Antimicrobial and antioxidant properties of byproduct extracts of mango fruit

Byproducts of fruit processing could have higher content of phenolic compounds that can act as antimicrobial and antioxidant agents. In this context, the main objective of this study was to obtain extracts from peel, seed, and unused flesh of Haden, Ataulfo and Tommy Atkins mango varieties, in order to measure their antioxidant and antimicrobial properties. The extraction was performed using different methods, such as methanolic-polar, methanolic-non-polar, ethanolic-polar, ethanolic-non-polar and water infusion. The total phenolic content of the ethanolic-non-polar extract from seed of mango Haden showed 875.06 mg/g, DPPH EC50: 0.04 mg/mL, cau-sing a 100 % inhibition of bacteria pathogens applying 25 mg/mL and inhibition of 89.78 % against Alternaria applying 6.25 mg/mL. The flesh always showed the lowest content and bioactivity of the tested parameters. These results demonstrate the antimicrobial and antioxidant potential uses of fruit byproducts as sources of bioactive compounds

Pomegranate (Punica granatum L.) Peel Extracts as Antimicrobial and Antioxidant Additives Used in Alfalfa Sprouts

Aqueous and ethanolic pomegranate peel extracts (PPE) were studied as a source of phenolic compounds with antimicrobial, anti-quorum sensing, and antioxidant properties. The aqueous extract showed higher total phenolic and flavonoid content (153.43 mg GAE/g and 45.74, respectively) and antioxidant capacity (DPPH radical inhibition: 86.12%, ABTS radical scavenging capacity: 958.21 mg TE/dw) compared to the ethanolic extract. The main phenolic compounds identified by UPLC-DAD were chlorogenic and gallic acids. The aqueous PPE extract showed antimicrobial activity against Listeria monocytogenes, Salmonella Typhimurium, Candida tropicalis (MICs 19–30 mg/mL), and anti-quorum sensing activity expressed as inhibition of Chromobacterium violaceum violacein production (%). The aqueous PPE extracts at 25 mg/mL applied on alfalfa sprouts reduced psychrophilic bacteria (1.12 Log CFU/100 g) and total coliforms (1.23 Log CFU/100 g) and increased the antioxidant capacity of the treated sprouts (55.13 mol TE/100 g (DPPH) and 126.56 mol TE/100 g (ABTS)) compared to untreated alfalfa. This study emphasizes PPE’s antioxidant and antimicrobial activities in alfalfa sprouts preservation

Antioxidant and Antimicrobial Capacity of Phenolic Compounds of Mango (Mangifera indica L.) Seed depending upon the Extraction Process

The extraction method is critical for the recovery of phenolic compounds. The main goal was to evaluate the effect of an extraction process from mango seed on their phenolic profile, antioxidant and antimicrobial capacities. Phenolic extraction was performed in different steps: maceration, alkaline hydrolysis, acid/alkaline hydrolysis, polar and non-polar fraction of an ethyl acetate separation.The macerated extract showed a higher variety of polyphenols from mango seed:gallic (138.36 µg/g dry weight), coumaric (65.36 µg/g), ferulic (1376.67 µg/g) , chlorogenic (57.75 µg/g) anddicaffeoylquinic (219.29 µg/g) acids, catechin (16.78 µg/g) and rutin (6678.62µg/g). In alkaline hydrolyzed extract most of these compounds were lost, ferulic acid decreased 1356.77 µg/g dw and gallic acid increased 1383.89 µg/g dw. Gallic and chlorogenic acids increased 165 and 969. 45 µg/g dw respectively in acid/alkaline hydrolyzed, 109.57 and 841.38 µg/g dw respectively in non-polar and 277.15 and 77.88 µg/g dw respectively in polar extracts related to the macerated extract. Rutin was found only in acid/hydrolyzed and non-polar extract in lesser amount (87.62 and 78.51 µg/g dw) compared to macerated extract. The content of phenolic compounds was higher for the macerated extract (phenols=484.42 mg GAE/g and flavonoids=86.59 mg QE/g) than for the other steps. Acid/alkaline hydrolysis increased the antioxidant activity (1787.67 μmol TE/g for DPPH and 3692.86 μmol TE/g for TEAC); while the alkaline hydrolysis increased the antimicrobial effectivity (MIC=2.5 mg/mL for bacteria and 0.5 mg/mL for yeast). Results indicate that the acid or alkaline hydrolysis yields a stronger antioxidant and antimicrobial extract

A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

Antimicrobial, antioxidant, and sensorial impacts of oregano and rosemary essential oils over broccoli florets

