Andrea Mendelová

Evaluation of carotenoids, polyphenols content and antioxidant activity in the sea buckthorn fruit

Normal 0 false false false SK X-NONE X-NONE Due to the content of biologically active substances, sea buckthorn ( Hippophae rhamnoides L.) has become the object of great interest of both, experts and the general public. It is appreciated particularly for the high content of vitamins and other biologically active substances, not only in berries but also in leaves and bark. The aim of the study was to evaluate the nutritional quality of sea buckthorn juice prepared from different varieties of sea buckthorn based on the content of total carotenoids, polyphenols and antioxidant activity. In this study we used varieties Hergo, Tytti, Vitaminaja, Raisa, Askola, Dorana, Slovan, Leikora, Bojan, Terhi and Maslicnaja. Content of different components was quantified using spectrophotometry. The total carotenoids content expressed as β-carotene content in juice ranged from 50.63 mg.100 g -1 DM to 93.63 mg.100 g -1 DM, the highest content was in variety Askola and the lowest one in Terhi. Total polyphenols content determined by Folin-Ciocalteu method ranged from 13.03 mg GAE. dm -3 DM to 25.35 mg GAE. dm -3 DM. The highest content was identified in juice of variety Dorana and the lowest one in Raisa. The antioxidant activity quantified by the FOMO method ranges from 45.11 g AA. dm -3 DM to 108.77 g AA. dm -3 DM. The highest antioxidant activity was determined in juice of Dorana and the lowest in variety Bojan

Antioxidant effect of natural honeys affected by their source and origin

Abstract In purpose to examine the antioxidant activity of 15 natural honeys of different origin ABTS method was used, total phenol content and dry matter content of honey samples were determined. Honeys were collected from different locations of Slovakia, Poland and Serbia and were represented as monofloral and multifloral samples (10) which originated from Poland and Slovakia, forest samples (4) originated from Serbia and honeydew honey. Average values of antioxidant activity observed in samples of honeys ranged from 0.62 to 4.63 mmol/kg. The highest antioxidant activity was detected in buckwheat honey and the lowest was shown in acacia honey. By observing the impact of individual honey samples on antioxidant activity it was found that the sample had a highly statistically significant effect. 10 homogeneous groups which varied in the antioxidant activity among each other were established by all 15 samples. Antioxidant activity of honeys could be a positive influence factor in terms of honey differentiation, especially in the case of the forest honeys collected from different places. Monofloral and multifloral honeys (10) established 5 homogenous groups, but in the case of several multifloral honeys which originated from different places of Poland and Slovakia no statistically significant differences were found.

Effect of drying temperature on lycopene content of processed tomatoes.

Recently it has been increasing interest worldwide in the production of dehydrated tomato products, which are used in food industry and in pharmacy. An important indicator of the quality of products, beside the microbiological stability is health safety and lycopene content. The aim of this work was to evaluate the effect of drying temperature on changes of the content of lycopene in selected varieties of tomato. Drying was performed at 45 °C, 70 °C and 90 °C. Varieties of Darina F1, Denar, Kecskemety, Orange, Paulina F1, Sejk F1 were used. Tomatoes were processed into dried slices with the dry matter content of 80-85%. Content of lycopene was determined spectrophotometrically. The content of lycopene in fresh tomatoes ranged from 63.378 mg 100 g -1 of dry matter (Orange) to 302.37 mg 100 g -1 of dry matter (Sejk F1). After drying at all temperatures, content of lycopene decreased on average of 64.48 to 68.3%. The most significant changes were found at temperature of 90 °C. Based on the results the most appropriate temperature for drying among the monitored temperatures was at 70 °C, in this case the content of lycopene in the product ranged from 12.839 mg 100 g -1 dry matter (Orange) to 115.9 mg 100 g -1 of dry matter.

ANALYSIS OF CAROTENOIDS AND LYCOPENE IN TOMATO (LYCOPERSICON ESCULENTUM MILL.) AND THEIR RETENTION IN TOMATO JUICE

800x600 Normal 0 21 false false false SK X-NONE X-NONE In this work we investigated the effect of variety and processing on the content of carotenoids and lycopene in fruits and Tomato juice from the fruit after heat treatment. The experiment included four varieties are edible tomato for industrial processing (Bab, Žiara PK, Sampion and Roti PK). The concentration of total carotenoids and lycopene were determined spectrophotometrically on UV-VIS spectrophotometer Jenway at a wavelength of 445 and 472 nm. The highest average content of carotenoids in fruits were recorded at a variety Roti PK (7.0 mg/100 g -1 ) and lowest in variety Bab (4.8 mg/100 g -1 ). Heat treatment had a statistically significant positive effect on the lycopene content, changes in carotenoid content were not significant. Effect of genotype (variety) for the content of the endpoint was significantly important. doi:10.5219/195 Normal 0 21 false false false SK X-NONE X-NONE

Evaluation of primary and secondary metabolites in selected varieties of potatoes.

