Contributions of protein and milled chitin extracted from domestic cricket powder to emulsion stabilization

• Published in: Current research in food science 2019-11, Vol.1, p.17-23
• Main Authors: Hirsch, Andrew, Cho, Young-Hee, Kim, Yuan H.Brad, Jones, Owen G.
• Format: Article
• Language: English
• Subjects: additives; adsorption; alkalinity; Chitin; creaming; Cricket; droplets; emulsifying; emulsifying properties; Emulsion; emulsions; flour; fractionation; Insect protein; Interfacial tension; light scattering; mineral content; Orthoptera; particle size; Pickering stabilizer; storage quality
• ISSN: 2665-9271; 2665-9271
• DOI: 10.1016/j.crfs.2019.09.002

Interfacial and emulsifying properties of fractionated cricket powder were assessed to identify whether emulsification properties originate from protein or chitin particles. Fractions extracted in alkaline water, containing high protein and mineral contents, increased the surface pressure of heptane-water interfaces with near-saturation equilibrium surface pressure of 31 mN/m. Dynamic surface pressure profiles indicated adsorption of protein clusters to the interface. Emulsification capacity of protein fraction was 50% greater than that of the source cricket flour, although oil-in-water emulsions prepared with 1–2% (w/w) protein fraction formed a cream layer within one day of storage. Emulsified layers persisted for up to 20 days, and light scattering measurements described a stable population with surface-volume-mean diameter of approximately 3 μm. Chitin-rich fractions milled to a particle size of 0.5–200 μm contributed negligible surface pressure, and its emulsification capacity was 5% of the value for the source cricket flour. Emulsions prepared with chitin-rich fractions coexisted with an unstable precipitate layer comprising 60% of the added solid, which was attributed to larger particles with poor emulsifying capability. Stable chitin-stabilized emulsion phases were resistant to creaming, yet volume-mean droplet diameter surpassed 50 μm within 24 h of storage. Both protein and chitin fractions have emulsifying capabilities but would require further processing or secondary additives to achieve desirable storage stability. [Display omitted] •Alkali-extracted proteins and chitin particles were obtained from ground cricket.•Protein fractions demonstrated strong surface activity.•Protein-stabilized emulsions creamed quickly but droplets grew slowly.•Only smallest of micrometer-scale chitin particles participated in emulsification.•Chitin-particle emulsions were prone to rapid droplet growth.