Josef Balík

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.

Advanced liquid chromatography/mass spectrometry profiling of anthocyanins in relation to set of red wine varieties certified in Czech Republic.

Hyphenation of micro-liquid and ultra-performance liquid chromatography with a hybrid (QqTOF) tandem mass spectrometry was studied from the viewpoint of their applicability for monitoring of anthocyanin dyes in various cultivars and different vintages of red wine. After appropriate optimization both techniques proved to be suitable for this task. UHPLC system provided lower LOD and LOQ values as well as higher productivity and precision of retention parameters and peak areas with respect to micro-LC method. On the other hand, micro-LC method offers significant savings of mobile phase, less contamination of ion source of mass spectrometer and makes the nebulization process in electrospray much easier. In combination with principal component analysis (PCA), the method allows to elucidate long-term relations in a complete set of certified red wine cultivars grown in South Moravia (certified in Czech Republic until year 2005). Among the studied varieties Rubinet exhibit a specific anthocyanin profile. Especially interesting is a high content of 3-coumaroylglucoside-5-glucosides of malvidin and peonidin. Those dyes can be used as markers of artificial color enhancement. Principal component analysis applied to data processed with regard to enzymatic activity markedly facilitate classification among varieties. This approach allows resolution of teinturiers, variety Blaufränkish and partial classification of other varieties.

Various Extraction Methods for Obtaining Stilbenes from Grape Cane of Vitis vinifera L.

Grape cane, leaves and grape marc are waste products from viticulture, which can be used to obtain secondary stilbene derivatives with high antioxidant value. The presented work compares several extraction methods: maceration at laboratory temperature, extraction at elevated temperature, fluidized-bed extraction, Soxhlet extraction, microwave-assisted extraction, and accelerated solvent extraction. To obtain trans-resveratrol, trans-ε-viniferin and r2-viniferin from grape cane of the V. vinifera variety Cabernet Moravia, various conditions were studied: different solvents, using powdered versus cut cane material, different extraction times, and one-step or multiple extractions. The largest concentrations found were 6030 ± 680 µg/g dry weight (d.w.) for trans-resveratrol, 2260 ± 90 µg/g d.w. for trans-ε-viniferin, and 510 ± 40 µg/g d.w. for r2-viniferin. The highest amounts of stilbenes (8500 ± 1100 µg/g d.w.) were obtained using accelerated solvent extraction in methanol.

Comparison of anthocyanins present in grapes of Vitis vinifera L. varieties and interspecific hybrids grown in the Czech Republic

Anthocyanins present in the grapes of nine grapevine (Vitis vinifera L.) varieties and ten interspecific hybrids were compared. Total anthocyanin levels were determined in fresh grapes and the values ranged from 0.50 g kg−1 to 4.99 g kg−1. A total of twenty-two different anthocyanins were identified. Malvidin 3-glucoside was the most abundant anthocyanin, with concentrations ranging from 30 % to 64 % of the totals observed. The ratio of acetylated to coumaroylated malvidin and peonidin derivatives ranged from 0.09 (variety: Regent) to 1.34 (variety: Cerason), depending on the variety. Diglucosylated anthocyanins were not found in particular interspecific hybrids such as the teinturier XIV 26–56, Laurot, Merlan, and Nativa.

Musts with an increased content of lignans from added spruce knot chips

Novotná P., Tříska J., Híc P., Balík J., Vrchotová N., Strohalm J., Houška M. (2016): Musts with an increased content of lignans from added spruce knot chips. Czech J. Food Sci., 34: 318–324. Red and white musts were enriched with the lignan hydroxymatairesinol, which is the main lignan contained in spruce knots. Chips from the milled spruce knots were then used to enrich grape musts. After enrichment, the musts were stored and samples were taken in 1, 5, 9, and 12 months. The samples were subjected to a variety of analyses and sensory evaluations. Analyses included hydroxymatairesinol and alpha-conidendrin content, antioxidant activity (determined by the FRAP method), content of total polyphenols, sensory evaluation (intensity of woody aroma, intensity of bitterness and astringent taste, and consumer acceptability), and must antimutagenicity. The analysis of variance allowed predicting which factors such as grape type, quantity of added wood chips, sugar addition, method of preservation, and storage time had the most significant influence on the analytical parameters (lignan content, antioxidant activity, and total polyphenol content). In all cases lignan content in the musts was significantly influenced by the addition of spruce wood chips. Total polyphenol content in the musts was significantly affected by the type of musts and by heat treatment (time of thermomaceration). Evaluation of must antimutagenicity showed that all samples, except the sample of white musts after thermomaceration without holding at temperature and without adding chips (10 g/20 kg mash), inhibited mutagenicity.