The aim of study was to determine primary and secondary metabolites in selected varieties of potatoes. Potatoes ( Solanum tuberosum L.) are good source of bioactive compounds, mainly phenols as one of the most important components. The chemical composition with reducing sugar, starch, ascorbic acid, total polyphenol and flavonoid content were analyzed in five potato varieties (Agria, Marabel, Red Anna, Picasso, Princess). Values of dry matter content ranged from 20.34 to 23.64%. In terms of tubers storage, its content above 20% is required. The highest level of starch was detected in variety Princess (16.82%). The lowest reducing sugar content was recorded by variety Marabel (0.08%). Similarly, low values reached varieties Princess (0.12%), Agria (0.14) and Red Anna (0.16%). These would be appropriate to use for food processing and for production of fried potato chips or fries. Variety Red Anna reached the highest amount of vitamin C (73.72 mg.kg -1 ). The lower levels of this vitamin showed tubers of varieties Picasso (35.02 mg.kg -1 ) and Princess (36.89 mg.kg -1 ). The antioxidant activity was measured with radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical as well as phosphomolybdenic assay. Potato varieties contained high levels of total polyphenols (0.474 – 1.550 mg GAE per dry weight) and flavonoids (1.407 – 15.933 μg QE per dry weight). The consumption of potatoes can provide nutritional value along with antioxidant potential that can be helpful for proper functioning of the body physiological systems. Statistical evaluation by the single factor analysis of variance detected high significant impact of variety on the content of all the analytical parameters in evaluated varieties of potato tubers. Normal 0 21 false false false SK X-NONE X-NONE

Sauvignon wine quality as affected by its processing and storage

The colour and limpidity are the first sensory attributes of wines that are appreciated by consumers, predisposing their acceptance or rejection. The aim of this work was to monitor the effect of harvest, processing (different clarification and treatment of must) and storage on the quality of Sauvignon wine. The wines were stored for two years in the wine cellar at 12°C and 70 % of humidity, in the bottles. The acid content, residual sugar and alcohol content among chemical parameters and sensory profile of wines were observed. Sensory quality of wines was evaluated by the aromatic profile (profile method). Based on acquired results, two years of wine storage significantly affected the total acid content of wines and alcohol content. Different treatments of must affected residual sugars, the variant with the maximum dose of the clarification preparation (highly pure cellulose, polyvinylpolypyrrolidone, gelatin and mineral adsorbents) showed statistically the highest content of residual sugars. From the sensory point of view, sensory profiles of wines were different compared to the first and second harvest of grape, sensory profiles of wines were changed also after two years of storage. The fourth variant appeared to be the best stable, treated with the addition of clarification preparation at the dose of 30 g. 100 L-1 must. Because from the same variety Sauvignon were produced wines of different chemical and sensory qualities, some gastronomy recommendations were done as well.

Winter squash (Cucurbita moschata Duch) fruit as a source of biologically active components after its thermal treatment

To one of the most valuable pumpkin fruit belongs winter squash ( Cucurbita moschata Duch). The aim of this work was to assess the quality of C. moschata fruit and to assess the dynamics of compositional changes after the heat treatment of the pulp. We used six varieties Liscia, Orange, Hannah, UG 201 F1, Waltham, Serpentine. In the samples were analyzed carbohydrate content (glucose, fructose and sucrose), total polyphenols, total carotenoids and antioxidant activity. The fresh pulp and pulp after the heat treatment were observed. Content of carbohydrates was determined by FTIR infrared spectroscopy. Content of total carotenoids, polyphenols and antioxidant activity was determined by spectrophotometry. As the dominant sugar was found to be sucrose. The lowest content of all carbohydrates was found in the variety Serpentine. Fructose content ranged from 7.59 to 12.32 g.100 g -1 dry matter, glucose content from 7.23 to 9.79 g.100 g -1 dry matter and sucrose content 38.67 to 55.94 g.100 g -1 dry matter. After processing there was found a decrease in the sucrose and the slight increase in glucose and fructose content. Total carotenoid content in fruits ranged from 39.01 to 97.67 g mg.100 g -1 dry matter, the content of total polyphenols from 443.98 to 565.44 mg GAE.100 g -1 dry matter and antioxidant activity from 680.18 to 851.87 mg AA.100 g -1 dry matter. After the heat treatment, there was found some decrease in total carotenoids, polyphenols and antioxidant activity as well.

