scholarly journals Reactive Oxygen Species and Antioxidants in Postharvest Vegetables and Fruits

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Karlia Meitha ◽  
Yonadita Pramesti ◽  
Sony Suhandono

Reducing oxidative species to non- or less-reactive matter is the principal function of an antioxidant. Plant-based food is the main external source of antioxidants that helps protect our cells from oxidative damage. During postharvest storage and distribution, fruits and vegetables often increase ROS production that is quenched by depleting their antioxidant pools to protect their cells, which may leave none for humans. ROS are molecules produced from oxygen metabolism; some of the most widely analyzed ROS in plants are singlet oxygen, superoxide, hydrogen peroxide, and hydroxyl radicals. ROS concentration and lifetime are determined by the availability and composition of the antioxidant system that includes enzymatic components such as SOD, CAT, and APX and nonenzymatic components such as vitamins, polyphenols, and carotenoid. Depending on its concentration in the cell, ROS can either be harmful or beneficial. At high concentrations, ROS can damage various kinds of biomolecules such as lipids, proteins, DNA, and RNA, whereas at low or moderate concentrations, ROS can act as second messengers in the intracellular signaling cascade that mediates various plant responses. Novel postharvest methods are sought to maintain fruit and vegetable quality, including minimizing ROS while preserving their antioxidant content.

2017 ◽  
Vol 114 (22) ◽  
pp. 5707-5712 ◽  
Author(s):  
Cristina E. Constantin ◽  
Catrin S. Müller ◽  
Michael G. Leitner ◽  
Wolfgang Bildl ◽  
Uwe Schulte ◽  
...  

Voltage-activated calcium (Cav) channels couple intracellular signaling pathways to membrane potential by providing Ca2+ ions as second messengers at sufficiently high concentrations to modulate effector proteins located in the intimate vicinity of those channels. Here we show that protein kinase Cβ (PKCβ) and brain nitric oxide synthase (NOS1), both identified by proteomic analysis as constituents of the protein nano-environment of Cav2 channels in the brain, directly coassemble with Cav2.2 channels upon heterologous coexpression. Within Cav2.2–PKCβ and Cav2.2–NOS1 complexes voltage-triggered Ca2+ influx through the Cav channels reliably initiates enzymatic activity within milliseconds. Using BKCa channels as target sensors for nitric oxide and protein phosphorylation together with high concentrations of Ca2+ buffers showed that the complex-mediated Ca2+ signaling occurs in local signaling domains at the plasma membrane. Our results establish Cav2–enzyme complexes as molecular entities for fast electrochemical coupling that reliably convert brief membrane depolarization into precisely timed intracellular signaling events in the mammalian brain.


2014 ◽  
Vol 4 (2) ◽  
pp. 64-68
Author(s):  
Aleksandra Michalska

Abstract Nowadays, thanks to greater awareness of society and development of restorative medicine, more and more attention is paid to preventive care. That is caused by the fact that there is little progress for both sexes in the frequency of healthy behavior: girls fall much worse than boys in terms of frequency of physical activity, they do not eat breakfast either; boys do not maintain a healthy diet and are reluctant to eat vegetables and fruits, they often drink high-calorie sodas and less frequently brush teeth. Though with age some improvements in oral hygiene and certain eating behaviors can be noticed. It has been determined that overweight and obesity is a serious problem, as they can contribute to developmental disorders. In this respect it should be the responsibility of teachers to provide individual physical education (according to medical qualifications), prevent various forms of discrimination and bullying among peers, provide individual counseling and health education, weight control of students. It has been defined that for modern teachers it is a difficult task as students rarely eat fruits and vegetables, do not care about hygiene and frequency of meals, have passive mode of leisure. The acquisition of health during puberty allows functioning smoothly in society. However, despite the continuous work on improving and introduction of new programs of health education classes into schools of Poland, children still suffer from health-related problems. According to epidemiological research most of children in Poland fall on obesity, overweight and accompanying disorders and allergies. Youth is also exposed to accidents and related injuries. The problem is that students do not receive assistance and necessary information.


2020 ◽  
Author(s):  
Guanjun Deng ◽  
Xinghua Peng ◽  
Zhihong Sun ◽  
Wei Zheng ◽  
Jia Yu ◽  
...  

Nature has always inspired robotic designs and concepts. It is conceivable that biomimic nanorobots will soon play a prominent role in medicine. In this paper, we developed a natural killer cell-mimic AIE nanoterminator (NK@AIEdots) by coating natural kill cell membrane on the AIE-active polymeric endoskeleton, PBPTV, a highly bright NIR-II AIE-active conjugated polymer. Owning to the AIE and soft-matter characteristics of PBPTV, as-prepared nanoterminator maintained the superior NIR-II brightness (quantum yield ~8%) and good biocompatibility. Besides, they could serve as tight junctions (TJs) modulator to trigger an intracellular signaling cascade, causing TJs disruption and actin cytoskeleton reorganization to form intercellular “green channel” to help themselves crossing Blood-Brain Barriers (BBB) silently. Furthermore, they could initiatively accumulate to glioblastoma cells in the complex brain matrix for high-contrast and through-skull tumor imaging. The tumor growth was also greatly inhibited by these nanoterminator under the NIR light illumination. As far as we known, The QY of PBPTV is the highest among the existing NIR-II luminescent conjugated polymers. Besides, the NK-cell biomimetic nanorobots will open new avenue for BBB-crossing delivery.


