Anna Sokół-Łętowska

Characteristics of antioxidant activity and composition of pumpkin seed oils in 12 cultivars.

The objective of this study was to determine the antioxidant properties, and provide characteristics, of the oil obtained from the seeds of 12 pumpkin varieties belonging to the species Cucurbita maxima Duch. and Cucurbita pepo L. Another objective was to establish which of the two extracting agents, ethanol or methanol, is more effective. The seeds of the pumpkin varieties examined differ in chemical composition and antioxidant activity. The seeds of the cultivars belonging to the species C. maxima are characterised by a higher content of fatty acids than are the cultivars of the species C. pepo. In the seed oil, unsaturated acids are dominant (oleic and linoleic), and their proportion depends on the pumpkin variety. The highest content of unsaturated acids has been measured in the oil extracted from the seeds of the cultivar, Jet F1 (C. pepo). Antioxidant activity analysis has produced the following findings. The seeds of the pumpkin varieties that belong to the species C. pepo exhibit better antioxidant properties, regardless of the extraction solvent used. 50% ethanol is more efficient than 80% methanol when used as an extracting agent. The antioxidant activity values obtained with 50% ethanol are higher than those achieved with 80% methanol. Owing to the considerable differences in composition among the fatty acids examined, it is possible to choose the desired pumpkin variety for the intended use.

Anthocyanin and antioxidant activity of snacks with coloured potato.

Coloured-fleshed potatoes of four varieties were used as raw material for coloured flour and fried snack production. The effects of thermal processes traditionally used in dried potato processing and in snack pellet manufacturing on anthocyanin profiles, total polyphenols and antioxidant properties of obtained half- and ready products were studied. There was a significant influence of potato variety on the experimental flour and snack properties. Flours with the highest antioxidant activities were obtained from Salad Blue and Herbie 26 potatoes; however, the flour prepared from the Blue Congo exhibited a much higher total polyphenol and anthocyanin content. Snacks produced with coloured flour had 2-3 times higher antioxidant activities, 40% higher contents of polyphenols, attractive colour and better expansion compared to control samples. The lowest losses of anthocyanins during snack processing were in snacks with flour from the purple-fleshed Blue Congo and red-fleshed Herbie 26.

Composition and antioxidant activity of red fruit liqueurs.

Fruits traditionally used for liqueurs are a good source of phenolic compounds endowed with antioxidant activity. The aim of this study was to compare the content of phenolic compounds and anthocyanins and the antioxidant capacity of liqueurs made from red fruits. The liqueurs were made from fruits of 10 species: chokeberry, cornelian cherry, black rose, blackcurrant, blackberry, raspberry, mahonia, sloe, strawberry, and sour cherry. The liqueurs from black rose, chokeberry, sloe and mahonia fruits contained the most of substances which react with the Folin-Ciocalteu reagent (671, 329, 271 and 218 mg GAE/100 mL, respectively) and had the highest antioxidant activity. The samples stored at a temperature of 30 °C had antioxidant activity from 3% to 11% lower than the fresh samples. After 6 months, anthocyanins degraded almost completely in the samples stored at 30 °C and at 15 °C there was from 0% (blackcurrant liqueurs) to 47% (sloe liqueurs) of their initial content and slightly more in sweet liqueurs.

Chemical Composition and Anti-Inflammatory Effect of Ethanolic Extract of Brazilian Green Propolis on Activated J774A.1 Macrophages

The aim of this study was to investigate the chemical composition and anti-inflammatory effect of ethanolic extract of Brazilian green propolis (EEP-B) on LPS + IFN-γ or PMA stimulated J774A.1 macrophages. The identification and quantification of phenolic compounds in green propolis extract were performed using HPLC-DAD and UPLC-Q-TOF-MS methods. The cell viability was evaluated by MTT and LDH assays. The radical scavenging ability was determined using DPPH• and ABTS•+. ROS and RNS generation was analyzed by chemiluminescence. NO concentration was detected by the Griess reaction. The release of various cytokines by activated J774A.1 cells was measured in the culture supernatants using a multiplex bead array system based on xMAP technology. Artepillin C, kaempferide, and their derivatives were the main phenolics found in green propolis. At the tested concentrations, the EEP-B did not decrease the cell viability and did not cause the cytotoxicity. EEP-B exerted strong antioxidant activity and significantly inhibited the production of ROS, RNS, NO, cytokine IL-1α, IL-1β, IL-4, IL-6, IL-12p40, IL-13, TNF-α, G-CSF, GM-CSF, MCP-1, MIP-1α, MIP-1β, and RANTES in stimulated J774A.1 macrophages. Our findings provide new insights for understanding the anti-inflammatory mechanism of action of Brazilian green propolis extract and support its application in complementary and alternative medicine.

