Active Dry Yeast: Lessons from Patents and Science

Abstract

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.

Cryopreservation: The secret of modern preservation of brewer’s yeasts – minireview

“…Likewise, drying methods have established their strong position in the brewing industry due to the fact that they are simple, fast and cost-effective. The literature describes a number of techniques ranging from preparation of active dried yeasts (ADY) to protocols incorporating yeasts into a gel structure (Gelinas, 2019;Nyanga et al, 2012;Jekins et al, 2011;Cyr et al, 2007;Nakasone et al, 2004). However, drying methods can influence the yeast viability undesirably.…”

Preservation of non‐Saccharomyces yeasts: Current technologies and challenges

“…Saccharomyces strains have been largely studied and many patents regarding the conservation of these yeasts can be found. Reviews regarding active dry yeast, compressed baker's yeasts, and baker's yeasts, focused mainly on S. cerevisiae, challenges, production, technologies, growth media, process and control can be found (Gélinas, 2010(Gélinas, , 2012(Gélinas, , 2014(Gélinas, , 2017(Gélinas, , 2019.…”

Gas sources in chemical leavening and other baker’s yeast substitutes: lessons from patents and science

“…To the knowledge of the author, a complete portrait of gas sources in baker’s yeast substitutes is not available. The aim of this study was to review the patent literature, a much neglected but highly relevant source of information (Gélinas, 2019), with support by science. This article should help readers to better understand long‐term evolution and future challenges associated with gas originating from sources other than dough fermentation.…”