Proteins of potatoes in relation to the content of cadmium in their tubers

In the work the influence of cadmium in soil on the range of cumulating in tubers of potatoes and in proteins of potatoes grown under model conditions of pot trial experiment and under the real conditions of locality Imeľ in Danube Lowland was surveyed. Under conditions of pot trial the increased contents in tubers positively correlated with contents of cadmium applied into soil; the highest content of Cd was assessed in variety Junior (from 0.211 mg.kg-1 FM in 1st variant to 0.715 mg.kg-1 FM in 4th variant). The influence of increased content of Cd was manifested statistically significant in the content of proteins also in the content of Cd in protein fractions (1st var. 0.026 (Asterix) – 0.045 (Agria) mg.kg-1 FM; 2nd var. 0.047 (Livera) – 0.085 (Asterix) mg.kg-1 FM; 3rd var. 0.06 (Livera) – 0.117 (Junior) mg.kg-1 FM; 4th var. 0.068 (Livera) – 0.142 (Asterix) mg.kg-1 FM). Contents of Cd in potatoes from locality Imeľ did not exceed the value 0.1 mg.kg-1 FM defined in PK SR. The average contents of proteins were in range from 1.19 % (Victoria) to 1.489 % (Adora), the average content of Cd cumulated in proteins was the highest in variety Vivaldi (1.317 μg.kg-1 FM). Positive correlation was confirmed between the content of Cd in potato tubers and in proteins only in Livera variety

Polyphenols in chosen species of legume - a review

Legumes belongs to the most important grain for human consumption. They have been cultivated for thousands of years, and have played an important role in the traditional diets of many regions throughout the world. The most legumes are widely consumed in fresh and processed forms. The traditional way of legume preparation includes soaking in water following by cooking and are usually consumed boiled as soup, occasionally as roasted grains too. Legume are widely known for their nutraceutical value, but there is relatively little information about their polyphenols content (with the exception of soya). Inspite of the fact that phenolics in general are not the substances with nutritious value, the interest in them is still persisting for their positive effects on human health. For these reasons this short review is focused on summary of legume polyphenols – identification and quantification of phenolic acids, flavonoids and tannins in raw or processed legumes and their role in these crops. Monitoring and surveying of the changes of polyphenolic compounds contents thus complete knowledge about bioactive substances content in legumes species. And seeing that legumes are considered an ideal complement to cereals in diets, they gain increasing attention as functional food items

Dependence among total polyphenols content, total antioxidant capacity and heavy metals content in potatoes

Polyphenols belong to the most significant compounds with antioxidant effects in potatoes. Their content depends on several factors. The most important factor is the variety of potatoes and the conditions of their growing such as temperature, rainfall, altitude, agronomic and chemical characteristics of the soil. We have compared two potato cultivars in the study which have been grown in the Slovak localities Dolné Obdokovce and Vrbová nad Váhom (cv. Agria) and Nitra, Radošina and Vrbová nad Váhom (cv. Impala). In lyophilized samples of potatoes total polyphenols content in ethanolic extracts using Folin-Ciocalteu agens and in methanolic extracts total antioxidant capacity using DPPH were spectrophotometrically determined. The average total polyphenols content in the potato variety Impala was 604.26 ±120.70 mg.kg-1 dry matter (DM) and 529.37 ±59.35 mg.kg-1 DM in the variety Agria. The average value of total antioxidant capacity, expressed in % inhibition, was 8.44 ±1.68% in the potato variety Impala and 8.09 ±1.14% in Agria. The results obtained were evaluated by One-way analysis of variance ANOVA (LSD-test), using Statistical Analysis Software Statgraphics. Mutual correlations among the total polyphenols content, total antioxidant capacity and heavy metals concent (Pb, Ni, Cd - determined using atomic absorption spectrometry (AAS) method: Cd, Pb: GF-AAS and Ni F-AAS) were evaluated using the correlation and regression analysis (Microsoft Excel). Statistically significant interdependence (p <0.05) was only confirmed between the Cd content and total antioxidant capacity in both cultivars, or between the Ni content and total antioxidant capacity in the variety Impala

Polyphenols and phenolic acids in sweet potato (Ipomoea batatas L.) roots

Sweet potato (Ipomoea batatas L.) is one of the most important food crops in the world. They are rich in polyphenols, proteins, vitamins, minerals and some functional microcomponents. Polyphenols are bioactive compounds, which can protect the human body from the oxidative stress which may cause many diseases including cancer, aging and cardiovascular problems.The polyphenol content is two to three times higher than in some common vegetables. Total polyphenols (determined spectrophotometrically) and phenolic acids (i.e. caffeic acid, chlorogenic acid and isomers - using high performance liquid chromatography) contents were determined in three varieties of sweet potatoes (O´Henry - white, Beauregard-orange and 414-purple). Phenolic compounds contents were determined in raw peeled roots, jackets of raw roots and water steamed sweet potato roots. For all analysis lyophilised samples were used. Total polyphenol content ranged from 1161 (O´Henry, flesh-raw) to 13998 (414, peel-raw) mg.kg-1 dry matter, caffeic acid content from the non-detected values (414, flesh-raw) to 320.7 (Beauregard, peel-raw) mg.kg-1 dry matter and 3-caffeoylquinic acid content from 57.57 (O´Henry, flesh-raw) to 2392 (414, peel-raw) mg.kg-1 dry matter. Statistically significant differences (p ≤0.05) existed between varieties, morphological parts of the root, or raw and heat-treated sweet potato in phenolic compounds contents

The influence of variety on the content of bioactive compounds in beetroot (Beta vulgaris L.)

