There are two things on the wish list of any food analyst performing fat extraction. They would like a fat extraction process that is highly reproducible and more cost-efficient. See five tips our food detectives offer to help optimise fat extraction and get these two items checked off the wish list easily.
Miss Mapple is convinced they need to use more fat extraction methods for fat determination at the agency. Together with Shallot Holmes they come up with a plan on how to convince their fellow food detectives of the merits of this method. This calls for a workshop.
Miss Mapple readies herself to showcase how fat extraction can be both highly reproducible and cost-efficient. But how can they optimise fat extraction? Miss Mapple summarises her findings in five key points:
- 1. Improve cost-efficiency by increasing recovery rate of the extraction
- To improve recovery rate and optimise fat extraction, you should ensure that the solubility of the components to be extracted in the selected extraction solvent are of similar polarity
- The extraction substance and extraction solvent must be well mixed
- Consider increasing the size and number of extraction solvent portions to increase recoveries but bear in mind the cost of solvent
- Carefully analyse the nature of the sample, including size, surface, homogeneity, potential content of moisture and enclosed fat.
- 2. Save time and money by speeding up your fat extraction
- To ensure maximal speed of your process, ensure your extraction substance and extraction solvent are well-mixed
- As a rule of thumb, the speed of extraction doubles for every temperature increase of 10°C
- Consider that samples with smaller particle sizes are extracted more quickly
- 3. Avoid wasting resources by ending your extraction process on time
- The concentration of soluble components in the extraction substance decreases steadily until it reaches a point where continuing the extraction is of no further value (this endpoint is called the practical conclusion). Finding the practical conclusion mostly depends on the solubility of the extracted substance and is a matter of experience. However, one common way to determine practical conclusion and optimise fat extraction is to verify the extraction method by using reference material with known fat content.
- 4. Include hydrolysis to achieve compliancy and reproducibility in fat extraction
- Miss Mapple reminds the team that they have discussed the benefits of hydrolysis in a previous blog post. She briefly reminds her colleagues that hydrolysis is a necessary method to reach compliancy with standards and regulations. The hydrolysis step takes place between sample homogenisation and extraction. Hydrolysis helps disrupt cell walls and break up lipid-protein bonds and fat emulsions. It is a necessary step in reference methods for total fat extraction, such as the ISO 8262-1 Weibull-Berntrop gravimetric method, as this step greatly improves precision, productivity and reproducibility.
- 5. Optimise fat extraction by using the most appropriate method for your needs
- There are different methods of fat extraction, each bringing its own set of benefits to the table. For example, Soxhlet extraction is the most robust and accepted method by industry standards. Hot extraction offers lower costs due to lower solvent consumption and faster processing times. Economic Continuous extraction offers high efficiency and faster analyte exchange due to higher sample temperatures. Miss Mapple recommends a nice webinar on how to use continuous extraction for quick, compliant results. She concludes by adding that:
- Whereas hot extraction is cheaper and faster, continuous extraction and Soxhlet extraction are easer to set up as methods and typically offer more reproducible results than hot extraction.
- The food detectives find themselves listening fully captivated by Miss Mapple’s talk. When she wraps up by offering them further resources on optimising fat extraction, even Eggcule Poirot, a harsh critic and Nancy Beef, who typically only likes NIR technology, appear to be convinced by Miss Mapple’s presentation. The team is happy that by implementing her tips, the fat extraction processes they recommend to their clients would be both economical and highly reproducible. Before they part for the day, they place a friendly wager on how many cases it will take before they work with fat extraction methods again. Keep coming back to see who wins.