Tunde Jurikova

Bioactive Compounds and Antioxidant Activity in Different Types of Berries

Berries, especially members of several families, such as Rosaceae (strawberry, raspberry, blackberry), and Ericaceae (blueberry, cranberry), belong to the best dietary sources of bioactive compounds (BAC). They have delicious taste and flavor, have economic importance, and because of the antioxidant properties of BAC, they are of great interest also for nutritionists and food technologists due to the opportunity to use BAC as functional foods ingredients. The bioactive compounds in berries contain mainly phenolic compounds (phenolic acids, flavonoids, such as anthocyanins and flavonols, and tannins) and ascorbic acid. These compounds, either individually or combined, are responsible for various health benefits of berries, such as prevention of inflammation disorders, cardiovascular diseases, or protective effects to lower the risk of various cancers. In this review bioactive compounds of commonly consumed berries are described, as well as the factors influencing their antioxidant capacity and their health benefits.

Edible Flowers—A New Promising Source of Mineral Elements in Human Nutrition

On a global scale, people are demanding more attractive and tasty food. Both the quality of foodstuffs and aesthetic aspects contribute to the appearance of consumed meals. The attraction and appeal of individual dishes could be enhanced by edible flowers. New information concerning the composition and nutritional value of edible flowers is also important and represents a sufficient reason for their consumption. The aim of this study is to contribute to the popularization of some selected edible flowers of ornamental plants involving altogether 12 species. The flowers were used to determine their antioxidant capacity, which fluctuated between 4.21 and 6.96 g of ascorbic acid equivalents (AAE)/kg of fresh mass (FM). Correlation coefficients between antioxidant capacity and the contents of total phenolics and flavonoids were r2 = 0.9705 and r2 = 0.7861, respectively. Moreover, the results were supplemented with new data about the mineral composition of edible flowers (mostly, not found in the available literature). The highest levels of mineral elements were observed in the flowers of species Chrysanthemum, Dianthus or Viola. The most abundant element was potassium, the content of which ranged from 1,842.61 to 3,964.84 mg/kg of FM.

Selected cultivars of cornelian cherry (Cornus mas L.) as a new food source for human nutrition

The aim of this work was to determine antioxidant activity in 12 cultivars of cornelian cherry (Cornus mas L.). Two assays based on ion reduction of ABTS (2,2´-azinobis(3-ethylbenzothiazoline-6sulphonate) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals were used for antioxidant activity. Total phenolic content of the fruit was analysed by Folin-Ciocelteau colorimetric method and ascorbic acid content was analysed using column chromatography - electrochemical detector (Coulochem III). The

Polyphenolic Profile and Biological Activity of Chinese Hawthorn (Crataegus pinnatifida BUNGE) Fruits

Chinese hawthorn (Crataegus pinnatifida Bge.) fruits are rich in polyphenols (e.g., epicatechin, procyanidin B2, procyanidin B5, procyanidin C1, hyperoside, isoquercitrin and chlorogenic acid)—active compounds that exert beneficial effects. This review summarizes all information available on polyphenolic content and methods for their quantification in Chinese hawthorn berries and the relationships between individual polyphenolic compounds as well. The influence of species or cultivars, the locality of cultivation, the stage of maturity, and extract preparation conditions on the polyphenolic content were discussed as well. Currently, only fruits of C. pinnatifida and C. pinnatifida var. major are included in the Chinese Pharmacopoeia. Recent trials have demonstrated the efficacy of Chinese hawthorn fruit in lowering blood cholesterol and the risk of cardiovascular diseases. The fruit has also demonstrated anti-inflammatory and anti-tumour activities. This review deals mainly with the biological activity of the fruit related to its antioxidant properties.

Phenolic content and antioxidant capacity in algal food products

The study objective was to investigate total phenolic content using Folin-Ciocalteu’s method, to assess nine phenols by HPLC, to determine antioxidant capacity of the water soluble compounds (ACW) by a photochemiluminescence method, and to calculate the correlation coefficients in commercial algal food products from brown (Laminaria japonica, Eisenia bicyclis, Hizikia fusiformis, Undaria pinnatifida) and red (Porphyra tenera, Palmaria palmata) seaweed, green freshwater algae (Chlorella pyrenoidosa), and cyanobacteria (Spirulina platensis). HPLC analysis showed that the most abundant phenolic compound was epicatechin. From spectrophotometry and ACW determination it was evident that brown seaweed Eisenia bicyclis was the sample with the highest phenolic and ACW values (193 mg·g−1 GAE; 7.53 µmol AA·g−1, respectively). A linear relationship existed between ACW and phenolic contents (r = 0.99). Some algal products seem to be promising functional foods rich in polyphenols.

Antioxidant and radical oxygen species scavenging activities of 12 cultivars of blue honeysuckle fruit.

Abstract Rop O., Řeznicek V., Mlcek J., Jurikova T., Balik J., Sochor J., Kramařova D., 2011. Antioxidant and radical oxygen species scavenging activities of 12 cultivars of blue honeysuckle fruit . Hort. Sci. (Prague), 38 : 63–70.The fruit of blue honeysuckle ( Lonicera caerulea L. var. kamtchatica (Sevast.) Pojark.) belongs to the fruit of great value because of itsunique chemical composition. The aim of our measurement of this fruit species was to select the cultivars which could be the most suitable food supplement in relation to strengthening human immunity system. The comparison of the fruit of 12 cultivars was made. The highest contents of polyphenolic substances were recorded in the cultivar Zolushka with the value of 9.03 g of gallic acid/kg fresh mass. In particular cultivars the DPPH (2,2-diphenyl-1-picrylhydrazyl) test was performed to determine antioxidant activity which ranged from 6.59–10.17 g of ascorbic acid equivalent/kg fresh mass. For comparison, scavenging activity of reactive oxygen species (superoxide anion, hydroxyl radical, and nitric oxide) was determined by using a 25% methanolic extract of fruit of particular cultivars. Antioxidant potential was also assessed using the rat liver slice model. The highest values of scavenging activity were found in the cultivars Zolushka, Goluboe vreteno, and Gerda. The cultivars Zolushka, Goluboe vreteno, and Gerda had also high values of flavonoids. The presented results may be used when popularizing this fruit species and also when studying the properties of new food and genetic resources.

