scholarly journals Ripe and Raw Pu-Erh Tea: LC-MS Profiling, Antioxidant Capacity and Enzyme Inhibition Activities of Aqueous and Hydro-Alcoholic Extracts

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 473 ◽  
Author(s):  
Gabriella Roda ◽  
Cristina Marinello ◽  
Anita Grassi ◽  
Claudia Picozzi ◽  
Giancarlo Aldini ◽  
...  

Herein, we reported a detailed profiling of soluble components of two fermented varieties of Chinese green tea, namely raw and ripe pu-erh. The identification and quantification of the main components was carried out by means of mass spectrometry and UV spectroscopy, after chromatographic separation. The antioxidant capacity towards different radical species, the anti-microbial and the enzyme inhibition activities of the extracts were then correlated to their main constituents. Despite a superimposable qualitative composition, a similar caffeine content, and similar enzyme inhibition and antimicrobial activities, raw pu-erh tea extract had a better antioxidant capacity owing to its higher polyphenol content. However, the activity of raw pu-erh tea seems not to justify its higher production costs and ripe variety appears to be a valid and low-cost alternative for the preparation of products with antioxidant or antimicrobial properties.

Antioxidants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 184 ◽  
Author(s):  
Lorena Martínez ◽  
Pedro Bastida ◽  
Julian Castillo ◽  
Gaspar Ros ◽  
Gema Nieto

Natural extracts obtained from fruit and vegetable processing are important sources of phenolic compounds and nitrates, with excellent antioxidant and antimicrobial properties. The aim of this study was to characterize and determine the antioxidant and antimicrobial capacity of several natural extracts (citric (Ct), acerola (Ac), rosemary (R), paprika, garlic, oregano, beet (B), lettuce (L), arugula (A), spinach (S), chard (Ch), celery (Ce), and watercress (W)), both in vitro and applied to a cured meat product (chorizo). For that, the volatile compounds by GC-MS and microbial growth were determined. The total phenolic and nitrate contents were measured and related with their antioxidant capacity (measured by DPPH, ABTS, FRAP, and ORAC methods) and antimicrobial capacity against Clostridium perfringens growth in vitro. In order to study the antioxidant and antimicrobial activities of the extracts in food, their properties were also measured in Spanish chorizo enriched with these natural extracts. R and Ct showed the highest antioxidant capacity, however, natural nitrate sources (B, L, A, S, Ch, Ce, and W) also presented excellent antimicrobial activity against C. perfringens. The incorporation of these extracts as preservatives in Spanish chorizo also presented excellent antioxidant and antimicrobial capacities and could be an excellent strategy in order to produce clean label dry-cured meat products.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Anderson Baptista ◽  
Reggiani Vilela Gonçalves ◽  
Josefina Bressan ◽  
Maria do Carmo Gouveia Pelúzio

The accentuated increase in the use of medicinal plants by the population to treat diseases makes it necessary to carry out pharmacological studies in order to contribute to the scientific knowledge and clarify the mechanisms involved in the main compounds present in these plants. Due to the difficulty of combating antimicrobial-resistant microorganisms, plants become a low-cost and effective alternative. The stem, fruit, and leaves of plants are used to measure antioxidant and antimicrobial capacity and to combat the oxidative degradation of free radicals produced in the presence of xenobiotics. A systematic review is a powerful tool that incorporates the variability among the studies, providing an overall estimate of the use of plant extracts as antioxidants and antimicrobial activities. In view of the controversies in the literature regarding the use of compounds from plants or the isolation and purification of the main substances for the prevention of bacterial various therapeutic actions, the aim of this was to present a systematic review on the antimicrobial and antioxidant properties of cashew (Anacardium occidentale), cajui (Anacardium microcarpum), and pequi (Caryocar brasiliense). The following databases were analyzed: PubMed/Medline, Virtual Health Library (LILACS and SciELO), and Science Direct. Out of 425 articles, 33 articles have been used in this study, which were also represented in the Prisma Statement. In vitro antioxidant tests were conducted in 28 studies using different methodologies. Most of the tests involving the studied species demonstrated positive antioxidant potential and antimicrobial properties. The results provide important data and perspectives into the use of natural products that can contribute to the treatment of various diseases.


