Paula Gimenez Milani

Este estudo comparou o potencial funcional e bioativo de suplementos proteicos veganos comerciais em relação ao whey protein isolado. O whey apresentou melhor perfil de aminoácidos com maiores teores de leucina, isoleucina e valina, enquanto as proteínas vegetais destacaram-se pelo elevado teor de arginina. Também apresentou maior solubilidade e atividade antioxidante por DPPH e ABTS+. A proteína do isolado de arroz apresentou a menor solubilidade, porém apresentou maior liberação proteica durante a digestão simulada. Os compostos fenólicos foram mais expressivos no blend de arroz e ervilha e no isolado de arroz. Ao longo da digestão simulada, observou-se redução de proteínas solúveis e modulação da atividade antioxidante associada à liberação de peptídeos bioativos, principalmente nas fases gástrica e intestinal. Nenhum isolado apresentou inibição expressiva da α-amilase ou da lipase pancreática, embora os isolados de soja e de arroz tenham demonstrado potencial dose-dependente. Os resultados demonstram que apesar das limitações tecnológicas das proteínas vegetais, destacam o potencial bioativo após a digestão e seu potencial como fontes proteicas funcionais.

This study investigated the biotechnological potential of Stevia rebaudiana rebaudiana stems as a functional co-product for the industry. The ethyl acetate fraction and its application as a protein conjugate was antioxidant, cytotoxicity, antimicrobials, anti-inflammatory and antidiabetic activities were assessed. The results revealed that the fraction possesses antioxidant capacity, demonstrating superior efficacy in inhibiting lipid oxidation (TBARS) compared to the isolated protein and significant results in the ORAC assay, in addition to exhibiting antimicrobial activity against bacteria and fungi. In the context of cellular health, the extract showed promising antitumor properties with the strategic advantage of not exhibiting cytotoxicity in normal cell lines, demonstrating biological selectivity. The fraction has the potential to be applied in metabolic control through the significant inhibition of α-amylase and lipase enzymes, suggesting that it needs to be studied as an anti-hyperglycemic and anti-lipidemic adjuvant, in addition to a relevant anti-inflammatory action in cellular models.

Os processos de separação por membranas têm se destacado na obtenção, purificação e caracterização de compostos bioativos devido à sua alta seletividade e eficiência. Com o aumento do interesse por compostos fenólicos e proteínas vegetais, as tecnologias de membranas, como microfiltração (MF), ultrafiltração (UF) e nanofiltração (NF), têm sido aplicadas para a recuperação desses compostos a partir de fontes naturais. A utilização de membranas permite a separação de substâncias com diferentes pesos moleculares, preservando as propriedades biológicas e garantindo um produto de alta qualidade. Apesar dos avanços, desafios como a incrustação das membranas e a otimização da seletividade permanecem, sendo áreas-chave para futuras pesquisas. Este trabalho revisa as principais aplicações dessas tecnologias nas indústrias alimentícia e farmacêutica, destacando as vantagens e limitações, bem como as perspectivas para o desenvolvimento de membranas mais eficientes e sustentáveis.

This study investigated hydroethanolic extracts (70:30 v/v) from leaves and stems of Stevia rebaudiana (UEM-13 variety), obtained by Soxhlet and Shaker extraction, focusing on bioactive properties. UHPLC-MS/MS and FTIR characterization identified phenolic and sweetening compounds. Both extracts exhibited significant antioxidant activity in DPPH, TBARS, OxHLIA, and ORAC assays. Soxhlet extraction was more effective in preserving phytochemicals and inhibiting α-amylase, whereas Shaker extraction showed greater pancreatic lipase inhibition. Both extracts demonstrated antimicrobial activity against pathogenic and foodborne bacteria, as well as antifungal effects. These findings highlight Stevia biomass as a promising source of compounds with antioxidant, antidiabetic, antilipid, and antimicrobial potential.

