Sadržaj rastvorljivih slobodnih fenolnih komponenata i antioksidativni kapaciteta zrna genotipova hlebne i durum pšenice

The objective of this study was to determine phenolic compounds and the total antioxidant capacity in the grain of ten bread (T. aestivum L.) and ten durum (T. durum Desf.) wheat genotypes. Soluble free forms of total phenolics, flavonoids, PVPP (polyvinylpolypyrrolidone) bound phenolics, proanthocyanidins and phenolic acids were investigated. In addition, the correlation coefficients between total antioxidant capacities and the concentration of different soluble free phenolic compounds, as well as between soluble free total phenolics and phenolic acids, flavonoids and PVPP bound phenolics were determined. Significant differences in the content of aceton/water extractable total phenolics, PVPP bound phenolics and phenolic acids between and within two wheat species were found. On the average, durum wheat samples had about 1.19-fold higher total phenolic compounds and about 1.5-fold higher PVPP bound phenolics than bread wheat samples. Three phenolic acids, ferulic, caffeic and chlorogenic, were detected in wholemeal bread wheat. Caffeic acid was not found in durum wheat samples whilst ferulic acid was the most abundant. Proanthocyanidins in bread and durum wheat genotypes were not detected. The antioxidant capacity measured as the DPPH radical scavenging activity was similar in wholemeal of bread and durum wheat, however, significant differences were observed among genotypes within species.Cilj ovih istraživanja bio je da se odredi sadržaj fenolnih komponenata i ukupni antioksidativni kapacitet zrna 10 genotipova hlebne (T. aestivum L.) i 10 genotipova durum (T. durum Desf.) pšenice. Rastvorljive slobodne forme ukupnih fenola, flavonoida, PVPP (polyvinylpolypyrrolidone) vezanih fenola, proantocijanidina i fenolnih kiselina bile su analizirane. Pored toga, korelacioni koeficijent između ukupnog antioksidativnog kapaciteta i koncentracije različitih slobodnih fenolnih komponenata, kao i između rastvorljivih slobodnih ukupnih fenola i fenolnih kiselina, flavonoida i PVPP vezanih fenola bio je određen. Značajne razlike nađene su u sadržaju aceton/voda ekstraktibilnih ukupnih fenola, PVPP vezanih fenola i fenolnih kiselina kako između dve vrste pšenice (durum i hlebne), tako i unutar vrste, odnosno između ispitivanih genotipova iste vrste. U proseku, durum pšenica imala je oko 1.2 puta više ukupnih fenola i oko 1.5 puta više PVPP vezanih fenola nego hlebna pšenica. Tri fenolne kiseline, ferulinska, kafeinska i hlorogena, bile su detektovane u etanolskom ekstraktu celog zrna hlebne pšenice. Kafeinska kiselina nije nađena u genotipovima durum pšenice, dok je ferulinska kiselina bila najzastupljenija u genotipovima obe vrste pšenice. Prisustvo proantocijanidina nije utvrđeno u genotipovima hlebne i durum pšenice. Antioksidativni kapacitet meren kao DPPH radikal vezujuća aktivnost bio je sličan između hlebne i durum vrste pšenice, ali su značajne razlike bile utvrđene između genotipova unutar vrste

Sadržaj antioksidativnih komponenata u semenu genotipova kukuruza sa različitim udelom DTP-a

In order to broaden the genetic base of maize (Zea mays L.) germplasm, it is necessary to integrate exotic materials into adapted breeding materials. The aim of the study was to compare antioxidative systems of two adapted maize inbred lines (A and B) with exotic germplasm, Drought Tolerant Population (DTP), and their backcrosses with DTP (A1, A2 and B1, B2). The content of low-molecular weight antioxidants, proline and phenolics, as well as antioxidant capacity, detected as free radical scavenging activities against DPPH radical, were measured in maize seeds. Proline content in both, embryo and endosperm was higher in backcrosses than in inbred lines and DTP, and increased in embryo by getting higher percentage of exotic germplasm. Contrary, phenolic content and DPPH radical scavenging activity of seeds, which were higher in adapted inbred lines than in DTP, were slightly decreased in their backcrosses with DTP.U cilju proširenja genetičke osnove germplazme kukuruza (Zea mays L.), neophodna je inkorporacija egzotičnog u lokalni adaptirani selekcioni materijal. U radu su upoređeni antioksidativni sistemi dve lokalne inbred linije (A i B) sa antioksidativnim sistemima egzotične germplazme (DTP) i povratnih ukrštanja tih inbred linija i DTP-a (A1, A2, B1 i B2). U semenu kukuruza meren je sadržaj antioksidanata male molekulske težine, prolina i ukupnih fenola, kao i antioksidativni kapacitet, izražen preko sposobnosti hvatanja slobodnih DPPH radikala. Rezultati su pokazali porast nivoa prolina, kako u klici, tako i u endospermu, kod A1, A2, B1 i B2 genotipova, u odnosu na čiste inbred linije i DTP. Takođe, nivo prolina se povećavao sa povećanjem udela egzotične germplazme. Nasuprot tome, kod čistih inbred linija je bio veći nivo ukupnih fenola i stepen hvatanja slobodnih DPPH radikala nego kod DTP-a, i sa tendencijom neznatnog smanjenja kod A1, A2, B1 i B2 genotipova

