I. Konopka - Academia.edu (original) (raw)

Papers by I. Konopka

Food Technology and Biotechnology, 2016

The study was carried out to optimize pumpkin oil recovery in the process of aqueous extraction p... more The study was carried out to optimize pumpkin oil recovery in the process of aqueous extraction preceded by enzymatic maceration of seeds, as well as to compare the quality of the obtained oil to the quality of cold-pressed pumpkin seed oil. Hydrated pulp of hulless pumpkin seeds was macerated using a 2 % (by mass) cocktail of commercial pectinolytic, cellulolytic and proteolytic preparations (Rohapect ® UF, Rohament ® CL and Colorase ® 7089). The optimization procedure utilized response surface methodology based on Box-Behnken plan of experiment. The optimized variables of enzymatic pretreatment were pH, temperature and maceration time. The results showed that the pH value, temperature and maceration time of 4.7, 54 °C and 15.4 h, respectively, were conducive to maximize the oil yield up to 72.64 %. Among these variables, the impact of pH was crucial (above 73 % of determined variation) for oil recovery results. The oil obtained by aqueous enzymatic extraction was richer in sterols, squalene and tocopherols, and only slightly less abundant in carotenoids than the cold-pressed one. However, it had a lower oxidative stability, with induction period shortened by approx. 30 % in relation to the cold-pressed oil.

LWT, 2020

This study analysed the impact of method of poppy seed lipid extraction (cold pressing, Soxhlet e... more This study analysed the impact of method of poppy seed lipid extraction (cold pressing, Soxhlet extraction with n-hexane, supercritical fluid extraction (SFE) with pure CO 2 and CO 2 with 10% of acetone, ethanol, or ethyl acetate as co-solvents) on the oil yield, recovery of total oil and the composition and quality indices of the obtained oils. According to the method of extraction used, the recovery of oil varied from 63.6% to 93.4%, while the fatty acid composition was constant, with a predominance of linoleic and oleic acids (ca 71% and 16% of total fatty acids, respectively). Phytosterol contents varied from 2521 mg/kg to 2933 mg/kg, with the highest variation of cycloartenol content. Tocopherols were determined at the level of 122-133 mg/kg, with only two homologues identified (α-and γ-tocopherols). It was found that γ-homologue constituted at least 93% of the total fraction. Squalene was determined in the amount of 21.3-35.0 mg/kg. Oils extracted by the use of SFE also contained small amounts of phenolic acids (up to 2.58 mg/kg). Among the tested quality indices, acid value and induction time were mostly affected by the method of extraction.

Molecules, 2012

A field study was performed to evaluate the effect of mineral (NPK) and organic-based fertilizers... more A field study was performed to evaluate the effect of mineral (NPK) and organic-based fertilizers such as compost (C), manure (FYM) and meat and bone meal (MBM) on the appearance (dimensions and color) of spring wheat kernels and on the total content in grain of main its phytochemicals (polyphenols, carotenoids and tocochromanols) and phenolic acids composition. Total phenolic compounds were determined using the Folin-Ciocalteu assay after alkaline hydrolysis of grain and carotenoids were analyzed spectrophotometrically. Composition of tocochromanols and phenolic acids was determined using RP-HPLC techniques. Only insignificant differences in the appearance of kernels and small changes in the content and composition of grain phytochemicals were noted between the studied fertilization systems. Among the analyzed phytochemicals the greatest variation was observed in the group of polyphenol compounds, with a stated increase of their total content of 6.7 and 11.2% in grain fertilized with MBM and compost, respectively. Simultaneously the grain from organic fertilization contained significantly less phenolic acids, and the decrease in their content ranged from 10.0% for FYM to 24.8%

Journal of the Science of Food and Agriculture, 2007

Abstract Sieve classification was used to prepare grain streams of distinct protein content and c... more Abstract Sieve classification was used to prepare grain streams of distinct protein content and composition. Both reverse-phase high-performance liquid chromatography and two-dimensional electrophoresis revealed differences in protein composition between large (F1), medium (F2–F3), and small (F4) kernel fractions of three Polish cultivars: Sukces and Tonacja (winter wheats) and Nawra (spring wheat). Statistical analysis indicated that grain protein composition is affected by the cultivar and kernel size, as well as by interaction of ...

