Comparison of MCFA and Other Methods of Terminating Alcohol Fermentation and Their Influence on the Content of Carbonyl Compounds in Wine

This study deals with the effects of the use of a mixture of medium-chain fatty acids (MCFA) at the end of the alcohol fermentation process on the content of carbonyl compounds in wine. During the experiment, the effects of the addition of MCFA at doses of 10 and 20 mg/L were compared to the termination of alcohol fermentation using cross-flow filtration and chilling treatments. Individual carbonyl compounds were determined by HPLC analysis. The experiment showed that the addition of MCFA caused a reduction of the acetaldehyde content compared to the chilling process, and a reduction of the diacetyl content compared to cross-flow filtration. Throughout the experiment, a lower level of total carbonyl compounds was observed after the addition of MCFA.O

The study of antioxidants in grapevine seeds

Grapevine seeds contain a large amount of antioxidant components, and are therefore recommended in the prevention and treatment of many diseases. For this research, we studied the antioxidant properties of grapevine seeds from the Marlen variety, as evidence suggests that these types have higher resistance against fungal diseases. Through high-performance liquid chromatography with UV/VIS detection, a total of 10 antioxidant components were selected for further investigation, specifically: catechin, epicatechin, rutin, quercitrin, quercetin, caftaric acid, caffeic acid, p-coumaric acid, ferulic acid, and gallic acid. The antioxidant activity was determinated spectrophotometrically through the adoption of three fundamentally different methods (the DPPH assay, the ABTS method, and the FRAP method). Using the Folin-Ciocalteu method, it was possible to determine the content of all the polyphenolic compounds. The results of the assessment antioxidant activity and the content of polyphenolic compounds were recalculated to gallic acid equivalents (GAE). The values of the antioxidant activity as determinated by the DPPH test were 6643 (+-154) mg of GAE; 1984 (+-88) mg of GAE when using the FRAP method; and 812 (+-31) mg of GAE when the ABTS method was utilised. The content of the total polyphenolic compounds came to 6982 (+-221) mg of GAE. The most abundant antioxidant was catechin, with a content of 115 mg.L-1, whilst the least represented compound was ferulic acid (0.139 mg.L-1). Overall, this study showed a high antioxidant potential of grapevine seeds.O

Assesment of the antioxidant activity and content of polyphenolic compounds in grapevine seeds

Our work was focused on the study of the antioxidant properties of grapevine seeds. We monitored the grapevine seeds of 6 cultivars of Vitis vinifera, L. (Nativa, Kofranka, Blaufränkish, Marlen, Cabernet Moravia and Italian Riesling). Antioxidant activity was determined by three principally different methods (DPPH, ABTS and FRAP), the content of the total polyphenolic compounds was determined by the Folin ciocalteu method, and the content of the total flavanols was determined by DMACA reagent (p-dimethylaminocinnamaldehyde). Results are presented as an equivalent of gallic acid in g.L-1, respectively were expressed as g.L-1 of catechin equivalents (DMACA method). The highest values of antioxidant activity were measured in the cultivar Nativa (DPPH - 7.75 g.L-1, ABTS - 4.888 g.L-1, FRAP - 4.25 g.L-1). Conversely, the lowest values of antioxidant activity were detected in the cultivar Kofranka (DPPH - 7.08 g.L-1, ABTS - 4.17 g.L-1, FRAP - 4.55 g.L-1). Cultivar Nativa also reached the highest content of flavonols (3.77 g.L-1). The highest measured values of the content of total polyphenolic compounds were identified in the cultivar Cabernet Moravia (15.2 g.L-1 of GAE). Conversely, the lowest values of the content of total polyphenolic compounds were detected in the cultivar Nativa (8.04 g.L-1). Pearson correlation coefficients were calculated for the existing values between antioxidant activity (DPPH, ABTS, FRAP), contents of flavonols, and contents of total polyphenols. The highest correlation coefficient was found between the DPPH and ABTS methods; specifically, it was 0.857.O

Health Beneficial Properties of Grapevine Seed Extract and Its Influence on Selected Biochemical Markers in the Blood, Liver and Kidneys of Rattus norvegicus

Cadmium (Cd) is a heavy metal that occurs in all areas of the environment, including the food chain. In the body, it causes oxidative stress by producing free radicals that are harmful to the cells. Grape seed extract (GSE) contains a wide range of biologically active components that help to neutralize the adverse effects of free radicals. In this study, the effects of GSE prepared form semi-resistant grapevine cultivar Cerason, which is rich in phenolics, on biochemical markers of brown rats exposed to the effects of cadmium were monitored. GSE increased the plasma antioxidant activity and, in the kidneys and the liver, Cd content was significantly lowered by GSE co-administration. Accordingly, the increase in creatinine content and alanine aminotransferase activity and the decrease of catalase and superoxide dismutase activities caused by cadmium were slowed down by GSE co-administration. The results of this work reveal that grape seed extract offers a protective effect against the intake of heavy metals into the organism.O

