Simulated Human Gastrointestinal Tract Research Articles

Characterization of a symbiotic beverage based on water-soluble soybean extract fermented by Lactiplantibacillus plantarum ATCC 8014.

The health benefits of functional foods are associated with consumer interest and have supported the growth of the market for these types of foods, with emphasis on the development of new formulations based on plant extracts. Therefore, the present study aimed to characterize a symbiotic preparation based on water-soluble soy extract, supplemented with inulin and xylitol and fermented by Lactiplantibacillus plantarum ATCC 8014. Regarding nutritional issues, the symbiotic formulation can be considered a source of fiber (2g/100mL) and proteins (2.6g/100mL), and it also has a low-fat content and low caloric value. This formulation, in terms of microbiological aspects, remained adequate to legal standards after storage for 60days under refrigeration and also presented an adequate quantity of the aforementioned probiotic strain, corresponding to 9.11 Log CFU.mL-1. These viable L. plantarum cells proved to be resistant to simulated human gastrointestinal tract conditions, reaching the intestine at high cell concentrations of 7.95 Log CFU.mL-1 after 60days of refrigeration. Regarding sensory evaluation, the formulation showed good acceptance, presenting an average overall impression score of 6.98, 5.98, and 5.16, for control samples stored for 30 and 60days under refrigeration, respectively. These results demonstrate that water-soluble soy extract is a suitable matrix for fermentation involving L. plantarum ATCC 8014, supporting and providing data on the first steps towards the development of a symbiotic functional food, targeting consumers who have restrictions regarding the consumption of products of animal origin, diabetics, and individuals under calorie restrictions.

Nanoscale ZnO Improves the Amino Acids and Lipids in Tomato Fruits and the Subsequent Assimilation in a Simulated Human Gastrointestinal Tract Model.

With the widespread use of nanoenabled agrochemicals, it is essential to evaluate the food safety of nanomaterials (NMs)-treated vegetable crops in full life cycle studies as well as their potential impacts on human health. Tomato seedlings were foliarly sprayed with 50 mg/L ZnO NMs, including ZnO quantum dots (QDs) and ZnO nanoparticles once per week over 11 weeks. The foliar sprayed ZnO QDs increased fruit dry weight and yield per plant by 39.1% and 24.9, respectively. It also significantly increased the lycopene, amino acids, Zn, B, and Fe in tomato fruits by 40.5%, 15.1%, 44.5%, 76.2%, and 12.8%, respectively. The tomato fruit metabolome of tomatoes showed that ZnO NMs upregulated the biosynthesis of unsaturated fatty acids and sphingolipid metabolism and elevated the levels of linoleic and arachidonic acids. The ZnO NMs-treated tomato fruits were then digested in a human gastrointestinal tract model. The results of essential mineral release suggested that the ZnO QDs treatment increased the bioaccessibility of K, Zn, and Cu by 14.8-35.1% relative to the control. Additionally, both types of ZnO NMs had no negative impact on the α-amylase, pepsin, and trypsin activities. The digested fruit metabolome in the intestinal fluid demonstrated that ZnO NMs did not interfere with the normal process of human digestion. Importantly, ZnO NMs treatments increased the glycerophospholipids, carbohydrates, amino acids, and peptides in the intestinal fluids of tomato fruits. This study suggests that nanoscale Zn can be potentially used to increase the nutritional value of vegetable crops and can be an important tool to sustainably increase food quality and security.

Role of microbial iron reduction in arsenic metabolism from soil particle size fractions in simulated human gastrointestinal tract

