Polyphenols and antioxidant activity in pseudocereals and their products

Pseudocereals are important as gluten-free crops that could be utilized as functional foods. They contain proteins with high biological value and also bioactive compounds such as phenolic compounds, flavonoids, vitamins, and minerals that can possess positive health effects on the body. Three types of pseudocereals (amaranth, buckwheat, and quinoa) were evaluated for polyphenols and antioxidant activity. Spectrophotometric methods were used for the determination of free phenols amount with Folin-Ciocalteu reagent, and total antioxidant capacity (TAC) with DPPH and ABTS reagents. Free phenols, the predominant part of polyphenols, were in pseudocereals in the range from 12.4 to 678.1 mg GAE.100g-1. The highest content of FP was found in buckwheat products (146.8 - 678.1 mg GAE.100g-1); quinoa and amaranth products reached much lower values (up to 226.1 mg GAE.100g-1). Antioxidant activity was in an agreement with the FP amounts order, the highest TAC values were again for buckwheat products (167.3 - 473.9 and 876.9 - 3524.8 mg TE.100g-1), followed by quinoa (78.2 - 100.6 and 738.9 - 984.5 mg TE.100g-1) and amaranth ones (25.0 - 69.7 and 118.2 - 431.4 mg TE.100g-1). A high positive correlation between FP amount and TAC values was evaluated for analyzed pseudocereals. The highest content of free phenols and the best antioxidant potential showed buckwheat wholemeal flour, so buckwheat could be characterized as a great source of free phenols with high antioxidant activity. © 2020 Potravinarstvo Slovak Journal of Food Sciences, Licence

Bioactive compounds evaluation in different types of Czech and Slovak honeys

Honey contains important bioactive compounds (enzymes, phenolic compounds, vitamins, and minerals) with several positive health effects for humans. In the study six types of honey (acacia, rape, floral, multi flower, forest, and honeydew honeys), of Czech and Slovak origin, were evaluated for bioactive compounds by means of color, polyphenols and antioxidant capacity analyses. The brightest color of honeys, the lowest values measured spectometrically, had acacia and rape honeys, followed by floral, and darker multi flower and forest honeys, and honeydew honeys. Polyphenols (PP) amount, determined by spectrophotometric method with Folin-Ciocalteu reagent, was highest for the darkest honeydew honeys, followed by multi flower and forest honey, brighter floral honeys, and rape and acacia honey. Honeys polyphenols were in the range from 54.0 to 254.2 mg GAE.100g -1 . The total antioxidant capacity (TAC) was analyzed by spectrometric methods with ABTS and DPPH reagents. Antioxidant capacity values are in agreement with the PP contents order. They were highest also for honeydew honeys (59.2 - 89.6 and 73.1 - 118.7 mg TE.100g -1 ), followed by multi flower (66.0 and 56.7 mg TE.100g -1 ) and forest honey (56.0 and 49.1 mg TE.100g -1 ), then floral honeys (33.0 - 49.2 and 27.8 - 38.7 mg TE.100g -1 ) and the lowest values for rape (19.0 and 28.1 mg TE.100g -1 ) and acacia (15.5 and 11.3 mg TE.100g -1 ) honey. A positive correlation between color, PP amount and TAC was evaluated for analyzed honeys. Darker honey samples showed higher values of phenolic compounds and antioxidant potential, therefore they belong to the honey types with higher amount of bioactive compounds such as antioxidants. © 2019 Potravinarstvo Slovak Journal of Food Sciences

New insights of the application of water or ethanol-water plant extract rich in active compounds in food

Plants are recognized as natural sources of antioxidants (e.g., polyphenols, flavonoids, vitamins, and other active compounds) that can be extracted by green solvents like water, ethanol, or their binary mixtures. Plant extracts are becoming more used as food additives in various food systems due to their antioxidant abilities. Their application in food increases the shelf life of products by preventing undesirable changes in nutritional and sensory properties, such as the formation off-flavors in lipid-rich food. This review summarizes the most recent literature about water or ethanol-water plant extracts used as flavors, colorings, and preservatives to fortify food and beverages. This study is performed with particular attention to describing the benefits of plant extract-fortified products such as meat, vegetable oils, biscuits, pastries, some beverages, yogurt, cheese, and other dairy products. Antioxidant-rich plant extracts can positively affect food safety by partially or fully replacing synthetic antioxidants, which have lately been linked to safety and health issues such as toxicological and carcinogenic consequences. On the other hand, the limitations and challenges of using the extract in food should be considered, like stability, level of purity, compatibility with matrix, price, sensory aspects like distinct taste, and others. In the future, continuous development and a tendency to use these natural extracts as food ingredients are expected, as indicated by the number of published works in this area, particularly in the past decade.Tomas Bata University in Zlin, TBU: IGA/FT/2023/003Tomas Bata University in Zlin [IGA/FT/2023/003