Effect of grape seed extract on quality of raw-cooked meat products

In the present study we aimed to evaluate the oxidative stability of Spis frankfurters after application of grape seeds extracts (Blauburger + Cabernet Sauvignon and Danube) in amount of 10 mL.kg -1 during 12 days of their storage at 4 °C. Sensory evaluation of Spis frankfurters was carried out after 4 days of storage by 6-point ranking system (Surface appearance and color, appearance and color when cut, texture, aroma and flavor). It was found that sensory quality of Spis frankfurters was not significantly ( p >0.05) affected by application of grape seed extracts. Oxidation stability of Spis frankfurters after 12 days of storage at 4 °C was positively influenced ( p ≤0.05) only in the group with addition of extract made from grape seed Blauburger +Cabernet Sauvignon. This may probably related with the higher antioxidant activity of extract of this variety (100.5%) compared to an extract made from grape seed variety of Danube (55.8%). Also, it was not found significant differences ( p >0.05) of antioxidant activity between extract made from grape seeds variety Danube compared with the control group. Normal 0 21 false false false SK X-NONE X-NONE

Quality assessment of juice prepared from different varieties of currant (Ribes L.)

In the Slovak Republic currants are traditionally grown species of small fruits mainly in house gardens. Although currently their area is very small compared to the other types of fruit. We can see the importance of growing this genus ( Ribes L.) in its good adaptability to climate conditions, in small growing demands and in stable production of nutritionally highly valuable fruit. Currant berries as well as fresh currant juice are characterized by the presence of whole complex of antioxidant active substances. The aim of this study was to evaluate the nutritional quality of currant juice prepared from various species and varieties of genus Ribes (L.). based on the content of their total polyphenols, anthocyanin dyes and antioxidant activity. In work we used varieties Blanka, Primus, Viktoria, Heinemannova neskora, Red Lake, Treny, Jonkheer van Tets, Fertodi, Titania, Triton and Ojebyn. Contents of evaluated components were assessed spectrophotometrically. Total polyphenol content of monitored samples determined by the Folin-Ciocalteu method reached values from 1897.43 mg GAE.dm -3 DM to 3712.21 mg GAE.dm -3 DM. The highest one was in juice from variety Primus and the lowest from variety Blanka. In white varieties of currant, the presence of anthocyanin dyes was immeasurable. In varieties of red and black currant anthocyanin dye content achieved values from 1947.64 mg.dm -3 DM (Jonkheer van Tets) to 4161.07 mg.dm -3 DM (Heinemannova neskora). The antioxidant activity determined by the FOMO method reached values from 4130.42 mg AA.dm -3 DM to 6571.69 mg AA.dm -3 DM. We recorded the highest antioxidant activity in juice of variety Fertodi and the lowest of variety Primus.

The Dynamics of Changes in Nutritionally Significant Ingredients of Carrot Juice after the Pasteurization

Abstract Carrot (Daucus carota L.) belongs to the most common type of vegetable because of its consumption, versatile usage in the canning industry and because of its beneficial effects on the health of consumers. It is valuable mainly because of the high content of β-carotene, B vitamins, vitamin C, carbohydrates and minerals. The aim of this work was to compare the quality of carrot juice from different varieties of carrots regarding the content of total carotenoids and polyphenols and also to assess the dynamics of their changes evaluated under the influence of the pasteurization (85 °C). There were selected varieties of carrot such as Baltimore F1, Exhibition F1, Kamaran F1, Napoli F1, Belgrado F1, Komarno F1, Nantes, Rubina and Nandrin F1. The highest content of carotenoids, assessed by the spectrophotometry, was determined in variety Kamaran F1 (213.66 mg 100 g−1 dry matter) and the lowest in Belgrado F1 (146.80 mg 100 g−1 dry matter). After the pasteurization, the content of carotenoid decreased and ranged from 128.04 mg 100 g−1 dry matter in variety Napoli F1 to 142.55 mg 100 g−1 in Kamaran F1. The highest content of polyphenol determined by the Folin Ciocalteu method was found in fresh juice of Rubina (922.80 mg GAE 100 g−1 dry matter) and the lowest in the variety Nantes (535.75 mg GAE 100 g−1 dry matter). After the pasteurization, the content of the monitored components was found to be 450.34 mg GAE 100 g−1 dry matter in Napoli F1 to 751.95 mg GAE 100 g−1 dry matter in Komarno F1 variety.