Encapsulação de Lactobacillus rhamnosus e farinha de uva por gelificação iônica

• Ano de defesa: 2026
• Autor(a) principal: Carreteiro, Milena Matesco
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por; eng
• Instituição de defesa: Universidade Tecnológica Federal do Paraná; Campo Mourao; Medianeira; Brasil; Programa de Pós-Graduação em Tecnologia de Alimentos; UTFPR
• Palavras-chave em Português: Probióticos; Prebióticos; Bactérias; Probiotics; Prebiotics; Bacteria; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA::TECNOLOGIA QUIMICA::ALIMENTOS; Tecnologia de Alimentos
• Link de acesso: http://repositorio.utfpr.edu.br/jspui/handle/1/40462

The use of dietary fibers derived from plant by-products as co-encapsulants has emerged as a promising strategy for the protection of probiotics and the addition of functionality to foods. Probiotics play a fundamental role in the modulation of the intestinal microbiota and the promotion of gastrointestinal health. This dissertation evaluated the application of grape flour as a co-encapsulant in the production of alginate capsules containing Lacticaseibacillus rhamnosus, considering its prebiotic potential and the impact on the strain's resistance to thermal conditions, simulated gastrointestinal conditions, and in a food matrix. The capsules showed high encapsulation efficiency, reaching 94.7% for pure alginate and 91.1% for the formulation containing grape flour, with moisture close to 96%. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) demonstrated that the incorporation of the flour modified the thermal behavior of the polymeric matrix, promoting later degradation and more stable thermal transitions, suggesting greater structural cohesion. The supplementation with grape flour increased bacterial growth to about 10.3 log in 24 hours, compared to approximately 7.0 log in the control, demonstrating its prebiotic effect. In thermal tests, the formulation with grape flour (SA/GF) showed greater resistance, maintaining 11 log after treatment at 72 °C/15 s and 5.15 log at 63 °C/30 min, values higher than those observed for pure alginate (SA) (7.15 and 7.08 log, respectively). The antioxidant activity determined by the 2,2- diphenyl-1-picrylhydrazyl (DPPH) method indicated a greater capacity for free radical inhibition for the formulation containing grape flour (20.6% at 100 mg/mL), compared to the co-encapsulated system with L. rhamnosus (12.6%) (p < 0.05), reinforcing the functional potential of the system. In the gastrointestinal simulation, the capsules with flour demonstrated greater resistance in the gastric phase, maintaining populations between 8.6 and 9.6 log CFU/g, while pure alginate reduced to 5.94 log after 90 minutes. The free cells showed complete loss of viability in acidic medium. In the intestinal phase, the formulation with flour maintained stable viability, reaching 9.45 log in 120 minutes, while pure alginate varied between 9.01 and 10.09 log. Free cells showed inferior performance, confirming the protective effect of encapsulation. Additionally, viability was evaluated in pasteurized orange juice stored at 4 °C for nine days. The free cells showed a rapid reduction, with a drop of over 2.5 log by the third day and approximately 3.0 log by the end of the period. In contrast, the encapsulated formulations exhibited a lower inactivation rate, with a reduction of less than 1 log observed in the formulation containing flour until the ninth day. In an integrated manner, the results demonstrate that grape flour acts as a functional co-encapsulant, providing thermal and gastrointestinal protection, greater stability in food matrices, and stimulation of probiotic growth, highlighting its potential for application in functional foods and the valorization of agro-industrial by-products.