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Efeito do tratamento térmico na textura e na bioacessibilidade protéica no desenvolvimento de um produto cárneo para pessoas acima dos 60 anos

2026-03-14T03:00:15Z

Title: Efeito do tratamento térmico na textura e na bioacessibilidade protéica no desenvolvimento de um produto cárneo para pessoas acima dos 60 anos Author(s)/Inventor(s): Capistrano, Ana Beatriz de Oliveira Advisor: Cabral, Lourdes Maria Corrêa Abstract: This study aimed to evaluate the effect of sample size (TA) and thermal lethality time (F₀) on the texture and protein bioaccessibility of beef strips processed in an autoclave and packed in flexible pouches. Seven experimental formulations were prepared: P1 (1 cm, 6 min), P2 (1 cm, 14 min), P3 (3 cm, 6 min), P4 (3 cm, 14 min), P5 (2 cm, 14 min), P6 and P7 (2 cm, 10 min). Samples were cut into cubes of approximately 2.5 cm in width and 5 cm in length, varying only in thickness according to the proposed TA. After processing, the following parameters were analyzed: texture (hardness, elasticity, chewiness, gumminess, shear force) and protein bioaccessibility (nitrogen recovery rate, degree of hydrolysis, and tyrosine release), with statistical analyses performed at a 5% significance level (p < 0.05). Results showed that sample size was the main factor influencing texture. Samples with TA = 1 cm presented lower shear force (5.68 ± 0.62 N in P1; 6.04 ± 1.15 N in P2) and greater tenderness, while 3 cm samples showed significantly higher values (54.55 ± 4.60 N in P3; 58.87 ± 7.86 N in P4), indicating increased mechanical resistance (p < 0.001). Hardness ranged from 17.48 ± 2.08 N (P2) to 61.18 ± 6.50 N (P3), and chewiness followed a similar pattern, from 2.21 ± 0.17 N (P2) to 14.66 ± 1.34 N (P3). Elasticity decreased with increasing F₀, with a significant difference between P1 and P4 (p = 0.037). Gumminess was affected by the interaction between TA and F₀, ranging from 5.66 ± 0.35 N (P2) to 22.47 ± 1.80 N (P3) (p < 0.01).Regarding protein bioaccessibility, P1 exhibited the highest nitrogen recovery rate (67.14%), while the lowest value was observed in P6 (49.58%). The degree of hydrolysis was highest in P3 (47.48 ± 4.34%), suggesting greater protein breakdown under 3 cm TA and 6 min F₀. Tyrosine release was more pronounced in intermediate samples (P6 and P7), reaching 766.67% an 758.34%, respectively. It is concluded that the modulation of TA and F₀ significantly influences meat texture and protein bioaccessibility. Smaller samples (TA = 1 cm), combined with short or intermediate processing times, resulted in better tenderness and greater protein retention. These conditions are promising for the development of meat products targeted at populations with specific needs, such as the elderly or individuals with chewing difficulties. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação

Avaliação da hidrólise enzimática de c-ficocianina extraída de Arthrospira sp. para estabilização em bebidas ácidas: uma abordagem proteômica para bebidas funcionais

