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In vitro antilisterial effect of essential oils by modeling of growth curve MIC values
No full textBackground: Listeria monocytogenes is food contaminant being widely tolerant to different
environmental factors. It is one of the most frequent causative agents of deaths among foodborne
pathogens.
Objectives: The aim was to examine the in vitro antilisterial effect of essential oils (EOs) of Juniperus
communis and Satureja montana.
Methods: EOs were chemically analyzed by GC/GC-MS. Antilisterial effect against ATCC19111 strain
and three primoisolates was determined in microdilution, checkerboard and time-kill assays. Results
of time-kill assay were used not only to analyze the type of interaction between EOs, but also to
determine the growth rates of curves obtained for different concentrations of test substances. By
plotting of growth rates as a function of applied concentrations, growth curve MIC was determined
as the concentration inducing neither the progression nor the regression of bacterial population.
Results: MIC values determined in microdilution assay and by modeling of time-kill assay growth
curves were in the ranges 0.5-1% and 0.03-0.14%, respectively. Multifold higher values of MIC
obtained in microdilution assay could be addressed to the feature that L. monocytogenes is more
resistant to different stressors in reduced oxygen environment. In addition, synergism of both EOs in
mixture treatment of isolates was determined in checkerboard and time-kill assays. In conclusion, J.
communis and S. montana EOs and their combinations could be the efficient inhibitors of the L.
monocytogenes growth. However, the fact that its susceptibility to antimicrobials is influenced with
environmental conditions requires the use of different experimental approaches in order to better
explore it
Characteristics of newly-bred domestic and introduced apricot cultivars (P. armeniaca L.) grown in the region of Čačak
No full textThe region of Čačak (central part of Serbia) is known as an apricot growing area. ‘Hungarian Best’ is the most grown cultivar in Serbia, followed by ‘Roksana’, ‘NS-4’, ‘NS Rodna’. The large number of cultivars ripens in the second half of July and they are commonly used for processing. The aim of this research was the evaluation of early- and late-season cultivars, in order to improve apricot cultivar assortment and enrich the offer of fresh fruits and products. Properties of nine apricot cultivars grafted onto Myrobalan (P. Cerasifera Ehrh.) were examined. Cultivar ‘Hungarian Best’ was used as a standard. The experiment was conducted during the two-year period (2017-2018) at the experimental orchard, located 10 km north-west from Čačak, in the village Gornja Gorevnica, located at 390 m altitude. The orchard was established in 2014, with 6 x 3.5 m tree spacing and vase training system. The earliest flowering onset was observed in the cultivars ‘Goldrich’ and ‘Tsunamy’ (‘Goldrich’ flowered 3 days and ‘Tsunamy’ 1-2 days before the control cultivar). On the other side, ‘Roksana’, ‘Farbaly’, ‘Kech Psar’ and ‘Zerdelija’ flowered 2-3 days after the control cultivar. ‘Tsunamy’ is particularly distinguished by its ripening time as an early-season cultivar (ripens at the beginning of June), while ‘Farbaly’ and ‘Kech Psar’ were determined as late-ripening cultivars (the second half of August). As regards fruit size, compared to ‘Hungarian Best’ (53.54 g), the largest fruit was in ‘Roksana’ (82.44 g), followed by ‘Zaklopačka Ruža’ (80.42 g) and ‘Goldrich’ (56.13 g). The highest soluble solids content was detected in the late-season cultivar ‘Kech Psar’ (24.46° Brix)
Plum fruits maturity indices and quality of plum brandy
No full textCertain plum cultivars are characterised by early development of blue skin colour, making it difficult to determine the right time to pick the fruits for the intended purpose of their use. This paper examines various maturity indices for fruits of the 'Čačanska lepotica' cultivar (firmness of fruit, fruit mass, stone ratio, soluble solids content, total sugars, and total acids content, pH value, value of individual pectin fractions, content of aromatic fruit components, as well as ratios between certain tested parameters) and their suitability as indicators of maturity level in fruits intended for the production of brandy. The fruits ripened on the tree and their picking for the intended brandy production was performed at four different degrees of ripeness, with the final harvest cycle being performed concurrently with the traditional harvest time for brandy plums (when fruits are fully ripe and slightly over-ripe). The same method of brandy processing was used with fruits from all four harvesting cycles. Brandies obtained in this manner were analysed for the contents of the most important volatile components (methanol, higher alcohols, ethyl acetate, acetaldehyde, benzaldehyde, and HCN). It was established that all of the produced brandies, regardless of the level of ripeness of plum fruits used in their production, fulfil the legal requirements regarding the levels of methanol, HCN, and total volatile components. Brandies produced using fruits of second and third level of maturity were granted higher sensory markings than fruits produced from the most mature plum fruits (fourth level of maturity), which are traditionally used in brandy production
