Faba bean as a novel brewing adjunct:consumer evaluation

The starch in the grains of legumes, such as faba bean (Vicia faba L.), offers an environmentally sustainable raw material for the brewing industry as their entire nitrogen fertiliser requirement can be provided by the natural process of biological nitrogen fixation. Faba bean is, therefore, distinguished from species such as spring barley (Hordeum vulgare L.), which require large amounts of synthetic nitrogen fertiliser. Consumer analysis of beer produced with faba bean as an adjunct compared with barley malt beers has not previously been assessed. This study evaluated the potential of beers brewed using 30% (w/w) dehulled bean (kernel) flour as an adjunct to malted barley, using a series of quantitative sensory tests. The first, a blind acceptance test with inferred preference, found no statistically significant difference in the taste score of the bean kernel flour adjunct beer when compared with conventional beer. In the second acceptance test, the knowledge that the beer was produced using beans did not affect the overall consumer impression of the beer, regardless of how this information was presented. These results suggest that the use of faba beans in brewing does not impact negatively on the taste or acceptability of the resultant bee

Improvement of the slide culture technique for the assessment of yeast viability

This work aimed to improve the slide culture technique (SCT) for the assessment of yeast viability. Thus, all the steps of the SCT were standardized: a sample of 20 L containing 1 × 105 cells/mL was placed in a ~ 20 × 20 mm YPD agar block and incubated for 1624 h, at 25°C. It was proposed the use of calcofluor white (CFW) to facilitate the microscopic observation of yeast cells. The viability of cell populations in different physiological states (healthy, ethanol stressed and starved cells), assessed by SCT (without or with CFW), did not differ significantly (p < 0.01). In addition, the viability of healthy and ethanol stressed cells determined by the SCT and the standard plate count technique (PCT) did not differ significantly (p < 0.01). In conclusion, the improved SCT is a fast and reliable alternative to PCT for the evaluation of yeast viability in research and in the industry.This study was supported by the Portuguese Foundation for Science and Technology under the scope of the strategic founding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). Manuela D. Machado and Catia A. Sousa gratefully acknowledge the post-doctoral (SFRH/BPD/72816/2010) and the doctoral grants (SFRH/BD/101452/2014), from FCT, respectively.info:eu-repo/semantics/publishedVersio