Gut microbiota provides protection against arsenic (As) induced toxicity, and As metabolism is considered an important part of risk assessment associated with soil As exposures. However, little is known about microbial iron(III) reduction and its role in metabolism of soil-bound As in the human gut. Here, we determined the dissolution and transformation of As and Fe from incidental ingestion of contaminated soils as a function of particle size (<250 μm, 100–250 μm, 50–100 μm and < 50 μm). Colon incubation with human gut microbiota yielded a high degree of As reduction and methylation of up to 53.4 and 0.074 μg/(log CFU/mL)/hr, respectively; methylation percentage increased with increasing soil organic matter and decreasing soil pore size. We also found significant microbial Fe(III) reduction and high levels of Fe(II) (48 %−100 % of total soluble Fe) may promote the capacity of As methylation. Although no statistical change in Fe phases was observed with low Fe dissolution and high molar Fe/As ratios, higher As bioaccessibility of colon phase (avg. 29.4 %) was mainly contributed from reductive dissolution of As(V)-bearing Fe(III) (oxy)hydroxides. Our results suggest that As mobility and biotransformation by human gut microbiota (carrying arrA and arsC genes) are strongly controlled by microbial Fe(III) reduction coupled with soil particle size. This will expand our knowledge on oral bioavailability of soil As and health risks from exposure to contaminated soils.

Analysis of the probiotic characteristics and adaptability of Lactiplantibacillus plantarum DMDL 9010 to gastrointestinal environment by complete genome sequencing and corresponding phenotypes

Here we aimed to explore some vital phenotypes and potential genes involved in probiotic functions and adaptive responses of Lactiplantibacillus plantarum DMDL 9010 (LP9010), isolated from Chinese traditional naturally fermented paocai. We found that LP9010 showed good tolerance to simulated human gastrointestinal tract, self-coagulation and cholesterol-reducing abilities, antioxidant and antimicrobial activities. Comparative genomic analysis of six L. plantarum strains showed that LP9010 contained 392 unique genes. LP9010 genome possessed 281 genes related to carbohydrate transport and metabolism, including 138 sugar transporters and 60 phosphotransferase system enzymes. LP9010 contained high number (98) of carbohydrate-active enzymes especially glycoside hydrolases and glycosyltransferases. Extensive stress-related proteins may help the survival of LP9010 under gastrointestinal environment including temperature, pH, bile, osmotic and oxidative stresses. Many surface or extracellular proteins identified in LP9010 can attribute to adhesion to various extracellular matrices or external environment. The plantaricin gene cluster of LP9010 showed high identity with that of the reference strain WCFS1. Three exopolysaccharide biosynthesis gene clusters, two in the chromosome and one in Plasmid 2 were present in LP9010, and only one cluster was highly homologous to WCFS1. This study provided new insights into the probiotic properties and interaction with gastrointestinal environment of LP9010.

Bioaccessibility of essential lipophilic nutrients in a chloroplast-rich fraction (CRF) from agricultural green waste during simulated human gastrointestinal tract digestion

An in vitro gastrointestinal human digestion model, with and without additional rapeseed oil, was used to measure the bioaccessibility of the major lipophilic nutrients enriched in chloroplasts: β-carotene; lutein; α-tocopherol; and α-linolenic acid. Chloroplast-rich fraction (CRF) material for this work was prepared from post-harvest pea vine field residue (pea vine haulm, or PVH), an abundant source of freely available, underutilised green biomass. PVH was either steam sterilised (100 °C for 4 min) and then juiced (heat-treated PVH, or HPVH), or was juiced fresh and the juice heated (90 °C for 3 min) (heat-treated juice, or HJ); the CRF from all biomass treatments was recovered from the juice by centrifugation. The impact of postharvest heat treatment of the biomass (HPVH), or of heat treatment of the juice (HJ) derived from the biomass, on the retention and bioaccessibility of the target nutrients was determined. The results showed that both heat treatments increased the apparent retention of β-carotene, lutein, α-tocopherol, and α-linolenic acid in the CRF material during digestion. The presence of edible oil during digestion did not dramatically affect the retention of these nutrients, but it did increase the bioaccessibility of β-carotene, lutein, and α-tocopherol from CRF material derived from heated biomass or juice. The presence of oil also increased the bioaccessibility of β-carotene, but not of lutein, α-tocopherol, or α-linolenic acid, from fresh CRF material.