2026-03-10T02:42:41Z

Title: Avaliação da hidrólise enzimática de c-ficocianina extraída de Arthrospira sp. para estabilização em bebidas ácidas: uma abordagem proteômica para bebidas funcionais Author(s)/Inventor(s): Ribeiro, Raphael de Oliveira Advisor: Valle, Anita Ferreira do Abstract: Currently, the search for natural dye alternatives in the food industry is increasing, aiming to replace synthetic colorants that may be harmful to health. Microalgae are among the main sources of such natural pigments, including phycobiliproteins. These molecules, composed of chromophores anchored to water-soluble proteins, play a crucial role in the photosynthetic cycle of these microorganisms and, once extracted, can be applied as natural additives. This project focuses on C-phycocyanin, a natural, non-toxic blue pigment widely used in the global food industry. The dye exhibits good stability within a pH range of 5.0 to 8.0 and at temperatures below 40 °C, which justifies studies regarding its stability under conditions outside these ideal ranges. Thus, the present work aims to develop and optimize strategies for stabilizing C-phycocyanin in carbonated beverages with a pH of 3.0 or below. The Cphycocyanin used in this study was extracted from optimized cultures of Arthrospira sp. Based on previous studies concerning strategies to stabilize the pigment under the aforementioned adverse conditions, the enzymatic hydrolysis of the dye was selected for further investigation. Preliminary tests involving reaction time, protease type, enzyme concentration, C-phycocyanin concentration, and solvent revealed which parameters should be fixed for subsequent stages of the study. Water was chosen as the solvent, and papain proved to be the enzyme with the best results. Through experimental designs, the optimal conditions for the hydrolysis of the pigment were determined: 37 °C, 30 minutes, and a papain concentration of 2.67 mg/mL. After 30 and 60 minutes of reaction, the hydrolysis pattern was evaluated using SDS-PAGE, which, due to the similarity of the protein band profiles, confirmed the optimal conditions previously established through the experimental designs. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação

Efeito do bioprocessamento enzimático de pães sobre o metabolismo de seus compostos fenólicos em indivíduos eutróficos e com obesidade

2026-02-15T03:00:11Z

Title: Efeito do bioprocessamento enzimático de pães sobre o metabolismo de seus compostos fenólicos em indivíduos eutróficos e com obesidade Author(s)/Inventor(s): Almeida, Suellen Silva de Advisor: Moreira, Daniel Perrone Abstract: The bioavailability of phenolic compounds may be limited by their form in the food matrix and by the high interindividual variability in metabolism, influenced by various factors, among which the composition of the gut microbiota stands out, differing between eutrophic and obese individuals. Strategies such as hydrothermal treatments and enzymatic bioprocessing, applied either individually or in combination, have shown promise in releasing phenolic compounds from the insoluble fraction, thereby positively affecting their bioaccessibility and bioavailability. In this thesis, the production kinetics of the enzymes amylase, peptidase, xylanase, and feruloyl esterase through solid-state fermentation of agro-industrial co-products (cocoa bran, wheat bran, and brewer’s spent grain) were initially evaluated for potential application in the bioprocessing of whole grain bread. All fermented co-products exhibited activity of the target enzymes, with brewer’s spent grain and wheat bran standing out due to higher xylanase (547.9 ± 11.4 U/g) and feruloyl esterase (1732.2 ± 278 mU/g) activities within the first 48 hours of fermentation. The bioprocessing of breads with these fermented co-products led to increases of 159% and 198% in soluble ferulic acid content, respectively, demonstrating that enzyme production via solid-state fermentation is a sustainable and effective approach for valorizing agro-industrial by-products and enhancing the nutritional quality of breads. As an alternative to enzyme production through fermentation, the effects of autoclaving and enzymatic bioprocessing—applied individually or in combination—were also assessed. The commercial enzyme Pentopan® 500 BG, used industrially to improve bread volume and appearance, was employed; it exhibited xylanase (15.0 ± 0.6 U/mg) and feruloyl esterase (6.7 ± 1.5 mU/mg) activities. Additionally, different drying methods were tested to identify the most effective technique for releasing ferulic acid, aiming at developing a bread with higher potential for clinical study application. The combination of autoclaving and enzymatic bioprocessing, along with drying at 95 °C for 30 minutes, promoted an 11-fold increase in the content of soluble phenolic compounds in wheat bran. The application of this processed bran in bread formulation resulted in products with soluble ferulic acid content (9.02 mg/100 g) exceeding values reported in the literature. Finally, a randomized, blinded, crossover clinical study (n=9) was conducted, involving eutrophic (n=5) and obese (n=4) individuals, who consumed both a control bread (soluble ferulic acid dose = 2.16 ± 0.27 mg) and a bioprocessed bread (ferulic acid dose = 11.13 ± 0.37 mg). Bioprocessing increased the glycemic response in obese volunteers, did not alter urinary excretion of hippuric acid over 48 hours, but significantly 11 impacted ferulic acid excretion, increasing it 14-fold. Body mass index did not appear to influence the excretion profile of the metabolites analyzed, which may be attributed to the small sample size or to the lack of detection of colonic metabolites, typically excreted later and related to gut microbiota activity. Publisher: Universidade Federal do Rio de Janeiro Type: Tese

