Amoebicidal, antimicrobial and in vitro ROS scavenging activities of Tunisian Rubus ulmifolius Schott, methanolic extract

Excitation of Reactive Oxygen Species and Damage to the Cell Membrane, Protein, and DNA are Important Inhibition Mechanisms of CO2 on Shewanella putrefaciens at 4 °C

To explore whether oxidative stress caused by 100% CO2 is an inhibitory mechanism against Shewanella putrefaciens, the oxidative stress reaction, antioxidant activity, and damage to the cell membrane, protein, and DNA of CO2-incubated S. putrefaciens at 4 °C were evaluated. Research demonstrated that CO2 caused more severe reactive oxygen species (ROS) accumulation. Simultaneously, weaker •OH/H2O2/O2•--scavenging activity and decreased T-VOC and GSH content were also observed. The activities of antioxidant enzymes (SOD, POD, CAT, and GPX) continuously declined, which might be attributed to the CO2-mediated decrease in the pH value. Correspondingly, the cell membrane was damaged with hyperpolarization, increased permeability, and more severe lipid peroxidation. The expression of total and membrane protein decreased, and the synthesis and activity of extracellular protease were inhibited. DNA was also subjected to oxidative damage and expressed at a lower level. All results collaboratively confirmed that ROS excitation and inhibition of antioxidant activity were important inhibition mechanisms of CO2 on S. putrefaciens.

Blackberries and Mulberries: Berries with Significant Health-Promoting Properties

Blackberries and mulberries are small and perishable fruits that provide significant health benefits when consumed. In reality, both are rich in phytochemicals, such as phenolics and volatile compounds, and micronutrients, such as vitamins. All the compounds are well-known thanks to their medicinal and pharmacological properties, namely antioxidant, anti-inflammatory, anti-cancer, antiviral, and cardiovascular properties. Nevertheless, variables such as genotype, production conditions, fruit ripening stage, harvesting time, post-harvest storage, and climate conditions influence their nutritional composition and economic value. Given these facts, the current review focuses on the nutritional and chemical composition, as well as the health benefits, of two blackberry species (Rubus fruticosus L., and Rubus ulmifolius Schott) and one mulberry species (Morus nigra L.).

From mango by-product to food packaging: Pectin-phenolic antioxidant films from mango peels

The objective of the study was to prepare active films based on pectin and polyphenol-rich extracts from Tommy Atkins mango peels. Aqueous and methanolic extracts showed a variety of phenolic compounds that were identified by UPLC-MS analysis, and a high content of total phenolics that were quantified by the Folin-Ciocalteau method. The methanolic extract showed better results in antioxidant tests and was more effective in inhibiting the growth of Gram-positive and Gram-negative bacteria. The pectin extracted from mango peels showed good thermal stability and a degree of methoxylation of 58.3% by ¹H NMR. The films containing the phenolic extracts showed lower water vapor permeability when compared to the control film (without any phenolic extracts). The incorporation of the extracts led to an increase in elongation (ε) and a decrease in tensile strength (σ) and modulus of elasticity (Y). The films with aqueous or methanolic extracts showed higher antioxidant activity in terms of inhibition of the DPPH radical. Therefore, the films developed in this work are presented as a promising alternative for food packaging and/or coating applications.

Traditional Applications of Tannin Rich Extracts Supported by Scientific Data: Chemical Composition, Bioavailability and Bioaccessibility

Tannins are polyphenolic compounds historically utilized in textile and adhesive industries, but also in traditional human and animal medicines or foodstuffs. Since 20th-century, advances in analytical chemistry have allowed disclosure of the chemical nature of these molecules. The chemical profile of extracts obtained from previously selected species was investigated to try to establish a bridge between traditional background and scientific data. The study of the chemical composition of these extracts has permitted us to correlate the presence of tannins and other related molecules with the effectiveness of their apparent uses. The revision of traditional knowledge paired with scientific evidence may provide a supporting background on their use and the basis for developing innovative pharmacology and food applications based on formulations using natural sources of tannins. This traditional-scientific approach can result useful due to the raising consumers' demand for natural products in markets, to which tannin-rich extracts may pose an attractive alternative. Therefore, it is of interest to back traditional applications with accurate data while meeting consumer's acceptance. In this review, several species known to contain high amounts of tannins have been selected as a starting point to establish a correlation between their alleged traditional use, tannins content and composition and potential bioaccessibility.