Cross-correlation of quality parameters of musts and wines enriched with lignans.

Novotná P., Tříska J., Híc P., Balík J., Vrchotová N., Strohalm J., Houška M. (2016): Cross-correlation of quality parameters of musts and wines enriched with lignans. Czech J. Food Sci., 34: 24–31. Hydroxymatairesinol (HMR) is the main lignan found in spruce knots. This lignan has been used for enrichment of musts and wines. Quality parameters of these products have been studied for several years and for storage times up to one year. Parameters included HMR concentration, antioxidant activities expressed as ferric reducing antioxidant power and 2,2-difenyl-1-picrylhydrazyl, total polyphenols, and sensory parameters, i.e. consumer acceptability. The main goal of this work was to study and provide relationships between the above mentioned quality parameters. We analysed cross-correlations of all these parameters and found statistically significant correlations between lignan concentration and consumer acceptability, which can be phrased as a warning against high lignan concentrations. The strongest correlations were found between antioxidant parameters and total polyphenol content that supports the antioxidative behaviour.

Variability in the Content of Trans-Resveratrol, Trans-ε-Viniferin and R2-Viniferin in Grape Cane of Seven Vitis vinifera L. Varieties during a Three-Year Study

Grape canes are a waste product from viticulture that show potential as an industrially extractable source of stilbenes, which are valuable for medical and other purposes. In this work, grape canes collected in three consecutive years (2014–2016) at six different places in South Moravia, Czech Republic were extracted, and the contents of trans-resveratrol, trans-ε-viniferin, and r2-viniferin were determined by high-performance liquid chromatography. The study included three blue grape varieties of Vitis vinifera L. (Cabernet Moravia, Blaufränkisch, and Piwi variety Laurot) and four white grape varieties (Chardonnay, Green Veltliner, Piwi variety Hibernal, and Piwi variety Malverina). From the viewpoint of producing extracts with high stilbenes content, the Hibernal variety is clearly the best. The mean amounts of the stilbenes for this variety at all localities and for all three years were 4.99 g/kg for trans-resveratrol, 3.24 g/kg for trans-ε-viniferin, and 1.73 g/kg for r2-viniferin. The influence of vintage, locality, and variety on the amounts of stilbenes was studied using PCA analysis. In contrast to expectations, there was no strong impact of locality on stilbenes content. The differences were varietal for most varieties, regardless of the area of cultivation. Laurot and Hibernal varieties did differ significantly in that respect, however, as they exhibited clear dependence on location.

Varietal Distributions of Stilbenes in Grape Cane of Vitis vinifera L.

Abstract Grape cane is a waste product from viticulture, which can be used as a source of stilbenes, such as resveratrol and viniferins with high antioxidant values. These stilbenes have also important healthy effects for humans. Resveratrol and viniferins are known as phytoalexins since 1977. Biomass of grape canes in annual pruning is a very valuable source of stilbenes, e.g. trans-resveratrol, and trans-ε-viniferin in dry grape canes. The main goal of this article was to compare the distribution of resveratrol and viniferins in the grape cane varieties of Laurot, Hibernal, Malverina and Chardonnay. The highest content of trans-resveratrol was found in Hibernal (6,111 mg kg−1); for trans-ε-viniferin and r2-vinifein, the highest levels were found in Malverina (2,211 and 654 mg kg−1). These compounds can be obtained from this waste product (grape cane), by easy extraction process in winemaking or food-processing industry.