In situ characterization of some sweet and sour cherry autochthonous genotypes in West Serbia region
No full textAutochthonous cherry genotypes in the Republic of Serbia can potentially provide a rich and useful genetic variability, especially for ripening time, fruit quality and resistance to diseases. Fruit Research Institute, Cacak has a long tradition in collecting new sweet and sour cherry genotypes, as well as in evaluation and utilization of autochthonous material with good agronomic properties. This study was carried out to determine the main biological properties of six sweet cherry (Prunus avium L.) genotypes ('GT-1', 'GT-2', 'GT-3', 'GT-4', 'GT-5', 'GT-6'), and eight sour cherry (Prunus cerasus L.) genotypes ('GV-1', 'GV-2', 'GV-3', 'GV-6', 'GV-7', 'GV-10', 'GV-12', 'GV-13'). Over two years (2016-2017), the following properties of in situ cherry genotypes in West Serbia region were investigated: ripening time, pomological properties (morphometric and chemical), and field resistance to causal agents of cherry diseases - cherry leaf spot (Blumeriella jaapii (Rehm.) v. Arx.), brown rot (Monilinia spp.) and cherry fruit fly (Rhagoletis cerasi L.). The highest average fruit weight among investigated sweet and sour cherry genotypes was found in 'GT-5' (11.00 g) and 'GV-13' (7.64 g), respectively. The highest soluble solids content was found in 'GT-1' and 'GT-3' (16.20%) and 'GV-7' (17.30%), respectively. In terms of field resistance to pathogens, 'GT-1', 'GV-6' and 'GV-10' showed the best performance. To avoid the loss of this material, it is necessary to collect and characterize these genotypes to allow their conservation in germplasm collections, and to provide preconditions for a successful cherry breeding work
Tree vigor, yield, fruit quality, and antioxidant capacity of apple (Malus x domestica Borkh.) influenced by different fertilization regimes: preliminary results
No full textTree growth, productivity, fruit quality attributes, and antioxidant activity were tested in apple cultivar Idared under different fertilization treatments from the 22nd to the 23rd year after planting in a heavy acidic soil under western Serbian conditions. Treatments included the use of aged cattle manure, compound NPK (15:15:15) mineral fertilizer, a multinutrient fertilizer commercially named Italpolina (ITP) (NPK + organic carbon + humic acids), two types of N mineral fertilizers (calcium ammonium nitrate [CAN] and urea), and control (no fertilization). Results showed that Idared trees were more vigorous when fertilized with the two N fertilizers than when treated with another mineral, organic, or multinutrient fertilizer. Urea promoted the highest yield per tree and unit area, while yield efficiency was the highest in the control and those under treatment with urea, compound NPK, and manure. Fertilizer regimes had a significant effect on fruit weight and flesh firmness, but their effects on fruit size and dimension ratio were not significant. Compound NPK resulted in the greatest fruit weight, whereas firmness and soluble solids content were the highest in manure treatment. Titratable acidity (TA) was the highest in control trees and after CAN application, while urea induced the highest ripening index. Fertilizer treatments had no significant effect on the contents of invert sugars, sucrose, and total sugars (TS). The TS/TA ratio was highest under urea treatment and lowest in the control and under CAN application. ITP led to the highest values for total phenolics, total non flavonoids, and total antioxidant capacity, while the highest total flavonoid content was obtained with compound NPK
Chemical and sensory characterization of plum spirits obtained from cultivar Cacanska Rodna and its parent cultivars