Characterization of an engineered live bacterial therapeutic for the treatment of phenylketonuria in a human gut-on-a-chip

Engineered bacteria (synthetic biotics) represent a new class of therapeutics that leverage the tools of synthetic biology. Translational testing strategies are required to predict synthetic biotic function in the human body. Gut-on-a-chip microfluidics technology presents an opportunity to characterize strain function within a simulated human gastrointestinal tract. Here, we apply a human gut-chip model and a synthetic biotic designed for the treatment of phenylketonuria to demonstrate dose-dependent production of a strain-specific biomarker, to describe human tissue responses to the engineered strain, and to show reduced blood phenylalanine accumulation after administration of the engineered strain. Lastly, we show how in vitro gut-chip models can be used to construct mechanistic models of strain activity and recapitulate the behavior of the engineered strain in a non-human primate model. These data demonstrate that gut-chip models, together with mechanistic models, provide a framework to predict the function of candidate strains in vivo.

Food-Grade Titanium Dioxide Particles Decreased the Bioaccessibility of Vitamin D3 in the Simulated Human Gastrointestinal Tract.

Food-grade titanium dioxide (E171) particles, as a "whiteness" additive, are often co-ingested with lipid-rich foods. Therefore, we explored the impact of E171 on lipid digestion and vitamin D3 (VD3) bioaccessibility encapsulated within oil-in-water emulsions in a simulated human gastrointestinal tract (GIT) model. VD3 bioaccessibility significantly decreased from 80 to 74% when raising E171 from 0 to 0.5 wt %. The extent of lipid digestion was reduced by E171 addition in a dose-dependent manner. VD3 bioaccessibility was positively correlated with the final amount of free fatty acids (FFAs) produced by lipid digestion (R2 = 0.95), suggesting that the reduction in VD3 bioaccessibility was due to the inhibition of lipid digestion by E171. Further experiments showed that E171 interacted with lipase and calcium ions, thereby interfering with lipid digestion. The findings of this study enhance our understanding toward the potential impact of E171 on the nutritional attributes of foods for human digestion health.

Food-grade titanium dioxide particles decrease the bioaccessibility of iron released from spinach leaves in simulated human gastrointestinal tract

E171 reduced Fe bioaccessibility of spinach in a simulated gastrointestinal tractviatwo mechanisms: the inhibition of α-amylase activity and adsorption of released Fe from spinach.

Effects of probiotic bacteria of Lactobacillus acidophilus and Lactobacillus casei on aflatoxin B1 detoxification within a simulated gastrointestinal tract model

The present study was objected to assess the ability of lactic acid bacteria in the reduction of aflatoxin B1 (AFB1) in a simulated human gastrointestinal tract. In this work, eight treatments were prepared to compare the ability of noted probiotic bacteria in AFB1 reduction in different simulated gastrointestinal conditions. The results of the present study revealed a significant reduction in AFB1 in all of the treatments in which the highest reduction rate was observed by L. acidophilus in the absence of sterilized milk. Moreover, the findings showed that bacteria, gastric juice, and small intestine may contribute to the reduction of AFB1.

Transformations of Ag2S nanoparticles in simulated human gastrointestinal tract: Impacts of the degree and origin of sulfidation

Engineered silver sulfide nanoparticles (e-Ag2S-NPs) are used in industry and can be released into the environment. Besides e-Ag2S-NPs, transformed silver sulfide nanoparticles (t-Ag2S-NPs) from silver nanoparticles are more likely to be the form that is widely distributed in the environment. Both e-Ag2S-NPs and t-Ag2S-NPs may be ingested and get into human gastrointestinal tract (GIT) through trophic transfer, posing a potential threat to human health. Nevertheless, knowledge of chemical stability of t-Ag2S-NPs and e-Ag2S-NPs in the human GIT is very limited. Herein e-Ag2S-NPs and a series of t-Ag2S-NPs with different degrees of sulfidation were selected as models for exposure to the simulated human GIT including mouth, stomach and small intestine phases under fed and fasted conditions. Silver ions were detected in the simulated saliva, gastric and small intestine fluids when t-Ag2S-NPs or e-Ag2S-NPs were incubated in the simulated GIT, but the amount (e.g., < 20 μg) of silver ion in each phase accounted for < 0.2‰ (w/w) of the silver added (i.e., 100 mg). Silver species of the residual particulate from each phase of the simulated GIT with t-Ag2S-NPs or e-Ag2S-NPs were thus analyzed through a developed analytical method that could selectively, successively and efficiently dissolve and quantify AgCl, Ag(0), and Ag2S in particulates. Both e-Ag2S-NPs and fully sulfidized t-Ag2S-NPs were shown to be highly stable in the simulated human GIT. Conversely, partially sulfidized t-Ag2S-NPs primarily underwent transformations in the mouth phase relative to stomach and small intestine phases regardless of fed or fasted status, wherein AgCl and Ag2S were observed besides Ag(0). The amount of Ag2S in the mouth phase negatively (r = −0.99, p < 0.001) correlated with the sulfidation degree of initial t-Ag2S-NPs. This work improved our understanding of potential transformations of t-Ag2S-NPs in the simulated human GIT, providing valuable information for future researches on evaluating health risks of ingested Ag2S-NPs.

