Purpose: The objective of this study was to evaluate the influence ofSaccharomyces boulardiion the kinetics of fermentation for organic and conventional apple pulp and to verify the effect of the antioxidant quercetin on the response to cellular oxidative stress.Design/methodology/approach: The kinetic parameters, the content of phenolic compounds, the quantity of quercetin and the antioxidant activity were determined during the fermentation process. The effect of quercetin on cellular oxidative stress was also investigated.Findings: The content of phenolic compounds, the antioxidant activity and the quercetin concentration were higher in the organic fermented apple pulp (ORG) than in the conventional fermented apple pulp (CON). However, both apple pulps were considered ideal substrates for the growth ofS. boulardii, suggesting that they are potentially probiotic. After fermentation, the quercetin concentration in the ORG treatment and YPDQ treatment (YPD broth with 0.1 mg quercetin rhamnoside/mL) increased viability by 9%, while in the CON treatment generated there was an increase of 6% in viability, compared to the YPD control treatment (YPD broth).Originality/value: The high concentration of quercetin in the organic apple pulp supports the proposal that quercetin reduces the oxidative stress mediated by reactive oxygen species through its antioxidant action onS. boulardiithat have similarities to mammalian eukaryotic cells. These findings suggest that fermented organic apple pulp could be consumed as a potential non-dairy probiotic product.

The underexplored fruit from the juçara palm tree (Euterpe edulis Martius) has bioactive compounds with antioxidant activities, such as phenolic acids and anthocyanins. This fruit’s pulp presents itself as an appropriate fermentation medium for probiotic bacteria growth. Therefore, this study was conducted to evaluate the effects of fermentation by Limosilactobacillus reuteri LR92 (JLR) and Bifidobacterium animalis ssp. lactis BB-12 (JBB) on the bioactive compound contents of the juçara pulp, before and after a gastrointestinal simulation. The pulp of the juçara fruit showed probiotic counts of 8.70 ± 0.07 log UFC/mL for JLR and 8.44 ± 0.09 log UFC/mL for JBB, after 24 h of fermentation. Fermentation with the strains used modified the proportions of fatty acids (fatty acids esters were quantified using a gas chromatography equipment) and fibers when compared to the non-fermented pulp. The antioxidant capacity determined by DPPH, FRAP and ABTS showed significant reduction after the gastrointestinal simulation for samples. Phenolic compound analysis by UPLC-MS/MS showed, after fermentation, a greater amount of ferulic, protocatechuic and catechin acids in the samples. These results show changes in the bioactive compounds due to the fermentation of the juçara pulp by probiotics. However, these compounds showed bioactive potential and were bioaccessible after the gastrointestinal simulation, with the pulp being a potential means for bacteria growth, which may bring health benefits.

Juçara fruits (Euterpe edulis Martius), an important palm tree native to the Atlantic Forest ecosystem, exhibit a rich diversity of microorganisms, including lactic acid bacteria (LAB). LAB are highly capable of synthesizing exopolysaccharides (EPS), which are extracellular carbohydrate biopolymers with techno-functional properties, and consequently, wide applicability. In the present study, the technical-functional information of the dextran produced by L. pseudomesenteroides JF17 was obtained by determining its physicochemical, rheological, water-holding, oil-holding, and emulsifying properties. Dextran-JF17 mainly comprised carbohydrates (87.87% ± 1.45%, w/w), along with 48.86% ± 1.2% (w/w) of soluble fibers and a low protein content (2.98% ± 0.49%, w/w). The dextran exhibited high water-holding (470.89% ± 39.67%, w/v) and oil-holding (89.945% ± 4.16%, w/v) capacities, with values close to those reported for other microbial EPS. The dextran-JF17 solutions with concentrations 0.5%, 1.0%, and 2.0% (w/v) exhibited the typical pseudoplastic non-Newtonian fluid behavior. The emulsifying capacity of dextran-JF17 was higher (26.73 ± 0.31 mL of oil/g dextran) than that of guar gum (15.45 ± 1.33 mL oil/gum). In addition, dextran-JF17 presented an emulsifying activity ​​of approximately 65% (w/v) ​​within 24 h, indicating a strong emulsion stabilization capacity. Collectively, these results suggested that dextran-JF17 is a good candidate for application as a viscosity, stabilizing, and emulsifying agent in the food and pharmaceutical industries.