Vegetable are widespread throughout the world and is a major part of the human diet. From the perspective of agricultural crops that belong to the group of Beta vulgaris (beetroot, mangold, sugar beets, fodder beet) are first-rate vegetables. Especially popular is used in the food industry for the production of sugar, various vegetable juices, coloring agents, and many other products. Beetroot (Beta vulgaris L.) is considered one of the ten most important vegetable in the world, thanks to the content of rare natural pigments (betalains), polyphenols, flavonoids, antioxidants, vitamins, minerals and fiber. In this work we evaluated content of bioactive substances, especially the content of total polyphenols, anthocyanins and antioxidant activity in several varieties (Cylindra, Kahira, Chioggia, Crosby Egyptian) of beetroot (Beta vulgaris L.). Samples of plant material were collected at full maturity stages from areas of Zeleneč (Czech Republic). Zeleneč is area without negative influences and emission sources. Samples of fresh beetroot (Beta vulgaris L.) were homogenized and were prepared as an extract: 50 g cut beetroot (Beta vulgaris L.) extracted by 100 mL 80% ethanol for sixteen hours. These extracts were used for analyses. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). The absorbance was measured at 765 nm of wavelength against blank. The content of total anthocyanins was measured at 520 nm wavelength of the blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl) at 515.6 nm in the spectrophotometer. In the present experiment it was detected, that total polyphenols content in samples ranges from 218.00 mg.kg-1 to 887.75 mg.kg-1, total anthocyanins content in samples ranges from 14.48 ±0.40 mg.kg-1 to 84.50 ±4.71 mg.kg-1 and values of antioxidant activity were in interval from 8.37 ±0.29% to 21.83 ±0.35%

Evaluation and comparison of bioactive substances in selected species of the genus Allium

Allium is a genus of some 650 species belonging to the family Liliaceae. However only a few of these are important as food plants, notably garlic (Allium sativum L.), onion (Allium cepa L.), leek (Allium porrum L.) and wild garlic (Allium ursinum L.). They contain many health beneficial substances, such as sulphur compounds, vitamins (vitamin C), mineral substances (Fe, Mg, Ca, P), polyphenols (especielly quercetin) and substances antioxidant activity and fiber. In this work we evaluated the content of bioactive substances, especially the content of total polyphenols and antioxidant activity in several species (red onion, yellow onion, white onion, garlic, leek, wild garlic) of the genus Allium. Samples of plant material were collected at full maturity stages from Zohor (Slovak Republic). Zohor is an area without negative influences and emission sources. Samples of fresh species of the genus Allium were homogenized and prepared as an extract: 25 g cut plants material (red onion, yellow onion, white onion, garlic, leek, wild garlic) extracted with 50 mL of 80% ethanol for sixteen hours. These extracts were used for analyzes. The content of total polyphenols was determined using the Folin-Ciocalteu reagent (FCR). The absorbance was measured at 765 nm of wavelength versus blank. Antioxidant activity was measured using DPPHË™ (2,2-difenyl-1-picrylhydrazyl) at 515.6 nm in the spectrophotometer. In the present experiment it was found that total polyphenols content in samples ranged from 83.59 mg.kg-1 to 758.63 mg.kg-1 and values of antioxidant activity were in the range from 7.19% to 53.55%

Effect of nitrogen application on selected nutritional components of potato tubers

In this work the influence of graduated nitrogene fertilizers doses to the soil on starch and vitamin C formation in potato tubers grown in field conditions in locality Veľká Čalomija was studied. The investigated potato cultivar Solara is medium early potato cultivar. The determined average starch content in potato samples ranged in interval 12,426 % - 15,084 %, while the highest starch content was determined in variant 1 (without nitrogen addition to the soil). The starch content in potato tubers was decreased in order: variant 1 (15,084 %) > variant 2 (14,427 %) > variant 3 (14,378 %) > variant 4 (14,023 %) > variant 5 (12,603 %) > variant 6 (12,426 %). The content of C vitamin was increased with the graduated nitrogen doses to the soil only till variant 4 and after that the content of vitamin C was decreased. The average content of C vitamin ranged in interval 3,786 - 6,225 mg.kg-1 of fresh matter

The role of sulphur on the content of total polyphenols and antioxidant activity in onion (Allium cepa L.)