Combination of oregano and rosemary essential oils (EOs) was proposed to obtain a better antimicrobial and antioxidant effect on fresh‐cut broccoli compared to the use of individual oils. In in vitro assays, EOs combinations (oregano + rosemary) were more effective to inhibit the growth of Escherichia coli O157:H7, Salmonella Choleraesuis, Listeria monocytogenes, and Staphylococcus aureus compared to individual EOs doses. Oregano EO showed a higher antioxidant power compared to rosemary tested by DPPH and TEAC methods. Moreover, oregano + rosemary EOs (concentrations of 0.24 + 0.91 mg/ml) added within pectin coatings reduced coliform counts by 1 log unit and yeasts and molds by 1.8 log of coated broccoli; meanwhile, individual application of EOs (oregano at 0.48 and rosemary at 1.82 mg/ml) was not as effective. It was demonstrated that a mixture of EOs offered antimicrobial protection to fresh‐cut broccoli without negatively affecting its sensorial acceptability, even when no significant increment in its antioxidant capacity was observed.Practical applicationsCombination of essentials oils with different composition reduces the amount andcosts of agents needed to inhibit bacterial growth and survival. The use of essential oils as oregano (Lippia graveolens) and rosemary (Rosmarinus officinalis) combined a diverse mixture of antibacterial compounds that could be a solution to avoid bacterial resistance developed for the treatment with single compounds. Additionally, the negative sensorial impact of higher single oils doses could be reduced when combined, creating a new range of flavors and odors.Fil: Alvarez, María Victoria. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Ingeniería en Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Ortega Ramírez, Luis A.. Centro de Investigación E/alimentos y Desarrollo A.c; MéxicoFil: Silva Espinoza, Brenda A.. Centro de Investigación E/alimentos y Desarrollo A.c; MéxicoFil: González Aguilar, Gustavo Adolfo. Centro de Investigación E/alimentos y Desarrollo A.c; MéxicoFil: Ayala Zavala, Jesús Fernando. Centro de Investigación E/alimentos y Desarrollo A.c; Méxic

Antimicrobial activity and thermal stability of rosemary essential oil:β−cyclodextrin capsules applied in tomato juice

Rosemary essential oil (RO) was encapsulated within β-cyclodextrin (β-CD) to offer thermal stability and preserve its antimicrobial activity. The identified RO volatiles were 1,8 cineole (52%), 3-carene (9.6%), and camphor (9.3%). The growth of Salmonella Typhimurium, Listeria monocytogenes, Candida tropicalis, and Saccharomyces pastorianus was inhibited by 10, 10, 4.5, and 1.5 mg of free RO per mL of media, respectively. However, RO exhibited its evaporation at 43 °C, losing 50% of its weight at 100 °C and decomposing at 130 °C. RO:β-CD, at a 16:84 wt ratio, showed the highest presence of RO volatiles (7.33 g of RO/100 g of capsules) and initiated its decomposition at 75 °C, accompanied by a 10% weight loss. These particles underwent decomposition at 290 °C. Infrared analysis of RO:β-CD showed molecular interactions between RO and β-CD. The minimal inhibitory concentrations of the encapsulated RO for S. Typhimurium, L. monocytogenes, C. tropicalis, and S. pastorianus were 14.66, 14.14, 2.05, and 3.07 mg/mL, respectively. RO capsules were stable during tomato juice pasteurization and maintained their antimicrobial activity. In conclusion, the encapsulation of RO by β-CD offered protection to the volatile constituents exposed to high temperatures and maintained its antimicrobial properties after the encapsulation process and pasteurization of tomato juice

Antioxidants in Oak (<i>Quercus</i> sp.): Potential Application to Reduce Oxidative Rancidity in Foods

This review explores the antioxidant properties of oak (Quercus sp.) extracts and their potential application in preventing oxidative rancidity in food products. Oxidative rancidity negatively impacts food quality, causing changes in color, odor, and flavor and reducing the shelf life of products. The use of natural antioxidants from plant sources, such as oak extracts, has gained increasing interest due to potential health concerns associated with synthetic antioxidants. Oak extracts contain various antioxidant compounds, including phenolic acids, flavonoids, and tannins, which contribute to their antioxidative capacity. This review discusses the chemical composition of oak extracts, their antioxidative activity in different food systems, and the safety and potential challenges related to their application in food preservation. The potential benefits and limitations of using oak extracts as an alternative to synthetic antioxidants are highlighted, and future research directions to optimize their application and determine their safety for human consumption are suggested

Using Sensory Evaluation to Determine the Highest Acceptable Concentration of Mango Seed Extract as Antibacterial and Antioxidant Agent in Fresh-Cut Mango

Plant extracts have the potential to be used as food additives; however, their use have been limited by causing undesirable changes in the sensory attributes of foods. We characterized the mango seed extract as a preserving agent for fresh-cut mangoes. We established the maximum concentration of extract that, while increasing the antioxidant activity, and limiting microbial contamination of the fruit, did not negatively affect fruit sensory acceptability. The extract contained 277.4 g gallic acid equivalent (GAE)/kg dw (dry weight) of polyphenols and 143.7 g quercetin equivalent (QE)/kg dw of flavonoids. Antioxidant capacity values were 2034.1 and 4205.7 &mu;mol Trolox equivalent (TE)/g against 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, respectively. Chromatographic analysis revealed the presence of gallic and chlorogenic acids. The extract (16 g/L) inhibited the growth of Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus and Listeria monocytogenes. The highest concentration with sensory acceptability was 6.25 g/L. At such concentration, the extract preserved fresh-cut fruits, increasing polyphenols (0.427 g GAE/kg fw (fresh weight)), flavonoid content (0.234 g QE/kg fw) and antioxidant activity (DPPH = 2.814 and ABTS = 0.551 mol TE/kg fw). It also reduced inoculated bacteria (range: 5.50 &times; 103 to 1.44 &times; 105 colony forming units (CFU)/g). These results showed the importance of considering consumer acceptability to determine the effective concentration of plant extracts as additives