Abstract Beer is a fermented beverage made from barley malt and hops under the action of a suitable yeast. The main function of hops in the brewing process is to provide bitterness, characteristic flavours and aromas to the beverage. However, hops only began to be added to the formulation of this beverage starting in the ninth century. Therefore, the use of other bitter plants as a substitute for hops may be a viable alternative. This study aimed at evaluating the use of artichoke as a total substitute for hops in American lager craft beer production. The substitution of hops with up to 2 g⋅L-1 artichoke resulted in a beer with a quality similar to that of the American lager beer traditionally found in the market. So, artichoke was confirmed to be a viable alternative for hops, having satisfactory physicochemical characteristics and good sensorial acceptance.

Resumo Este estudo teve como objetivo melhorar as condições físicas e nutricionais do processo de produção de carotenoides pela recém-isolada Rhodotorula mucilaginosa, uma levedura basidiomiceta vermelha. A melhoria da bioprodução de carotenoides foi obtida pela técnica de delineamento experimental, alterando as características dos processos [agitação (130 rpm a 230 rpm) e temperatura (25 °C a 35 °C)] com sete experimentos, e após um planejamento fracionário 25-1 para a classificação dos fatores relevantes que constituem o meio de cultura (glicose, extrato de malte, extrato de levedura, peptona e pH inicial). Um delineamento experimental de segunda ordem completo foi realizado para otimizar a composição do meio de cultura e as variáveis foram: extrato de levedura (0,5 a 3,5 g/L), peptona (1 a 5 g/L) e pH inicial (5,5 a 7,5), com 17 experimentos. A produção máxima de carotenoide foi de 4.164,45 μg/L (252,99 μg/g) em 144 h, em meio YM com 30 g/L de glicose, 10 g/L de extrato de malte, 2 g/L de extrato de levedura e 3g/L de peptona, e pH inicial 6, 130 rpm a 25 °C. Neste trabalho, as fontes de nitrogênio foram os fatores que mais influenciaram o acúmulo de carotenoides intracelular. A levedura R. mucilaginosa apresentou alta produção em nível de bancada, podendo ser promissora para a produção comercial.

Abstract This study aimed to improve the physical and nutritional process conditions for the production of carotenoids by the newly isolated Rhodotorula mucilaginosa, a red basidiomycete yeast. The carotenoid bioproduction was improved using an experimental design technique, changing the process characteristics of agitation (130 rpm to 230 rpm) and temperature (25 °C to 35 °C) using seven experiments, followed by a 25-1 fractional design to determine the relevant factors that constitute the culture medium (glucose, malt extract, yeast extract, peptone and initial pH). A complete second order experimental design was then carried out to optimize the composition of the culture medium, the variables being yeast extract (0.5 to 3.5 g/L), peptone (1 to 5 g/L) and the initial pH (5.5 to 7.5), with 17 experiments. The maximum carotenoid production was 4164.45 μg/L (252.99 μg/g), obtained in 144 h in YM (yeast malt) medium with 30 g/L glucose, 10 g/L malt extract, 2 g/L yeast extract, 3 g/L peptone, an initial pH 6, 130 rpm and 25 °C, demonstrating the potential of this yeast as a source of bio-pigments. In this work, the nitrogen sources were the factors that most influenced the intracellular accumulation of carotenoids. The yeast R. mucilaginosa presented high production at a bench level and may be promising for commercial production.

Resumo Este trabalho teve como objetivo a recuperação de compostos fenólicos a partir de resíduos da indústria cafeeira e a avaliação de sua capacidade antioxidante. Os resíduos (casca, polpa e borra de café) foram obtidos de diferentes etapas do processamento industrial do café. Os extratos fenólicos foram obtidos usando-se uma mistura de acetona e água. O teor de compostos fenólicos variou entre 72,88 e 159,50 mg AG g–1 resíduo. Mediante cromatografia líquida de alta eficiência foi detectado e quantificado o ácido clorogênico na casca e na polpa de café. Foi avaliada a capacidade antioxidante dos extratos fenólicos, verificando-se sua capacidade sequestrante de radicais DPPH e sua ação redutora sobre radicais peroxila. O resíduo com maior capacidade antioxidante foi a casca de café. Esses resultados sugerem a possibilidade de reutilização dos resíduos da indústria do café para a obtenção de compostos antioxidantes, pois tais compostos têm inúmeras aplicações nas áreas de alimentos, cosméticos e farmacêutica.

Summary The aim of this study was to recover the phenolic compounds from coffee industry residues and evaluate their antioxidant capacity. The residues (husk, pulp and spent coffee) were obtained from different steps of the industrial processing of coffee. The phenolic extracts were obtained using a mixture of acetone and water and the phenolic compound contents ranged between 72.88 and 159.50 mg GA g–1 residue. Chlorogenic acid was detected and quantified in the coffee husk and pulp by high performance liquid chromatography (HPLC). The antioxidant capacity of the phenolic extracts was evaluated and they showed DPPH radical scavenging ability and reducing action against peroxyl radicals. The residue with the highest antioxidant capacity was the coffee husk. The results suggest the possibility of reusing the coffee industry residues to obtain antioxidant compounds, since these compounds have numerous applications in the food, cosmetic and pharmaceutical industries.