Sulphur is one of the most important elements in plants. Sulphur also positive influences on growth functions (nitrogen metabolism, enzyme activity and protein and oil synthesis), yield and quality bulbs of onion. In this experiment was watched the progress of making the total polyphenols content in different levels of fertilizer sulphur in onion during vegetation. In the work we watched also the influence of sulphur fertilization on the antioxidant activity. Sulphur was added in amounts 7.3 mg.kg-1 S, 11 mg.kg-1 S and 14,6 mg.kg-1 S. Samples of fresh onion we collected at the beginning, in the middle and in the end of vegetation period and we prepared an extract: 50 g cut onion extracted by 100 ml 80% ethanol according sixteen hours. These extracts were used for experiment. The content of total polyphenols was estimated by using Folin-Ciocalteau reagent. The absorbance was measured at 765 nm of wave length against blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl) at 515.6 nm in the spectrophotometer. Our values of total polyphenolic content during vegetation period  were in range from 508.16 ±27.59 mg.kg-1 to 638.2 ±12.84 mg.kg-1. The highest content of total polyphenolics was recorded at the end of the vegetation period (638.32 ±12.84 mg.kg-1) in III. sampling (incorporation of sulphur in quantity of 14.6 mg S.kg-1soil). This increase was statistically significant (P-value = 2.10-3). The lowest content of total polyphenols was measured in  the middle of vegetation period  (415.41 ±13.32 mg.kg-1) in II. sampling (incorporation of sulphur in quantity of 11 mg S.kg-1soil). Another indicator that has been evaluated and compared was the influence of sulphur fertilization on the antioxidant activity. The highest values of antioxidant activity were recorded at the end of vegetation period in all variants. The lowest value of antioxidant activity (25.41 ±7.67%) was measured in three sampling in II.variant

Evaluation and comparison of the content of total polyphenols and antioxidant activity in onion, garlic and leek

Onion, leek and garlic as onion family are a great source of freely available health-promoting and chemoprotective compounds (polyphenols, flavonoids, fructooligosaccharides, thiosulfinates and other sulfur compounds, vitamins). Chemoprotective compounds belong between natural components. Onion, garlic and leek have high nutritional value. They are an important component of our human diet and we used them as a preventive factor for many diseases of civilization (cancer, coronary heart diseases, and atherosclerosis). In this work we watched and evaluated content of total polyphenols and antioxidant activity in onion, garlic and leek. Samples of plant material (onion, garlic and leek) we collected at the stage of full maturity in the area of Pružina. Pružina is area without negative influences and emission sources. Samples of fresh onion, garlic and leek were homogenized and were prepared an extract: 25 g cut onion, garlic and leek extracted by 50 ml 80% ethanol accourding sixteen hours. These extracts were used for analyses. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). Antioxidant activity was measured by using a compound DPPH (2.2-diphenyl-1-picrylhydrazyl). In the present experiment it was detected, that total polyphenols content in samples ranges from 210.67 mg/kg (leek) - 429.58 mg/kg (onion). Statistically significant highest value of total polyphenols was recorded in onion (389.64 to 429.58 mg/kg). Statistically significant the lowest content of total polyphenols was recorded in leek (210.67 - 254.80 mg/kg). Another indicator that has been evaluated and compared was the antioxidant activity of onion, garlic and leek. Statistically significant highest value of antioxidant activity was recorded in onion (20.22 - 25.76%). Statistically significant the lowest value of antioxidant activity was recorded in garlic (4.05 - 5.07%). Based on the measured values of AOA in onion, garlic and leek samples can be classified as follows: onion (20.22 - 25.76%) > leek (8.55 - 12.92%) > garlic (4.05 - 5.07%)

Varietal dependence of chemoprotective substances in fresh and frozen spinach (Spinacia oleracea, L.)

Spinach (Spinacia oleracea L.) is an important source of bioactive compounds. It is commonly consumed fresh or frozen products. Spinach is rich sources of polyphenols, it is a good source of vitamin C and has potential beneficial properties for human health. This study provides some knowledge about content of total polyphenols, and antioxidant activity in selected varieties of fresh and frozen spinach samples. Four spinach cultivars (̓Boa ̓, ̓ Hudson ̓, ̓Chica ̓, ̓Trombone ̓) were analysed. The content of the total polyphenols (TPC) was determined by the Folin-Ciocalteu reagent (FCR). Antioxidant activity (AA) was measured using a compound DPPH (2,2-diphenyl-1-picrylhydrazyl). The content of total polyhenols in fresh samples of spinach ranged from 975 ±97.15 mg.kg-1 to 1493 ±50.42 mg.kg-1 and values of antioxidant activity were in interval from 77.55 ±0.34% to 82.57 ±0.83%. The highest level of TP content in fresh spinach was recorded in variety Hudson (1493 mg.kg-1) and the lowest in variety Chica (975 mg.kg-1). Between these varieties statistically significant difference in the content of total polyphenols was found. The highest value of antioxidant activity in fresh spinach was recorded in variety Trombone (82.57%) and the lowest in variety Boa (78.59%). This difference was also statistically significant. The highest level of TP content in frozen spinach samples was found in variety Hudson (1749 mg.kg-1) and the lowest in variety Chica (855 mg.kg-1). The values of antioxidant activity in frozen spinach samples were in range from 45.86 ±7.84%to 79.67 ±0.88%. The highest value of antioxidant activity in frozen spinach was found in variety Hudson (79.67%) and the lowest in variety Chica (45.86%).