13,584
edits
Changes
no edit summary
<youtube width="300" height="200">9a-ZpF2LDm8</youtube>
* See also [[100% Lactobacillus Fermentation]].
Some strains of ''L. plantarum'' cultured from Tibetan yaks have been found to have varying levels of bacteriocin activity as well. These strains produced a "class II enterocin" that inhibits the growth of ''E. coli'' and ''Staphylococcus aureus''. A strain of ''Pediococcus pentocaseus'' was also found to produce this enteriocin <ref>[https://www.sciencedirect.com/science/article/pii/S0882401017314559 Antibacterial activity of Lactobacillus plantarum isolated from Tibetan yaks. Lei Wang, Hui Zhang, Mujeeb Ur Rehman, Khalid Mehmood, Xiong Jiang, Mujahid Iqbal, Xiaole Tong, Xing Gao, Jiakui Li. 2017.]</ref>.
===Gluten Reduction===
In recent years, there has been an increase in the number of people with gluten intolerance or perceived/believed gluten intolerance whose resulting gluten-free diets that are unbalanced from low fat from carbohydrates, and this has lead to research on whether or not ''Lactobacillus'' fermented grain beverages or beers can produce gluten reduced beverages. Some lactic acid bacteria produce specific peptidase enzymes during growth that break down gluten by cleaving bonds between the amino acids in gluten, similar to how lactic acid bacteria can break down head retention proteins (see [[Lactobacillus#Foam_Degradation|Foam Degradation above]]) <ref name="Bradauskiene_2019">[http://agris.fao.org/agris-search/search.do?recordID=LV2019000334 Fermentation with Lactobacillus strains for elimination of gluten in wheat (Triticum aestivum) by-products. Vijole Bradauskiene, Lina Vaiciulyte-Funk, Edita Mazoniene, Darius Cernauskas. 2019. DOI: http://doi.org/10.22616/FoodBalt.2019.029.]</ref>.
Taubman et al. published a paper in the MBAA Technical Quarterly that reported that a strain of ''L. brevis'', ''L. curvatus'', ''L. plantarum'', and ''Pediococcus pentosaceus'' that were found to reduce gluten in sourdough bread making had a similar functionality when fermenting wort. They found that these strains reduced gluten to undetectable levels in 5-7 weeks. However, they lost the ability to reduce gluten when co-fermented with yeast, probably due to competition from the yeast. The wort that was fermented with only one of the lactic acid bacteria strains and no yeast resulted in an unpleasant fermented beverage. The researchers also reported analyzing commercial sour beers and finding some with reduced levels of gluten, but did not offer an explanation on how to accomplish this <ref>[https://www.mbaa.com/publications/tq/tqPastIssues/2018/Pages/TQ-55-1-0305-01.aspx Microbial Gluten Reduction in Beer Using Lactic Acid Bacteria and Standard Process Methods. Brett F. Taubman, Stephan Sommer, Jacob Edwards, Travis Laws, Logan Hamm, and Brenton A. Frank. 2018. DOI: https://doi.org/10.1094/TQ-55-1-0305-01.]</ref><ref>[http://masterbrewerspodcast.com/094-microbial-gluten-reduction-in-beer-using-lactic-acid-bacteria-and-standard-process-methods "094: Microbial Gluten Reduction in Beer Using Lactic Acid Bacteria and Standard Process Methods". Master Brewers Association Podcast. June 2018.]</ref>. The researchers hypothesized that the cause of the off-flavors in the 100% ''Lactobacillus'' fermentations were due to oxygen and hydrogen sulfide in the headspace of the fermenters and that further experiments with purging the oxygen and hydrogen sulfide from the head space should be done, however, previous research has shown that wort fermented with only ''Lactobacillus'' does not fully attenuate which leaves ample amounts of residual sugar available for contaminants to potentially produce off-flavors (assuming they can withstand the low pH produced by the lactic acid bacteria fermentation). Performing long fermentations with only ''Lactobacillus'' are generally not recommended due to the residual sugar left by 100% ''Lactobacillus'' fermentation. For example, it is recommended to [[Wort_Souring#Souring_in_the_Boiler_.28Kettle_Sour.29|kettle sour]] within 24-48 hours in order to lower the risk of off-flavor development. Attenuation/ethanol/final gravity measurements were not reported in this study.
==See Also==