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

Study of carbonyl compounds in white wine production

Carbonyl compounds, especially acetaldehyde in white wines which have a detrimental effect on the aroma and overall stability of wine, were studied. Seven wine samples of Grüner Veltliner were produced of one input raw material of grapes, all with different dosage of SO2. The sulfur dioxide was maintained at a fixed level during the maturation process and sampled at six months. The grapes were processed, fermented, aged for three months in stainless steel tanks, prepared for bottling, bottled, and then aged in the bottle. In the samples taken, the volume of acetaldehyde, pyruvate, 2-oxoglutarate, diacetyl, and acetoin was determined by HPLC with diode array detection. Individual forms of SO2 were determined by iodometric titration. The wine that was matured on the lees and without the addition of SO2 (variant (0/0/0)) contained the lowest amount of all compounds measured. For example, the volume of acetaldehyde for this wine was 2.7 mg/L at the end of the experiment. The results of the sensory analysis showed that such wine could compete with wines with higher SO2 content without any problems.O

Phenolic Composition and Antioxidant Activity of Peel, Pulp and Seed Extracts of Different Clones of the Turkish Grape Cultivar ‘Karaerik’

The Erzincan plain is one of the richest regions in Turkey in terms of plant biodiversity. In this region, the famous grape cultivar ‘Karaerik’ has always dominated grape production due to its berry characteristics. The cultivar shows great morphological variation at clonal level. In this study, the total phenolic content and antioxidant activity of peel, pulp and seed extracts of nine ‘Karaerik’ clones sampled from same location were investigated. The Folin–Ciocalteu method was used to determine the total phenolic content of peel, pulp and seed extracts of nine clones. To determine antioxidant activity, three well known assays such as DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), FRAP (Ferric Reducing Antioxidant Power) and TEAC (Trolox Equivalent Antioxidant Capacity) were used. In addition, the correlation between total phenol content and DPPH, FRAP and TEAC was determined. Results showed that among the tissues, seed samples in berries of all clones had the highest total phenol content and antioxidant activity determined by three assays. Seed samples were followed by peel and pulp for total phenolic content and antioxidant activity. Among the nine ‘Karaerik’ clones, Clone 8 had the highest total phenolic content (149 mg GAE/100 g FW) while Clone 3 had the lowest (111 mg GAE/100 g FW). Peel, pulp and seed samples of nine ‘Karaerik’ clones showed strong antioxidant activity in DPPH, FRAP and TEAC assays. In particular, grape seeds were found rich for better in phenolic compounds including gallic acid, quercetin, catechin, chlorogenic acid, caffeic acid and p-coumaric acid. Clones such as 7, 8 and 9 higher antioxidant activity may present great potential for grape breeders and the food industry as well as healthconscious consumers

Nutraceutical and functional properties of peel, pulp, and seedextracts of six ‘Köhnü’ grape clones

Grape production has a long history in the Elazig province and surrounding vicinity andproduced grapes have been used for table consumption and also processed into traditional beverages, ̧Sıra (special non-alcoholic grape juice) and wine. In the Elazig province, the main grape cultivars are‘A ̆gın Beyazı’, ‘Öküzgözü’, ‘Bo ̆gazkere’, ‘ ̧Silfoni’, ‘Tahannebi’, and ‘Köhnü’. Among them, ‘Köhnü’cultivar is highly preferred by consumers due to its black color and perfect berry characteristics. Thecultivar has grown for centuries in different parts of Elazig and shows a great variability for mostof its morphological and biochemical characteristics. In the present study, we aimed to determinemorphological and biochemical traits in six ‘Köhnü’ clones sampled from Elazı ̆g. The cluster weightof six clones was found between 334–394 g. The highest total phenolic content was observed inseeds followed by peel and pulp samples. The seed extract of Clone 2 had the highest total phenoliccontent at 254 mg gallic acid equivalent/100 g fresh weight. The results also showed that peel, pulp,and seed samples of ‘Köhnü’ grape clones had considerable amounts of antioxidant componentsdetermined by DPPH (1,1-Diphenyl-2-picryl-hydrazyl), FRAP (ferric reducing antioxidant power),and TEAC assays and might be rich sources of natural antioxidants. Among the six ‘Köhnü’ clones,Clone 3, and Clone 6 differed from the others in respect to the highest cluster weight, the highestconcentrations of total phenolic content, and antioxidant activity. The results also implied thatall clones could be used potentially as a readily accessible source of natural antioxidants and as apossible pharmaceutical supplement

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

The study of antioxidant components in grape seeds

The paper deals with the study of antioxidant properties of extracts from vine seeds (Vitis vinifera L.) using spectrometric and chromatographic techniques. Ten vine varieties (Cerason, Laurot, Kofranka, Gewürztraminer, Hibernal, Blaufrankisch, Zweigeltrebe, Erilon, Palava, and Welschriesling) obtained from the years 2015, 2016, and 2017 were selected for the study. The antioxidant activity was determined spectrophotometrically using four fundamentally different methods; the content of total polyphenolic compounds was determined using the Folin-Ciocalteu method. In 2015, the content of 14 antioxidants (gallic acid, caffeic acid, coumaric acid, coutaric acid, ferulic acid, fertaric acid, trans-piceid, trans-piceatannol, rutin, quercetin-3-β-d-glucoside, quercitrin, myricetin, catechin, and epicatechin) were studied. The results of the study show the high content of antioxidant components in grape seeds and the differences in content in individual varieties and in individual years.[IGA-ZF/2020-AP006]; [CZ.02.1.01/0.0/0.0/16_017/0002334