The use of fruit extracts for production of beverages with high antioxidative activity

Free radicals and reactive oxygen species can cause many diseases of the circulatory and nervous system as well as tumors. There are many ways of preventing and treating these diseases including the consumption of products that contain significant amounts of antioxidant compounds, such as polyphenols and antioxidative vitamins. However, currently food stores offer mainly convenient food, ready-to-eat foodstuffs or highly processed products. During numerous technological treatments they have been deprived of many valuable compounds occurring in fresh products. Therefore, an important element of the food production technology is to ensure a proper composition of valuable human health-promoting compounds, mostly vitamins, minerals and polyphenols in final food product. Consumers often and willingly drink beverages. They are also a good starting base for supplementation. Drinks can be enriched with polyphenols, which may reduce the risk of lifestyle diseases, owing to their antiradical potential. The aim of this study was to use the fruit extracts for beverages enrichment in order to increase their antioxidative potential and polyphenol content. For the experiment the fruits of Cornelian cherry, lingonberry, elderberry, hawthorn and Japanese quince were used. Fruit was extracted with 80% ethanol, and then thickened by distillation under reduced pressure. Extracts were used to enrich the apple, orange and grapefruit beverages. Antioxidative activity and total polyphenols content in final beverages were determined. Also, sensory analysis was carried out. The fortification of tested beverages resulted in an increased antioxidative activity and total polyphenol content in case of all applied fruit extracts. Among the beverages composed, the best antioxidative properties were found in a beverage of red grapefruit, whereas the best organoleptically evaluated was the orange beverage. The scores of on the sensory evaluation revealed that the addition of extracts from Japanese quince fruit (in the case of apple and orange beverages) and lingonberry extract (grapefruit beverage) were preferred than the other samples

Role of bifidobacteria in the hydrolysis of chlorogenic acid

This study aimed to explore the capability of potentially probiotic bifidobacteria to hydrolyze chlorogenic acid into caffeic acid (CA), and to recognize the enzymes involved in this reaction. Bifidobacterium strains belonging to eight species occurring in the human gut were screened. The hydrolysis seemed peculiar of Bifidobacterium animalis, whereas the other species failed to release CA. Intracellular feruloyl esterase activity capable of hydrolyzing chlorogenic acid was detected only in B. animalis. In silico research among bifidobacteria esterases identified Balat_0669 as the cytosolic enzyme likely responsible of CA release in B. animalis. Comparative modeling of Balat_0669 and molecular docking studies support its role in chlorogenic acid hydrolysis. Expression, purification, and functional characterization of Balat_0669 in Escherichia coli were obtained as further validation. A possible role of B. animalis in the activation of hydroxycinnamic acids was demonstrated and new perspectives were opened in the development of new probiotics, specifically selected for the enhanced bioconversion of phytochemicals into bioactive compounds

Soluble polysaccharides reduce binding and inhibitory activity of tea polyphenols against porcine pancreatic α-amylase

The effects of three soluble polysaccharides on the inhibitory activity of tea polyphenols against porcine pancreatic α-amylase (PPA) were studied through PPA inhibition, half inhibition concentration (IC50), inhibition kinetics and fluorescence quenching. The results show that citrus pectin, wheat arabinoxylan and oat β-glucan could each increase the IC50 values and competitive inhibition constants (Kic), and decrease the fluorescence quenching constants (KFQ) of tea polyphenols interacting with PPA. The data show a competitive interaction equilibrium among polysaccharides, polyphenols and PPA. For individual polyphenols, there were negative linear correlations between both the values of 1/Kic and KFQ and that of IC50 with and without polysaccharides, indicating that the decreased inhibitory activity of polyphenols induced by the polysaccharides was caused by the reduced binding of polyphenols with PPA. Additionally, the slopes of the linear relationship between IC50 and Kic and that between KFQ and 1/Kic remained stable with and without polysaccharides, suggesting that these constants may be combined to characterize the effects of soluble polysaccharides on the PPA inhibition by polyphenols

Prebiotic effects of olive pomace powders in the gut: In vitro evaluation of the inhibition of adhesion of pathogens, prebiotic and antioxidant effects

