaza particles which absorbed on the oil–water interfaces. Different rheological models were tested on the formed HIPEs, indicating the outstanding stability of such emulsions. Concomitantly, a percolating 3D-network was formed in the Pickering HIPES stabilized by chalaza which provided the emulsions with viscoelastic and self-standing features. Moreover, the current study provides an attractive strategy to convert liquid oils to viscoelastic soft solids without artificial trans fats.

Formation of Natural Egg Yolk Granule Stabilized Pickering High Internal Phase Emulsions by Means of NaCl Ionic Strength and pH Change

“…This result implied that EYGs at high NaCl ionic strengths (>0.2 M) could be well adsorbed to the oil-water interface and had the ability to form stable oil-in-water HIPEs. At NaCl ionic strengths above 0.2 M, the presence of network structure in the emulsion implied the formation of stronger emulsion gels [ 7 ], which was similar to the result of high viscoelasticity of HIPEs in rheological properties. Large droplets of HIPEs could be observed at low NaCl ionic strength (0 and 0.1 M), which was consistent with the results of particle size distribution.…”

“…While φ exceeded 0.83, the droplets of HIPEs underwent deformation due to dense packing, especially at φ of 0.85. Similarly, the HIPEs stabilized by egg chalaza also show the phase inversion with 86% oil content [ 7 ]. The accumulation and deformation of droplets into irregular shape was a distinct microstructural feature of HIPEs [ 31 ].…”

“…The HIPEs stabilized by EYGs under suitable NaCl ionic strength and pH were viscoelastic and self-supporting. Therefore, the HIPEs stabilized by EYGs had great potential to substitute for PHOs in the food field [ 7 ].…”

“…HIPEs stabilized by low molecule inorganic particles are not suitable for the food industry due to their high cost, high dosage, environmental pollution, and food safety [ 6 ]. However, HIPEs stabilized by food-derived Pickering particles have more advantages: less dosage required, better storage stability, high environmentally friendly degree (easy degradation), safety, and non-toxic side effects [ 7 ]. In addition, Pickering particles are irreversibly adsorbed to the oil-water interface, and the strong gravitational interaction between the particles also forms a rigid layer to protect the oil droplets [ 8 ].…”

Development of a High Internal Phase Emulsion of Antarctic Krill Oil Diluted by Soybean Oil Using Casein as a Co-Emulsifier

“…For example, Williams [ 13 ] studied effects of 8 surfactants and 22 cosurfactants on the stability of a styrene-based HIPE. Because more and more well-informed consumers are seeking organic or clean label products [ 14 , 15 ], particles of biopolymers such as proteins, polysaccharides, and lipids have been suggested as an alternative to synthetic surfactants traditionally used in highly concentrated edible emulsions [ 16 , 17 , 18 ]. To enhance the capability of biopolymer particles to stabilize HIPEs, the particles usually need to be physically or chemically modified [ 18 , 19 , 20 ].…”