Natural extracts have bioactive compounds concentrated in leaves, peels, and seeds. In this research, pomegranate peel extract was tested as a natural conservant for bread. The hydroalcoholic extract of pomegranate peel was obtained by dehydrating the peels, powdering them, and then performing a maceration in 70% ethanol; high-performance liquid chromatography characterized the extract to quantify punicalagin. Fungal strains (e.g., Penicillium paneum, Penicillium citrinum, Cladosporium spp., and Aspergillus chevalieri) isolated from deteriorated commercial bread were used to determine antifungal activity via minimum inhibitory concentration/ fungicidal concentration, mycelial growth, and spore inhibition tests, with morphological effects assessed by scanning electron microscopy. Additionally, the preservative potential of the extract was evaluated by applying different concentrations to bread samples and monitoring microbial growth over time. The extract demonstrated potent antifungal activity, with minimum inhibitory concentrations of 2.50% for Penicillium paneum, 1.25% for Penicillium citrinum, and 5.0% for Aspergillus chevalieri, while Cladosporium strains showed resistance. In bread preservation tests, pomegranate peel extract at concentrations of 0.625–2.50% maintained low mold and yeast counts up to the 25th day, demonstrating comparable performance to synthetic preservatives. The hydroalcoholic extract of pomegranate has shown efficiency as a preservative and natural alternative for combating and preventing fungal infections in bakery products.

Introduction/Objective: The ethanolic pretreatment of stevia leaves is considered ecologically favorable and increases its yield, purity level, and sensory profile of sweeteners. We investigated the by-product generated so that we can provide a viable and applicable destination to effectively contribute to the production and industrial chain of stevia sweeteners. Recently, an antioxidant and antidiabetic fraction was obtained through stevia methanolic extraction. However, this process is costly, has a low yield, and is non-green. In this study, we got an antioxidant fraction of stevia from its pretreatment by-product, the ethanolic extract, characterized its bioactive compounds – mainly phenolic acids and flavonoids – and evaluated its antidiabetic and antilipid capacity. Methods: The ethanolic extract was fractionated, then the ethyl acetate fraction was microencapsulated. Physicochemical, Mass Spectrometry (UHPLC/MS-MS), scanning electron microscopy, microencapsulation efficiency, and antioxidant capacity analyses were carried out. The antioxidant capacity was evaluated. Antihyperglycemic capacity was assessed by inhibition of α-glucosidase and α-amylase. For antilipid potential, inhibition of pancreatic lipase was measured. Results: Antioxidant potential was observed mainly in the fraction. Microencapsulation improved the stability of the fraction. Mass spectrometry allowed comparison with phenolic and flavonoid compounds from the methanolic and ethanolic fractions of the by-product. Many compounds were coincident, which may explain the similar antioxidant capacity found. The samples showed more than 90% inhibition of alpha-glucosidase, which may indicate potential antidiabetic activity. All samples showed inhibition of the pancreatic lipase enzyme higher than 80%, reaching 91.05% for the free fraction. Conclusion: This study represented the recovery of a by-product and showed that this antioxidant fraction deserves further investigation for its bioactive potential, especially antioxidant, antidiabetic, and anti-lipid.

Introduction: The antioxidant fraction of Stevia rebaudiana has important antidiabetic potential, is poorly soluble, and has low stability, which makes its applicability difficult. Materials and Methods: In this study, Stevia's fraction was obtained, characterized by Ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLCMS/ MS), and microencapsulated with maltodextrin (MDF), gum arabic (GAF), whey protein + maltodextrin (MDWF), and whey protein + gum arabic (GAWF). Then, the following parameters were evaluated: stability and antioxidant capacity over 30 days, physicochemical characteristics, preservation of bioactive compounds by digestion, and in vitro antidiabetic activity. Results and Discussion: The microcapsule with gum arabic showed better microencapsulation efficiency, while its version with maltodextrin provided increased solubility. Microencapsulation reduced the humidity and water activity in the microcapsules, except for the microcapsules containing gum arabic. The combination of maltodextrin and whey protein showed greater luminosity and a whiter powder. The microcapsules with maltodextrin and its mixture with gum arabic kept the phenolic compounds stable for 30 days. The microencapsulation with whey protein increased the antioxidant activity after 15 days of the process and during in vitro digestion. All samples showed 96% inhibition of the α-glucosidase enzyme, and only the microcapsule with maltodextrin inhibited α-amylase (58%). Conclusion: This study showed paramount results so that Antioxidant Stevia Fraction (ASF) can effectively be an adjuvant product to prevent and treat diabetes.