Technological and probiotic potential of autochthonous lactic acid bacteria from spontaneously fermented dromedary milk

This work aimed to identify autochthonous lactic acid bacteria (LAB) from spontaneously fermented dromedary milk and explore their technological and probiotic properties in vitro. Analysis of the strains by 16S rDNA gene sequencing revealed four strains as Enterococcus faecalis, one strain as Enterococcus faecium, one strain as Lactococcus lactis, and four strains as Streptococcus pasteurianus. However, two strains (LEFS 42 and LEFS 55) showed a low 16S similarity (97.60% and 97.54%, respectively) with the type strain Streptococcus suis 92-2742T. All the tested LAB strains possessed acidifying and proteolytic capacities. Most of them were lipolytic (83.33%) and had the ability to produce exopolysaccharides (91.67%). All the studied LAB strains were non-hemolytic and exhibited antibacterial activity and sensitivity toward five antibiotics. Streptococcus sp. LEFS 55 had the highest hydrophobicity, autoaggregation, and coaggregation abilities. Moreover, all the isolated strains were able to resist simulated human gastrointestinal tract conditions and scavenge DPPH and ABTS radicals. Practical applications Nutritional and medicinal values of dromedary milk can be further increased after fermentation. Commercially available starter cultures are from bovine-based dairy industry being not competitive with endogenous microbiota of dromedary milk, which might not give a desirable final product. However, to date, few attempts have been performed to isolate and characterize lactic acid bacteria from spontaneously fermented dromedary milk. Besides, the probiotic potential of autochthonous lactic acid bacteria from fermented dromedary milk remains unexplored. Hence, this study aimed to identify autochthonous lactic acid bacteria from spontaneously fermented dromedary milk and to investigate their technological and probiotic potential. The isolation of autochthonous lactic acid bacteria with technological and probiotic properties from dromedary milk allows the production of fermented dromedary milk with functional properties and the diversification of dromedary milk products.

Soil washing with biodegradable chelating agents and EDTA: Technological feasibility, remediation efficiency and environmental sustainability

In washing soils contaminated with toxic metals, the replacement of recalcitrant EDTA with biodegradable chelators has gained high expectations. Herein we investigated the feasibility of using EDTA and biodegradable GLDA, EDDS and IDS under conditions pertinent to operational remediation technology, in a pilot-scale experiment. GLDA and IDS did not precipitate from process solutions, which lessened their recyclability. In other process parameters, chelator supplement, Na-saturation of process solutions and processing time, EDTA outperformed biodegradable chelators. Treatment with EDTA was also the most effective in total Pb and Zn removal and least impacted soil properties. GLDA was slightly better in Cd removal. EDDS and IDS were inefficient. All chelators effectively removed easily-available Pb, Zn and Cd from the exchangeable soil fraction. EDTA was the most efficient chelator in reducing the bioaccessibility of Pb and GLDA in reducing the bioaccessibility of Cd from simulated human gastrointestinal tract. Treatment with GLDA had an edge in reducing plant bioaccessibility of toxic metals, but induced worrying leachability of Pb. This was 8.3-times higher than with the process with EDTA and 3.4-times higher than in original soil. In general, our results demonstrate the advantage of EDTA over tested biodegradable chelators in process and remediation efficiency and environmental safety.