No full textDuring the two-year research, a comparative analysis of the contents of 24 major volatile compounds and sensory characteristics of the plum spirits produced by spontaneous alcoholic fermentation of the plum mashes with or without stones from cultivar Cacanska Rodna and its parent cultivars - Stanley and Pozegaca were carried out. The plum spirits obtained from Cacanska Rodna cultivar contain lower amounts of methanol, 1-hexanol, ethyl acetate and acetaldehyde and higher amounts of 3-methyl-1-butanol and 2-phenyl-ethanol than the spirits from its parent cultivars. Contents of 1-propanol, 1-butanol and hexanoic acid in the spirits obtained from Cacanska Rodna cultivar were lower than the contents in the spirits from Pozegaca and higher than those in the spirits obtained from Stanley. The sensory quality of plum spirits, in addition to the cultivar, has been significantly influenced by the presence of stones in the mash during processing of plums into spirits. In processing plums with stones, the best-graded plum spirit was from Pozegaca (17.88), whereas in processing without stones, the best was Cacanska Rodna spirit (17.78). The spirits obtained from Stanley cultivar had the lowest sensory grades regardless of the processing method
Влияние на нова технология на отглеждане върху антиоксидантния капацитет и фенолното съдържание на къпина ‘Чачанска Бестрна’
No full textThe investigation was conducted in a ‘Čačanska Bestrna’ blackberry orchard set up using the intensive cultivation technology, i.e. with pre-formed double- sloping eaves (rain-shield). Considering that the Serbian blackberry yield suffers an annual loss of around 30% due to gray mould caused by the phytopathogenic fungi Botrytis cinerea Pers., introduction of more intensive blackberry cultivation systems is imperative in order to prevent adverse action of rain and other abiotic components, thus securing continuous harvest and supply of improved quality fruits. This cultivation technology contributes to a higher content of high-quality fruits, i.e. prevention of gray mould, while at the same time securing continual harvesting, 133
regardless of the environmental conditions. Each blackberry sample was analysed for phenolic acids (protocatechuic, 4-hydroxybenzoic, vanillic, ellagic, gallic, p-coumaric, caffeic, and ferulic acids), flavonoids (quercetin), anthocyanidins (cyanidin), total phenolics, total anthocyanins, and Trolox-equivalent antioxidant capacity. The analysis was conducted using high-performance liquid chromatography (HPLC) and spectrophotometric techniques. Regarding the identified phenolic compounds, the blackberries grown under the rain-shield recorded higher values of these components, with the exception of the ellagic acid. Significant higher value of the total phenolic and total anthocyanin content recorded in blackberries grown using the rain-shield was 396.44 and 75.85 mg/100 g FW. There was not significant effect of intensive growing technology on total antioxidant capacity in blackberries and ranged from 2.68 to 2.70 Trolox mmol/100 g FW.Изследването е проведено в къпи- ново насаждение от "Чачанска Бестрна", създадено по интензивна технология на отглеждане, т.е. с предварително оформени двускатови стрехи (съоръ- жение за отглеждане под покритие). Като се има предвид, че добивът на
сръбски къпини претърпява годишна загуба от около 30% поради сиво гниене ричинено от фитопатогенни гъби Botrytis cinerea Pers., въвеждането на поинтензивна система за тглеждане еналожително за да се предотврати неблагоприятното въздействие на дъж да и други абиотични фактори, като по този начин се осигури непрекъснат добив и предлагане на плодове с подобро качество. Тази технология на отглеждане благоприятства по голямо количество висококачествени плодове, т.е. предотвратява сивото гниене и в същото време осигурява непрекъсната реколта, независимо от условията на околната среда. Всяка проба от къпините е из- следвана за фенолни киселини (прото- катехинова, 4-хидроксибензоена, вани- лова, елагинова, галова, р-кумаринова, кафеена и ферулова киселини), флавоноиди (кверцетин), антоцианидини
(цианидин), общи феноли, общи антоцианини и тролокс еквивалентен антиоксидантен капацитет. Анализът е проведен чрез високоефективна течна хроматография (HPLC) и спектрофотометрични техники. По отношение на установените фенолни съединения, къпи- ните, отглеждани под покритие, отбе- лязват по-високи стойности на тези компоненти, с изключение на елагино- вата киселина. Значително повисока стойност на общите феноли и общи антоцианини е отчетена в къпини, отглеждани под покритие 396.44 и 75.85 mg/100 g FW. Не е установено значимо въздействие от интензивната технология на отглеждане върху общия антиоксидантен капацитет, кaто той варира от 2.68 до 2.70 Тролокс mmol/100 g FW
Molecular and biological characterization of Black raspberry necrosis virus on red raspberry in Serbia
No full textBlack raspberry necrosis virus (BRNV) is considered as economically important virus infecting raspberries. In black raspberry (Rubus occidentalis L.) BRNV is causing cane tip necrosis, but infected red raspberry (Rubus idaeus L.) cultivars in general do not express foliar symptoms.
