How microbes in 'starter cultures' make fermented sausage tasty

Date:
August 5, 2020
Source:
American Chemical Society
Summary:
Microbes in 'starter cultures' impart a distinctive tang and longer
shelf life to food like sourdough bread, yogurt and kimchi through
the process of fermentation. To get a better grasp of how microbes
do this in fermented sausages, such as chorizo and pepperoni,
researchers show that these tiny organisms change the composition of
fatty acids in these meats, contributing to many desirable traits.



FULL STORY ========================================================================== Microbes in "starter cultures" impart a distinctive tang and longer
shelf life to food like sourdough bread, yogurt and kimchi through
the process of fermentation. To get a better grasp of how microbes do
this in fermented sausages, such as chorizo and pepperoni, researchers reporting in the Journal of Agricultural and Food Chemistry carefully
show that these tiny organisms change the composition of fatty acids in
these meats, contributing to many desirable traits.


========================================================================== Fatty acids and related compounds can influence the quality of fermented
foods.

For example, one species of bacteria in sourdough cultures produces a
type of fatty acid that increases bread's resistance to mold. Scientists, however, haven't had a good handle on how specific cultures drive the
formation of these and other similar compounds in meat, partially because
some of the previous studies on meats have not included a bacteria-free control. To better understand the link between microbes and molecules,
Nuanyi Liang and colleagues wanted to see how the production of fatty
acids within sausages varied depending on the microbial culture used to
ferment it.

To do so, they prepared the meat three ways. In one method, they included
only the bacterium Latilactobacillus sakei; in another preparation, they
used both L. sakei and Staphylococcus carnosus. Both of these samples
were made in such a way as to prevent contamination from bacteria in the environment. They treated the third sample -- the control -- with an
antibiotic solution to eliminate the microbes naturally living within
the sausage. Over the course of 20 days, they checked the sausages and
found a markedly different profile for microbe-free sausage compared to
the sausage containing either of the two microbial cultures. For example,
the researchers observed that linolenic acid, an unsaturated fatty acid,
was accumulating in the microbe-free sausage but not in the cultured
sausage. Differences emerged between the two sets of microbes as well,
with the sausage containing the L. sakei culture alone, for example,
producing higher levels of coriolic acid, which has antifungal activity
and, at higher concentrations, also imparts bitter taste. A better understanding of the biochemistry by which microbes influence the
quality of sausage and other fermented foods will aid the production of consistent, long-lasting and good- tasting products, the researchers say.


========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Nuanyi Liang, Kaixing Tang, Jonathan M. Curtis, Michael G. Ga"nzle.

Identification and Quantitation of Hydroxy Fatty Acids in Fermented
Sausage Samples. Journal of Agricultural and Food Chemistry, 2020;
DOI: 10.1021/acs.jafc.0c02688 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200805110129.htm

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