Steric stabilization of phycobiliprotein loaded liposome through polyethylene glycol adsorbed cellulose nanocrystals and their impact on the gastrointestinal tract

The goal of the study was to encapsulate phycobiliprotein (PBP), a seaweed bioactive compound with the help of liposome and stabilized through polyethylene glycol adsorbed cellulose nanocrystals (CNC). The study investigated the stability of CNC coating and the release of PBP compounds using a simulated human gastrointestinal tract (GIT) model. Adsorption of polyethylene glycol (PEG) with molecular weights of 400–4000 gmol-1 on desulfated CNCs (DCs) did not show any significant stability of liposomes during in-vitro GIT experiments. The effect of GIT phase on the quality characteristics of the sample revealed that the simulated gastric juice phase of GIT helps on desorption of polyethylene glycol from desulfated CNCs surface followed by precipitation of DCs. This phenomena confirmed the effective agglomeration of liposomes in the gastric phase of the GIT. The liposomes stabilized through the higher molecular weight of PEG adsorbed with DCs (i.e., DPCs-4000, DPCs-1500, and DPCs-1000) displayed a higher degree of anti-agglomeration behavior as compared to the lower molecular weight of PEG with desulfated CNCs (DPCs-600 and DPCs-400). However, liposomes stabilized through pure DCs displayed insignificant (p > 0.05) effect on the stability of PBP loaded liposomes. We concluded that the adsorption of PEG onto DCs surface was enough to stabilize PBP loaded liposomes in a mouth and saliva environment. This finding is relevant to understand the stability of CNC as coating material and PBP as core bioactive compounds in the human digestive system for potential nutraceutical and food applications.

Virulence, attachment and invasion of Caco-2 cells by multidrug-resistant bacteria isolated from wild animals

Wild animals may be considered important reservoirs for bacterial pathogens and, consequently, possible sources of infection for humans. In this study, selected multidrug-resistant bacteria (Acinetobacter spp., Aeromonas salmonicida, Klebsiella pneumoniae, Pseudomonas fluorescens and Shewanella putrefaciens) isolated from wild animals were characterized on their ability to attach and invade/internalize human colonic carcinoma (Caco-2) cells. In addition, the viability of these bacteria to survive under simulated human gastrointestinal tract conditions as well as the production of virulence factors (homoserine lactones signal molecules, gelatinases, proteases, siderophores and biofilm formation) were studied. The results suggests that all the bacteria presented the capacity to attach and internalize into Caco-2 cells. A. salmonicida and P. fluorescens exhibited the highest ability to internalize. These bacteria were also found to be the highest proteases producers. A. salmonicida and K. pneumoniae survived under simulated human gastrointestinal conditions. These were the bacteria with the highest capacity to produce biofilms. K. pneumoniae was the only bacterium producing siderophores. Taken together, the present results reinforce the need for the “One Health” initiative, underscoring the environment and the animals as important reservoirs of infectious determinants.

Transformation and Speciation Analysis of Silver Nanoparticles of Dietary Supplement in Simulated Human Gastrointestinal Tract.

Knowledge of the physicochemical properties of ingestible silver nanoparticles (AgNPs) in the human gastrointestinal tract (GIT) is essential for assessing their bioavailability, bioactivity, and potential health risks. The gastrointestinal fate of AgNPs and silver ions from a commercial dietary supplement was therefore investigated using a simulated human GIT. In the mouth, no dissolution or aggregation of AgNPs occurred, which was attributed to the neutral pH and the formation of biomolecular corona, while the silver ions formed complexes with biomolecules (Ag-biomolecule). In the stomach, aggregation of AgNPs did not occur, but extensive dissolution was observed due to the low pH and the presence of Cl-. In the fed state (after meal), 72% AgNPs (by mass) dissolved, with 74% silver ions forming Ag-biomolecule and 26% forming AgCl. In the fasted state (before meal), 76% AgNPs dissolved, with 82% silver ions forming Ag-biomolecule and 18% forming AgCl. A biomolecular corona around AgNPs, comprised of mucin with multiple sulfhydryl groups, inhibited aggregation and dissolution of AgNPs. In the small intestine, no further dissolution or aggregation of AgNPs occurred, while the silver ions existed only as Ag-biomolecule. These results provide useful information for assessing the bioavailability of ingestible AgNPs and their subsequently potential health risks, and for the safe design and utilization of AgNPs in biomedical applications.