Content of polyphenols in coloured and yellow fleshed potatoes during dices processing.

The purpose of the research was to examine the effect of the laboratory production of dried potato dice on the content of phenolic compounds in one yellow-fleshed potato variety and four blue-fleshed potatoes varieties. Coloured-flesh potato varieties were characterised by about three times higher amount of total phenolic content than traditional yellow-fleshed ones. The predominating phenolic acids in potato were chlorogenic acid and its isomers, which account about 90% of total phenolic content in tubers. The phenolic acid content decreased by 80% after peeling the blue-fleshed potatoes and by 60% after peeling the yellow variety. The dried potato dice obtained from yellow-fleshed potatoes had no content of phenolic acids but produced from colour-fleshed potatoes contained about 4% of the original phenolic content of the raw material. Chlorogenic acid amounted about 97% of total phenolic acid content, and the rest was neochlorogenic acid.

Ethanolic Extract of Polish Propolis: Chemical Composition and TRAIL-R2 Death Receptor Targeting Apoptotic Activity against Prostate Cancer Cells

Propolis possesses chemopreventive properties through direct anticancer and indirect immunomodulatory activities. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) plays a significant role in immunosurveillance and defense against cancer cells. TRAIL triggers apoptosis upon binding to TRAIL-R1 (DR4) and TRAIL-R2 (DR5) death receptors expressed on cancer cell surface. The activation of TRAIL apoptotic signaling is considered an attractive option for cancer prevention. However, as more tumor cells are reported to be resistant to TRAIL-mediated death, it is important to develop new strategies to overcome this resistance. The aim of this study was to investigate the chemical composition and proapoptotic mechanism of ethanolic extract of Polish propolis (EEP-P) against cancer cells. The identification and quantification of phenolic compounds in propolis extract were performed using HPLC-DAD and UPLC-Q-TOF-MS methods. TRAIL-resistant LNCaP prostate cancer cells were treated with EEP-P and TRAIL. Cytotoxicity was measured by MTT and LDH assays. Apoptosis was detected using annexin V-FITC staining by flow cytometry and fluorescence microscopy. Death receptors expression was analyzed using flow cytometry. Pinobanksin, chrysin, methoxyflavanone, p-coumaric acid, ferulic acid and caffeic acid were the main phenolics found in EEP-P. Propolis sensitized LNCaP cells through upregulation of TRAIL-R2. These results suggest that EEP-P supports TRAIL-mediated immunochemoprevention in prostate cancer cells.

The Effect of Nitrogen Fertilization Methods on Yield and Chemical Composition of Pumpkin (Cucurbita Maxima) Fruits Before and After Storage

