Post-harvest UV-B treatment of White Sultanina grapevine berries

The grapevine berries are an important source of phenolic compounds. In this study, White Sultanina berries were treated with UV radiation and followed quantitative change of these secondary metabolites. In the skin of cv. White Sultanina table grapes, a phenolic acid and several mono-glycosilated flavonols were identified by HPLC-DAD. The aim of this work was to alter this profile, to improve antioxidant properties. Resveratrol contents of berry skins have already been successfully increased using UV-C or UV-B radiation (Cantos et al. 2000) in another variety (cv. Napoleon). In this study, we report a UV-B-inducible increase in flavonoid-glycosides observed 2 h after 30 min exposure to 11.5 W/m2 radiation flux (physical dose) from a narrow band source (VL-215M centred at 312 nm, Vilbert Lourmat, France). This was accompanied by higher antioxidant capacities of berry skin extracts, in accordance with the observed strong antioxidant capacities of quercetin-glycosides in vitro (Csepregi et al. 2016, Csepregi and Hideg 2018). Differences between UV-B-treated berries and untreated controls were less pronounced when assayed after a longer storage period following irradiation at 20 ℃ under low fluxes (60 µmol m-2s-1) of photosynthetically active radiation. Berry skin photosynthesis, measured as photochemical yield using imaging PAM (Heinz Walz GmbH, Effeltrich, Germany) temporary increased after the UV-B treatment, then declined, suggesting a possible metabolic source of increased flavonol biosynthesis. These experiments suggest that UV-B irradiation of table grapes can be beneficial in terms of increasing the content of potentially health-promoting flavonol derivatives

Efficacy of Coronavirus Disease (COVID-19) Safety Protocol at the 2021 Wrestling European Olympic Games Qualifier Organized in Budapest = A koronavírus-járvány (COVID-19) biztonsági protokolljának hatékonysága a 2021-es olimpiai játékok európai kvalifikációs birkózóversenyén, Budapesten

Bevezetés és cél: A COVID-19 világjárvány számos nehézséget okoz a többnapos nemzetközi sportesemények szervezésében. Ennek oka - részben - a sportolók közötti szoros fizikai kapcsolat, amely köztudottan elősegíti a vírus terjedését, még az egyéni sportágakban, például a birkózásban is. Ezért a birkózóselejtezőn rendkívül fontos volt a betegség szűrésének bevezetése, és a fertőzött résztvevők kizárása (majd elkülönítése). Az orvosi csapat és a COVID-marsallok együtt dolgoztak egy szűrési protokoll kidolgozásán, és céljuk volt, hogy a verseny során teszteljék annak hatékonyságát. Anyag és módszerek: A versenyen 37 ország 281 versenyzője vett részt. A Magyarországra való belépés kritériuma a polimeráz láncreakció (PCR) negatív tesztje, járványügyi és tüneti negativitás volt 72 órán belül. Antigén gyorsteszteket (ART) és szükség esetén újratesztelést is végeztünk. Kiutazáskor negatív PCR-teszt, vagy a karanténidőszak lejárta után kiállított igazolás volt szükséges. Eredmények: Összesen 1287 PCR-tesztet és 1250 gyorstesztet végeztünk. Érkezéskor 21 PCR-pozitív (1,4%) személy volt, akiket karanténba helyeztek. Az induláskor 6 PCR-teszt volt pozitív (0,47%). Az akkreditációkor elvégzett ART tesztek közül egy volt pozitív. Következtetés: Az egészségügyi személyzet sikeres protokollt dolgozott ki a COVID-19 szűrésére és a résztvevők izolálására, amit az induláskor tapasztalt nagyon alacsony pozitivitás is jelez. Így ez a protokoll alkalmazható többnapos nemzetközi sportesemények szervezésénél. Introduction and Aim: The pandemic Covid-19 imposes several difficulties to organize multi-day international sports events. This is - in part - due to the close physical contact among the athletes, known to promote the spread of virus, even in individual sports, such as wrestling. Thus, at the Wrestling Qualifier it was of utmost importance to introduce screening for the disease and exclude infected participants (and then isolate them). The medical team and the COVID Marshals worked together on developing a screening protocol and aimed to test the efficacy during this competition. Material and Methods: The event was attended by 281 competitors from 37 countries. The criteria to enter Hungary were a negative polymerase chain reaction (PCR) test, epidemiological and symptomatic negativity within 72 hours. We also performed Antigen rapid tests (ART, chromatographic immunoassay) and retesting if necessary. Upon departure a negative PCR test or a certificate issued after the end of the quarantine period was required. Results: In total, 1,287 PCR tests and 1,250 rapid tests were performed. At arrival, there were 21 PCR positive (1.4%) individuals, and they were quarantined. At the departure 6 PCR tests were positive (0.47%). One of the ARTs performed at the accreditation was positive. Conclusion: The medical staff has developed a successful protocol to screen for Covid-19 and isolate participants as indicated by the very low positivity for Covid-19 at departure. Thus such protocol can be used for organizing multi-day international sports events