European Food Research and Technology, 2019

Only low molecular, simple phenolic acids and their dimers can be easily absorbed by intestinal c... more Only low molecular, simple phenolic acids and their dimers can be easily absorbed by intestinal cells. In this study, the changes in free (unbound) phenolic acids and antioxidative capacity were tracked from flour, through bread to final in vitro bread hydrolysate. The initial material of the study included wholemeal flours made of common wheat, spelt wheat and rye, fermented with baker's yeast Saccharomyces cerevisiae or by the use of baking starter made of lactic acid bacteria Lactobacillus casei and L. brevis cultures with S. chevalieri yeast. A significant overall increase in free phenolic acids in breads and their hydrolysates was found, with the highest increase found for rye samples. The impact of the fermentation type was not consistent, showing additional crucial factors of used flours, which can affect final results. The free phenolic acid content in all the samples was correlated with the antioxidant capacity.

Przegląd Zbożowo-Młynarski, 2017

Rośliny Oleiste - Oilseed Crops, 1999

Bromatologia i Chemia Toksykologiczna, 2012

ABSTRACT Badano zmiany zawartości wolnych związków fenolowych w produktach pszennych i żytnich (m... more ABSTRACT Badano zmiany zawartości wolnych związków fenolowych w produktach pszennych i żytnich (mąka wyciągowa, razowa, otręby) poddanych fermentacji mlekowej oraz w kiełkującym ziarnie pszenicy. Stwierdzono, że tempo wzrostu zawartości wolnych związków fenolowych jest uzależnione od rodzaju procesu (fermentacja, kiełkowanie), a w przypadku fermentacji od rodzaju produktu zbożowego. Wykazano, że już 12-godzinne kiełkowanie ziarna pszenicy daje produkt o zawartości wolnych polifenoli zbliżonej do próbki fermentowanej przez 24 godziny. Analiza procesu fermentacji wskazuje, że bardziej podatne na rozpad są kompleksy kwasów fenolowych obecnych w ziarnie żyta. Można przypuszczać, że zastosowanie tradycyjnych technologii fermentacji na zakwasach i/lub zastosowanie w recepturach pieczywa mąki z ziarna podkiełkowanego pozwoli na zwiększenie w diecie łatwo dostępnych polifenoli.

International Journal of Food Properties, 2018

This study was conducted to characterize the lipid fraction of 15 chia seed samples originating f... more This study was conducted to characterize the lipid fraction of 15 chia seed samples originating from five countries (Argentina, Paraguay, Uganda, Bolivia, and Peru). On average, chia seeds contained 34.5 g oil per 100 g dry-solids, in which the average contents of sterols, tocopherols, squalene, carotenoids, and phenolic compounds were 7,061, 600, 17.7, 2.2, and 9.7 mg/kg of oil, respectively. Alpha-linolenic acid share varied from 54.35% to 60.48%, and was accompanied by declining shares of linoleic, palmitic, oleic, and stearic acid, respectively. Principal component analysis showed that chia oil induction time was positively correlated with tocopherols and phenols, while negatively with quality indices and squalene content.

The Polish Journal of Natural Sciences is indexed and abstracted in Biological Abstracts and Bios... more The Polish Journal of Natural Sciences is indexed and abstracted in Biological Abstracts and Biosis Previews The Journal is also available (from volume 22) in electronic form. The online edition is hosted by MetaPress (www.metapress.com) in partnership with Versita (www.versita.com) PL ISSN 1643-9953 © Copyright by Wydawnictwo Uniwersytetu Warmińsko-Mazurskiego

Roczniki Państwowego Zakładu Higieny, 2004

... Fermentation time and type of additives used for bread preparation have also some influence P... more ... Fermentation time and type of additives used for bread preparation have also some influence Page 68. 60 KA. Skibniewska, Ł. ... 2. Brzozowska A: Procesy technologiczne a biodostępność składników mineralnych z produktów spożywczych. Przem. Spoż. 1996, 50, 33-35. ...

Italian Journal of Food Science, 2016

The paper proposes the development of blends of vegetable oils with a high content of easily oxid... more The paper proposes the development of blends of vegetable oils with a high content of easily oxidizable unsaturated fatty acids with sea-buckthorn fruit oil as a natural method of their preservation. The predominant lipophilic compounds in sea-buckthorn oil included β-carotene, α-tocopherol, and β-sitosterol. Strong correlations were found between oxidative stability of the blends and α- and β-tocopherols, lutein and β-carotene concentration (r ranging from 0.96 to 0.99). The observed effect may result from both the particularly huge increase in the carotenoid content (from 64- to 171-fold) in the obtained blends, and the synergistic interaction between tocopherol mixtures and carotenoids.

Progress in Plant Protection, 2000