Consumer acceptance of milk beverages as probiotic beverages is directly linked to their sensory qualities, such as flavor, consistency, visual appearance, and mouthfeel. Overall, products that exhibit syneresis are often viewed as inferior. Thus, this study was conducted to investigate the effects of high-intensity ultrasound on the production of probiotic strawberry beverages, aiming primarily to stabilize the beverage by reducing syneresis and improving sensory properties without compromising the viability of probiotic microorganisms. The effects of the ultrasound processing time (2.5, 5, 7.5, and 10 min) on the physical, chemical, and sensory properties of the beverages were analyzed. Ultrasound was applied using a 750-wW ultrasonic processor (Cole-Parmer^®, 750 W, Vernon Hills, IL, USA) at 40% amplitude, consuming 300 W and resulting in an acoustic power density of 1.2 W/mL. The results indicate that ultrasound significantly influenced the syneresis of the samples, with intermediate times (5 and 7.5 min) demonstrating lower liquid separation. Notably, the U7.5 treatment exhibited syneresis values of 52.06% ± 2.14, 60.75% ± 2.33, and 61.17% ± 1.90 at days 1, 14, and 28, respectively, corresponding to reductions of approximately 18%, 12%, and 11% compared to the control (63.43% ± 0.93, 68.81% ± 0.56, and 68.59% ± 0.10, respectively). The fatty acid composition showed changes according to storage time. Notably, palmitic acid (C16:0) concentrations were above 30 g/100 mL, and the ω6/ω3 ratio ranged from 5.92 to 7.47, falling within the recommended dietary values. Ultrasound also reduced the amount of sucrose in the samples, which may benefit the growth of probiotic microorganisms. In terms of sensory analysis, the ultrasound-treated samples (2.5 to 7.5 min) were preferred by the evaluators compared to the control sample. Furthermore, ultrasound treatment did not result in the inactivation of probiotics, supporting its potential for enhancing probiotic beverage quality. Thus, high-intensity ultrasound proved to be a promising technology for enhancing the quality of probiotic strawberry beverages by reducing syneresis, affecting fatty acid composition, and improving sensory characteristics. This may open up new opportunities in the food industry for more appealing and healthier probiotic products.

This study aimed to developed a coffee brew sweetened with UEM 13 variety stevia leaves. The stevia leaves were submitted to an ethanolic elution pretreatment and compared to untreated sample. The coffee brew sweetened with pretreated and untreated stevia were produced and compared to a coffee without stevia, and with a stevia tea produces with pretreated and untreated leaves. The beverages were characterized by physico-chemical and instrumental parameters, bioactive compounds, and antioxidant activity. The pretreatment was successfully performed in stevia leaves, without significant loss of steviol glycosides and minimal changes to color parameters. The coffee brew with stevia pretreated leaves kept the same steviol glycosides content than coffee with untreated ones. The stevia addition to coffees presented influence on solids due carbohydrate and reducing sugar increase, improving the coffee brew viscosity. Regarding bioactive compounds and antioxidant activity, some influence of percolation saturation process may be observed for coffee in comparison with control coffee brew and stevia tea. Although pretreated and untreated leaves did not differ for steviol glycosides content, physico-chemical influences of them were observed in coffee brew in a most pronounced way. The stevia leaves may be used as coffee sweetener replacing sucrose added in 28.98% to 38.58%.