Fruit and vegetable intake among college students in Nitra - Comparative study

The aim of the study was to collect and analyse the frequency of fruit (fresh, dried, canned and nuts) and vegetable (fresh, tinned, legumes, soya) consumption in the group of 242 respondents aged 19 - 22 years-students of Constantine the Philosopher University in Nitra; to evaluate differences according to field of study and language in which they study (Hungarian or Slovak) by questionnaire method. On the base of collected data it can be concluded that in general the consumption of fresh fruits and vegetables can be considered as very low (only once a day) together with canned and dried fruit (nuts) and tinned vegetable (rarely). Furthermore, the majority of respondents took legumes only 1 - 3 times a week or rarely and soya had never been consumed. The statistically significant differences between college students of PEEH and the rest of assayed group of students had not been confirmed so the higher level of knowledge in health has not been connected with the higher consumption of fruits and vegetables. On the other hand, statistically significant differences have been proved between the following assayed groups of university students: RTH ↔ RTS (χ 7.90, p < 0.05), J ↔ RTH (χ 9.99, p < 0.05), J ↔ RTS (χ 10.00, p < 0.05), J ↔ PEES - SK (χ 9.91, p < 0.05). Statistically significant differences were assayed also in consumption of dried fruits or nuts among the following field of study: J ↔RTS (χ 9.48, p < 0.01), RTH ↔ RTS (χ 12.57, p < 0.05), RTS↔PEES (χ 8.19, p < 0.01). Consumption of fresh vegetables was statistically different between the students J↔RTS (χ 9.95, p < 0.05) and RTS ↔PEES (χ 8.19, p < 0.01). © 2016 Potravinarstvo. All rights reserved

Mapping of traditional and regional varieties of apple trees and pear trees in Kroměříž area

In the present work, the current state and representation of traditional and regional fruit varieties of apple trees and pear trees in the form of high-trunk were surveyed in the territory of southeastern Kroměříž district in the region of the Litenčice Hills. The research was carried out during the years 2009 - 2013. The variety, the age of the tree, the growth characteristics (tree height, trunk thickness, crown diameter and dryness) and health status were evaluated. The record of 972 old fruit trees of apple and pear trees were registered in selected municipalities. Pomological determination was made on 840 trees, of which 700 were apple trees and 140 were pear trees. In total, 104 varieties of apples and 44 varieties of pears were found. The most common apple varieties were 'Baumannova reneta and 'Panenské české and the most common pear varieties were 'Boscova and 'Hardy. Out of the total number of fruit trees recorded, 274 were nominated for conservation in respective genepools, of which 57 were pear trees and 217 were apple trees. The main criteria for this selection were the overall condition of the tree and its perspective, the quality of the fruit, the variety and its importance. The results of this work will be used to restore and settle the existing orchards and alley in the region. The identified species and variety composition will be used for newly established thickets in the extensive farming system and involvement in the territorial system of ecological stability of the studied area.O

Evaluation of fruit anatomy, accumulation and detection of polyphenols in black crowberry (empetrum nigrum) from NW Slovakia

The aim of our research was to connect the detailed study of fruit anatomy of black crowberry (Empetrum nigrum) with identification and detection of the main non-anthocyanin polyphenolic compounds. Our experimental results showed that the highest accumulation of anthocyanin bodies occurred in mature fruits in outer layers during fruit development. The shape of the anthocyanin bodies was most often globular, spherical, hemispherical and intermediate types were present only occasionally. Mature cells of the gynoecium and pericarp generally contain anthocyanin bodies incorporated inside vacuoles. The observed compounds accumulated in cells were rutin, quercetin and catechins, resveratrol, coumaric, p-coumaric, caffeic, ferulic acids, gale, vanilic, syringe, cinnamic and caffeic acids. These compounds were selected because of their proposed positive effects on health. The analyses of the polyphenolic spectrum showed predominance of ferrulic acid together with gallic acid and catechins with quercetin.[VEGA 1/0047/19]; [KEGA 012UKF-4/2019