Fotoreaktív nanorészecskék hatása vörösborszőlő-fajták levelének polifenol összetételére és tápelemtartalmára

A különleges tulajdonságokkal rendelkező nanoszerkezetű anyagok hasznosítása az iparban, a mezőgazdaságban és gyógyászatban egyaránt folyamatosan növekszik. A fotoreaktív titán-dioxid (TiO2) nanorészecskék sajátsága, hogy UV-fény hatására reaktív oxigén származékokat (ROS generálnak, melyek jelentős antimikrobiális hatással bírnak, így a növényre kijuttatva potenciális növényvédőszerként funkcionálhatnak. A növényekben keletkező ROS a növények élettani folyamatainak szabályozásában is részt vesznek, ezért a mesterségesen, TiO2 nanorészecskék segítségével keltett ROS a célzott antimikrobiális aktivitás mellett a levelek metabolizmusára is hatással lehet. Ez a hatás lehet negatív, mivel a ROS nagy mennyiségben sejtkárosító, de lehet pozitív is, a természetes úton keletkező ROS hatásához hasonlóan a stresszvédő utakat aktiváló. Habár a TiO2, mint alternatív növényvédőszer a gyakorlatban nagy érdeklődésre tarthat számot, ftotoxicitásáról még csak nagyon kevés információ áll rendelkezésünkre. Ebben a munkában azt tanulmányoztuk, hogy a levelek felszínére juttatott és ott napsugárzásnak kitett TiO 2 nanorészecskék miként befolyásolják a szőlőlevelek teljes fenolos tartalmát(antioxidáns kapacitását) és polifenol proflját. Ezek a paraméterek érzékenyen jelzik a növény oxidatív stresszre adott válaszreakcióit.Nyomon követtük továbbá a levelek makro- és mikroelem összetételének változását is. Szabadföldi kísérletben öt vörösborszőlő-fajtát (Cabernet sauvignon, Cabernet franc, Merlot, Kékfrankos és Kadarka) vizsgáltunk. Nagyhatékonyságú folyadékkromatográfás mérésekkel kimutattuk, hogy szőlőfajtától függően a levelek kaftársav és flavonol-glikozid tartalma a kezelést követően szignifkánsan emelkedett. A levelek teljes fenolos tartalmának növekedése szintén szignifkáns volt. Mindemellett ICP-AES méréseink azt mutatták, hogy TiO2 nanorészecskék a levelek főbb makro- és mikroelemeinek (Ca, Mg, K, B és Mn) koncentrációját ugyancsak növelték

Postharvest UV-A and UV-B treatments may cause a transient decrease in grape berry skin flavonol-glycoside contents and total antioxidant capacities

Controlled postharvest abiotic stresses have already been shown to affect the secondary metabolism of freshproduce.Weappliedbroadbandultraviolet(either312nmcentredUV-Bor355nmcentredUV-A)radiationonharvested berry clusters of the red table grapeEmperor, and measured berry skin antioxidant capacities andphenolicprofiles2,24and48hafterthesetreatments.Therewasnosignificantchangeintheamountofcaftaricacid,thedominantphenolicacidcomponentfeaturinghigherUV-BthanUV-Aabsorbingcapacity.Ontheotherhand, but both types of UV treatment decreased the amounts of the two major quercetin-glycosides 2h afterirradiation. This effect was temporal, and concentration recovered during berry storage at 20°C under lowintensitylight.BerryskinUV-AandUV-Babsorbingcapacitiesshowedthesame,transitionaldecreaseregardlessof the wavelength of the irradiation. In the whole data set, antioxidant capacities and quercetin-glycosidecontent data showed strong and positive correlations. Berry skin peroxidase activity, as visualized with diami-nobenzidine-staining showed a transitional increase after 2h in response to both UV treatments. These datasuggestthattheobservedUV-inducedpostharvestchangesinphenolicmetabolitesarerelatedtotheoxidationofflavonols as peroxidase substrates rather than to direct UV photo-effects

How do grapevine leaf phenolic contents respond to daily changes in environmental factors?

