Medium factors affecting extracellular protease activity by Bacillus sp. HTS 102—A novel wild strain isolated from Portuguese merino wool

The synthesis of an extracellular protease by Bacillus sp. HTS102—a wild strain recently isolated from the wool of Portuguese Merino ewes, was optimized. This protease is thermostable and particularly resistant to harsh environmental conditions—and appears to bear a unique ability to hydrolyze keratin-rich solid materials. Following a preliminary screening for the most relevant medium factors involved in processing, a fractional factorial design (2VI 6-1) was applied to ascertain the effects of six relevant parameters— viz. yeast extract concentration, peptone level, inoculum size, stirring rate, temperature and pH. The concentrations of yeast extract and peptone, as well as the incubation temperature and pH were found to play significant roles; and the 2-factor interaction between yeast extract level and pH was also significant. A 2.2-fold increase in the overall level of protease synthesis was eventually attained, with the improved medium relative to the basal medium—which is noteworthy when compared with competing proteases and previous optimization efforts.info:eu-repo/semantics/publishedVersio

Applied microbiology on poultry industry: from nutrition to the gut microbiota

Poultry products (i.e., meat and eggs) are one of the major protein sources for the human diet. The animal’s diet is one of the key elements that the poultry industry has been focused on, to improve the animal’s performance, maintaining their healthy growth and, ultimately, high quality end products. The incorporation of functional ingredients in feed formulations, aiming to provide extra benefits and/or prevent diseases, has been considered efficient in maintaining the animal’s productivity and simultaneously ensure its well-being. Nutrient’s bioavailability varies throughout digestion and absorption within the poultry’s gastrointestinal tract (GIT). A reliable in vitro model, as the one developed and used in this study, capable of mimicking all digestion, absorptive and cecal fermentation processes, is a useful tool to study the potential benefits of feed supplemented with functional and/or bioactive ingredients. The developed in vitro gastrointestinal model simulates the chemical, enzymatic, and mechanical conditions prevailing in the chicken´s GIT, from beak to cecum. Fresh broiler’s cecal samples were used as inoculum for batch cecal fermentation and the impact of different feed formulations, on bacteria modulation, organic acids, and total ammonia nitrogen production, were assessed. Overall, this approach enables to evaluate, as close to reality as possible, the potential of target additives, providing a trustworthy tool for the development of functional feeds.info:eu-repo/semantics/acceptedVersio

Human and animal in vitro gastrointestinal models: importance and applications

info:eu-repo/semantics/publishedVersio

Potentialities of the extraction technologies and use of bioactive compounds from winery by-products: a review from a circular bioeconomy perspective

Agro-industrial by-products and by-products from the wine industry (pomace, peels, leaves, stems, and seeds) represent a potential economic interest because they are usually relevant natural sources of bioactive compounds, which may present significant biological activities related to human health and well-being. This article aims to review wine and winery industry by-products as potential natural sources of antioxidant, antimicrobial, anti-inflammatory, antiaging, and anticancer compounds, as well as briefly highlighting the extraction methods used to obtain these bioactive compounds and explore their potential applications in the food, cosmetic, and packaging industries. Although there are some studies of wine industry by-products with different origins, this revision will be mainly focused on the Portuguese vineyard industry since it represents an import industrial sector as proof of the diversity of the bioactive compounds identified. Therefore, the recovery of these bioactive molecules that act as antioxidants and health-promoting agents may promote a variety of industries at the same time as the circular economy.info:eu-repo/semantics/publishedVersio

Effect of blanching, storage and drying conditions on the macro-composition, color and safety of mealworm Tenebrio molitor larvae

For food applications, the processing conditions applied to edible insects should present low energy requirements and environmental impact, while also assuring high quality and safety. The main goal of this study was to assess how different blanching, storage and drying conditions influence the quality and safety of Tenebrio molitor larvae. The different operations included blanching treatments (water-immersion or steaming), post-blanching storage (freezing or refrigeration) and drying methods (oven, microwave or freeze dryer). To monitor the impact on the quality of T. molitor dry matter content, water activity (aw), color and macro-nutrient composition were evaluated, while microbiological analyses were performed to assess the impacts on quality and safety. Blanching, particularly immersion-blanching, improved the lightness of the larvae, both before and after drying. Both blanching treatments reduced the Total Viable Count (TVC) and Enterobacteriaceae loads. Regarding the drying methods, freeze drying led to the best color conservation, while drying with an oven led to the lowest moisture content and aw. The application of drying methods further contributed to the reduction of TVC and Enterobacteriaceae, assuring low loads even after 3 months of storage, with the freeze dryer resulting in the lowest reductions, including an increase in yeast and mold count.info:eu-repo/semantics/publishedVersio