2020 ◽  
Vol 16 (7) ◽  
pp. 998-1004
Author(s):  
Aziz H. Rad ◽  
Raana B. Fathipour ◽  
Fariba K. Bidgoli ◽  
Aslan Azizi

Background and Objectives: Tea is considered one of the most consumed drinks around the world and the health benefits of it have recently attracted the attention of different researchers. It has also been proven beneficial in preventing the danger of some diseases like cancer and cardiovascular problems. Further, lipid oxidation is one of the major problems in food products. Considering the above-mentioned issues, the present review focused on various techniques used to extract polyphenols from different kinds of tea, as well as their use in the food industry. Results and Conclusion: Based on our findings in this review, the main components of tea are polyphenols that have health benefits and include catechins, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, gallic acid, flavonoids, flavonols, and theophlavins. From these components, catechin is regarded as the most beneficial component. Many techniques have been discovered and reformed to extract tea compounds such as solvent-based extraction, microwave-assisted water extraction, and ultrasound-assisted extraction techniques. Overall, the microwave-assisted water extraction method is a useful method for extracting tea polyphenols, which may be used in the meat, oil, and dairy industries.


2010 ◽  
Vol 5 (2) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Maria Graça Miguel ◽  
Cláudia Cruz ◽  
Leonor Faleiro ◽  
Mariana T. F. Simões ◽  
Ana Cristina Figueiredo ◽  
...  

The essential oils from Foeniculum vulgare commercial aerial parts and fruits were isolated by hydrodistillation, with different distillation times (30 min, 1 h, 2 h and 3 h), and analyzed by GC and GC-MS. The antioxidant ability was estimated using four distinct methods. Antibacterial activity was determined by the agar diffusion method. Remarkable differences, and worrying from the quality and safety point of view, were detected in the essential oils. trans-Anethole (31-36%), α-pinene (14-20%) and limonene (11-13%) were the main components of the essentials oil isolated from F. vulgare dried aerial parts, whereas methyl chavicol (= estragole) (79-88%) was dominant in the fruit oils. With the DPPH method the plant oils showed better antioxidant activity than the fruits oils. With the TBARS method and at higher concentrations, fennel essential oils showed a pro-oxidant activity. None of the oils showed a hydroxyl radical scavenging capacity >50%, but they showed an ability to inhibit 5-lipoxygenase. The essential oils showed a very low antimicrobial activity. In general, the essential oils isolated during 2 h were as effective, from the biological activity point of view, as those isolated during 3 h.


Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 137
Author(s):  
Xinzhen Fan ◽  
L’Hocine Yahia ◽  
Edward Sacher

Microbes, including bacteria and fungi, easily form stable biofilms on many surfaces. Such biofilms have high resistance to antibiotics, and cause nosocomial and postoperative infections. The antimicrobial and antiviral behaviors of Ag and Cu nanoparticles (NPs) are well known, and possible mechanisms for their actions, such as released ions, reactive oxygen species (ROS), contact killing, the immunostimulatory effect, and others have been proposed. Ag and Cu NPs, and their derivative NPs, have different antimicrobial capacities and cytotoxicities. Factors, such as size, shape and surface treatment, influence their antimicrobial activities. The biomedical application of antimicrobial Ag and Cu NPs involves coating onto substrates, including textiles, polymers, ceramics, and metals. Because Ag and Cu are immiscible, synthetic AgCu nanoalloys have different microstructures, which impact their antimicrobial effects. When mixed, the combination of Ag and Cu NPs act synergistically, offering substantially enhanced antimicrobial behavior. However, when alloyed in Ag–Cu NPs, the antimicrobial behavior is even more enhanced. The reason for this enhancement is unclear. Here, we discuss these results and the possible behavior mechanisms that underlie them.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Crosino ◽  
Elisa Moscato ◽  
Marco Blangetti ◽  
Gennaro Carotenuto ◽  
Federica Spina ◽  
...  

AbstractShort chain chitooligosaccharides (COs) are chitin derivative molecules involved in plant-fungus signaling during arbuscular mycorrhizal (AM) interactions. In host plants, COs activate a symbiotic signalling pathway that regulates AM-related gene expression. Furthermore, exogenous CO application was shown to promote AM establishment, with a major interest for agricultural applications of AM fungi as biofertilizers. Currently, the main source of commercial COs is from the shrimp processing industry, but purification costs and environmental concerns limit the convenience of this approach. In an attempt to find a low cost and low impact alternative, this work aimed to isolate, characterize and test the bioactivity of COs from selected strains of phylogenetically distant filamentous fungi: Pleurotus ostreatus, Cunninghamella bertholletiae and Trichoderma viride. Our optimized protocol successfully isolated short chain COs from lyophilized fungal biomass. Fungal COs were more acetylated and displayed a higher biological activity compared to shrimp-derived COs, a feature that—alongside low production costs—opens promising perspectives for the large scale use of COs in agriculture.


