Antioxidant activity of wheat and buckwheat flours

Antioxidative activities of wheat flours (type 500 and wholegrain) and buckwheat flours (light and wholegrain) were tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH·)-scavenging activity, reducing power and chelating activity on Fe2+. Also, the content of the total phenolics of ethanolic extracts was estimated. Polyphenolics content (expressed as gallic acid equivalent, GAE) in wheat flours varied between 37.1 and 137.2 μg GAE/g extract, while its content in buckwheat flour were at least four time higher and ranged between 476.3 and 618.9μg GAE/g extract. Ethanolic extracts of buckwheat flours exhibited higher antioxidant activities in all the assays, except for chelating activity. Regarding all the obtained results, it can be concluded that bakery products produced with buckwheat flour could be regarded as potential functional foods

Thymol depletion in the pig stomach

Aromatic plants and their extracts have been used in human and veterinary medicine since ancient times. However, the exact mode of action and kinetics or these compounds are generally poorly understood. The aim of this work was to determine the degradation and absorption kinetics of thymol in the pig stomach. An improved GC method was developed to easily measure the thymol content in samples extracted into ethylacetate. The GC separation was achieved on a 30 m × 0.25 mm ™ 0.25 mm film thickness Equity™ - 1701 fused silica capillary column, resulting in a standard curve over 1-500 mg/L. Isolated pig stomach was incubated for 360 min at 37 °C in an incubator with 95% O2:5% CO2 atmosphere on an oscillating plate at 40 rpm. Tyrode's solution pH 6.5 was used as incubation fluid. Pig stomach contents were inoculated with thymol (1.7 mM), and samples were collected at intervals during incubation and were extracted as is or after treatment with a lysis buffer. The lysis buffer was used to release thymol that may have been internalized by endogenous bacteria. Thymol concentrations in unlysed stomach samples decreased rapidly, being reduced more than twofold during 30 min incubations. Conversely, thymol concentrations in lysed samples increased rapidly, following 60 min incubations, concentrations were achieved at twice those measured in unlysed stomach contents at the beginning of the incubation. Thymol concentrations in lysed samples remained nearly double those in unlysed samples even after 360 min. Differing thymol concentrations measured in lysed and unlysed samples suggest luminal depletion resulting from bacterial uptake of thymol. Upon ingestion, luminal depletion would be expected to occur rapidly in stomach contents, but whether this sequestration would make thymol unavailable for absorption in the stomach or more distally is not known. Further investigation is needed to identify the bacteria responsible for this "thymol sequestration" phenomenon

Ex Vivo Absorption of Thymol and Thymol-beta-D-glucopyranoside in Piglet Everted Jejunal Segments

Food-producing animals are reservoirs of Campylobacter, a leading bacterial cause of human foodborne illness. The natural product thymol can reduce the survivability of Campylobacter, but its rapid absorption in the proximal gastrointestinal tract may preclude its use as a feed additive to reduce intestinal colonization of these pathogens. This work examined the ex vivo absorption of thymol and thymol-beta-D-glucopyranoside in everted porcine jejunal segments, as the latter was hypothesized to be more resistant to absorption. A modified gas chromatography and extraction method was developed to determine 1.0-500 mg/L thymol. From 1 and 3 mM solutions, 0.293 +/- 0.04 and 0.898 +/- 0.212 mM thymol, respectively, p = 0.0347, were absorbed, and 0.125 +/- 0.041 and 0.317 +/- 0.143 mM thymol-beta-D-glucopyranoside, respectively, p = 0.0892, were absorbed. Results indicate that thymol-beta-D-glucopyranoside was absorbed 2.3 to 2.8 times less effectively than thymol, thus providing evidence that thymol-beta-D-glucopyranoside may potentially be used as a feed additive to transport thymol to the piglet lower gut

Comparative effect of thymol or its glucose conjugate, thymol-beta-d-glucopyranoside, on Campylobacter in avian gut contents