2018 ◽  
Vol 16 (1) ◽  
pp. 103-117
Author(s):  
Nurul Istiqomah ◽  
Nunung Sri Mulyani ◽  
Izza Mafruhah ◽  
Dewi Ismoyowati

Indonesia as an agricultural country has the potential to compete in the agricultural market in the international market, in line with the existence of the ASEAN / ASEAN Free Trade Area (AFTA) Free Market. Ngawi Regency is a fertile area and is one of the buffer zones of the agricultural sector in East Java. Horticulture commodities are one of the main sources in the agricultural sector, because they have high potential and can contribute to the economy of a region. Horticultural commodities in the form of fruits and vegetables are an important food source to meet the nutritional needs of the community. Agriculture with a focus on horticultural crops in Ngawi Regency was developed with a cluster system based on the level of progress, harvest area and by considering agro-climate to map the superior horticultural commodities. The purpose of this study was to map the conditions of horticultural agriculture and analyze problems in the cluster of horticulture plants in Ngawi Regency. The research method is a mixed method using descriptive analysis, Geographic Information System (GIS), and using the Analysis Hierarchy Process (AHP). The conclusion of this study is that the potential development of horticultural clusters in Ngawi Regency requires structuring and developing the location of base commodities in accordance with the conditions of the agro-ecosystem. The development of existing commodities at these base points will make the commodity superior and support the creation of horticultural cluster centers and the development of existing agribusiness in an area. Development of horticulture base commodities for seasonal vegetables and fruits can be adjusted to the LQ results for each sub-district in Ngawi Regency. The results of the Indepth interview processed using AHP obtained results that in fact there were three main factors in the development of clusters, namely production consisting of four derivative factors namely research and development, superior seeds, fertilizers and anti-pest drugs and then marketing with derivative factors namely product standardization, packaging , traditional markets and modern markets. Then the third factor of the institution consists of training, networking, government support and assistance. 


Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 60
Author(s):  
Vincenzo Michele Sellitto ◽  
Severino Zara ◽  
Fabio Fracchetti ◽  
Vittorio Capozzi ◽  
Tiziana Nardi

From a ‘farm to fork’ perspective, there are several phases in the production chain of fruits and vegetables in which undesired microbial contaminations can attack foodstuff. In managing these diseases, harvest is a crucial point for shifting the intervention criteria. While in preharvest, pest management consists of tailored agricultural practices, in postharvest, the contaminations are treated using specific (bio)technological approaches (physical, chemical, biological). Some issues connect the ‘pre’ and ‘post’, aligning some problems and possible solution. The colonisation of undesired microorganisms in preharvest can affect the postharvest quality, influencing crop production, yield and storage. Postharvest practices can ‘amplify’ the contamination, favouring microbial spread and provoking injures of the product, which can sustain microbial growth. In this context, microbial biocontrol is a biological strategy receiving increasing interest as sustainable innovation. Microbial-based biotools can find application both to control plant diseases and to reduce contaminations on the product, and therefore, can be considered biocontrol solutions in preharvest or in postharvest. Numerous microbial antagonists (fungi, yeasts and bacteria) can be used in the field and during storage, as reported by laboratory and industrial-scale studies. This review aims to examine the main microbial-based tools potentially representing sustainable bioprotective biotechnologies, focusing on the biotools that overtake the boundaries between pre- and postharvest applications protecting quality against microbial decay.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monika Rusin ◽  
Joanna Domagalska ◽  
Danuta Rogala ◽  
Mehdi Razzaghi ◽  
Iwona Szymala

AbstractChemical contamination of foods pose a significant risk to consumers. A source of this risk is due to the consumption of products contaminated with heavy metals such as cadmium (Cd) and lead (Pb). The aim of the study was to research the levels of Cd and Pb contamination of selected species of vegetables and fruits in the form of fresh, frozen, dried and processed products. The goal was to verify which of these food groups was more contaminated with heavy metals. The study covered 370 samples of fruits and vegetables including apples, pears, grapes, raspberries, strawberries, cranberries, as well as beetroots, celeries, carrots and tomatoes. The content of Cd and Pb was determined by atomic absorption spectrometry. Quantitative results were analyzed using statistical models: analysis of variance, outlier analysis, post-hoc multiple comparison Tukey test. The tests showed that the levels of Cd and Pb concentration in samples of fresh, processed, frozen and dried fruits and vegetables varied substantially. The highest concentrations were recorded in dried products. Several fruit and vegetable samples exceeded the maximum permissible concentrations of Cd and Pb. The contamination of these products could be a significant source of consumer exposure to heavy metals when these products are a part of the diet.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 875
Author(s):  
Gerald Thiel ◽  
Tobias Schmidt ◽  
Oliver G. Rössler