Učinak mikronizacije na sastav i svojstvo brašna dobivenog od bijelog, žutog i crvenog zrnja kukuruza

The process of micronisation, a short time high temperature process that utilizes electromagnetic radiation in the infrared region to rapidly heat materials, is often used to improve storage stability of whole grain flour. In this work the consequences of such temperature treatment on the quality and solubility of proteins, viscosity, content of total phenolics, tocopherols, ß-carotene, as well as the antioxidant properties of maize (Zea mays L.) flour are presented. For these studies three maize hybrids were used: the semi-flint hybrid ZP 633 with pronounced yellow kernels, ZP Rumenka with dark red pericarp and yellow endosperm, and ZP 551b hybrid which is characterized by white kernels. The process of micronisation did not change the content of crude protein, the amount of albumin, globulin and zein were decreased, while glutelin remained the same or increased after micronisation. As a consequence of thermal effect on maize protein, tryptophan content was significantly decreased. Micronisation had a significant effect on the pasting properties of the selected maize flour. Viscosity of all micronised flour samples increased constantly, but without reaching a peak during heating of the slurry to 95 °C. At 95 °C it was slightly higher, but final viscosity at 50 °C was significantly lower. The micronisation treatment decreased the content of bioactive compounds (tocopherols, ß-carotene) naturally present in the raw grains. The whole grain flour from micronised grain, with modified nutritional and technological characteristics, represents a good raw material for production of gluten-free products.Mikronizacija, tj. postupak kratkotrajnog izlaganja materijala visokoj temperaturi pomoću elektromagnetskoga zračenja u infracrvenom području, često se primjenjuje za poboljšanje stabilnosti pri skladištenju cjelovitoga brašna žitarica. U radu je ispitan utjecaj takva postupka na kakvoću i topljivost proteina, viskoznost, udio ukupnih fenola, tokoferola i β-karotena, te na antioksidativna svojstva kukuruznoga brašna. Upotrijebljena su tri hibrida kukuruza (Zea mays L.): ZP 633, polutvrdunac izrazito žutih zrna; ZP Rumenka, tamnocrvenoga perikarpa i endosperma žute boje, te ZP 551b bijelih zrna. Mikronizacija nije utjecala na udio sirovih proteina, ali je smanjila udio albumina, globulina i zeina, dok je udio glutelina ostao nepromijenjen ili se neznatno povećao. Nakon toplinske obrade udio se triptofana znatno smanjio. Mikronizacija je također uvelike utjecala na vezivna svojstva brašna. Povećana je viskoznost svih uzoraka brašna, ali nije dosegla vrhunac zagrijavanjem suspenzije do 95 ºC. Na 95 ºC viskoznost je bila nešto veća, dok je pri završetku mikronizacije na temperaturi od 55 °C bila kudikamo manja. Mikronizacijom se smanjio udio bioaktivnih spojeva (fenola, tokoferola i β-karotena) prisutnih u sirovom zrnju. Cjelovito brašno dobiveno mikronizacijom zrnja žitarica zbog svojih je hranjivih i tehnoloških svojstava dobra sirovina za dobivanje bezglutenskih proizvoda

Comparative effects of regulated deficit irrigation (RDI) and partial root-zone drying (PRD) on growth and cell wall peroxidase activity in tomato fruits