Polyphenols content and antioxidant activity of paprika and pepper spices

Paprika spices (Capsicium annuum) and black pepper spices (Piper nigrum) are very popular seasonings for culinary and industrial utilization due to the change of sensory quality (taste, aroma, color) of foods and meals with their addition; their health promoting properties; and also, relevant antioxidant activity. Polyphenols are often responsible for the antioxidant capacity of plant products therefore in our study the content of polyphenols (TP) and antioxidant activity (TAA) were assessed in two common culinary spices - paprika spices (12, ground powder spices) and pepper spices (20, unground and ground, black, green, white and colored spices) of Czech, Austrian, and Slovak producers. These parameters were determined using spectrometric method, for total polyphenols method with Folin-Ciocaulteu reagent; the antioxidant activity (TAA) of aqueous and ethanolic extracts of spices was measured by DPPH method with IC50 evaluation. For paprika the total polyphenol content ranged from 14.67 to 28.78 mg GAE.g-1. However, there is only weak connection between the pungency of the spices and the polyphenolic amount, the hotter samples of paprika spices have slightly higher values of TP than sweet types. Also, more pungent paprika products showed a higher potency in scavenging of DPPH free radical than sweeter ones; and ethanolic extracts had slightly higher TAA values (8.73 to 16.17 mg AAE.g-1) than aqueous spice extracts (4.45 to 16.24 mg AAE.g-1). Phenolic amount for pepper spices was assessed in the range of 12.03 to 22.88 mg GAE.g-1. Generally, paprika spices contained more polyphenols than pepper spices. The values of TAA of pepper spices were in the range from 7.07 to 15.81 mg AAE.g-1 for aqueous extracts and from 8.25 to 15.93 mg AAE.g-1 for ethanolic extracts respectively. The highest TAA values were observed for white ground pepper and unground black pepper spices. Unground black pepper samples had higher TAA than ground black pepper. The extent of antioxidant activity of paprika and pepper spices was quite similar. The total phenolics contents in spices were correlated to antioxidant activity only slightly. © 2017 Potravinarstvo Slovak Journal of Food Sciences, License

Reproductive biology of two edible honeysuckles [Lonicera edulis Turcz. ex Freyn., Lonicera kamtchatica (Sevast.) Pojark.] in the conditions of southwestern Slovakia

The formation and development of reproductive organs and fruits was examined for two edible honeysuckle species Lonicera edulis Turcz. ex. Freyn. and Lonicera kamtchatica (Sevast.) Pojark. 'Gerda' using cytological and embryological methods. We found out that the flower initiation has began during June in the conditions of southwestern Slovakia. Male and female arche spores were differentiated before entering winter dormancy. In most cases we have observed normally developed tetrads, normal appearance of microspores, two-celled polen grains and mature pollen grain. In both species a sufficient amount of normally developed pollen grains was observed. Disturbances during female gametophyte development occurred occasionally, most mature ovules contained 7 cells female gametophyte. Our research pointed to fact that the species are protogynous. Flowering usually takes place in the first half of April. The fruits were mature in the second half of May. We have found that 10 to 11 fully developed seeds have evolved in the fruits of both representatives of Lonicera on average. The above results show the suitability of L. edulis and L. kamtchatica cultivation in SW Slovakia with a relatively low risk of fruit loss due to climatic conditions.European CommunityEuropean Community (EC) [26220220180, VEGA 1/0047/19

Black crowberry (Empetrum nigrum L.) flavonoids and their health promoting activity

Nowadays, much research attention is focused on underutilized berry crops due to the high antioxidant activity of fruits. Black crowberry (Empetrum nigrum L.) represents an important source of flavonols (quercetin, rutin, myricetin, naringenin, naringin, morin, and kaempferol) and anthocyanins. The fruit components could be utilised as natural colourants or as a part of functional foods and, because of the high antioxidant activity, the berries of black crowberry can be used in the treatment of diseases accompanied with inflammation, or as an effective antibacterial and antifungal remedy. Moreover, the reduction of lipid accumulation and total cholesterol as well as an improvement of postprandial hyperglycaemia have been proven. This review summarizes for the first time the main antioxidants (flavonoids) of black crowberry fruits, with a focus on their health promoting activity. © 2016 by the authors; licensee MDPI.TBU in Zlin [IGA/FT/2016/008, IGA 11/2016/591 ZF MENDELU, KEGA 038SPU-4/2014

Comparison of antioxidant activity, content of polyphenols and flavonoids in liturgical and common wines

This article deals with the comparison of biologically active substances (antioxidant capacity, content of polyphenols and flavonoids) in samples of common and liturgical wines. For determination were chosen these varieties Pinot Noir, Red Traminer and Chardonnay. The total content of polyphenols and flavonoids were found by visible diode array spectrophotometer. For determination of total antioxidant capacity was used the DPPH test. Results of this paper did not prove a general difference between liturgical and common wines, although between individual samples a statistically significant difference was found. Furthermore, the results show considerably higher values of biologically active substances in red wines Pinot Noir against white wine Red Traminer and Chardonnay - the total antioxidant capacity was considerably in excess of values up to 30 times, the total content of polyphenols up to 50 times and the total content of flavonoids up to 50 times. From the content of biologically active substances point of view, the red wine is recommended for human health. © 2019 Potravinarstvo Slovak Journal of Food Sciences