Supplementary data related to this article can be found at https:// doi.org/10.1016/j.foodhyd.2020.106312Olive pomace is a biowaste rich in polyphenols and insoluble dietary fibre with high potential to develop new value chains towards a sustainable and circular bioeconomy. Regarding gut health, olive pomace phenolics and insoluble dietary fibre (after possible fermentation) could act as antioxidants, antimicrobial and prebiotic agents. These potential beneficial effects on the gut were analysed for two powders from olive pomace: liquid-enriched powder (LOPP) - mostly source of phenolics - and pulp-enriched powder (POPP) - main source of insoluble dietary fibre. LOPP and POPP were subjected to an in vitro simulated gastrointestinal digestion followed by in vitro faecal fermentation. The undigested fraction retained in the colon was analysed regarding its potential antioxidant, antimicrobial and prebiotic effects. LOPP and POPP did not impact the gut microbiota diversity negatively, showing a similar ratio of Firmicutes/Bacteroidetes compared to a positive control (FOS). LOPP exhibit a positive (similar to FOS) effect on the Prevotella spp./Bacteroides spp. ratio. Both powders also promoted more the production of short-chain fatty acids (mainly acetate?>?butyrate?>?propionate) than FOS. Both powders showed also significant total phenolic content and oxygen radical absorbance capacity during faecal fermentation until 48?h. Besides that, these powders showed mucin-adhesion inhibition ability against pathogens, principally POPP against Bacillus cereus (22.03?±?2.45%) and Listeria monocytogenes (20.01?±?1.93%). This study demonstrates that olive pomace powders have prebiotic effects on microbiota, including the stimulation of short-chain fatty acids production, potential antioxidant and antimicrobial activity which could improve human gut health.Tˆania I. B. Ribeiro thanks the FCT - Fundação para a Ciência e Tecnologia, Portugal and Association BLC3 – Technology and Innovation Campus, Centre Bio R&D Unit for the PhD Grant SFRH/BDE/108271/2015. This work was supported by National Funds from FCT - Fundação para a Ciência e a Tecnologia, Portugal through the project MULTI-BIOREFINERY - SAICTPAC/0040/2015 (POCI-01-0145-FEDER- 016403). We would also like to thank the scientific collaboration under the FCT project UID/Multi/50016/2019.info:eu-repo/semantics/publishedVersio

Impact of Flavonoids on Cellular and Molecular Mechanisms Underlying Age-Related Cognitive Decline and Neurodegeneration

Purpose of Review This review summarises the most recent evidence regarding the effects of dietary flavonoids on age-related cognitive decline and neurodegenerative diseases. Recent Findings Recent evidence indicates that plant-derived flavonoids may exert powerful actions on mammalian cognition and protect against the development of age-related cognitive decline and pathological neurodegeneration. The neuroprotective effects of flavonoids have been suggested to be due to interactions with the cellular and molecular architecture of brain regions responsible for memory. Summary Mechanisms for the beneficial effects of flavonoids on age-related cognitive decline and dementia are discussed, including modulating signalling pathways critical in controlling synaptic plasticity, reducing neuroinflammation, promoting vascular effects capable of stimulating new nerve cell growth in the hippocampus, bidirectional interactions with gut microbiota and attenuating the extracellular accumulation of pathological proteins. These processes are known to be important in maintaining optimal neuronal function and preventing age-related cognitive decline and neurodegeneration

Gut microbiota functions: metabolism of nutrients and other food components

The diverse microbial community that inhabits the human gut has an extensive metabolic repertoire that is distinct from, but complements the activity of mammalian enzymes in the liver and gut mucosa and includes functions essential for host digestion. As such, the gut microbiota is a key factor in shaping the biochemical profile of the diet and, therefore, its impact on host health and disease. The important role that the gut microbiota appears to play in human metabolism and health has stimulated research into the identification of specific microorganisms involved in different processes, and the elucidation of metabolic pathways, particularly those associated with metabolism of dietary components and some host-generated substances. In the first part of the review, we discuss the main gut microorganisms, particularly bacteria, and microbial pathways associated with the metabolism of dietary carbohydrates (to short chain fatty acids and gases), proteins, plant polyphenols, bile acids, and vitamins. The second part of the review focuses on the methodologies, existing and novel, that can be employed to explore gut microbial pathways of metabolism. These include mathematical models, omics techniques, isolated microbes, and enzyme assays