Recovery of Residual Brewer’s Yeast by Electroactivation

Yeasts resulting from the brewing process (RBY) are a valuable by-product, with an important content of minerals, vitamins and, especially, proteins. The purpose of the research was the electroactivation of RBY and the simultaneous obtaining of two products—protein concentrates and hydrolyzed protein from residual brewer’s yeast. Electroactivation is a non-residual process, without the use of chemical reagents and relatively inexpensive. The variation of the electroactivation conditions allowed the separation of 90% - 94% of the proteins in the form of protein concentrates. During the process, it is attested to increase the pH value and decrease the redox potential, which characterizes the multiple redox processes that take place in the cathode cell, including sedimentation at the isoelectric point. The presence of albumin in the protein fractions of RBY allows the formation of protein complexes with calcium, attributing a higher biological value to the obtained products.

The Economic Potential of Brewer’s Spent Grain (BSG) as a Biomass Feedstock

This paper analyzes a pro-forma economic market and supply chain system for the reuse of a lignocellulose (brewer’s spent grain) in an industrial biotechnology environment. An extant literature review was conducted, followed by a technical analysis of BSG, and the development of a supply chain system and economic market analysis based upon a participant brewing company and industry experts. In this paper, it was found that, even with the potential for future improvements in the conversion of brewer’s spent grain (BSG) from an efficiency standpoint, this industrial residual is supply chain prohibitive as a biofeedstock in comparison to other lignocellulose materials, therefore, centralized market relationships would not be advantageous for sellers and buyers. Future research should consider the viability of centralized supply chain structures for alternatives that may exist as future bio-feedstocks.

Fluid dynamics analysis and pyrolysis of brewer’s spent grain in a spouted bed reactor

Brewer’s spent grain (BSG) is a large-scale agroindustrial waste that could be more efficiently utilized. This waste is composed of lignocellulosic material and so may serve as a good source of biomass for thermochemical conversion. The present study investigated the fluid dynamics behavior of mixtures of sand and BSG in a spouted bed to assess the viability of the thermochemical conversion of this biomass via fast pyrolysis. Fluid dynamics analyses were performed while varying the mass fraction of BSG (6–80%) and the static bed height (6.6–13.4 cm). Empirical equations for predicting the minimum spouting conditions and the mixing index were obtained using a regression technique, and the selected fluid dynamics parameters were employed in the spouted bed pyrolysis. The bio-oil resulting from this process was rich in phenolic compounds, various nitrogenated compounds (representing precursors for pharmaceuticals) and long-chain hydrocarbons. The products obtained from the analytical and spouted bed pyrolysis processes were also compared.

Effect of Fish Meal Replacement by Unconventional Meal in the Post-Larval Diet of Clarias Gariepinus in Benin (West Africa)

To reduce the pressure on aquatic resources due to the use of fishmeal in fish feed, the mastery and use of alternative sources of fishmeal in all stages of fish development are essential. Five diets including 4 experimental and one control diet were considered. Experimental diets of post-larvae were developed from unconventional ingredients in which fishmeal was completely replaced by a mixture of brewer’s yeast, chicken viscera and maggots. These foods were tested on Clarias gariepinus post-larvae with an initial average weight of 80 ± 1 mg. 1500 fish individuals were equally distributed in 15 concrete basins with a volume of 500 L forming five treatments in triplicate. Fish individuals were fed, manually at a ration rate of 20%, four times per day. The specific growth rates were 8.38%/day in imported food and 6.35%/day in the experimental food receiving 45.5% of protein from unconventional meal. Similar results were obtained with the feed consumption index. These encouraging results show that it is possible to partially or completely replace fishmeal in catfish feed and obtain an economically profitable production. The recovery of waste such as chicken viscera, brewer’s yeast and soybean meal in fish food formulation as tested in this study is a good contribution to environmental sanitation.

Acute Toxicity and Antipyretic Activities of a Methanolic Extract of Alchornea cordifolia Leaves

Alchornea cordifolia (Euphorbiaceae) is a very prized plant among traditional healers in Africa. Its leaves are used for its antipyretic properties in traditional areas. The aim of our study is to determine the acute toxicity and the antipyretic activity of a methanolic extract of Alchornea cordifolia leaves. Acute toxicity was assessed by measuring mortality, changes in body weight, spontaneous movements, and normal rectal temperature in mice. Antipyretic activity was evaluated by brewer’s yeast-induced hyperpyrexia in rats according to Teotino method (1963). The antipyretic effect of methanolicextract of Alchornea cordifolia leaves was compared with paracetamol (100 mg/kg bw) orally. Groups of mice treated with doses of 6500;3250;1625 and 812.5mg/kg of the extract did not show any mortality, nor significant alteration of body weight, nor alteration of spontaneous movements. However, incomplete reversed dose-dependent hypothermic activity was observed with doses of 50.78;101.56;203.12;406.25;and 812.5 mg/kg p.o. of the extract, showing acute toxicity of this plant. In the antipyretic assay, the extract with doses of 50.78;101.56;203.12;406.25;and 812.5 mg/kg p.o. exhibited a significant dose-dependent antipyretic activity similar to paracetamol (100 mg/kg bw) in rats. Thus Alchornea cordifolia may inhibit prostaglandins-biosynthesis from hypothalamus. Our results support claims on its traditional uses in management of fever. However Alchornea cordifolia may affect hypothalamus not only during fever but also when body temperature is normal.

Production of fermented tea petal decoction with insights into in vitrobiochemical tests,antioxidant assay and GC-MS analysis

This research work was designed to attempt and propose the first report on production and biochemical characterization of fermented tea flower petal decoction or simply tea petal wine.The tea petal decoction and brewer’s yeast or Saccharomyces cerevisiae were co-cultured for fermentation.Antioxidant activity and chromatographic separation of potential candidates were assessed.Primary investigations for qualitative characters on this fermented broth revealed the presence of steroids,tannin,flavonoids,phenol,cardiac glycosides,coumarin,caffeine etc.Our manufactured fermented broth showed high free radical scavenging activity after 2 months of aging.High DPPH scavenging activities were also observed in solvent fractions of acetone,ethanol and methanol.The antioxidant activity,alcohol percentage and other qualities were seen to be gradually increased during aging.Gas chromatography-mass spectrometry analysis revealed the presence of 44 compounds including many potential antioxidant molecules and other bioactive agents.Hopefully,presence of alcohol with medicinally active compounds and antioxidant activity will make it as acceptable as a good wine and tea flower as economically functional.

Stresses Imposed on Yeast During Brewing Fermentations and Their Effect on Cellular Activity

Brewer’s yeast strains are exposed to a spectrum of threats and“in-sults”thatcultures encounter during wort fermentation.Culture storage(including acid washing)andtheir propagation can also stress yeast systems.Stresses are a plethora of parameters that ayeast culture toler-ates during its propagation,stprage,and throughout and between wortfermentations.Stress can result in a number of effects on a yeast cul-ture.These includedecreases in yeast viability and vitality,depletion of intracellular glycogen,increases intrehalose,and excretion of intra-cellular proteinase A and other proteinases,with effects onbeer foam stability.Shear of cell wall components will also occur.In addition,modification ofa culture’s flocculation characteristics can result,to-gether with the formation of unfilterablemannan-protein beer hazes,Finally,increases in respiratory deficient(petite)and other yeastmu-tants have been reported.