The effects of regulated deficit irrigation (RDI) and partial root-zone drying (PRD) on tomato fruit growth and cell wall peroxidase activity in tomato exocarp were investigated in growth chamber conditions. The RDI treatment was 50% of water given to fully irrigated (FI) plants and the PRD treatment was 50% of water of FI plants applied to one half of the root system while the other half dried down, with irrigation shifted when soil water content of the dry side decreased 15-20%. RDI significantly reduced fruit diameter, though PRD reduced fresh weight while having no significant effect on fruit diameter. The activity of peroxidase was significantly higher in RDI and PRD treated plants compared to those of FI. Differences between RDI and PRD were expressed on temporal basis. In the fruits of RDI treated plants peroxidase activity began to increase in the phase when fruit growth started to decline with the peak of enzyme activity of 6.1 HRPEU g(-1) FW reached in the phase of mature green fruits when fruit growth rate was minimal. Increase of peroxidase activity in PRD fruits coincided with the ripening phase and the peak of enzyme activity (5.3 HRPEU g(-1) FW) was measured at the end of fruit ripening. These data potentially identified contrasting and different roles of tomato exocarp cell wall peroxidase in RDI and PRD treated plants. In RDI treated plants peroxidase may have a role in restricting fruit growth rate, although the increase in enzyme activity during ripening of PRD treated fruit pointed out that peroxidase may also control fruit maturation by inducing more rapid process.This is the peer-reviewed version of Savić, S., Stikić, R., Vucelić-Radović, B., Bogicević, B., Jovanović, Z.,& Hadži-Tašković-Šukalović, V.. (2008). Comparative effects of regulated deficit irrigation (RDI) and partial root-zone drying (PRD) on growth and cell wall peroxidase activity in tomato fruits. in Scientia Horticulturae Amsterdam : Elsevier., 117(1), 15-20. [https://doi.org/10.1016/j.scienta.2008.03.009

Modification of antioxidant systems in cell walls of maize roots by different nitrogen sources

Antioxidant systems of maize root cell walls grown on different nitrogen sources were evaluated. Plants were grown on a medium containing only NO3- or the mixture of NO3-+NH4+, in a 2:1 ratio. Eleven-day old plants, two days after the initiation of lateral roots, were used for the experiments. Cell walls were isolated from lateral roots and primary root segments, 2-7 cm from tip to base, representing zones of intense or decreased growth rates, respectively. Protein content and the activity of enzymes peroxidase, malate dehydrogenase and ascorbate oxidase ionically or covalently bound to the walls, as well as cell wall phenolic content and antioxidant capacity, were determined. Cell walls of plants grown on mixed N possess more developed enzymatic antioxidant systems and lower non-enzymatic antioxidant defenses than cell walls grown on NO3-. Irrespective of N treatment, the activities of all studied enzymes and protein content were higher in cell walls of lateral compared to primary roots. Phenolic content of cell walls isolated from lateral roots was higher in NO3--grown than in mixed N grown plants. No significant differences could be observed in the isozyme patterns of cell wall peroxidases isolated from plants grown on different nutrient solution. Our results indicate that different N treatments modify the antioxidant systems of root cell walls. Treatment with NO3- resulted in an increase of constitutive phenolic content, while the combination of NO3-+NH4+ elevated the redox enzyme activities in root cell walls

Maize seedling performance as a potential index for drought tolerance

Twenty-six maize landraces were tested in order to evaluate maize seedling performance as an index for drought tolerance in adult plants. Samples were subjected to polyethylene glycol-induced osmotic stress at the early seedling stage. Grain yield was obtained in field experiments under well-watered (OC) and a combination of drought and high plant density (HD) conditions. Osmotic stress caused a reduction in seedling growth (length, fresh and dry weight), and increase in the shoot and in particular the root proline contents in the majority of landraces, and variations in root peroxidase (POD) activity. Genotypes displaying more pronounced root growth reduction and higher proline contents exhibited decreased POD activity under osmotic stress. Direct positive correlations between the proline content and growth inhibition, and between the proline and soluble protein content were established. Correlations between the changes in POD activity and growth parameters were significant and positive, and significant but negative with the changes in the proline content. In the field, water stress led to a reduction in grain yield in all of the tested landraces. Correlations between grain yield from both experimental sets (OC and HD) and osmotic-induced changes in seedling root growth were negative, which was opposite to the highly significant and positive correlations between the changes in the seedling root proline content and yield. Also, genotypes with the highest seedling root proline content increase under osmotic stress, exhibited the highest stress tolerance index (STI) based on grain yield achieved under both field conditions. Our results indicate that lower changes in POD activity and especially an increased proline content after exposure to osmotic stress during the early seedling stage could be considered as useful indices to facilitate selection efficiency for drought tolerance in adult plants

Učinak mikronizacije na sastav i svojstvo brašna dobivenog od bijelog, žutog i crvenog zrnja kukuruza