Development and characterization of a novel sustainable probiotic goat whey cheese containing second cheese whey powder and stabilized with thyme essential oil and sodium citrate

Probiotic goat whey cheeses with added second cheese whey powder (SCWP) were developed, resulting in creamy and spreadable products. The products contained Lactobacillus rhamnosus and Bifidobacterium animalis, as well as thyme essential oil and sodium citrate. Matrices of probiotic whey cheeses, with and without additives, were produced and stored at 5 °C for 21 days. Microbial and chemical profiles were evaluated weekly. The composition of the optimum matrix, formulated with whey cheese, probiotic culture, SCWP, thyme essential oil and sodium citrate (WCPSTC) was, expressed in % (w/w): protein (10.78 ± 0.08), fat (7.59 ± 0.03), dry matter (25.64 ± 0.13), ash (2.81 ± 0.02) and lactose (3.16 ± 0.04). Viable cell numbers of both probiotic cultures in matrix WCPSTC remained above 107 CFU g−1. This finding is of the utmost importance since it proves that both probiotic bacteria, citrate and thyme essential oil can be combined in order to increase the shelf-life and functional value of dairy products. All matrices’ pH values decreased during storage, yet only matrix WCPSTC remained above 5.0 pH units. The results indicated that the development of a probiotic whey cheese incorporating a dairy by-product, SCWP, is possible without compromising its chemical, microbiological or sensorial stability.info:eu-repo/semantics/publishedVersio

Lignin from sugarcane bagasse as a prebiotic additive for poultry feed

Diet is a crucial factor on health and well-being of livestock animals. Nutritional strengthening with diet formulations is essential to the livestock industry and animal perfor-mance. Searching for valuable feed additives among by-products may promote not only circular economy, but also functional diets. Lignin from sugarcane bagasse was proposed as a potential prebiotic additive for chickens and incorporated at 1 % (w/w) in commercial chicken feed, tested in two feed forms, namely, mash and pellets. Physico-chemical characterization of both feed types with and without lignin was performed. Also, the prebiotic potential for feeds with lignin was assessed by an in vitro gastrointestinal model and evaluated the impact on chicken cecal Lactobacillus and Bifidobacterium. As for the pellet's physical quality, there was a higher cohesion of the pellets with lignin, indicating a higher resistance to breakout and lignin decreases the tendency of the pellets for microbial contamination. Regarding the prebiotic potential, mash feed with lignin showed higher promotion of Bifidobacterium in comparison with mash feed without lignin and to pellet feed with lignin. Lignin from sugarcane bagasse has prebiotic potential as additive to chicken feed when supplemented in mash feed diets, presenting itself as a sustainable and eco-friendly alternative to chicken feed additives supplementation.info:eu-repo/semantics/publishedVersio

Ingredients from integral valorization of Isabel grape to formulate goat yogurt with stimulatory effects on probiotics and beneficial impacts on human colonic microbiota in vitro

Isabel grape (IG) products have high contents of phenolic compounds and fiber recognized for their positive impacts on microorganisms associated with health benefits to host. This study evaluated the effects of goat yogurts formulated with ingredients from IG integral valorization on the growth and metabolism of different probiotic strains, as well as on the population of selected bacterial groups and metabolic activity of human colonic microbiota in vitro. Goat yogurts with IG ingredients (IGI) stimulated the growth of tested Lactobacillus and Bifidobacterium probiotic strains during a 48-h cultivation, as well as decreased the pH values and enhanced the organic acid production. Goat yogurts with IGI increased the population of Lactobacillus spp. and Bifidobacterium spp. during a 24-h in vitro colonic fermentation. A stable Firmicutes:Bacteroidetes ratio close to 1 was found in media with goat yogurt formulations during the colonic fermentation, being similar to the effect caused by fructooligosaccharides. Goat yogurt formulations with IGI caused increased production of short-chain fatty acids and sugar consumption during colonic fermentation. Goat yogurts with IGI should be a valuable strategy for development of novel added-value foods with beneficial effects on gut microbiota and human health.info:eu-repo/semantics/publishedVersio