Influence of gastrointestinal environment on free radical generation of silver nanoparticles and implications for their cytotoxicity

With the increasing number of applications of silver nanoparticles (Ag NPs) in consumer products, including food contact applications, it is important to understand potential health effects of ingestion of Ag NPs. The biosafety analysis of Ag NPs in various mammalian cells has been widely studied; however, the influence of the gastrointestinal environment on the physicochemical properties and toxicity of Ag NPs has not been fully addressed. In the present study, we investigated the impact of simulated human gastrointestinal tract (GIT) fluids on the physicochemical properties of Ag NPs and their impact on the in vitro cytotoxicity of Ag NPs in intestinal epithelial (Caco-2) cells. Polyvinylpyrrolidone (PVP)-coated Ag NPs of different sizes (30, 50, 100 nm) were incubated in three GIT fluids that differed in composition and pH (1.6, 5.0, 6.5) and were designed to mimic human gastric fluid in a fasted state (FaSSGF), human intestinal fluid in a fasted state (FaSSIF), and human intestinal fluid in a fed state (FeSSIF). Time-dependent decreases in UV–Vis absorption and increases in dynamic light scattering (DLS) were observed during the three-hour incubation of Ag NPs in GIT fluids. The results of transmission electron microscopy (TEM) coupled with energy dispersive X-ray spectroscopy (EDS) suggested that the Ag NPs aggregated and precipitated as AgCl salts in the presence of FaSSGF and FeSSIF. In the presence of FaSSGF and hydrogen peroxide (H2O2), a particle size- and concentration-dependent generation of hydroxyl radicals (OH) was detected by electron spin resonance (ESR) spectroscopy. When compared to the effects observed with the incubation of Ag NPs in H2O, incubation of Ag NPs in FaSSGF showed decreased cellular uptake in Caco-2 cells. In contrast, the incubation of Ag NPs in FeSSIF demonstrated increased cellular uptake and cytotoxicity. The results of this study demonstrate that GIT fluids have a significant influence on the physicochemical properties and cytotoxicity of Ag NPs and they provide valuable information that may be used in the safety evaluation of Ag NPs for consumer products.

Probiotic properties of Weissella cibaria and Leuconostoc citreum isolated from tejuino – A typical Mexican beverage

The survival of bacterial strains isolated from tejuino was evaluated in the human gastrointestinal model (ARIS) using saline solution and simulated food as matrices. Antagonistic activity towards pathogenic bacteria, short-chain fatty acids production and adhesion to HT-29 cells were also studied. Leuconostoc citreum CIATEJ BI–49.1, Weissella cibaria CIATEJ BI–48.1, Chryseobacterium bovis CIATEJ BI–55.1 and Bacillus safensis CIATEJ BI–75.1 were selected and inoculated in ARIS model. B. safensis and C. bovis were unable to survive the simulated human gastrointestinal tract conditions. Leu. citreum seemed to be more resistant to gastrointestinal conditions than W. cibaria, recovering 7–8 log CFU/mL. In the antagonistic assay, Leu. citreum showed the highest (p < 0.05) inhibition towards S. aureus and S. Typhimurium strains, while W. cibaria had the highest (p < 0.05) activity towards L. monocytogenes. In regards of short chain fatty acids production, Leu. citreum showed highest (p < 0.05) production of formic, propionic and butyric acids (0.10, 37.52 and 2.65 g/L, respectively) and higher percentage of adhesion to HT-29 cells (approximately 25%) than W. cibaria (approximately 0.5%). Leu. citreum could be a potential probiotic strain due to its tolerance to gastrointestinal conditions, antagonistic activity towards foodborne pathogens, short-chain fatty acids production and adhesion to HT-29 cells.