Desenvolvimento e avaliação da composição química de smoothies de açaí adicionados da biomassa de Spirulina (Arthrospira maxima)

2026-03-11T23:07:23Z

Title: Desenvolvimento e avaliação da composição química de smoothies de açaí adicionados da biomassa de Spirulina (Arthrospira maxima) Author(s)/Inventor(s): Marinho, Luísa Madeira Advisor: Moreira, Daniel Perrone Abstract: In the last decades, changes to feeding habits and society life style is responsible for a increasce in the search for low processing and nutrient rich food. In this context, the alimentary industry is focused in introduce raw material that increasce the nutritional content of the food and on the development of practical products that are healthy to the consumer. The Arthrospira maxima biomass is a promissing ingredient due to its nutritional value, around 50 - 70 % of proteins in its composition, beside several minerals and anti-inflamatory and antioxidants composts. In this manner, the objective of this study was to develop powder formulations destined to the production of açaí smoothies, with the addition of micro-algae A. maxima biomass, aiming for a technological inovation in the search of a more nutritious alimentation. Initially, there were developed drinks prototype with 5% and 10% microalgae addition, those analyzed for protheic content, lipids, ash, humidity and carbohydrates. The formulation of 10% added microalgae was the most promissing in the nutritional aspect, but presented technological difficulties due to the microalgea characteristic flavor and smell. So, the A. maxima biomass content was reduced in the formulations and the microalgea growth was optimized under the following conditions: temperature of 30 °C ± 2 °C, irradiance of 120 μmol of fótons.m-2.s-1 and 12:12h luminosity of light:dark. Under those conditions, the A. maxima biomass presented a mineral and proteic content of respectively, 71,2 % and 12,69 %.The formulation were then ajusted in such manner to allow the development of the final formulations (smoothies) with different flavours (natural, banana and banana with guaraná), elaborated with the finality of combining the nutritional benefits of the microalgae biomass and açaí, with the sensorial charateristics that are desirable by the consumer. The formulations were analyzed for the total proteic content, lipids, ashes, humidity, pH, soluble fibers and phenolic compounds colour instrumentation. All of them stood out for presenting a significative proteic and mineral content increasce, when compared to its controls. The proteic content in the smoothies varied from 5,87 % to 7,22 %, representing an increasce bigger then 70 % in the proteic content of the formulation when compared to its controls. The pH of the formulations could be characterized as acid, once presented values lower then 4,7, what could represent an important barrier against the growth of microorganisms. In respect to the 10 instrumental colour, the total difference between the control formulation and the smoothies varied from 10,47 to 12,13, showing an evident change of colour when adding A. maxima biomass, since the ΔE* change was bigger then 5,0. Two anthocyanins were identified in the formulations, possibly cyanidin-3-O-rutinoside and pelargonidin-3-O-glucoside.The quantification revealed no significant difference in anthocyanin content between the control samples and the smoothies, with total values ranging from 34.6 to 36.1 mg/100 g. Therefore, it was perceveid that the addition of A. maxima biomass promoted a significative increasce in the nutritional quality of the drinks, and even though the microalgae presents characteristics that could cause impact on fundamental attributes for the consumer acceptance, it presents great potential to employed in health product, offering significative nutritional benefits. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação