Floating sphere assay: A rapid qualitative method for microvolume analysis of gelation

Area of Science:

• Food Science
• Biochemistry
• Materials Science

Background:

• Growing demand for gelatin and its sustainability concerns necessitate new gelling agents.
• Existing gelation assays are resource-intensive, hindering the discovery of novel gelling proteins.
• There is a critical need for efficient, high-throughput screening methods for gelling proteins.

Purpose of the Study:

• To introduce and validate a novel, miniaturized assay for determining minimum gelling concentration.
• To assess the assay's efficacy in screening for gelling proteins and its consistency with established methods.
• To demonstrate the assay's utility in differentiating gel strengths.

Main Methods:

• Development of the 'Floating Sphere Assay,' a simple, economical, and miniaturized gelation test.
• Assay utilizes minimal sample volumes (as low as 50 μl) to determine minimum gelling concentration (MGC).
• Validation against standard gelation methods using gelatin, κ-carrageenan, and gellan gum.

Main Results:

• The Floating Sphere Assay accurately determined MGCs for gelatin, κ-carrageenan, and gellan gum.
• Results were consistent with traditional gelation testing methods.
• The assay successfully differentiated gel strengths of gellan gum at varying pH levels (3.5 vs. 7.0).

Conclusions:

• The Floating Sphere Assay is a reliable, cost-effective, and miniaturized method for MGC determination.
• This assay facilitates high-throughput screening, significantly accelerating the discovery of novel gelling proteins.
• It offers a promising tool for identifying sustainable alternatives to gelatin in the food industry.