Robert Nagy

Mr. Robert Nagy

University of Debrecen Faculty of Agricultural and Food Sciences and Environmental Management, Debrecen, Hungary
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 December 2020 in Processes
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Journal Article
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Robert NagyRobert Nagy
Robert Nagy
EMEndre Mathe
Endre Mathe
JCJános Csapó
János Csapó
Péter SiposPéter Sipos
Péter Sipos
Carbohydrates are one of the most important nutrients in human consumption. The digestible part of carbohydrates has a significant role in maintaining the energy status of the body and the non-digestible parts like dietary fibers have specific nutritional functions. One of the key issues of food processing is how to influence the technological and nutritional properties of carbohydrates to meet modern dietary requirements more effectively, considering particularly the trends in the behavior of people and food-related health issues. Physical processing methods have several advantages compared to the chemical methods, where chemical reagents, such as acids or enzymes, are used for the modification of components. Furthermore, in most cases, these is no need to apply them supplementarily in the technology, only a moderate modification of current technology can result in significant changes in dietary properties. This review summarizes the novel results about the nutritional and technological effects of physical food processing influencing the starch and dietary fiber content of plant-derived foodstuffs.

1 June 2021 in Acta Agraria Debreceniensis
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Robert NagyRobert Nagy
Robert Nagy
ESErzsébet Szőllősi
Erzsébet Szőllősi
PMPiroska Bíróné Molnár
Piroska Bíróné Molnár
EMEszter Murányi
Eszter Murányi
RCRóbert Czimbalmos
Róbert Czimbalmos
Péter SiposPéter Sipos
Péter Sipos
Cereal-based products are one of our main energy sources, and are consumed on a daily basis. One of the weaknesses of wheat based products is their low antioxidant content. Sorghum is a minor cereal, mostly consumed in Africa and Asia. Amongst other phenolic components it contains tannins, which are potent antioxidants and have other positive effect on human health, for example anti-tumor, anti-inflammatory and anti-viral/bacterial effect. We evaluated the tannin content (vanillin-HCL) and antioxidant capacity (DPPH) of sorghum varieties (Alföldi1, Zádor, Foehn, Albita, Albanus) grown in Hungary, with two type of agronomy technology.. Red varieties especially Alföldi1 and Zádor had higher tannin contents than white varieties. The highest condensed tannin content was 1470±73 mg 100g-1 (Control, Alföldi1), 1810±154 mg 100g-1 (Fertilized, Alföldi1), and the highest total antioxidant capacity was 2099±19 mg 100g-1 (Control, Alföldi1) and 2117±26 mg 100g-1 (Fertilized, Alföldi) We found that sorghum type, variety and color influence their tannin and antioxidant contents in general.

25 March 2023 in Agriculture
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Robert NagyRobert Nagy
Robert Nagy
EMEszter Murányi
Eszter Murányi
PMPiroska Bíróné Molnár
Piroska Bíróné Molnár
JSJudit Szepesi
Judit Szepesi
Zoltán GyőriZoltán Győri
Zoltán Győri
Péter SiposPéter Sipos
Péter Sipos
Sorghum bicolor (L.) Moench is an increasingly important crop grown in many countries as a food source due to its excellent nutritional value, drought and pest resistance, and gluten-free properties. In this study, the bioactive profiles and antioxidant potentials of brans of six sorghum varieties were evaluated using spectrophotometric methods. The effects of weather and environmental conditions and different nitrogen nutrition were also evaluated. The bran of red varieties contained a higher amount of polyphenols and tannins and exhibited higher antioxidant capacities than the bran of white varieties, with the exception of one red genotype. The highest total polyphenol contents were measured in samples from two red varieties (Zádor, Alföldi1) with 1084.52 ± 57.92 mg 100 g−1 GAE and 1802.51 ± 121.13 mg 100 g−1 GAE values, respectively, while condensed tannin content varied between 0.50 mg g−1 and 47.79 mg g−1 in sorghum brans. Red varieties showed higher antioxidant activities/capacities with 70–281 µmol TE g−1 and 71–145 µmol TE g−1 for DPPH and TEAC. Correlation analysis showed a strong interaction between DPPH, TEAC, and the amounts of polyphenols and tannins, but not with FRAP values. In conclusion, red-colored varieties are a good source of polyphenols, but seed color alone is not enough to determine the nutritional value of a genotype, and the environmental conditions greatly affect the bioactive profile of sorghum.