By-Products of Agri-Food Industry as Tannin-Rich Sources: A Review of Tannins' Biological Activities and Their Potential for Valorization

During recent decades, consumers have been continuously moving towards the substitution of synthetic ingredients of the food industry by natural products, obtained from vegetal, animal or microbial sources. Additionally, a circular economy has been proposed as the most efficient production system since it allows for reducing and reutilizing different wastes. Current agriculture is responsible for producing high quantities of organic agricultural waste (e.g., discarded fruits and vegetables, peels, leaves, seeds or forestall residues), that usually ends up underutilized and accumulated, causing environmental problems. Interestingly, these agri-food by-products are potential sources of valuable bioactive molecules such as tannins. Tannins are phenolic compounds, secondary metabolites of plants widespread in terrestrial and aquatic natural environments. As they can be found in plenty of plants and herbs, they have been traditionally used for medicinal and other purposes, such as the leather industry. This fact is explained by the fact that they exert plenty of different biological activities and, thus, they entail a great potential to be used in the food, nutraceutical and pharmaceutical industry. Consequently, this review article is directed towards the description of the biological activities exerted by tannins as they could be further extracted from by-products of the agri-food industry to produce high-added-value products.

Rubus ulmifolius Schott fruits: A detailed study of its nutritional, chemical and bioactive properties

There is a growing interest in wild edible species that represent a source of several health-promoting compounds, providing a potential strategy to diversify and enrich the daily diet. The aim of the present work was to characterize the nutritional and chemical composition of Rubus ulmifolius Schott fruits. Furthermore, their antimicrobial activity, non-anthocyanin and anthocyanin phenolic profile were also determined. According to the obtained results, R. ulmifolius fruits exhibited a high concentration in carbohydrates and a low fat content, in comparison with the other nutrients and non-nutrients detected in this sample. The colour parameters demonstrated differences in a* and b* parameters after lyophilisation process. Glucose and fructose were the most abundant free sugars detected and quinic acid showed the highest content compared to the other five organic acids identified. The fatty acids profile revealed 25 compounds, being mostly represented by polyunsaturated fatty acids and evidencing linolenic and α-linolenic acid as the most abundant. All tocopherol isoforms were detected, revealing γ-tocopherol with highest amount. Cyanidin-3-O-glucoside, ellagic acid pentoside, ellagic acid glucuronide and sanguiin H-10 were the main phenolic compounds present, which could be related to the antimicrobial activity (MIC values ranging between 5 and 20 mg/mL) revealed by R. ulmifolius fruits. These results showed that this fruit is a good source of nutrients as also non-nutrient compounds, with human health benefits.

Blackberry (Rubus ulmifolius Schott): Chemical composition, phenolic compounds and antioxidant capacity in two edible stages

The berries of the genus Rubus has been highlighted as important source of bioactive and health promoting constituents, however, information about chemical composition and antioxidant potential of the specie Rubus ulmifolius are still scarce. In this regard, this study aimed to assess the physicochemical characteristics, total monomeric anthocyanins (TMA), individual phenolics, minerals, sugars, and antioxidant properties of mature and fully mature R. ulmifolius. With the advance of maturation, changes in the physicochemical composition suggest pleasant characteristics for consumption especially in the fully mature stage. High levels of TMA and sugars (fructose and glucose) were also verified in the fully mature stage, as well as, expressive antioxidant potential, with values of 241.06 μM Fe⁺² g^-1 for ferric reducing antioxidant power and 28.22 mg gallic acid equivalent g^-1 for Folin-Ciocalteu reducing capacity (all expressed in dry matter, DM). In contrast, minerals (potassium, calcium, sodium) and most of the studied phenolic compounds showed the highest concentrations in mature fruits. Among the phenolics investigated, 26 compounds were identified and quercetin and isoquercitrin were the predominant phenolic compounds in the fruit. The results reinforce the nutritive and antioxidant potential of Rubus ulmifolius in both maturation stages studied.

Phenolic Compounds Determined by LC-MS/MS and In Vitro Antioxidant Capacity of Brazilian Fruits in Two Edible Ripening Stages

The aim of this study was to investigate the free individual phenolics and the in vitro antioxidant capacity of blackberry, acerola, yellow guava, guabiju, jambolan and jabuticaba fruits in two edible stages. Of the thirty-three phenolics investigated by liquid chromatography - tandem mass spectrometry (LC-MS/MS), twenty-five were quantified and the major ones were catechin, isoquercitrin, epicatechin and gallic acid. The highest values for the total phenolic content (in dry matter) were observed for acerola (83.6 to 97.7 mg gallic acid equivalents g^-1 DM) and blackberry (18.9 to 28.3 mg gallic acid equivalents g^-1 DM); however, acerola, jabuticaba, and blackberry showed the highest antioxidant capacities (134.6 to 1120.4 mg Trolox equivalents g^-1 for 2,2-diphenyl-1-picrylhydrazyl and 43.6 to 501.8 μmol Trolox equivalents g^-1 for ferric reducing antioxidant power). For most fruits, the antioxidant capacity decreased during the ripening, possibly due to a decrease in the concentration of most of the phenolics.