Active Dry Yeast: Lessons from Patents and Science


Gélinas, P. (2019). Active Dry Yeast: Lessons from Patents and Science,

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Subject: Active dry yeast
A) What was the problem or subject?
- Yeast is available in dry form, which allows it to be kept longer than fresh yeast. The secrets of its manufacture are carefully guarded by the industry. Patents are neglected sources of information and make it possible to follow the evolution of the technologies.
- We catalogued and analyzed 280 patents and 212 scientific articles in depth. The documents applied mainly to the production of bread and, to a lesser extent, wine.
B) Why is this so important and for whom?
- Fermentation scientists: They have little knowledge of the evolution of technologies for dry yeast production and of past and current challenges.
- Authors of scientific journals: For the first time ever, statistics on all patents and published scientific articles on a research topic were compared in detail.
C) What answers were found?
- This technology is more than 200 years old. The long-term survival of dehydrated yeast cells has gradually improved with the strains, the cultivation methods and, to a lesser extent, the drying conditions. More recently, the main focus has been on protecting yeast cells during their rehydration, the most critical factor.
- Patents contain a lot of unique information that is not available in the scientific literature.
D) What are the benefits? What will happen next?
- Scientists now have access to condensed information to better understand the past and future challenges of dry yeast production.
- In the future, any serious review of the scientific literature should absolutely include patents.
How can I get more details?
- Pierre Gélinas, PhD, Research Scientist, Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada;


© 2019 Institute of Food Technologists® In the production of fermented foods, long-term preservation of the activity of microbial starters is a critical issue. The aim of this review was to determine key challenges in the production and use of active dry yeast over time and to compare statistics on letters patent for inventions and applied scientific articles as indicators of technological evolution. The review covers 280 original patent specifications and 212 applied scientific articles issued between 1796 and 2018, not including documents in basic science or without obvious application in fermented foods. The main subject matter was baking and the other entries applied to wine and, to a lesser extent, beer and spirits. Very popular in patents granted in the 19th century until about 1935 but ignored in the scientific literature, dehydrated yeast preparations often consisted of wet biomass concentrates mixed with large amounts of water-absorbing agents. Long-term survival of dehydrated yeast cells progressively improved with specific strains, growth conditions, and, to a lesser extent, drying conditions. Since the 1990s, both inventors and scientists have mainly targeted yeast cells protection during rehydration, a most critical factor. Proper review of the scientific literature would be incomplete unless it includes patents, a much ignored but relevant source of information.

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