Grapevine leaves are rich in phenolic compounds, many of which are – among fulfilling other roles – efficient antioxidants (Csepregi et al. 2016, Csepregi and Hideg 2017). The long-term aim of a recently launched project is to explore the functional plasticity of phenolic compounds in grapevine leaves. Here we present results of a pilot study, registering and analysing hour-by-hour changes in photosynthesis, phenolic profiles and antioxidant capacities of South-facing Pinot noir leaves between 7 am and 7 pm during a clear summer day mid-July at Pécs (N46.071, E18.156). During this 12h period, photosynthetically active radiation (PAR) was 80-2130 µmol/m2/s and UV radiation (UV-A+B) varied between 5-46.1 kJ/m2 as physical dose measured on site. Local data were separated into UV-B (280-315 nm) and UV-A (315-400 nm) regions based on a model calculation (NCAR). Total adaxial flavonoid content (measured as Dualex flavonoid index) varied between 88% and 112% of the daily average and showed strong positive correlations with PAR, UV-A, UV-B, leaf temperature and net CO2 assimilation. Stomatal conductance (gs) was positively correlated with PAR, UV-A and UV-B. However, substomatal CO2 concentrations (Ci) were only correlated with PAR (positively) and not with UV. Hourly changes in leaf antioxidant capacities and phenolic profiles measured with HPLC-DAD complete the analysis

Amended synthesis of vitamin B6 causes altered antioxidant responses to supplemental UV-B in Arabidopsis thaliana

We previously showed that UV-B can increase metabolic hydrogen peroxide (H2O2)concentrations in leaves and that it is able to convert H2O2 to hydroxyl radicals (•OH) (Czégény et al. 2014). Thus, efficient scavenging of H2O2 and •OH are expected to be important aspects in a successful acclimation to UV-B. Vitamin B6 has an essential role both in plant development and stress tolerance (Raschke et al. 2011). In addition to their coenzyme function in several biosynthetic pathways (Drewke and Leistner 2001), B6 derivates are potent quenchers of ROS(Havaux et al. 2009, Matxain et al. 2009). In this study, we used Arabidopsis thaliana mutants (rsr4-1) reduced in B6 biosynthesis (Wagner et al. 2006) to investigate how vitamin B6 derivates of contribute to the plants’ acclimation to supplemental UV-B in growth chambers. In response to UV-B both mutant and wild type (C24) leaves altered their antioxidant profiles – including increases in B6 derivates. Wild type plants avoided oxidative stress via increasing peroxidase acitivities. Mutants, however, showed elevated catalase and markedly decreased SOD activities, although these were not sufficient to maintain leaf photochemistry. Responses are also discussed in terms of changes in leaf B6 profiles and ROS reactivities of these compounds

Changes in grapevine leaf phenolic profiles during the day are temperature rather than irradiance driven

Photosynthesis parameters, adaxial flavonoid index, phenolic profiles and antioxidant capacities of south-facing sun exposed grapevine leaves (Vitis vinifera, Pinot Noir cultivar) were measured hourly between 7 a.m. and 7 p.m. on a clear summer day. Changes in these parameters were statistically compared to changes in environmental conditions, including solar irradiance (photosynthetically active and UV radiations), leaf and air temperature, and relative air humidity. Epidermal UV absorbance, characterised by the flavonoid index, and total extractable phenolic contents were correlated to distinct environmental parameters. The former was positively correlated to irradiance and leaf temperature, while the latter was positively correlated to air temperature. HPLC phenolic profiling identified a positive correlation between air temperature and amounts of the dominant flavonol component, quercetin-3-O-glucuronide. The only phenolic component statistically connected to the flavonoid index was quercetin-3-O-glucoside. This correlation was positive and both parameters decreased during the day, although changes in the amount of this flavonol component showed no correlation to environmental factors. Total antioxidant capacities of leaf extracts were positively correlated to solar UV, and leaf and air temperature, but not to photosynthetically active radiation. Positive correlations of quercetin-3-O-glucoside contents with the flavonoid index, with photosynthesis and with sub-stomatal CO2 concentration suggest a special protective role of this flavonol. A short-term negative effect of solar UV-A and UV-B on photosynthetic CO2 uptake was also identified, which was unrelated to changes in stomatal conductance. A hypothesis is presented assuming UV- and photorespiration-derived hydrogen peroxide as the driver of daily changes in leaf antioxidant capacities