Przemiany związków polifenolowych w symulowanym przewodzie pokarmowym człowieka

Przemiany związków polifenolowych w symulowanym przewodzie pokarmowym człowieka

Interactions between ferulic and chlorogenic acids as a main factor determining antiradical activity of wholemeal wheat bread enriched with green coffee

The hydroxyl radical (·OH) is primarily responsible for the cytotoxic effects of oxygen. Hydroxyl radicals can be produced from O2 under stress conditions and are involved in numerous disorders such as inflammations. Interactions between potentially mastication extractable (BE), potentially bioaccessible (DE) and potentially bioavailable (AE) compounds able to scavenge OH· radicals derived from green coffee and wholemeal wheat flour were studied. Green coffee (Coffea arabica) beans (GCB) and wheat bread flour (600 g), type 2000 (average 1,8 g/100 g ash content, humidity14 g/100 g) were used. Results were compared with those obtained for pure chlorogenic and ferulic acids (Sigma-Aldrich, Poland). For interactions determination the isobolographic analysis was used. BE, DE and AE phytochemicals were released during digestion in the simulated human gastrointestinal tract. For functional food preparation bread flour was replaced with GCB flour at 1 to 5% levels (GC1, GC2, GC3, GC4 and GC5, respectively). Taking into account the isobole shape it may be concluded that chlorogenic and ferulic acids acted synergistically. In the same way acted BE and AE compounds derived from tested raw materials. Only in the case of DE additive interactions were found. GCB addition significantly enriched wheat bread with antiradical compounds. The highest activity was found for extracts obtained after simulated digestion which indicates high potential bioaccessibility of active compounds. Most importantly, these phytochemicals were highly bioavailable in vitro. Due to fact that bread is one of the main products consumed in the cultural area of many countries and resignation from its consumption for many people is impossible, the proposed product is mainly targeted at this group of consumers – it is a compromise between "traditional" and pro-health food.

Sprouting and elicitation with natural elicitors as an effective tools for improving antioxidant activity of potentially bioaccessible wheat phytochemicals

Antioxidant activity of potentially bioaccessible phytochemicals from 4-days-old sprouts of Polish winter wheat (Triticum aestivum ssp. vulgare) cultivars: Bogatka, Mulan and Muszelka were studied. Before germination seeds were treated with three kinds of natural elicitors: 0.1% (w/v) of Saccacharomyces cerevisiae (SC) extract, 0.1% (w/v) Salix daphnoides (SD) bark extract and their combinations (1:1, SCD) and distilled water (control) (6h, 25 °C) and were germinated at 20 °C in darkness. Potentially bioaccessible phytochemicals were released during digestion in the simulated human gastrointestinal tract. Antiradical activity (ABTS radical cation decolorization; AA), ferric reducing power (FRAP), Fe(II) ions chelating ability (CHEL) and ability to prevent linoleic acid against oxidation (LPO) were estimated. The analysis of variance (ANOVA) and Tukey's post-hoc test were used to compare groups (α= 0.05). Sprouting significantly decreased AA activity of potentially bioaccessible phytochemicals from Mulan and Bogatka, whereas such impact on Muszelka sprouts was not observed. Elicitation with all elicitors significantly increased AA activity of Bogatka sprouts, whereas in the case of Muszelka and Mulan such impact was observed after treatment with SD and SCD. Sprouting significantly increased RP and CHEL in respect of wheat variety. Treatment not influenced on RP of Bogatka sprouts. Sprouting and treatments with all elicitors significantly increased LPO activity of potentially bioaccessible compounds from Bogatka and Muszelka sprouts. Elicitation significant increased LPO. Treatments with all elicitors increased CHEL activity of potentially bioaccessible compounds from Bogatka and Muszelka seeds, whereas in the case of Mulan SCD was not effective. Especially high effect of SD was obtained for antiradical activity, chelating power and ability to lipid prevention.