The process of micronisation, a short time high temperature process that utilizes electromagnetic radiation in the infrared region to rapidly heat materials, is often used to improve storage stability of whole grain flour. In this work the consequences of such temperature treatment on the quality and solubility of proteins, viscosity, content of total phenolics, tocopherols, ß-carotene, as well as the antioxidant properties of maize (Zea mays L.) flour are presented. For these studies three maize hybrids were used: the semi-flint hybrid ZP 633 with pronounced yellow kernels, ZP Rumenka with dark red pericarp and yellow endosperm, and ZP 551b hybrid which is characterized by white kernels. The process of micronisation did not change the content of crude protein, the amount of albumin, globulin and zein were decreased, while glutelin remained the same or increased after micronisation. As a consequence of thermal effect on maize protein, tryptophan content was significantly decreased. Micronisation had a significant effect on the pasting properties of the selected maize flour. Viscosity of all micronised flour samples increased constantly, but without reaching a peak during heating of the slurry to 95 °C. At 95 °C it was slightly higher, but final viscosity at 50 °C was significantly lower. The micronisation treatment decreased the content of bioactive compounds (tocopherols, ß-carotene) naturally present in the raw grains. The whole grain flour from micronised grain, with modified nutritional and technological characteristics, represents a good raw material for production of gluten-free products.Mikronizacija, tj. postupak kratkotrajnog izlaganja materijala visokoj temperaturi pomoću elektromagnetskoga zračenja u infracrvenom području, često se primjenjuje za poboljšanje stabilnosti pri skladištenju cjelovitoga brašna žitarica. U radu je ispitan utjecaj takva postupka na kakvoću i topljivost proteina, viskoznost, udio ukupnih fenola, tokoferola i β-karotena, te na antioksidativna svojstva kukuruznoga brašna. Upotrijebljena su tri hibrida kukuruza (Zea mays L.): ZP 633, polutvrdunac izrazito žutih zrna; ZP Rumenka, tamnocrvenoga perikarpa i endosperma žute boje, te ZP 551b bijelih zrna. Mikronizacija nije utjecala na udio sirovih proteina, ali je smanjila udio albumina, globulina i zeina, dok je udio glutelina ostao nepromijenjen ili se neznatno povećao. Nakon toplinske obrade udio se triptofana znatno smanjio. Mikronizacija je također uvelike utjecala na vezivna svojstva brašna. Povećana je viskoznost svih uzoraka brašna, ali nije dosegla vrhunac zagrijavanjem suspenzije do 95 ºC. Na 95 ºC viskoznost je bila nešto veća, dok je pri završetku mikronizacije na temperaturi od 55 °C bila kudikamo manja. Mikronizacijom se smanjio udio bioaktivnih spojeva (fenola, tokoferola i β-karotena) prisutnih u sirovom zrnju. Cjelovito brašno dobiveno mikronizacijom zrnja žitarica zbog svojih je hranjivih i tehnoloških svojstava dobra sirovina za dobivanje bezglutenskih proizvoda

Genetička varijabilnost sadržaja albumina i globulina i aktivnosti lipoksigenaze i peroksidaze između genotipova hlebne i durum pšenice

The classical Osborne wheat proteins fraction (albumin-globulin), as well as several polypeptides from the non-gluten protein fraction using SDS-PAGE analyses were determined in the grain of five bread (T. aestivum L.) and five durum wheat (T. durum Desf.) genotypes. In addition, the activity rate of lipoxygenase (LOX) and peroxidase (POD) enzymes implicated in the antioxidant metabolism was determined. Albumins and globulins in wheat grains were characterized by rich protein pattern - the number of bands varied from 19 to 23 and they were defined by molecular weight 76.4-12.4 kDa. The great differences between bread and durum wheat polypeptide contents were found. Result pointed out that polypeptides with molecular weight of 65.6, 43.5 and 32.9 kDa could be used to differentiate the bread from durum wheat. Significant differences in the LOX and POD activity between and within two wheat species were detected. Present study showed in durum wheat a lower activities of LOX and POD enzymes for about 45 and 22%, respectively, than in bread wheat. Our results could be useful for plant breeders in screening and selecting of better raw materials with high protein quality for the flour, breadmaking and pasta industry.Određen je sadržaj albuminsko-globulinske frakcije, kao i polipetida koji ulaze u sastav ovih neglutenskih proteina korišćenjem SDS-PAGE analize u zrnu pet genotipova hlebne pšenice (T. aestivum L.) i pet genotipova durum pšenice(T. durum Desf.). Pored toga, određena je aktivnost oksidativnih enzima, lipoksigenaze (LOX) i peroksidaze (POD), koji su uključeni u metabolizam antioksidanasa.Albumisko- globulinska frakcija proteina zrna pšenice karakterisala se bogatom proteinskom šemom - broj traka na gelu je varirao od 19 do 23, a molekulska masa izolovanih proteina kretala se od 76.4 do 12.4 kDa. Detektovani polipeptidi u zrnu genotipova hlebne i durum pšenice razlikovali se u sadržaju. Rezultati ukazuju da bi se polipeptidi molekulskih masa 65.6, 43.5 i 32.9 kDa mogli koristiti za razlikovanje hlebne i durum pšenice. Između i unutar analiziranih vrsta pšenice detektovana je značajna razlika u aktivnosti enzima LOX i POD. Rezultati pokazuju nižu aktivnost LOX i POD u zrnu durum pšenice za 45, odnosno 22% u odnosu na hlebnu pšenicu.Dobijeni rezultati mogu doprineti selekciji osnovnog materijala visokog kvaliteta proteina za upotrebu u pekarstvu i industriji testenina

