Optimised processing of faba bean (Vicia faba L.) kernels as a brewing adjunct

Pulse (Fabaceae) grains, such as peas and beans, are derived from crops that are usually cultivated in the absence of mineral nitrogen fertiliser as these crops can obtain their nitrogen requirement naturally from the air via biological nitrogen fixation. Therefore, pulses present a significantly lower greenhouse gas (GHG) footprint than crops demanding nitrogen fertiliser, whilst also offering significant quantities of starch for the brewing and distilling industries. Mitigation of agriculture derived GHG emissions through utilisation of pulses can have a positive environmental impact. To this end, the potential of exploiting dry, dehulled faba bean (Vicia faba L.) kernel flour as an adjunct for beer production was evaluated. The impact of different temperature regimes and commercial enzymes were assessed for their effect on wort: viscosity; run‐off rate; primary amino nitrogen content and, fermentability. Faba beans demonstrated insufficient endogenous enzyme capacity for starch conversion and generated a viscous wort. However, using a stepped temperature mashing regime and exogenous enzyme additions, the faba bean wort was comparable in processability and fermentability to that of 100% malted barley wort. The faba based beer and co‐product qualities demonstrate the environmental, nutritional and commercial potential of pulses in brewing. © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling     

Comparison of gas chromatographic volatile profiling methods for assessing the flavour quality of kenyan black teas

A comparison is made of the various ratios used to quantify black tea aroma such as: ratio of sum of gas chromatographic peak areas of compounds eluting before linalool (3,7-dimethyl-1,6-Octadien-3-ol) to those eluting after linalool (Wickremasinghe-Yamanishi ratio); gas chromatographic peak areas of compounds imparting sweet flowery aroma (Group II volatile flavour compounds) to those imparting green grassy aroma (Group I volatile flavour compounds), Owuor's flavour index; ratio of the sum of gas chromatographic peak area of the terpenoids to non-terpenoids, i.e. Mahanta ratio; and gas chromatographic peak area of linalool to E-2-hexena1, i.e. Yamanishi-Botheju ratio. The Wickremasinghe-Yamanishi ratio and Owuor's flavour index showed a significant relationship, the Mahanta ratio showed a significant but poor relationship, and the Yamanishi-Botheju ratio had no relationship with the tasters evaluation of Kenyan clonal CTC black teas. Similar results were obtained from orthodox black teas manufactured from different varieties.     

Microbial incorporation of 13C-labeled acetate at the field scale: detection of microbes responsible for reduction of U(VI)

A field-scale acetate amendment experiment was performed in a contaminated aquifer at Old Rifle, CO to stimulate in situ microbial reduction of U(VI) in groundwater. To evaluate the microorganisms responsible for microbial uranium reduction during the experiment, 13C-labeled acetate was introduced into well bores via bio-traps containing porous activated carbon beads (Bio-Sep). Incorporation of the 13C from labeled acetate into cellular DNA and phospholipid fatty acid (PLFA) biomarkers was analyzed in parallel with geochemical parameters. An enrichment of active sigma-proteobacteria was demonstrated in downgradient monitoring wells: Geobacter dominated in wells closer to the acetate injection gallery, while various sulfate reducers were prominent in different downgradient wells. These results were consistent with the geochemical evidence of Fe(III), U(VI), and SO(4)2- reduction. PLFA profiling of bio-traps suspended in the monitoring wells also showed the incorporation of 13C into bacterial cellular lipids. Community composition of downgradient monitoring wells based on quinone and PLFA profiling was in general agreement with the 13C-DNA result. The direct application of 13C label to biosystems, coupled with DNA and PLFA analysis,     

Experiments on Marine Wastewater Diffusers with Multiport Rosettes

The dispersion capabilities of two types of marine wastewater diffusers, one with risers containing eight radial ports (rosette) and the other with the ports uniformly distributed, were directly compared in laboratory experiments for three scenarios: stationary and flowing unstratified, and flowing stratified. Tracer concentration fields were measured with a three-dimensional laser-induced fluorescence system. The dispersion capabilities, particularly dilution, of the two diffuser types were similar. The primary differences occurred with no current where the rosette diffuser plumes were bent inwards, causing a dynamic interaction. This resulted in a small reduction in near field dilution, an increase in the spreading layer thickness, and a decrease of the near field length. These differences were virtually eliminated by a flowing current when the eight individual plumes from a rosette first merged with themselves and then with those from neighboring risers to become laterally quite uniform at the end of the near field. The major near field characteristics were primarily determined by the buoyancy flux per unit length. Temporal concentration fluctuations were high close to the diffuser and then decreased and leveled off near the end of the near field where the discharge-induced turbulence collapses. The fluctuations do not go to zero, however, owing to remnants of previous fluctuations.