The Effect of Nitrogen Fertilization Methods on Yield and Chemical Composition of Pumpkin (Cucurbita Maxima) Fruits Before and After Storage In field experiment pumpkin of Amazonka and Karowita cvs (Cucurbita maxima) were fertilized at the rate of 200 kg N·ha-1 in the following methods: 1-100 kg N·ha-1 preplant broadcasting + 100 kg N·ha-1 as top dressing in form of 4 foliar sprays, 2-100 kg N·ha-1 preplant band placement on strips of 50 cm wide + 100 kg N·ha-1 as top dressing broadcasted on total area of field, 3- placement of N in rate of 200 kg N·ha-1 as a nests placement 25 cm apart from plant, 4-organic fertilization with composted cattle manure at the rate of 40 t·ha-1 applied in 50 cm wide strips. There were estimated total and marketable yield and chemical composition of fruits before and after 90 days of storage. Broadcasting of nitrogen gave the higher yield of fruit than banded or nested placement of this nutrient. Banded placement of nitrogen affected in the highest vitamin C content as well as higher levels of total and reducing sugars and carotenoids than in other methods of nitrogen placement. Before storage the fruits had higher amounts of soluble solids, dry matter, carotenoids, vitamin C as well as total and reducing sugars than after 90 days of storage. Wpływ Metody Nawożenia Azotem na Plonowanie i Skład Chemiczny Owoców Dyni (Cucurbita Maxima) Przed i po Przechowywaniu W doświadczeniu polowym dwie odmiany dyni olbrzymiej (Amazonka, Karowita) nawożono dawką 200 kg N·ha-1 w następujący sposób: 1 - 100 kg N·ha-1 przedwegetacyjnie na całą powierzchnię + 100 kg N·ha-1 pogłównie w postaci 4 oprysków dolistnych, 2 - 100 kg N·ha-1 miejscowo w pasy o szerokości 50 cm + 100 kg N·ha-1 pogłównie na całą powierzchnię, 3 - 200 kg N·ha-1 gniazdowo 25 cm od rośliny na głębokość 10 cm, 4 - w pasy o szerokości 50 cm obornik w dawce 40 t·ha-1. Oceniano wielkość plonu ogólnego i handlowego oraz skład chemiczny owoców przed i po przechowywaniu przez 90 dni w temperaturze 12°C przy wilgotności względnej powietrza 75%. Tradycyjne wnoszenie azotu na całą powierzchnię pola pozwoliło na uzyskanie istotnie większego plonu niż przy pasowym lub gniazdowym użyciu tego składnika. Owoce dyni nawożonej przedwegetacyjnie w sposób pasowy zawierały najwięcej witaminy C, charakteryzowały się również wysoką zawartością cukrów redukujących i ogółem oraz karotenoidów. Owoce bezpośrednio po zbiorze posiadały więcej substancji rozpuszczalnych, suchej masy, karotenoidów, jak również cukrów redukujących ogółem i witaminy C.

Characteristics of organic acids in the fruit of different pumpkin species.

The aim of the research was to determine the composition of organic acids in fruit of different cultivars of three pumpkin species. The amount of acids immediately after fruit harvest and after 3 months of storage was compared. The content of organic acids in the examined pumpkin cultivars was assayed using the method of high performance liquid chromatography (HPLC). Three organic acids (citric acid, malic acid, and fumaric acid) were identified in the cultivars, whose content considerably varied depending on a cultivar. Three-month storage resulted in decreased content of the acids in the case of cultivars belonging to Cucurbita maxima and Cucurbita pepo species, while a slight increase was recorded for Cucurbita moschata species.

Composition and quantification of major polyphenolic compounds, antioxidant activity and colour properties of quince and mixed quince jams

Abstract Aims: The aim of the study was to establish whether the addition of some berries and fruits during quince jam processing, improves its colour and enriches it in polyphenol compounds, other than those found in quince fruits. Methods: Phenolic compounds were identified and quantified by LC-MS Q/TOF and HPLC. Antioxidant activity was measured by ABTS, DPPH and FRAP methods. The colour of jams was expressed as L, a*, b* value. Results: The total content of polyphenolic compounds in quince jam was 484.5 mg/100 g. The highest level of phenolic compounds and antioxidant activity (p < 0.05) was observed in samples with the addition of chokeberry > black currant > flowering quince. The colour of examined jams could be due to the type of fruit addition, the nature of the pigments in these fruits. Conclusion: Overall, the results indicated that some mixed jams can represent a good source of antioxidant compounds and can have an attractive colour for the consumer.

Characterization of Phenolic Compounds of Thorny and Thornless Blackberries

The aim of this study was to identify and compare the contents of phenolic acids, tannins, anthocyanins, and flavonoid glycosides in thorny and thornless blackberries. Five thorny and nine thornless cultivars were used for this study. Thirty-five phenolic compounds were determined in the examined fruits, and one phenolic acid, three ellagic acid derivatives, one anthocyanin, and six flavonols were characterized for the first time in blackberries. The thornless fruits were characterized by a higher content of anthocyanins (mean = 171.23 mg/100 g FW), ellagitannins (mean = 3.65 mg/100 g FW), and ellagic acid derivatives (mean = 2.49 mg/100 g FW), in comparison to thorny ones. At the same time, in thorny fruits, the contents of hydroxycinnamic acids (mean = 1.42 mg/100 g FW) and flavonols (mean = 5.70 mg/100 g FW) were higher.