Comparison of the influence of defined storing conditions on asian and european pear cultivars

The study observed changes in the material composition of European (Conference) and Asian (Yali) pears during the storage period at different temperatures. Three different temperatures were selected for storing, i.e. 1 °C, 5 °C and 20 °C. Assessed for each of the pieces of fruit were flesh firmness, titratable acidity, soluble solids content, content of organic acids, and production of ethylene and carbon dioxide. Fruit stored at 1 °C and 5 °C was analysed before the moment of putting to the store and then after 25, 55 and 70 days of storing. Fruit stored at 20 °C was analysed before the moment of putting to the store and then after 14, 22 and 30 days of storing. The respiration intensity observed through carbon dioxide production at refrigeration conditions was approximately of the same progress for both of the varieties. For the Yali variety, the intensity of respiration of the fruit at the start of the storing period strongly decreased.The same progress was recorded for the Conference variety. Storing at 20 °C increased the respiration intensity. The varieties Yali and Conference which were stored under the temperature of 5 °C had the highest CO 2 production after 70 days of storage. For both varieties the lowest ethylene production during storage was observed at 1 °C. Ethylene production was higher in Yali pear fruits. The Yali variety stored at 20 °C from the beginning produced up to 10 times higher concentration of ethylene than the fruit of the Conference variety. The highest amount of ethylen by the Conference variety was produced by the fruits which were stored under the temperature of 5 °C. At the beginning of the storage period the Conference pears had two-fold higher flesh firmness than the Yali fruit. Fruits of the varieties Yali and Conference which were stored 70 days under the temperature of 1 °C had the highest flesh firmness. For soluble solids and titratable acidity no clear progress was recorded. Malic acid was predominant in both varieties. The Yali fruit contained more citric acid than the Conference fruit. In both varieties soluble solids gradually increased in the early days of storage at all of the monitored temperatures.

The possibilities of increasing lignan content in food

Lignans are bioactive substances which belong to polyphenols. This compounds can be found in plants including coniferous trees. Lignans are secondary plant metabolites with wide range of biological effects, such as antimicrobial, antivirus or anticancer. They also serve as antioxidants and are naturally occurring compounds which are found in food rich in fibre. There are more than 200 lignans that originate from more than 70 plant families. They can be found in all parts of the plant, mainly in seeds. Almost 37% of total lignan intake in human diet comes from drinking tea and coffee. Fruit and vegetable contain only about 1% of lignans, but they are also significant source of lignans because they are consumed in higher amounts than seeds. 7-hydroxymatairesinol is the main representative of lignans. It is white powder with great health benefits and it is present in the knots of coniferous trees, especially in knots of spruce. Lignans were extracted from the knots and used for fortifying fruit and vegetable spreads. Subsequently, the fortified products became subject to sensory analysis, their antioxidant capacity was measured by the FRAP method, total polyphenols content was found and lignan content determined using the HPLC method. The aim was enriching commonly consumed foods by healthy lignans to avoid negative effects on the sensory quality of these products by the bitter taste of the lignan extract. Of the tested foods, plum jam and red pepper paste are the best options as they best block the bitter taste of lignans. There was a positive increase in antioxidant capacity in food products fortified by the lignan extract. For plum jam, strawberry jam, strawberry spread and red pepper paste, the more lignans were added to the products, the greater was the level of antioxidant capacity. The highest antioxidant capacity was reached in samples with the added amount of 340 mg of lignan per kg of product. As with the antioxidant capacity, total polyphenols content is dependent on the quantity of added lignans. Plum jam is the only exception, for which there was no statistically evident difference between the doses of 170 mg and 340 mg of lignans per kg. The values of lignans measured for samples with added 340 mg of lignans per kg range from 313 mg to 339 mg. For samples with addition of 170 mg of lignans per kg the measured values range from 129 to 164 mg per kg. Although lignans are beneficial for health, they are not acceptable to deteriorate taste of the product. The samples containing the highest dose of lignans, i.e. 340 mg of lignans per kg, were rated as the least acceptable by consumer. Evaluated as the most suitable in this regard was plum jam with a dose of 170 mg of lignans per kg of product where lignans were not found to possess a sensory effect on the acceptability of the product.