Urszula Gawlik-Dziki

Antioxidant and anticancer activities of Chenopodium quinoa leaves extracts – In vitro study

The nutraceutical potential of Chenopodium quinoa Leaves (ChL) was assessed through analyses of their phenolic content, elucidation of the effect of ChL phenolic compounds on cancer cell properties and estimation of their antioxidative activity, bioaccessibility and bioavailability in vitro. Considerable amounts of ferulic, sinapinic and gallic acids, kaempferol, isorhamnetin and rutin were observed in the chemical ChL extract and were linked with its inhibitory effect on prostate cancer cell proliferation, motility and cellular competence for gap junctional communication. Both extracts, chemical and obtained after simulated digestion, exerted an inhibitory effect on lipoxygenase activity, paralleled by their considerable chelating, antioxidative, antiradical and reducing power. These observations indicate that phenolic ChL compounds may exert a chemopreventive and anticarcinogenic effect on oxidative stress and ROS-dependent intracellular signaling via synergic effects. The relatively high potential bioaccessibility and bioavailability of the compounds probably responsible for these effects demonstrates the suitability of ChL for dietary supplementation.

The influence of protein–flavonoid interactions on protein digestibility in vitro and the antioxidant quality of breads enriched with onion skin

Different types of breads enriched with onion skin were studied. The objectives were twofold: to show and examine protein-phenolic interactions and to discuss results concerning phenolic content, antioxidant activity and protein digestibility in the light of in vitro bioaccessibility. Phenolic contents and antiradical abilities were linked with the level of onion skin supplement however, the amounts determined were significantly lower than expected. Fortification influenced protein digestibility (a reduction from 78.4% for control breads to 55% for breads with a 4% supplement). Electrophoretic and chromatographic studies showed the presence of indigestible protein-flavonoid complexes - with molecular weights about 25 kDa and 14.5 kDa; however, the reduction of free amino group levels and the increase in chromatogram areas suggest that flavonoids also bind to other bread proteins. The interaction of phenolics with proteins affects antioxidant efficacy and protein digestibility; thus, they have multiple effects on food quality and pro-health properties.

Bread enriched with quinoa leaves – The influence of protein–phenolics interactions on the nutritional and antioxidant quality

This paper investigates the functional and potential biological properties of bread fortified with quinoa leaves (QL) in the light of protein-phenolic interactions. The addition of QL changed the textural properties of bread crumb. With the replacement of wheat flour by QL (1-5%), a linear increase in crumb hardness, cohesiveness and gumminess was observed. Fortification positively affected antioxidant properties and phenolic contents; however, in some cases experimental values were significantly lower than those predicted. The QL addition affected nutrient content and digestibility. The starch digestibility of the bread investigated in this study was inversely proportional to the percentage content of QL (the changes in protein digestibility were not so pronounced). Increasing peak areas of extracts obtained after digestion of fortified bread and the significant reduction of free amino groups confirm the presence of interactions between phenolics and proteins. The quality of fortified bread is strongly affected by phenolic compounds and food matrix interactions.

Quality and antioxidant properties of breads enriched with dry onion (Allium cepa L.) skin

The aim of the study was to investigate the effect on the antioxidant properties and sensory value of bread of adding ground onion skin (OS). For a determination of bioaccessibility and bioavailability in vitro the human gastrointestinal tract model was used. OS contained mastication-extractable quercetin (4.6 mg/g). Quercetin from OS was highly bioaccessible during in vitro conditions, but only approximately 4% of quercetin released during simulated digestion was bioavailable in vitro. The antioxidant potential of bread with OS was significantly higher than the activity noted in the control. In particular, OS addition significantly fortificated bread with bioaccessible lipid oxidation preventers and compounds with reducing and chelating abilities. The 2-3% OS addition caused significant improvement of antioxidant abilities (further increases in the OS supplement did not increase the activity of bread). Sensory evaluation showed that replacement of wheat flour in bread with up to 3% OS powder gave satisfactory consumer acceptability.

Effect of hydrothermal treatment on the antioxidant properties of broccoli (Brassica oleracea var. botrytis italica) florets.

In the extracts of fresh raw and frozen broccoli, caffeic, ferulic, sinapinic acids and kaempferol were identified. Boiling reduced the amounts of caffeic acid and kaempferol in both samples. The concentration of polyphenols was 2.69mg/g fresh mass and 0.96mg/fresh mass in fresh raw broccoli and frozen raw broccoli, respectively. Boiling significantly decreased the amounts of phenolic compounds in fresh broccoli (1.58mg/g of fresh mass). In the case of frozen broccoli, boiling increased the concentration of polyphenols by 38%. Fresh broccoli extract neutralized free radicals by 19.87%. Boiling significantly reduced its antiradical activity (to 15.06%). Samples of frozen broccoli had a 27.06% antiradical ability. Boiling did not change the antiradical activity in frozen broccoli case. Hydrothermal processing significantly influenced on the ability of the extracts to inhibit the decolorization of β-carotene emulsion. The extract of fresh broccoli had a higher activity when uncooked. Boiling seemed to increase this activity in the case of frozen broccoli samples. The results of the studies on the ability of broccoli extracts to inhibit linoleic acid autooxidation were ambiguous and depended on the method applied. No correlation was found between the content of phenolic compounds and the antioxidant activity of the extracts, regardless of the experimental variant and technique used.