Uso integral da uva Isabel na elaboração de novos produtos com valor nutricional e potencial funcional

The benefits of grape consumption are widely recognized and mostly due to phenolic compounds. These beneficial effects will depend on the bioaccessibility of these compounds on grape and its derivatives. This study elaborated two formulations of Isabel grape preparation: PAX (with agave and xylitol) and PS (with sucrose); and two formulations of Isabel grape flour: FAX (from the PAX process residues) and the FS (from the PS process residues). The products were analyzed regarding their nutritional and antioxidant properties; their phenolic compounds’ bioaccessibility was also verified through a simulated digestion model. The preparation and flour exhibited relevant sugars levels (10.83-49.71 g 100 g-1). Those produced with natural sweeteners had a reduction in sugar concentration of 51% and 29% for preparation and flour, respectively, compared to formulations with sucrose, with the high fiber content in the flour is being further highlighted (20.14-21.95 g 100 g-1). The catechin (2.37-28.11 mg 100 g-1) was the most bioaccessible compound (22% to 168%), which together with the caftaric acid (2.31-69.43 mg 100 g-1) and malvidin 3-glucoside (8.65-16.47 mg 100 g-1) represent the compounds observed in greater quantity. The preparations showed higher bioaccessibility regarding grapes and flours for most of the phenolic compounds. Furthermore, the products elaborated presented higher values of anthocyanins and antioxidant activity than the in natura grape, highlighting the beneficial effect of grape processing.Os benefícios do consumo da uva já são amplamente reconhecidos e devem-se em grande parte aos compostos fenólicos. Esses efeitos benéficos irão depender da bioacessibilidade desses compostos na uva e em seus derivados. Foram elaboradas duas formulações de preparado de uva Isabel: PAX (com agave e xilitol) e PS (com sacarose); e duas formulações de farinha de uva Isabel: FAX (a partir do resíduo do processamento do PAX) e FS (a partir do resíduo do processamento do PS). Os produtos foram analisados quanto às suas propriedades nutricionais e antioxidantes, e a bioacessibilidade de seus compostos fenólicos foi verificada por meio de um modelo de digestão simulada. O preparado e a farinha apresentaram níveis relevantes de açúcares (10,83-49,71 g 100 g-1), sendo que aqueles produzidos com adoçantes naturais tiveram uma redução na concentração dos açúcares de 51% e 29% para o preparado e a farinha, respectivamente, em comparação com formulações com sacarose, destacando-se também o alto teor de fibras na farinha (20,14-21,95 g 100 g-1). A catequina (2,37-28,11 mg 100 g-1) foi o composto mais bioacessível (22% a 168%), que juntamente com o ácido caftárico (2,31-69,43 mg 100 g-1) e o malvidina 3-glicosídeo (8,65-16,47 mg 100 g-1) representam os compostos observados em maior quantidade. O preparado teve maior bioacessibilidade tanto em relação à uva quanto à farinha para a maioria dos compostos fenólicos. Além disso, os produtos elaborados apresentaram maiores valores de antocianinas e atividade antioxidante que a uva in natura, destacando o efeito benéfico do processamento da uva.info:eu-repo/semantics/publishedVersio

Biochemical and thermodynamic characteristics of a new serine protease from Mucor subtilissimus URM 4133

A protease from the fungus Mucor subtilissimus URM 4133, capable of producing bioactive peptides from goat casein, was purified. SDS-PAGE and zymography showed a molecular mass of 30 kDa. The enzyme was active and stable in a wide pH range (6.0–10.5) and (5.0–10.5), respectively. Optimum temperature was at 45–50 °C and stability was above 80 % (40 °C/2 h). Activity was not influenced by ions or organic substances (Triton, Tween, SDS and DMSO), but was completely inhibited by PMSF, suggesting that it belongs to the serine protease family. The Km and Vmax were 2.35 mg azocasein.mL-1 and 333.33 U.mg protein-1, respectively. Thermodynamic parameters of irreversible denaturation (40–60 °C) were enthalpy 123.63 – 123.46 kJ.mol-1, entropy 120.24–122.28 kJ.mol-1 and Gibbs free energy 85.97 – 82.45 kJ.mol-1. Any peptide sequences compatible with this protease were found after analysis by MALDI-TOF, which suggests that it is a new serine protease.info:eu-repo/semantics/publishedVersio