30 October 2023 in Agronomy
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Prokisch JózsefProkisch József
Prokisch József
DSDaniella Sári
Daniella Sári
AMArjun Muthu
Arjun Muthu
Robert NagyRobert Nagy
Robert Nagy
Hassan Ragab El-RamadyHassan Ragab El-Ramady
Hassan Ragab El-Ramady
Judit DobránszkiJudit Dobránszki
Judit Dobránszki
Natural resources including water, energy, and food have an increase in demand due to the global population increases. The sustainable management of these resources is an urgent global issue. These resources combined in a very vital nexus are called the water–energy–food (WEF) nexus. The field of nanotechnology offers promising solutions to overcome several problems in the WEF nexus. This review is the first report that focuses on the suggested applications of nanofibers in the WEF sectors. An economic value of nanofibers in WEF sectors was confirmed, which was mainly successfully applied for producing clean water, sustainable energy, and safe food. Biotechnological solutions of nanofibers include various activities in water, energy, and food industries. These activities may include the production of fresh water and wastewater treatment, producing, converting, and storing energy, and different activities in the food sector. Furthermore, microbial applications of nanofibers in the biomedicine sector, and the most important biotechnological approaches, mainly plant tissue culture, are the specific focus of the current study. Applying nanofibers in the field of plant tissue culture is a promising approach because these nanofibers can prevent any microbial contamination under in vitro conditions, but the loss of media by evaporation is the main challenge in this application. The main challenges of nanofiber production and application depend on the type of nanofibers and their application. Different sectors are related to almost all activities in our life; however, enormous open questions still need to be answered, especially the green approach that can be used to solve the accumulative problems in those sectors. The need for research on integrated systems is also urgent in the nexus of WEF under the umbrella of environmental sustainability, global climate change, and the concept of one’s health.

30 November 2024 in Potato Research
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ZRZoltan Repas
Zoltan Repas
Robert NagyRobert Nagy
Robert Nagy
ZPZsolt Géza Polgár
Zsolt Géza Polgár
Zoltán GyőriZoltán Győri
Zoltán Győri
The aim of this study was to determine the nutritional values related to structural stability during the storage of freeze-dried potato cubes and investigate the colour changes that occur during boiling, freeze-drying, and rehydration, as well as the suitability of rehydration and, on the basis of this information, establish varietal characteristics suitable for the use of technology. Nine different potato varieties were analysed. Significant relationships were detected between the amount of dry matter protein and starch content and the colour and colour change values. Significant relationship was measured between the amount of protein calculated in dry matter and the structural stability and rehydration suitability of freeze-dried boiled potatoes. According to our study, the optimal varieties for freeze-dried boiled potatoes were those with high protein content in dry matter, which provided maximum structural stability during storage and optimal properties for short-term rehydration at low temperatures. Based on our study, potato varieties that are suitable for processing by freeze-drying technology can be easily selected and our study provides useful information for breeders, growers, and food processors to achieve their goals in food processing.

11 February 2025 in Journal of microbiology, biotechnology and food sciences
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Robert NagyRobert Nagy
Robert Nagy
PAPál Anna
Pál Anna
EMEszter Murányi
Eszter Murányi
JRJudit Remenyik
Judit Remenyik
Péter SiposPéter Sipos
Péter Sipos
Sorghum is a drought tolerant, gluten–free cereal, which is known for the abundance of polyphenol compounds, including flavonoids. It is proved that these compounds have important health benefits as antioxidants and anti–inflammatory agents. They are found in seed walls in a free form or in a bound, esterified form, which affects their digestion and utilization. The main purpose of this research was to evaluate the ratio of free and bound polyphenols in sorghum brans extracted with different solvents, and see how the extraction step can influence the physiology importance of a sorghum extract. Solvents had significant effects on the polyphenol and flavonoid content of free polyphenol extracts, but there was not any difference in terms of their antioxidant activities. In case of bound fractions from different extractions, there were significant differences in all parameters, except for the flavonoid content. Correlation analysis showed strong connection between parameters, and there were differences in correlation between extraction. Among the two varieties, Alföldi1 had significantly higher content of total phenol, flavonoid and higher values of antioxidant capacity as well compared to Zádor in both extractions. In this research only the effect of the extraction solvent was evaluated, but further investigation is necessary to specify more extraction factors. This research aimed to emphasize the importance of extractant selection in determination of bioactive compounds from plants. Our results highlights that selecting the proper extractant is essential for determination of total polyphenolic content, however, the analysis if antioxidant power is not sensitive for extraction agents.