Barbara Baraniak

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.

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.

Biologically active peptides obtained by enzymatic hydrolysis of Adzuki bean seeds

This study investigated the antioxidant and antihypertensive activities of peptides obtained from protein fractions of Adzuki bean seeds. Peptides were obtained by the use of hydrolytic enzymes in vitro under gastrointestinal conditions. A determination was made of the activity of the peptide inhibitors of the angiotensin I converting enzyme (ACE), and the antiradical and ion chelating activity of peptides from different protein fractions. The highest peptide levels after the absorption process (<7 kDa) were noted in the albumin fraction (50.69 μg/ml). Furthermore, it was found that peptides from the prolamin fraction were characterised by the highest antiradical activity and ACE inhibitory activity (IC50=0.17 mg/ml). Peptides obtained from the globulin fraction showed the highest ability to chelate iron ions, and peptides from the glutelin fraction were characterised as being the most effective in the chelation of copper ions.

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.

The impact of fermentation and in vitro digestion on formation angiotensin converting enzyme (ACE) inhibitory peptides from pea proteins.

Pea seeds were fermented by Lactobacillus plantarum 299v in monoculture under different time and temperature conditions and the fermented products were digested in vitro under gastrointestinal conditions. After fermentation and digestion ACE inhibitory activity was determined. In all samples after fermentation no ACE inhibitory activity was noted. Potentially antihypertensive peptides were released during in vitro digestion. The highest DH (68.62%) were noted for control sample, although the lowest IC50 value (0.19 mg/ml) was determined for product after 7 days fermentation at 22 °C. The hydrolysate characterised by the highest ACE inhibitory activity was separated on Sephadex G10 and two peptides fractions were obtained. The highest ACE inhibitory activity (IC50=64.04 μg/ml) for the first fraction was noted. This fraction was separated by HPLC and identified by LC-MS/MS and the sequence of peptide derived from pea proteins was determined as KEDDEEEEQGEEE.

Anti-inflammatory and antioxidative activity of anthocyanins from purple basil leaves induced by selected abiotic elicitors

This paper investigates changes in the anti-inflammatory and antioxidative activity of anthocyanins from purple basil (Ocimum basilicum L.) leaves induced by arachidonic acid (AA), jasmonic acid (JA) and β-aminobutyric acid (BABA). The anthocyanins content was significantly increased by all elicitors used in this study; however, no increase was observed in the antioxidant activity of the analyzed extracts. Additionally, a significant decrease by about 50% in the ability to chelate Fe(II) was noted. Further, an increase in the potential anti-inflammatory activity of basil anthocyanins was observed after treatment with each the abiotic elicitor. The IC50 value for lipoxygenase inhibition was almost twice as low after elicitation as that of the control. Also, cyclooxygenase inhibition by anthocyanins was stimulated by abiotic elicitors, except for JA-sample. Additionally, HPLC-analysis indicated that elicitation with AA, JA and BABA caused increases in content most of all anthocyanin compounds.

Influence of elicitation with H2O2 on phenolics content, antioxidant potential and nutritional quality of Lens culinaris sprouts

BACKGROUND The use of lentil sprouts as bioreactors for obtaining low-processed food with modified composition and biological activity was studied. Special emphasis was placed on the nutritional quality. Sprouts metabolism was elicited with 20 mmol L⁻¹ and 200 mmol L⁻¹ H₂O₂. The polyphenolics content and antioxidative abilities at different germination stages of lentil were studied. RESULTS Both sprouting and elicitation significantly influenced the nutritional and nutraceutical quality of sprouts. In comparison to control conditions both treatments gave an increase in caffeic, salicylic acid and genistein contents in 4-day-old sprouts and p-hydroxybenzoic, chlorogenic, o-coumaric, p-coumaric acids and naringenin, (+)-catechin contents for 6-day-old sprouts. Elicitation significantly increased the ability to prevent lipid against peroxidation. The antioxidant potential was the most effectively elevated in 6-day-old sprouts. Elicitation caused a significant decrease in protein content associated with a significant elevation in the non-protein nitrogen content. Induction of sprout metabolism caused a decrease of bioavailable starch and subsequent elevation of resistant starch content. CONCLUSION The significantly elevated antioxidant potential, high content of resistant starch and low starch bioaccessibility of sprouts elicited with H₂O₂ indicated that this technology allows the production of functional food products with particular characteristics.

Nutritional and Antioxidant Potential of Lentil Sprouts Affected by Elicitation with Temperature Stress

The influences of temperature stress on antioxidant potential and nutritional quality of lentil sprouts were studied. Temperature treatments (TC, 1 h at 4 °C; TH, 1 h at 40 °C) significantly improved the nutraceutical potential without any negative effect on nutritional quality. In comparison to control, elicited sprouts were characterized by elevated content of condensed tannins, flavonoids, and total phenolics. The highest content of total phenolics and flavonoids was determined for 6-day-old TH sprouts -23.7 ± 0.87 and 2.50 ± 0.07 mg/(g of dry weight (DW)), respectively. The general trend of antiradical, lipid preventing, and reducing properties in elicited sprouts indicates a significantly improvement of these activities. The highest reducing power was determined for 6-day-old sprouts induced at TH (0.43 ± 0.02 mmol of Trolox/(g of DW)), while the lowest for 3-day-old sprouts elicited at TC (0.29 ± 0.02 mmol of Trolox/(g of DW)). Both modifications effectively elevated the ability to prevent lipids against oxidation (in 3-day-old sprouts a 3.3- and 4-fold increase for TC and TH, respectively).

Characterization of films based on chitosan lactate and its blends with oxidized starch and gelatin.

Minimal inhibitory concentration (MIC) of chitosan lactate (CHL) was tested against bacteria and phytopathogenic fungi. Then, the structural, physicochemical and antimicrobial properties of films based on CHL, oxidized potato starch (OPS), and gelatin (GEL) were investigated. With the exception of Rhizopus nigricans, CHL was effective against the target organisms. Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) were more sensitive to CHL than Gram-negative bacteria (Pectobacterium carotovorum and Escherichia coli). Cryo-SEM images showed total miscibility between the polymers in the blends and the ATR-FTIR spectra revealed that there was an interaction among the polymeric components. Pure CHL films displayed the highest moisture content (25.51%), water vapor permeability (48.78gmmm(-2)d(-1)kPa(-1)), and the lowest tensile and puncture strength (2.00 and 1.45MPa, respectively) among the studied films. CHL50/GEL50 films had lower permeability, higher mechanical strength, and lower elongation compared to CHL50/OPS50 films. Films obtained from CHL and CHL50/GEL50 were completely water-soluble and did not show sorbitol recrystallization. The incorporation of CHL into OPS and GEL films did not affect their transparency and improved UV-blocking capacity. CHL films were the only ones that exhibited antibacterial efficiency. Antifungal activities against Alternaria alternata and Monilinia fructigena were detected for CHL and CHL50/GEL50 films.