Agro-industrial wastes are produced in large quantities around the world from the processing and manufacturing of food and beverages. The disposal of these wastes into the environment leads to damage to ecosystems owing to their composition rich in organic matter. In this context it may be noted that the brewing industry, whose production process includes processing steps and fermentation of vegetable raw materials such as barley and/or other grains used as adjuncts and hops, generates various byproducts. The worldwide consumption of these beverages and the current model of breweries, which includes production on a large scale, lead to the generation of large amounts of brewery waste, namely spent grain, hot trub and residual yeast. Owing to its composition, these residues exhibit significant potential for application in bioprocess technologies. In this study the three residues mentioned had their composition determined as a function of moisture, ash, total organic carbon (TOC), total and soluble nitrogen, reducing sugar and soluble free amino nitrogen. Moreover, the residues were characterized for total acidity, pH and chemical oxygen demand (COD) of total and soluble fractions. The three residues evaluated had high moisture content (>80%) and high organic matter content (TOC and COD,~50% and >1000 mg/g, respectively), which can highlights the significant protein fraction (almost 50% for hot trub and residual yeast), suggesting the possibility of using these wastes for recovery.

A large amount of agro-industrial waste is produced annually around the world from the beneficiated agricultural products or in food industrialization. The disposal of these residues in the environment results in a lot of inconvenience to the ecosystem, due to its significant nutritional value and high concentration of organic compounds that confers a high biochemical oxygen demand to the waste's degradation. In this context, brewing industry is among these activities, which includes in its production stages the processing and fermentation of vegetable feedstock, such as barley malt and other grains, and hops, generating several by-products. Many factors, such as environmental policies, possible scarcity of non-renewable sources, and problems related to the improper use of renewable raw materials, leads to the development of new processes that could generate less waste or reused those produced in order to add greater value to the residue. This article presents a review of the solid wastes in brewing industry, which are the brewer spent grain, the hot trub, the residual yeast and the diatomaceous earth, describing how they are obtained in the brewery process, their characterization and chemical composition, and the potential applications in bioprocesses technologies. The main fraction common to all revised waste is the protein fraction, in addition to various constituents of interest, such as minerals, carbohydrates and phenolic compounds. The main current applications are in the area of animal feed and human nutrition.

A consistência e a viscosidade do iogurte são uns dos principais fatores envolvidos na qualidade e aceitação do produto. Dessa forma, este trabalho apresenta um estudo de comparação reológica entre iogurtes comerciais do Rio de Janeiro, Brasil, em cujas formulações constam diferentes espessantes. Foram utilizadas três grandes marcas do mercado e, entre os espessantes utilizados, estão: goma guar, goma xantana, goma carragena, goma alfarroba e carboximetilcelulose. Previamente às análises reológicas, as amostras de iogurtes foram submetidas à determinação do pH, da acidez (expressa em ácido láctico) e da umidade. As curvas de fluxo e de viscosidade foram obtidas em reômetro rotacional Thermo Haake Mars com geometria placa/placa (35 mm de diâmetro), com variação de taxa de cisalhamento entre 0,02 e 100 s-1 (curva ascendente), e 100 e 0,02 s-1 (curva descendente), em um tempo total de 20 minutos. Foi determinada a histerese como a área entre as curvas e ajustados os modelos de Bingham, Casson, Herschel-Bulkley e Ostwald de Waele. Foram realizados também testes de tixotropia, pela medição da viscosidade em função do tempo a uma taxa constante de 100 s-1, por 10 minutos. Estes foram ajustados pelo modelo de Weltman. Além disso, foram verificadas alterações no comportamento reológico em função da variação de temperatura (4 a 24 ºC), cujos resultados foram avaliados pela Equação de Arrhenius. Todas as amostras de iogurte analisadas apresentaram comportamento pseudoplástico e tixotrópico. Todos os modelos foram bem ajustados para as curvas de fluxo, exceto o modelo de Weltman, que não representou bem os testes de tixotropia.

SummaryThis study evaluated the use of three solid brewery wastes: brewer's spent grain, hot trub and residual brewer's yeast, as alternative media for the cultivation of lactic acid bacteria to evaluate their potential for proteolytic enzyme production. Initially, a mixture experimental design was used to evaluate the effect of each residue, as well as different mixtures (with the protein content set at 4 %) in the enzyme production. At predetermined intervals, the solid and liquid fractions were separated and the extracellular proteolytic activity was determined. After selecting the best experimental conditions, a second experiment, factorial experimental design, was developed in order to evaluate the protein content in the media (1 to 7 %) and the addition of fermentable sugar (glucose, 1 to 7 %). Among the wastes, residual yeast showed the highest potential for the production of extracellular enzymes, generating a proteolytic extract with 2.6 U/mL in 3 h. However, due to the low content of the fermentable sugars in the medium, the addition of glucose also had a positive effect, increasing the proteolytic activity to 4.9 U/mL. The best experimental conditions of each experimental design were reproduced for comparison, and the enzyme content was separated by ethanol precipitation. The best medium produced a precipitated protein with proteolytic activity of 145.5 U/g.

