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

PLoS One. 2022 Jul 8;17(7):e0266309. doi: 10.1371/journal.pone.0266309. eCollection 2022.

Abstract

A huge, unprecedented demand for gelatin coupled with its implications on global sustainability has resulted in the need to discover novel proteins with gelling attributes for applications in the food industry. Currently used gelation assays require large sample volumes and thus the screening for novel gelling proteins is a formidable technical challenge. In this paper, we report the 'Floating Sphere Assay' which is a simple, economical, and miniaturized assay to detect minimum gelling concentration with volumes as low as 50 μl. Results from the Floating Sphere Assay are consistent with currently used methods for gelation tests and accurately estimate the Minimum Gelling Concentrations (MGCs) of gelatin, κ-carrageenan and gellan gum. The assay was also able to differentiate the strengths of strong and weak gellan gum gels prepared at pH 3.5 and pH 7.0 respectively. The Floating Sphere Assay can be utilized in high-throughput screens for gelling proteins and can accelerate the discovery of gelatin substitutes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrageenan
  • Colloids
  • Gelatin*
  • Gels
  • Polysaccharides, Bacterial*

Substances

  • Colloids
  • Gels
  • Polysaccharides, Bacterial
  • Carrageenan
  • Gelatin

Grants and funding

This research was supported by the Singapore Food Story Seed grant (191W1038) awarded to PA. UJT is funded by the A*STAR Graduate Scholarship. JCWH is supported by the A*STAR Research Internship programme. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.