Effect of Micronisation on the Composition and Properties of the Flour from White, Yellow and Red Maize

The process of micronisation, a short time high temperature process that utilizes electromagnetic radiation in the infrared region to rapidly heat materials, is often used to improve storage stability of whole grain flour. In this work the consequences of such temperature treatment on the quality and solubility of proteins, viscosity, content of total phenolics, tocopherols, beta-carotene, as well as the antioxidant properties of maize (Zen mays L.) flour are presented. For these studies three maize hybrids were used: the semi-flint hybrid ZP 633 with pronounced yellow kernels, ZP Rumenka with dark red pericarp and yellow endosperm, and ZP 551b hybrid which is characterized by white kernels. The process of micronisation did not change the content of crude protein, the amount of albumin, globulin and zein were decreased, while glutelin remained the same or increased after micronisation. As a consequence of thermal effect on maize protein, tryptophan content was significantly decreased. Micronisation had a significant effect on the pasting properties of the selected maize flour. Viscosity of all micronised flour samples increased constantly, but without reaching a peak during heating of the slurry to 95 degrees C. At 95 degrees C it was slightly higher, but final viscosity at 50 degrees C was significantly lower. The micronisation treatment decreased the content of bioactive compounds (tocopherols, beta-carotene) naturally present in the raw grains. The whole grain flour from micronised grain, with modified nutritional and technological characteristics, represents a good raw material for production of gluten-free products

Hemijska kompozicija kao parametar kvaliteta ZP sorti soje i pšenice

This research is focused on the analysis of chemical characteristics of ZP soybean and wheat genotypes, as well as, on nutritional differences between this two complementary plant species. The experimental material consisted of two bread (ZP 96/I and ZP 87/Ip), two durum (ZP 34/I ZP and ZP DSP/01-66M) wheat genotypes and four soybean varieties (Nena, Lidija, Lana and Bosa) of different genetic background. All ZP soybean genotypes, except the Lana, had over 40% of total proteins by dry matter. Lana and Lidija, variety of recent creation, developed as a result of selection for specific traits, had high oil content. Wheat genotypes had much a lower content of ash, oil, total and water soluble proteins than soybean cultivars. The highest oil, total and water soluble proteins content was detected in grain of durum genotype ZP DSP/01-66M. Lignin content varies much more among soybean than among the wheat genotypes. Generally, contents of total phenolics, carotenes and tocopherol were more abundant in ZP soybean than bread and durum wheat genotypes.Cilj ovog rada je analiza hemijskih karakteristika ZP genotipova soje i pšenice, kao i nutritivne razlike između ove dve komplementarne biljne vrste. Eksperimentalni materijal obuhvata dva hlebna, dva durum genotipa pšenice i četiri ZP genotipa soje različitog genetičkog porekla. Svi ZP genotipovi soje osim Lane, imaju preko 40% ukupnih proteina. Lana i Lidija, nedavno stvorene sorte, nastale kao rezultat selekcije za specifična svojstva, imaju visok sadržaj ulja. Genotipovi pšenice imaju znatno niži sadržaj pepela, ulja, ukupnih i u vodi rastvorljivih proteina nego genotipovi soje. Najviši sadržaj ulja, ukupnih i u vodi rastvorljivih proteina je nađen u durum genotipu ZP DSP/01-66M. Sadržaj lignina varira značajno više između genotipova soje nego pšenice. Generalno, sadržaj ukupnih fenola, karotina, i tokoferola je obilniji u ZP genotipovima soje nego u pšenici