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

Bioactive compounds, antioxidant activity, and biological effects of european cranberry (vaccinium oxycoccos)

Lesser known fruits or underutilized fruit species are recently of great research interest due to the presence of phytochemicals that manifest many biological effects. European cranberry, Vaccinium oxycoccos fruit, as an important representative of this group, is a valuable source of antioxidants and other biologically active substances, similar to American cranberry (V. macrocarpon) which is well known and studied. European cranberry fruit is rich especially in polyphenolic compounds anthocyanins (12.4⁻207.3 mg/100 g fw), proanthocyanins (1.5⁻5.3 mg/100 g fw), and flavonols, especially quercetin (0.52⁻15.4 mg/100 g fw), which mostly contribute to the antioxidant activity of the fruit. Small cranberry is also important due to its various biological effects such as urinary tract protection (proanthocyanidins), antibacterial and antifungal properties (quercetin, proanthocyanidins, anthocyanins), cardioprotective (proanthocyanidins) and anticancer activities (proanthocyanidins), and utilization in food (juice drinks, jams, jellies, sauces, additive to meat products) and pharmacological industries, and in folk medicine.internal grant agency of Tomas Bata University in Zlin [IGA/FT/2018/006, VEGA 1/0083/16

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

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

Natural fruit beverages fortified by biologically active substances of grape vines

Based on the study of general knowledge of biochemical and all subsequent developmental studies of organic matter, especially products of grapevine and selected fruit products, a comprehensive study of processing technologies is prepared. Use of a combination of vine products and fruit products in the form of natural grapes. Beverages are researched and developed to be purely natural on the basis of grape musts, blue and white, either individually and again separately in targeted combinations, both biochemically, organoleptically and colorfully, with fruit sources. The core of grape value of biologically active substances is an integral and essential new part and condition of designing these beverages. Their increased biological values, which create the preconditions for containment and if properly managed on the basis of scientific knowledge, may in some cases almost result in the elimination of synthetic additives. It should be noted that 20 - 25% of the adult population suffers from many unexpected allergies, for example, to the sulphite content, although its content in the final product does not exceed the health-approved normatives. And there are many other, interrelated relationships. Beverages are technologically dealt with both without alcohol fermentation and with this fermentation, but only based on their compositional natural resources. They are therefore suitable for the entire population profile. The whole set contains 7 variants and a combination of natural beverages from different fruits. Including natural beverages with or without alcoholic fermentation from the must of white wine grapes, the juice of apple puree with those of biologically active substances from the products grapevine. Three months of monitoring and determination of basic (oenological) values and biologically active substances were performed on these products. The high-performance liquid chromatography method with a refractometric detector determined amount of sugar and alcohol, whilst titrating determined total and volatile acids and free sulfur dioxide. Yeast assimilable nitrogen, total anthocyanins and polyphenols were determined by spectrophotometry, antioxidant activity by DPPH and ABTS methods. © 2019 Potravinarstvo Slovak Journal of Food Sciences

Quercetin and its anti-allergic immune response

Quercetin is the great representative of polyphenols, flavonoids subgroup, flavonols. Its main natural sources in foods are vegetables such as onions, the most studied quercetin containing foods, and broccoli; fruits (apples, berry crops, and grapes); some herbs; tea; and wine. Quercetin is known for its antioxidant activity in radical scavenging and anti-allergic properties characterized by stimulation of immune system, antiviral activity, inhibition of histamine release, decrease in pro-inflammatory cytokines, leukotrienes creation, and suppresses interleukin IL-4 production. It can improve the Th1/Th2 balance, and restrain antigen-specific IgE antibody formation. It is also effective in the inhibition of enzymes such as lipoxygenase, eosinophil and peroxidase and the suppression of inflammatory mediators. All mentioned mechanisms of action contribute to the anti-inflammatory and immunomodulating properties of quercetin that can be effectively utilized in treatment of late-phase, and late-late-phase bronchial asthma responses, allergic rhinitis and restricted peanut-induced anaphylactic reactions. Plant extract of quercetin is the main ingredient of many potential anti-allergic drugs, supplements and enriched products, which is more competent in inhibiting of IL-8 than cromolyn (anti-allergic drug disodium cromoglycate) and suppresses IL-6 and cytosolic calcium level increase. © 2016 by the authors; licensee MDPI.internal grant agency of Tomas Bata University in Zlin [IGA/FT/2016/008, IGA ZF 2016

Polyphenols and antioxidant capacity in different types of garlic

Garlic contains important biologically active compounds such as phytoncides, antioxidants and others. There belong organosulfur compounds, allyl thiosulfinates and phenolic compounds (phenolic acids, flavonoids), vitamins (E and C) and some minerals, that all have several positive effects on human health. In the work five types of raw garlic (Allium sativum) of Czech, Chinese and Spanish origin, and bear's garlic (Allium ursinum), and two dried garlic products, were evaluated for polyphenols content and antioxidant capacity. The highest values of total polyphenols (TP), analyzed by spectrometric method with Folin-Ciocalteu reagent, had fresh samples of bear's and Spanish garlic; the lowest ones were evaluated for Czech garlic bulbs (92.2-119.6 mg GAE.100g-1 fw) and dry garlic products (70.1-84.5 mg GAE.100g-1). The total antioxidant capacity (TAC) was determined by spectrometric methods with DPPH and ABTS reagents. To types of fresh garlic with the best values of antioxidant capacity, evaluated by both methods, belong bear's and Spanish garlic, followed by Chinese and Czech garlic samples. These values are in agreement with polyphenols content in garlic bulbs. Dry garlic products had the highest values of TAC. Content of polyphenols and antioxidant capacity values were positively correlated, higher correlation value was detected for TP and TAC-ABTS (0.973) than for TP and TAC-DPPH (0.873). Bear's garlic and garlic belong to the vegetable types with high amount of biologically active compounds such as antioxidants. © 2018 Potravinarstvo Slovak Journal of Food Sciences

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

Monitoring of bioactive compounds of tomato cultivars as affected by mulching film

The influence of varieties and the effect of mulching film on antioxidant capacity, polyphenol content, ascorbic acid content, and yield of tomato fruits were investigated. Results of two years (2012 and 2013) investigations were compared. The results proved a statistically significant effect of year, mulching film, and variety on the content of total polyphenols (0.92-1.49 g gallic acid equivalents per kg of fresh weight (FW), ascorbic acid (26.66-38.62 mg per 100 g FW), and antioxidant capacity (1.12-1.94 g ascorbic acid equivalents per kg FW), while the values were the highest in 2013 and in uncovered soil. Conversely, a higher yield was found in mulching film compared with uncovered soil, also in 2013 (48.65-120.38 t ha-1). There was a negative correlation between the yield and the content of bioactive compounds (BC) and antioxidant capacity. The content of bioactive substances, antioxidant capacity, and yield of tomato fruits is dependent on the vintage, agronomical interventions, and genotype. © 2018 M. Valšíková et al., published by Sciendo 2018