This study aimed to develop and evaluate fermented milk by Lactobacillus reuteri LR92 with addition of juçara pulp (FMJ) and reuterin production in situ. The fermentation process was analyzed for 24 hours and the storage of FMJ for 30 days at 4 °C. During the fermentation, there was consumption of 25% (w / v) of lactose and increase of 0.01 to 0.85% (w / v) of lactic acid. The FMJ presented 0.43 ± 0.01 mM of reuterin, inhibiting Staphylococcus aureus strains under in vitro test. For the carbohydrates, the percentages (g.100g-1) found were 7.31 ± 1.07; 9.19 ± 0.82; 1.60 ± 0.50 and 0.08 ± 0.00 for sucrose, lactose, galactose and fructose respectively. The survival of L. reuteri, present in FMJ, was 2.47 log CFU / mL after 6 hours of gastrointestinal simulation. In sensory analysis FMJ received a grade 7 for global acceptance indicating good acceptance of the product.

This work aimed to use soy germ in soymilk supplementation and to verify the impact on the development of a fermented product. During the fermentation process, the L. reuteri growth, the bioactive compounds and antioxidant activity were determined. The Central Composite Rotational Design (CCRD) was applied to evaluate the independent variables: fermentation time and temperature in the fermentation process of the soybean germ-soymilk. In addition, the texture profile of the product and the influence of fermentation on the isoflavones profile and phenolic compounds content were evaluated during 30 days under refrigeration. The fermented soy germ-soymilk (FSG) reached the maximum response for growth in 24 h at 36 ºC. The counts of L. reuteri reached values ​​of 8.44 ± 0.05 log CFU.g-1 in the FSG. FSG had a higher content of total isoflavone (15.74 mg.g-1) and phenolic compounds (303.37 mg EAG.100 g-1) compared to fermented soymilk (FS). The antioxidant activity of FSG and FS based on the scavenging of the radicals DPPH● and ABTS●+ was higher than in soymilk. FSG showed microbiological and functional stability during storage at 4ºC for 30 days. The findings suggest that the supplementation of soymilk with germ increases beneficial compounds and antioxidant properties. Keywords: Antioxidant. Aglycones. Functional Food. Isoflavones. Probiotic. Resumo Este estudo teve como objetivo incorporar gérmen de soja na suplementação de extrato de soja e verificar o impacto no desenvolvimento de um produto fermentado. Durante o processo de fermentação foi determinado o crescimento de L. reuteri, os compostos bioativos e a atividade antioxidante. Um Planejamento Central Composto Rotacional (DCCR) foi utilizado para avaliar as variáveis ​​independentes: tempo de fermentação e temperatura no processo de fermentação do extrato de soja contendo gérmen de soja (FSG). Além disso, foi avaliado o perfil de textura do produto e a influência da fermentação no perfil das isoflavonas e no conteúdo dos compostos fenólicos durante 30 dias sob refrigeração. O extrato de soja fermentado com gérmen (ESGS) obteve a resposta máxima de crescimento em 24 h a 36 ºC. com 8,44 ± 0,05 log UFC.g-1. O ESGS apresentou maior conteúdo de isoflavonas totais (15,74 mg.g-1) e compostos fenólicos (303,37 mg de EAG.100 g-1) em comparação com o extrato de soja fermentada (FS). A atividade antioxidante de FSG e FS baseada na eliminação dos radicais DPPH● e ABTS●+ foi maior no FSG e mostrou estabilidade microbiológica e funcional durante o armazenamento a 4 ºC durante 30 dias. Os resultados sugerem que o FSG resultou em maiores concentrações de compostos bioativos e atividade antioxidante. Palavras chaves: Antioxidante. Agliconas. Alimento Funcional. Isoflavonas. Probiótico.