Abstract:Beer is a fermented drink produced from a wort comprised of barley malt, hops, and water in combination with activity from the yeast strains of the genus Saccharomyces. The beverage is consumed around the world and has a global market controlled by several multinational companies. However, in recent years, it has been possible to note an increase in the number of microbreweries and homebrewers, necessitating additional research both to develop and increase competitiveness of this market sector as well as to improve product quality and promote the reduction of production costs. The process of milling barley malt is often not considered relevant to these goals; however, this operation is influential with regard to, for example, mashing yield, the concentration of polyphenols in beer, and the quality of wort clarification. Therefore, this work evaluates the wet (10%, 20%, 30%, 40%, and 50% moisture content) and dry barley malt milling process as well as analyzes particle size distribution and the mean diameter of particles. The milled grains were submitted to a mashing process to evaluate how particle size contributes to the conversion of starch to sugars and the availability of polyphenols on sweet wort. The results indicate the best milling conditions to obtain a good mashing yield while preserving as much malt husk as possible to facilitate wort clarification.

Beer is the most consumed alcoholic beverage in the world. In order to reduce processing time and meet the fast market demand, several measures are taken by the breweries, such as exogenous enzymes supplementation and changes in the mash profile. The present study aims to evaluate the effect of proteolytic step suppression and the addition of exogenous proteases in mashing on wort and beer composition. For that, an experimental design was elaborated, which resulted in the production of four different worts and beers, with and without realization of the proteolytic step during the mashing, and with and without the addition of exogenous proteases. The brewer's worts were analyzed for the following parameters: °Plato, extract, total nitrogen and free amino nitrogen content. The amino acids cysteine, histidine, phenylalanine, lysine, tryptophan and arginine were quantified in sweet worts by capillary electrophoresis. The beers produced were analyzed for alcohol content, real extract, total nitrogen and free amino nitrogen content, fermentation efficiency and the mass of coagulable matter. The addition of proteolytic extract promoted higher fermentation efficiency and an increase of the extract, as well as the contents of amino acids and total nitrogen in the sweet wort.

The direct and simultaneous determination of cysteine, histidine, phenylalanine, lysine, tryptophan and arginine in brewery worts by capillary zone electrophoresis (CZE) was applied to evaluate the effects of temperature control and protease supplementation during mashing on the changes of these amino acids (AAs) wort composition. A cation exchange resin was used for AAs extraction from wort samples prior to CZE determination. The separation was achieved using a 50 mmol/L phosphate buffer at pH 12.5, containing 0.4 mmol/L cetyltrimethylammonium bromide (CTAB), as background electrolyte (BGE) solution; -20 kV; 20°C and hydrodynamic injection time of 15 s, at 50 mbar. Recovery evaluation using worts led to values between 83.1 and 96.2%, demonstrating the method feasibility, which was successfully applied in the quantification of AAs in wort samples. This study showed that temperature control and addition of exogenous proteases in the mashing may increase the AAs concentration in wort, improving the final product quality (beer). The present method is a good alternative for monitoring specific AAs in worts and their determination can allow the brewing process optimization.

The study evaluated the antimicrobial activity based on chromatographic analysis of ethanolic extract of Funtumia elastica leaves and stem bark. Funtumia elastica leaf and stem bark samples were air dried, grinded and extracted in ethanol by soxhlet extraction. The defatted ethanol extract was partitioned in dilute sodium hydroxide, hydrochloric acid and chloroform to obtain basic, neutral and acidic metabolites. The phytochemical test on the defatted crude extract of Funtumia elastica leaf and stem bark show the presence of tannins, alkaloids, flavonoids, saponins, terponoids, anthraquinone, phenolics and steroids. The crude extract, basic, neutral and acidic metabolites, and the fractions obtained by thin layer chromatography were screened for their antimicrobial activity at concentration of 100mg/ml against Streptococcus pneumoniae(sp), Staphylococcus aureus(sa), Salmonella typhi(st), Escherichia coli(ec) and Candida albicans(ca). The results show that the crude extract of stem with inhibition zone diameter(mm) of 22, 18, 20, 22 and 20 against (sp), (sa), (st), (ec) and (ca) respectively had better antimicrobial activity than the crude extract of leaf with inhibition zone diameter(mm) of 16,10,16,14 and 12 against (sp), (sa), (st), (ec) and (ca) respectively. Also the TLC fractions exhibited lower antimicrobial activity when compared to that of the basic metabolites. The fractions obtained by thin layer chromatography which showed promising antimicrobial activity were analysed by gas chromatography mass spectroscopy (GC/MS). The GC/MS spectra revealed thirty-nine peaks from which thirty nine compounds were identified. The identified compounds were mainly carboxylic acids and esters. The results of antimicrobial screening show that the crude extracts of the stem bark with inhibition zone diameter (mm) of 22, 18, 20, 22 and 20 were comparable to the standard drugs ciprofloxacin with inhibition zone diameter (mm) of 18, 20, 20, and 15 and gentamycin with inhibition zone diameter (mm) of 10, 20, 15, 12, and 18.