Aneta Kopeć

Biofortification of Carrot (Daucus carota L.) with Iodine and Selenium in a Field Experiment

The low content of iodine (I) and selenium (Se) forms available to plants in soil is one of the main causes of their insufficient transfer in the soil-plant-consumer system. Their deficiency occurs in food in the majority of human and farm animal populations around the world. Both elements are classified as beneficial elements. However, plant response to simultaneous fertilization with I and Se has not been investigated in depth. The study (conducted in 2012–2014) included soil fertilization of carrot cv. “Kazan F1” in the following combinations: (1) Control; (2) KI; (3) KIO3; (4) Na2SeO4; (5) Na2SeO3; (6) KI+Na2SeO4; (7) KIO3+Na2SeO4; (8) KI+Na2SeO3; (9) KIO3+Na2SeO3. I and Se were applied twice: before sowing and as top-dressing in a total dose of 5 kg I⋅ha-1 and 1 kg Se⋅ha-1. No negative effects of I and Se fertilization were noted with respect to carrot yield. Higher accumulation and the uptake by leaves and storage roots of I and Se were obtained after the application of KI than KIO3, as well as of Na2SeO4 than Na2SeO3, respectively. Transfer factor values for leaves and roots were about a dozen times higher for Se than for I. Selenomethionine content in carrot was higher after fertilization with Na2SeO4 than with Na2SeO3. However, it was the application of Na2SeO3, KI+Na2SeO3 and KIO3+Na2SeO3 that resulted in greater evenness within the years and a higher share of Se from selenomethionine in total Se in carrot plants. Consumption of 100 g f.w. of carrots fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 can supply approximately or slightly exceed 100% of the Recommended Daily Allowance for I and Se. Moreover, the molar ratio of I and Se content in carrot fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 was the best among the research plots.

The Impact of Carrot Enriched in Iodine through Soil Fertilization on Iodine Concentration and Selected Biochemical Parameters in Wistar Rats

Iodine is one of the trace elements which are essential for mammalian life. The major objective of iodine biofortification of plants is to obtain food rich in this trace element, which may increase its consumption by various populations. Additionally, it may reduce the risk of iodine deficiency diseases. In this research for the first time we have assessed the bioavailability of iodine from raw or cooked carrot biofortified with this trace element on iodine concentration in selected tissues and various biochemical parameters as well as mRNA expression of some genes involved in iodine metabolism in Wistar rats. Statistically, a significantly higher iodine level was determined in urine, faeces and selected tissues of rats fed a diet containing biofortified raw carrot as compared to a diet without iodine and a diet containing control cooked carrot. Biofortified raw carrot significantly increased triiodothyronine concentration as compared to animals from other experimental groups. The highest thyroid stimulating hormone level was determined in rats fed control cooked carrots. mRNA expression of selected genes was affected by different dietary treatment in rats’ hearts. Biofortified raw and cooked carrot could be taken into account as a potential source of iodine in daily diets to prevent iodine deficiency in various populations.

The effects of peeling and cooking on the mineral content and antioxidant properties in carrots enriched with potassium iodate and/or selenite (SeIV) and selenite (SeVI)

Abstract Research covered six variants: control, unfertilized carrots and carrots fertilized with: KIO3, Na2SeO4, Na2SeO3, KIO3 and simultaneously with Na2SeO4, and fertilized with KIO3 and simultaneously Na2SeO3. Carrots enriched with iodate or selenite, or both iodate and selenite, were characterized by higher amount of these minerals. Changes to the content of micro- and macroelements, during the cooking time of the carrots, both in peeled and unpeeled carrots, did not head in the same direction (increase, decrease and no change). However, cooking an unpeeled carrot generally resulted in the increased content of polyphenol and carotenoids. On the other hand, cooking peeled carrots led to a decrease in the content of polyphenol and a general lack of change in carotenoid content in relation to the unpeeled cooked carrot. During cooking, the antioxidant activity of the carrot being assessed changed together with the direction of changes in polyphenol content but not in line with the direction of changes in carotenoids.

Assessment of polyphenols, beta-carotene, and vitamin C intake with daily diets by primary school children.