In vitro digestibility and starch content, predicted glycemic index and potential in vitro antidiabetic effect of lentil sprouts obtained by different germination techniques.

The study focuses on changes in starch content and expected glycemic index (eGI) caused by different sprouting methods of lentil. On germination, a decrease was observed in total starch content (TS), α-amylase inhibitors activity (αAI) and eGI values. After elicitation, the highest TS content was determined in 3-day-old control sprouts (100.9 mg/gf.m.), whereas the lowest was in 4-day-old sprouts induced with 300 mM NaCl (57.8 mg/gf.m.). Resistant starch (RS) content was most effectively increased by induction with 600 mM mannitol. The highest eGI values were determined for 3-day-old sprouts induced with 300 mM NaCl, whereas the lowest were for 6-day-old sprouts induced with 100mM NaCl. In treated sprouts starch digestibility was connected with αAI activity and RS content. Sprouting conditions can modify starch content, its potential bioavailability and eGI values. Optimization of this process will allow for the maximum nutritional benefit.

Comparison of phenolic acids profile and antioxidant potential of six varieties of spelt (Triticum spelta L.).

Phenolic acids profile and antioxidant activity of six diverse varieties of spelt are reported. Antioxidant activity was assessed using eight methods based on different mechanism of action. Phenolic acids composition of spelt differed significantly between varieties and ranged from 506.6 to 1257.4 μg/g DW. Ferulic and sinapinic acids were the predominant phenolic acids found in spelt. Total ferulic acid content ranged from 144.2 to 691.5 μg/g DW. All analyzed spelt varieties possessed high antioxidant potential. In spite of the fact that bound phenolic acids possessed higher antioxidant activities, analysis of antioxidant potential and their relationship with phenolic acid content showed that free phenolics were more effective. Eight antioxidant methods were integrated to obtain a total antioxidant capacity index that may be used for comparison of total antioxidant capacity of spelt varieties. Total antioxidant potential of spelt cultivars were ordered as follows: Ceralio > Spelt INZ ≈ Ostro > Oberkulmer Rotkorn > Schwabenspelz > Schwabenkorn.

Anticancer and antioxidant activity of bread enriched with broccoli sprouts.

This study is focused on antioxidant and anticancer capacity of bread enriched with broccoli sprouts (BS) in the light of their potential bioaccessibility and bioavailability. Generally, bread supplementation elevated antioxidant potential of product (both nonenzymatic and enzymatic antioxidant capacities); however, the increase was not correlated with the percent of BS. A replacement up to 2% of BS gives satisfactory overall consumers acceptability and desirable elevation of antioxidant potential. High activity was especially found for extracts obtained after simulated digestion, which allows assuming their protective effect for upper gastrointestinal tract; thus, the anticancer activity against human stomach cancer cells (AGS) was evaluated. A prominent cytostatic response paralleled by the inhibition of AGS motility in the presence of potentially mastication-extractable phytochemicals indicates that phenolic compounds of BS retain their biological activity in bread. Importantly, the efficient phenolics concentration was about 12u2009μM for buffer extract, 13u2009μM for extracts after digestion in vitro, and 7u2009μM for extract after absorption in vitro. Our data confirm chemopreventive potential of bread enriched with BS and indicate that BS comprise valuable food supplement for stomach cancer chemoprevention.

Grinding and Nutritional Properties of Six Spelt (Triticum aestivum ssp. spelta L.) Cultivars

ABSTRACT Some physical, technological, nutritional, and nutraceutical determinants of six spelt varieties were evaluated. The grains were characterized by similar grain hardness and gave similar breakage patterns on a hammer mill and relatively low grinding energy requirements. The highest protein content was determined for Spelt I.N.Z. and Schwabenkorn (155 mg/g db), whereas the lowest was for Ceralio (98 mg/g db). The total starch content in tested cultivars averaged about 500 mg/g db; however, significant differences were observed for resistant and potentially bioavailable starch. The highest starch digestibility was observed for Ostro, Schwabenspelz, and Spelt I.N.Z. (about 45%), whereas the lowest was for Ceralio (about 33%). Chemically extractable total phenolic compounds content did not differ between cultivars. When flavonoids contents were compared, however, significant differences were observed; their contents ranged from 0.61 to 2.12 mg/g db (Spelt I.N.Z. and Schwabenkorn, respectively). The ab...

Influence of wheat kernel physical properties on the pulverizing process.

The physical properties of wheat kernel were determined and related to pulverizing performance by correlation analysis. Nineteen samples of wheat cultivars about similar level of protein content (11.2–12.8xa0% w.b.) and obtained from organic farming system were used for analysis. The kernel (moisture content 10xa0% w.b.) was pulverized by using the laboratory hammer mill equipped with round holes 1.0xa0mm screen. The specific grinding energy ranged from 120xa0kJkg−1 to 159xa0kJkg−1. On the basis of data obtained many of significant correlations (pu2009<u20090.05) were found between wheat kernel physical properties and pulverizing process of wheat kernel, especially wheat kernel hardness index (obtained on the basis of Single Kernel Characterization System) and vitreousness significantly and positively correlated with the grinding energy indices and the mass fraction of coarse particles (> 0.5xa0mm). Among the kernel mechanical properties determined on the basis of uniaxial compression test only the rapture force was correlated with the impact grinding results. The results showed also positive and significant relationships between kernel ash content and grinding energy requirements. On the basis of wheat physical properties the multiple linear regression was proposed for predicting the average particle size of pulverized kernel.