Multiple roles for Vitamin B6 in plant acclimation to UV-B

Abstract Direct and indirect roles of vitamin B6 in leaf acclimation to supplementary UV-B radiation are shown in vitamin B6 deficient Arabidopsis thaliana mutant rsr4-1 and C24 wild type. Responses to 4 days of 3.9 kJ m−2 d−1 biologically effective UV-B dose were compared in terms of leaf photochemistry, vitamer content, and antioxidant enzyme activities; complemented with a comprehensive study of vitamer ROS scavenging capacities. Under UV-B, rsr4-1 leaves lost more (34%) photochemical yield than C24 plants (24%). In the absence of UV-B, rsr4-1 leaves contained markedly less pyridoxal-5′-phosphate (PLP) than C24 ones, but levels increased up to the C24 contents in response to UV-B. Activities of class-III ascorbate and glutathione peroxidases increased in C24 leaves upon the UV-B treatment but not in the rsr4-1 mutant. SOD activities remained the same in C24 but decreased by more than 50% in rsr4-1 under UV-B. Although PLP was shown to be an excellent antioxidant in vitro, our results suggest that the UV-B protective role of B6 vitamers is realized indirectly, via supporting peroxidase defence rather than by direct ROS scavenging. We hypothesize that the two defence pathways are linked through the PLP-dependent biosynthesis of cystein and heme, affecting peroxidases

Correlations between Total Antioxidant Capacity, Polyphenol and Fatty Acid Content of Native Grape Seed and Pomace of Four Different Grape Varieties in Hungary

Grape pomace is a valuable source of various bioactive compounds such as plant-derived polyphenols and polyunsaturated fatty acids (PUFAs). The commercial demand of grape skin and seed powders as nutraceuticals is still growing. However, no distinction is currently made between unfermented native grape seed and grape seed pomace powders regarding their antioxidant activities. Our aim was to find the relationship between the polyphenol and fatty acid content as well as the antioxidant capacity of native and fermented grape seeds of four different grape varieties harvested in the Villány wine region. According to our results, none of the three investigated polyphenols (resveratrol, rutin, quercetin) could be detected in native grape seed samples in correlation with their significantly lower total antioxidant capacities compared to fermented seed samples. Pinot Noir (PN) grape seed pomace samples with the highest resveratrol and oil content showed significantly higher total antioxidant capacity than Cabernet Sauvignon (CS), Syrah (S) and Blue Portugal (BP) samples. Based on the statistical analysis, positive correlation was found between the fatty acid content and the resveratrol concentration in the pomace samples of different grape varieties. In contrast, rutin concentrations were negatively proportional to the fatty acid content of the fermented samples. No significant correlation was found considering the quercetin content of the samples. According to our findings, grape pomace seems a more promising source in the production of nutraceuticals, since it contains polyphenols in higher concentration and exerts significantly higher antioxidant activity than native grape seeds

Comparative Study on Grape Berry Anthocyanins of Various Teinturier Varieties

The red-fleshed grape cultivars, called teinturier or dyer grapes, contain anthocyanins in both the skin and flesh. These phenolic compounds exhibit excellent coloring ability, and as antioxidants, they are important bioactive compounds in food crops. In this work, anthocyanin patterns of grape berries of fifteen teinturier varieties collected from the gene bank located at Pécs in the southwest of Hungary were compared. Anthocyanin profiles of numerous varieties originating from Hungary such as ‘Bíborkadarka’, ‘Kármin’, ‘Kurucvér’, and ‘Turán’ are reported for the first time. Anthocyanins extracted separately from the skin and juice were analyzed using high-performance liquid chromatography coupled with a photodiode array detector. For the identification of compounds, high-resolution orbitrap mass spectrometry was used. All in all, twenty-one anthocyanins were identified and quantified. We found that anthocyanin patterns differed significantly in the skin and juice for all investigated cultivars. For Vitis vinifera varieties, the predominant anthocyanin in the skin was malvidin-3-O-glucoside, while the main pigment in the juice was peonidin-3-O-glucoside. For the first time, a significant amount of diglucosides was detected in two Vitis Vinifera cultivars with a direct relationship. In general, the pigment composition of the skin was much more complex than that of the juice. The comparative study with presented patterns gives valuable and beneficial information from a chemotaxonomical point of view. Our results also help to choose the appropriate teinturier varieties with the desired anthocyanins for food coloring or winemaking purposes