From 2014−2018, a number of 105 samples from 9 red raspberry cultivars (‘Almira’, ’Fertödi Zamatos’, ’Glen Ample’, ’Meeker’, ‘San Rafael’, ’Polana’, ’Polka’, ’Tulameen’ and ‘Willamette’) were collected from different localities in Serbia. Samples were tested on the BRNV presence by reverse transcription-polymerase chain reaction (RT-PCR) using specific primers targeting 417 bp nucleotide (nt) fragment of the RNA-dependent RNA polymerase (RdRp) region of RNA 1 of the BRNV genome. BNRV was detected in 19 samples in cultivars ’Fertödi Zamatos’, ’Polana’, ’Tulameen’ and ‘Willamette’.
A 417nt sequence of the RdRp was determined for 5 isolates. The nt sequences of these isolates were 94.2−99.7% identical. When compared to available sequences of BRNV isolates from North America and Europe, Serbian isolates showed significant divergence (80.0−82.2% of nt identity).
A portion of the BRNV infected plants of cultivar ’Fertödi Zamatos’ were further tested on indicator R. occidentalis by inarch bottle grafting. Two months after inoculation cane tip begun to curl down and became necrotic on all inoculated plants. Non-grafted control plants were symptomless
Escherichia coli and Salmonella spp. in Gruža reservoir Lake (Serbia) pretection zone: A danger for drinking water safety
No full textFor all living organisms, water is the most vital and important matter for survival. Today, in many under-developed and developing countries, waterborne diseases still pose a major risk in drinking water. Agricultural practices have often proved to be the main source of faecal pollution, with septic systems also identified as sources of serious epidemics of E. coli. Understanding the effects of intensive land use on water resources is essential for the preservation of natural resources and improving environmental quality. In order to determine the presence of certain types of microorganisms in the soil of Gruža Lake protection zone the number E. coli and Salmonella were analysed. Analysing the presence of E. coli and Salmonella in the investigated groups of farmland soils, it has been noted that E.coli is present in 80% of the total plantation area under investigated vegetable gardens, while Salmonella at the same percentage of the area under stubbles. E. coli is present in a significant percentage of land under stubble-fields, meadows and plough fields, in 40 to 58.3% of the samples in the order. Salmonella is present in the soils under arable land and vegetables with 41.7 to 60.0% of the sampled land. The lowest number of both pathogens relates to the land under cereal crops. Management of aquatic ecosystems in the agricultural regions must take into account potential sources of faecal contamination
Fosfor-Biofertilizator u tehnologiji gajenja voćaka
No full textTehničkim rešenjem je dizajniran novi Fosfor-Biofertizator koji će omogućiti bolјe snadbevanje bilјaka sa fosforom na ekološki i ekonomski opravdan način. Aktivnu komponentu biofertilizatora predstavlјa specifičan konzorcijum bakterija koje su poreklom iz različitih tipova zemlјišta, rizosfere, bilјaka i komposta. Ove bakterijske populacije spadaju u grupu bakterija stimulatora bilјnog rasta koji različitim mehanizmima obavlјaju solubilizaciju fosfora. Tehničko rešenje bazirano je na iskorišćavanju velikog zemlјišnog mikrobnog biodiverziteta koje će doprineti bolјem snabdevanju voćaka sa fosforom na održiv način. Rezultati testiranja Fosfor-Biofertizatora u voćarskoj proizvodnji pokazali su da njegova primena predstavlјa dobar ekološki alat za snadbevanje voćarskih kultura sa fosforom i može predstavlјati sastavni deo tehnologije održive proizvodnje voćarskih kultura. Primena novog Fosfor-Biofertilizatora, doprinosi i povećanju opšte biogenosti zemlјišta, što dodatno utiče na stimulaciju bilјnog rasta i usvajanje ostalih hraniva. Takođe, primena biofertilizatora povećava efikasnost unetih mineralnih đubriva, što može rezultirati racionalnijoj primeni mineralnih đubriva i sa tog aspekta ima ekonomsku opravdanost uz ekološke koristi po životnu sredinu