Bloom is a test used to measure the strength of a gel, most commonly gelatin. The test was originally developed and patented in 1925 by Oscar T. Bloom.1 The test determines the weight in grams needed by a specified plunger (normally with a diameter of 0.5 inch) to depress the surface of the gel by 4 mm without breaking it at a specified temperature.2 The number of grams is called the Bloom value, and most gelatins are between 30 and 300 g Bloom. The higher a Bloom value, the higher the melting and gelling points of a gel, and the shorter its gelling times.2 This method is most often used on soft gelatin capsules ("softgels"). To perform the Bloom test on gelatin, a lab keeps a 6.67% gelatin solution for 17–18 hours at 10 °C prior to testing it.
Various gelatins are categorized as "low Bloom", "medium Bloom", or "high Bloom", but there are not universally defined specific values for these subranges. Gelatin is a biopolymer material composed of polypeptide chains of varying length. The longer the chain, the higher the Bloom number:3
| Category | Bloom number (Bloom strength) | Average molecular mass | Examples |
|---|---|---|---|
| Low Bloom | 30–1504 | 20,000–25,000 | Beef hide low Bloom gelatin (USP-NF)5 |
| Medium Bloom | 150–225 | 40,000–50,000 | Gelatin type B6 |
| High Bloom | 225–325 | 50,000–100,000 | Gelatin type A6 |
References
References
- "US1540979 Machine for testing jelly strength of glues, gelatins, and the like". Google Patents. Retrieved 1 September 2016.
- Schrieber, Reinhard; Gareis, Herbert (27 June 2007). Gelatine Handbook: Theory and Industrial Practice. Wiley. ISBN 978-3-527-61097-6.
- "Gelatins—product information sheet" (PDF). Sigma-Aldrich. Retrieved 24 August 2017.
- Hanani, Z.A. Nur (2016). "Gelatin". Encyclopedia of Food and Health. pp. 191–195. doi:10.1016/B978-0-12-384947-2.00347-0. ISBN 978-0-12-384953-3.
Gel strength and viscosity are the most important physical properties of gelatin. Gel strength, also known as 'bloom' value, is a measure of the strength and stiffness of the gelatin, reflecting the average molecular weight of its constituents, and is usually between 30 and 300 bloom (< 150 is considered to be a low bloom, 150–220 a medium bloom, and 220–300 a high bloom). Higher bloom value indicates greater gelatin strength. Based on the type of product required and its function, a different bloom value for gelatin is applied.
- "GELATIN - LOW BLOOM - BEEF-HIDE - NF by Vyse Gelatin Company - Food, Beverage & Nutrition". www.ulprospector.com. Archived from the original on 15 December 2023. Retrieved 15 December 2023.
- Felix, Pascal (18 November 2003). Characterization and Correlation Analysis of Pharmaceutical Gelatin (Thesis).
External links
External links
- Phillips, Glyn O.; Williams, Peter A., eds. (2021). Handbook of Hydrocolloids. doi:10.1016/C2018-0-04245-0. ISBN 978-0-12-820104-6.