The aim of this study was to analytically evaluate the daily intake of total polyphenols, β-carotene, and vitamin C by 10- to 12-year-old children. Twenty four–hour dietary recalls were collected in spring and autumn 2006 from students in Krakow and Skawina (Malopolska region, Poland). The content of vitamin C, polyphenols, and β-carotene was determined in reconstructed daily diets. Statistical analysis did not show any significant differences between the mean intake of measured compounds according to school location, gender, or season. Diets of children contained adequate amounts of polyphenols in relation to the recommended values. Intake of β-carotene usually exceeded the recommended retinol equivalent; in contrast, vitamin C did not meet requirements. Increased consumption of fruits and vegetables rich in vitamin C is recommended.

Intake of Vitamin C, β-Carotene, and Polyphenolic Compounds by Children and Adolescents from Orphanages

Objective: The objective of this study was analytical assessment of the concentration of selected antioxidants as well as total antioxidant capacity of daily diets of children and adolescents from orphanages in Krakow (Poland). Methods: Daily diets of children and adolescents were collected in 4 seasons of the year from 7 orphanages located in Krakow. The concentrations of vitamin C, β-carotene, polyphenolic compounds, and antioxidant capacity were measured. Results: The lowest content of vitamin C in diets of children and adolescents was measured in diets collected in autumn. The estimated average requirement (EAR) was in the range 49.0%–76.4%. In winter the content of this compound was significantly higher in daily diets (113.9%–192.0% coverage of EAR) compared to the level of this nutrient in daily diets from other seasons. The content of β-carotene, lower than 50% of EAR value, calculated as the vitamin A equivalent, has been demonstrated in 4 orphanages in summer and in one in spring and autumn. The highest mean content of this antioxidant in daily diets was found in winter, when β-carotene intake met recommendations in the range 131%–368%. The mean concentration of polyphenolic compounds per year was in the range 301.5–537.5 mg/person/day. It has been observed that diets during the winter and autumn generally provide higher amounts of polyphenols than in other seasons. The highest antioxidant activity was measured in diets collected during the winter season. Conclusions: The results indicate that the diets of children and adolescents should contain more fresh vegetables and fruits, which are good source of natural antioxidants.

Identification of polyphenolic compounds and determination of antioxidant activity in extracts and infusions of buckwheat leaves

The objective of this study was to determine the chemical composition in the dried leaves and the content of bioactive compounds, antioxidant activity as well as the identification of polyphenolic compounds not only in extracts but also in infusions prepared from leaves of selected strains of buckwheat. To the best of our knowledge, it is the first comprehensive and in-depth study, which focuses on identification and quantitative determination of individual polyphenolic compounds of buckwheat leaves. Furthermore, the aim of presented research is to analyse the new, unknown strains of buckwheat. A statistically significant effect of strain on the content of individual components was observed. The extracts contained more polyphenols and were characterized by higher antioxidant activity than infusions. Strains DW15 and DWO Karzel were characterized by one of the highest contents of polyphenols, dietary fibre, protein, ash and antioxidant activity. Phenolic acids (3,5-diCQA, ferulic acid, sinapinic acid, p-coumaric acid), flavanones (hesperidin), flavonoids (isorhamnetin) as well as flavanols (catechin) and flavonols (rutin, quercetin) in the extracts and infusions, were found. Both extracts and infusions were the richest in ferulic acid. These studies indicate that the buckwheat leaves can be used for preparation of various types of tea and can also be introduced for consumers as the source of bioactive compounds.

The petioles and leaves of sweet cherry ( Prunus avium L.) as a potential source of natural bioactive compounds

Edible fruits are known as source of bioactive compounds, however, growing interest in the use of plant byproducts has been observed in last few years. The objective of study was to compare the chemical composition, fatty acid profile, content of bioactive compounds, including the HPLC analysis of anthocyanins and antioxidant activity of sweet cherry fruit, petioles and leaves of the following cultivars: Burlat, Kordia and Regina. In the fruit, the major fatty acid was oleic acid, and in the petioles—palmitic acid and in the leaves—the γ-linolenic acid. The petioles were characterized by the highest antioxidant activity and content of polyphenols, whereas the anthocyanins were detected only in fruit. Two anthocyanins were identified: cyanidin 3-glucoside and cyanidin 3-rutinoside. Fruit of cultivar Kordia as well as petioles and leaves of cultivars Burlat and Regina had the highest antioxidant activity. There is a need for further research (especially in vivo studies). This knowledge can be used to create a new functional food and to better use of byproducts of sweet cherry production.