Ca2+ ions function as second messengers regulating many intracellular events, including neurotransmitter release, exocytosis, muscle contraction, metabolism and gene transcription. Cells of a multicellular organism express a variety of cell-surface receptors and channels that trigger an increase of the intracellular Ca2+ concentration upon stimulation. The elevated Ca2+ concentration is not uniformly distributed within the cytoplasm but is organized in subcellular microdomains with high and low concentrations of Ca2+ at different locations in the cell. Ca2+ ions are stored and released by intracellular organelles that change the concentration and distribution of Ca2+ ions. A major function of the rise in intracellular Ca2+ is the change of the genetic expression pattern of the cell via the activation of Ca2+-responsive transcription factors. It has been proposed that Ca2+-responsive transcription factors are differently affected by a rise in cytoplasmic versus nuclear Ca2+. Moreover, it has been suggested that the mode of entry determines whether an influx of Ca2+ leads to the stimulation of gene transcription. A rise in cytoplasmic Ca2+ induces an intracellular signaling cascade, involving the activation of the Ca2+/calmodulin-dependent protein phosphatase calcineurin and various protein kinases (protein kinase C, extracellular signal-regulated protein kinase, Ca2+/calmodulin-dependent protein kinases). In this review article, we discuss the concept of gene regulation via elevated Ca2+ concentration in the cytoplasm and the nucleus, the role of Ca2+ entry and the role of enzymes as signal transducers. We give particular emphasis to the regulation of gene transcription by calcineurin, linking protein dephosphorylation with Ca2+ signaling and gene expression.


FACE ◽  
2021 ◽  
pp. 273250162110243
Author(s):  
Mikhail Pakvasa ◽  
Andrew B. Tucker ◽  
Timothy Shen ◽  
Tong-Chuan He ◽  
Russell R. Reid

Hedgehog signaling was discovered more than 40 years ago in experiments demonstrating that it is a fundamental mediator of limb development. Since that time, it has been shown to be important in development, homeostasis, and disease. The hedgehog pathway proceeds through a pathway highly conserved throughout animals beginning with the extracellular diffusion of hedgehog ligands, proceeding through an intracellular signaling cascade, and ending with the activation of specific target genes. A vast amount of research has been done elucidating hedgehog signaling mechanisms and regulation. This research has found a complex system of genetics and signaling that helps determine how organisms develop and function. This review provides an overview of what is known about hedgehog genetics and signaling, followed by an in-depth discussion of the role of hedgehog signaling in craniofacial development and carcinogenesis.


2016 ◽  
Vol 43 (4) ◽  
pp. 324 ◽  
Author(s):  
Supriya Tiwari ◽  
Rüdiger Grote ◽  
Galina Churkina ◽  
Tim Butler

High concentrations of ozone (O3) can have significant impacts on the health and productivity of agricultural and forest ecosystems, leading to significant economic losses. In order to estimate this impact under a wide range of environmental conditions, the mechanisms of O3 impacts on physiological and biochemical processes have been intensively investigated. This includes the impact on stomatal conductance, the formation of reactive oxygen species and their effects on enzymes and membranes, as well as several induced and constitutive defence responses. This review summarises these processes, discusses their importance for O3 damage scenarios and assesses to which degree this knowledge is currently used in ecosystem models which are applied for impact analyses. We found that even in highly sophisticated models, feedbacks affecting regulation, detoxification capacity and vulnerability are generally not considered. This implies that O3 inflicted alterations in carbon and water balances cannot be sufficiently well described to cover immediate plant responses under changing environmental conditions. Therefore, we suggest conceptual models that link the depicted feedbacks to available process-based descriptions of stomatal conductance, photosynthesis and isoprenoid formation, particularly the linkage to isoprenoid models opens up new options for describing biosphere-atmosphere interactions.


Author(s):  
Kapil Telang ◽  
Rahul Jain ◽  
Ajoy Sodani ◽  
Prachi Shaw ◽  
Susmit Kosta

The current study was aimed to find out whether the COVID-19 virus is detectable upon the fruits and vegetables after coming in close contact with a patient suffering from nSARS-CoV-2. We included ten subjects, who tested positive for nSARS-CoV-2 RNA within seven days of the experiment. After explaining the experiment, a tray filled with seasonal vegetables and fruits were placed in front of them. The tray remained within their reach, for next thirty minutes. The subjects were requested to remove their face masks and remain so throughout the task. They were requested to manipulate the food articles the way they liked. Subjects were instructed to cough into their hands and then to manipulate each item at least 5 times, during the experiment. Thereafter, the trays were moved into an open and shaded area with free flow of natural air but no direct sunlight. After 1-hour, swabs were taken from surfaces of items by thoroughly rubbing over each of them. Samples were sent immediately to our RT-PCR lab. The nSARS-CoV-2 RNA was not detected, from the samples collected from the fruit/vegetable, at the end of one hour of the direct exposure to the COVID-19 patients. Our results suggest, even after direct exposure to and significant handling by the COVID-19 patients the nSARS-CoV-2 RNA remains undetected after one hour of storage in open. The fruits and vegetables, in real-life situations, are unlikely to act as a fomite and play any significant role in the spread of this disease.


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