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1567
Author(s):  
Ippolito Camele ◽  
Daniela Gruľová ◽  
Hazem S. Elshafie

Several economically important crops, fruits and vegetables are susceptible to infection by pathogenic fungi and/or bacteria postharvest or in field. Recently, plant essential oils (EOs) extracted from different medicinal and officinal plants have had promising antimicrobial effects against phytopathogens. In the present study, the potential microbicide activity of Mentha × piperita cv. ‘Kristinka’ (peppermint) EO and its main constituents have been evaluated against some common phytopathogens. In addition, the cell membrane permeability of the tested fungi and the minimum fungicidal concentrations were measured. The antifungal activity was tested against the following postharvest fungi: Botrytis cinerea, Monilinia fructicola, Penicillium expansum and Aspergillus niger, whereas antibacterial activity was evaluated against Clavibacter michiganensis, Xanthomonas campestris, Pseudomonas savastanoi and P. syringae pv. phaseolicola. The chemical analysis has been carried out using GC-MS and the main components were identified as menthol (70.08%) and menthone (14.49%) followed by limonene (4.32%), menthyl acetate (3.76%) and β-caryophyllene (2.96%). The results show that the tested EO has promising antifungal activity against all tested fungi, whereas they demonstrated only a moderate antibacterial effect against some of the tested bacteria.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2436
Author(s):  
Abubakar Sadiq Mohammed ◽  
Martina Meincken

Low-cost wood–plastic composites (WPCs) were developed from invasive trees and recycled low-density polyethylene. The aim was to produce affordable building materials for low-cost social housing in South Africa. Both raw materials are regarded as waste materials, and the subsequent product development adds value to the resources, while simultaneously reducing the waste stream. The production costs were minimised by utilising the entire biomass of Acacia saligna salvaged from clearing operations without any prior processing, and low-grade recycled low-density polyethylene to make WPCs without any additives. Different biomass/plastic ratios, particle sizes, and press settings were evaluated to determine the optimum processing parameters to obtain WPCs with adequate properties. The water absorption, dimensional stability, modulus of rupture, modulus of elasticity, tensile strength, and tensile moduli were improved at longer press times and higher temperatures for all blending ratios. This has been attributed to the crystallisation of the lignocellulose and thermally induced cross-linking in the polyethylene. An increased biomass ratio and particle size were positively correlated with water absorption and thickness swelling and inversely related with MOR, tensile strength, and density due to an incomplete encapsulation of the biomass by the plastic matrix. This study demonstrates the feasibility of utilising low-grade recycled polyethylene and the whole-tree biomass of A. saligna, without the need for pre-processing and the addition of expensive modifiers, to produce WPCs with properties that satisfy the minimum requirements for interior cladding or ceiling material.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Balungile Madikizela ◽  
Ashwell Rungano Ndhlala ◽  
Jeffrey Franklin Finnie ◽  
Johannes Van Staden

Respiratory ailments are major human killers, especially in developing countries. Tuberculosis (TB) is an infectious disease causing a threat to human healthcare. Many South African plants are used in the traditional treatment of TB and related symptoms, but there has not been a sufficient focus on evaluating their antimicrobial properties. The aim of this study was to evaluate the antimicrobial properties of plants used traditionally to treat TB and related symptoms against microorganisms (Klebsiella pneumoniae, Staphylococcus aureus,andMycobacterium aurumA+) associated with respiratory infections using the microdilution assay. Ten plants were selected based on a survey of available literature of medicinal plants used in South Africa for the treatment of TB and related symptoms. The petroleum ether, dichloromethane, 80% ethanol, and water extracts of the selected plants were evaluated for antibacterial activity. Out of 68 extracts tested from different parts of the 10 plant species, 17 showed good antimicrobial activities against at least one or more of the microbial strains tested, with minimum inhibitory concentration ranging from 0.195 to 12.5 mg/mL. The good antimicrobial properties ofAbrus precatorius, Terminalia phanerophlebia, Indigofera arrecta,andPentanisia prunelloidesauthenticate their traditional use in the treatment of respiratory diseases. Thus, further pharmacological and phytochemical analysis is required.


Proceedings ◽  
2020 ◽  
Vol 66 (1) ◽  
pp. 9
Author(s):  
Yoram Gerchman

Plants have been explored and used as sources for antimicrobial extract and compounds for many years, but galls—specialized structures forms on such by diversity of organisms—have been explored much less. Aphid galls host many insects in closed, humid and sugar rich environments for long periods. We have tested the antimicrobial properties of Slavum wertheimae aphid galls on Pistacia atlantica. Secondary metabolites were extracted from leaves and galls with organic solvents, and essential oils with Clevenger, and tested by disk diffusion assay and volatile effect on bacteria and fungi, respectively. The results demonstrated that gall extracts/essential oils had much stronger activity against the diversity of bacteria and fungi. The large diversity of galls suggest they could be explored as source for novel compounds.


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