Effect of five different stages of ripening on chemical compounds in medlar (Mespilus germanica L.).

The study of changes of nutritional value of fruit during the ripening process can help estimate the optimal date for fruit harvesting to achieve the best quality for direct consumption and further utilization. The aim of this study was to monitor the changes of chemical composition of medlar fruit (Mespilus germanica L.) measured at five various ripening stages including 134, 144, 154, 164 and 174 days after full bloom (DAFB). Fruits were analyzed and ascorbic acid (AA) and total phenolic compound content with respect to the total antioxidant activity were determined. In addition, selected micronutrients and macronutrients were monitored. The results of our experiments demonstrate that ascorbic acid, total phenolic compound content and total antioxidant activity decreased significantly with increasing time of ripeness. The decreasing tendency in potassium, calcium and magnesium contents during the ripening stages was also determined. During the ripening period, the content of all micronutrients as well as phosphorus and sodium was balanced, with no statistically significant differences between the monitored ripening stages, which can be considered as a positive fact with respect to ideal consumption quality of fruit.

Use of Liquid Chromatography with Electrochemical Detection for the Determination of Antioxidants in Less Common Fruits

Neurodegenerative disorders (NDD) have become the common global health burden over the last several decades. According to World Health Organization (WHO), a staggering 30 million people will be affected by Alzheimer’s disease in Europe and the USA by 2050. Effective therapies in this complex field considering the multitude of symptoms associated with NDD indications, have not been found yet. Based on the results of NDD related studies, prevention appears to be the promise alternative. Antioxidative and anti-inflammatory properties are hypothesized for natural phenolics, a group of plant secondary products that may positively impact neurodegenerative diseases. In these studies, phenolic-rich extracts from less common fruit species: Blue honeysuckle (Lonicera edulis, Turcz. ex. Freyn), Saskatoon berry (Amelanchier alnifolia Nutt.), and Chinese hawthorn (Crateagus pinnatifida Bunge) were obtained and analyzed to detect neuroprotective substances content and establish a potential therapeutic value. High performance liquid chromatography with electrochemical detection was optimized and further applied on analysis of the extracts of less common fruit species. It was observed that Chinese hawthorn and Blue honeysuckle extracts are potent source of neuroprotective phenolic antioxidants. In accordance the results, it appears that the fruit or formulated products may have the potential for the prevention of neurodegenerative diseases.

Antioxidant properties of European cranberrybush fruit (Viburnum opulus var. edule)

In the literature there is little available information concerning European cranberrybush fruit (Viburnum opulus var. edule). This plant can be cultivated, even in harsh climatic conditions, because of its low environmental demands, and it is possible to harvest the fruit even in the snow cover. The aim of this study was to determine the content of polyphenolics, antioxidant activity, flavonoids and vitamin C in the fruit of three cultivars ´Leningradskaya otbornaya´, ´Souzga´ and ´Taezny rubiny´ of this species. In the case of polyphenolics, high contents [up to 8.29 g of gallic acid/kg of fresh mass (FM)] were observed. The 1,1´-diphenyl-2-picrylhydrazyl (DPPH) and 2,2´-azinobis-3-ethyl-benzthiazino-6-sulphonic acid (ABTS) tests were applied to determine antioxidant activity, which was also high in comparison with other fruit species. The corresponding correlations between the polyphenolic content and antioxidant activity were in case of the DPPH test r2 = 0.88 and for the ABTS test r2 = 0.98. For comparison, the scavenging activity towards reactive oxygen species (superoxide anion, hydroxyl radical and nitric oxide) was determined by using a 25% fruit extract of particular cultivars. Antioxidant efficiency was also assessed using the rat liver slice model. Furthermore, the contents of flavonoids and vitamin C were assayed, giving values of 4.89 g/kg and 1.64 g/kg FM, respectively. The work should contribute to the popularization of this species as a promising crop plant in human nutrition.

Evaluation of Polyphenolic Profile and Nutritional Value of Non-Traditional Fruit Species in the Czech Republic — A Comparative Study

Dry matter, organic acids, ascorbic acid, minerals (nitrogen, phosphorus, potassium, calcium, magnesium, sodium) and polyphenolic profile of a number of non-traditional fruit species and their genotypes, namely blue honeysuckle (Lonicera spp.), Saskatoon berry (Amelanchier alnifolia), black mulberry (Morus nigra), Tomentosa cherry (Prunus tomentosa Thunb.) and jostaberry (Ribes nigrum x Grossularia uva-crispa) were investigated. The results showed that Lonicera genotypes displayed high levels of ascorbic acid and they were rich in minerals, with the cultivar ‘Amfora’ achieving the leading position in nitrogen, phosphorus and potassium content among all lesser known fruit species. Amelanchier cultivars represented a valuable source of ascorbic acid and calcium, ‘Tišňovský’ and ‘Smoky’ together with Morus nigra ‘Jugoslavska’ accumulated the highest level of examined polyphenolic compounds. Regular consumption of studied less common fruit species can bring health benefits so they can represent a high potential value for fruit growers and in addition they can be utilised as functional foods.