Campylobacter jejuni is an important human food-borne pathogen that can contaminate meat and poultry during processing. Consequently, strategies are sought to reduce the carriage of C. jejuni in food animals before they arrive at the abattoir. Thymol is a natural product that reduces survivability of Campylobacter in vitro, but its rapid absorption from the proximal alimentary tract limits its bactericidal efficacy in vivo. Thymol-beta-d-glucopyranoside is more resistant to absorption than free thymol, but its administration to chickens has not been reported. In the present studies, 1mM thymol-beta-d-glucopyranoside was shown to exhibit near equal anti-Campylobacter activity as 1mM thymol when incubated anaerobically in avian crop or cecal contents in vitro, resulting in reductions of 1.10-2.32 log(10) colony forming units mL(-1) in C. jejuni concentrations after 24h incubation. In a follow-up live animal study, oral administration of thymol-beta-d-glucopyranoside, but not free thymol, significantly lowered (>10-fold) recovery of Campylobacter from the crop of market-aged broilers when compared to placebo-treated controls (n = 6 broilers/treatment). Neither thymol-beta-d-glucopyranoside nor thymol affected recovery of Campylobacter from cecal contents of the treated broilers. These results indicate that rapid absorption or passage of free thymol from the crop precluded its anti-Campylobacter activity at this site and throughout the entire gastrointestinal tract. Conversely, lower recovery of Campylobacter from the crop of birds treated with thymol-beta-d-glucopyranoside indicates this conjugate was retained and able to be hydrolyzed to biologically active free thymol at this site as intended, yet was not sufficiently protected to allow passage of efficacious amounts of the intact glycoside to the lower gut. Nevertheless, these results warrant further research to see if higher doses or encapsulation of thymol-beta-d-glucopyranoside or similar glycosides may yield an efficacious additive to reduce carriage of Campylobacter as well as other pathogens throughout the avian gut

Comparison of anti-Campylobacter activity of free thymol and thymol-beta-D-glucopyranoside in absence or presence of beta-glycoside-hydrolysing gut bacteria

Thymol is a natural product that exhibits antimicrobial activity in vitro but in vivo results indicate that absorption within the proximal alimentary tract precludes its delivery to the distal gut. Presently, the anti-Campylobacter activity of thymol was compared against that of thymol-beta-D-glucopyranoside, the latter being resistant to absorption. When treated with 1 mM thymol, Campylobacter coli and jejuni were reduced during pure or co-culture with a beta-glycoside-hydrolysing Parabacteroides distasonis. Thymol-beta-D-glucopyranoside treatment (1 mM) did not reduce C coli and jejuni during pure culture but did during co-culture with P. distasonis or during mixed culture with porcine or bovine faecal microbes possessing beta-glycoside-hydrolysing activity. Fermentation acid production was reduced by thymol-beta-D-glucopyranoside treatment, indicating that fermentation was inhibited, which may limit its application to just before harvest. Results suggest that thymol-beta-D-glucopyranoside or similar beta-glycosides may be able to escape absorption within the proximal gut and become activated by bacterial beta-glycosidases in the distal gut. Published by Elsevier Ltd

Lipid oxidative changes in traditional dry fermented sausage Petrovská klobása during storage

The influence of drying and ripeninig conditions (traditional and industrial) in the production of dry fermented sausage Petrovská klobása, on fatty-acid composition and oxidative changes in lipids, during 7 months of storage, was investigated. During the storage period, the sum of unsaturated fatty acids and the content of free fatty acids were significantly higher (p<0.05), while the content of malondialdehyde was significantly lower in the sausage subjected to traditional conditions of drying and ripening. At the end of the storage period, contents of pentanal and hexanal in the sausage subjected to traditional conditions of drying and ripening (4.03 μg/g and 1.67 μg/g, respectively) were significantly lower (p<0.05) in comparison with these contents in the sausage subjected to industrial conditions of drying and ripening. Traditional conditions of drying and ripening at lower temperatures have led to lower oxidative changes in lipids in traditional dry fermented sausage Petrovská klobása during storage period. [Projekat Ministarstva nauke Republike Srbije, br. TR31032

<i>Ex Vivo</i> Absorption of Thymol and Thymol-β‑d‑glucopyranoside in Piglet Everted Jejunal Segments

Food-producing animals are reservoirs of <i>Campylobacter</i>, a leading bacterial cause of human foodborne illness. The natural product thymol can reduce the survivability of <i>Campylobacter</i>, but its rapid absorption in the proximal gastrointestinal tract may preclude its use as a feed additive to reduce intestinal colonization of these pathogens. This work examined the <i>ex vivo</i> absorption of thymol and thymol-β-d-glucopyranoside in everted porcine jejunal segments, as the latter was hypothesized to be more resistant to absorption. A modified gas chromatography and extraction method was developed to determine 1.0–500 mg/L thymol. From 1 and 3 mM solutions, 0.293 ± 0.04 and 0.898 ± 0.212 mM thymol, respectively, <i>p</i> = 0.0347, were absorbed, and 0.125 ± 0.041 and 0.317 ± 0.143 mM thymol-β-d-glucopyranoside, respectively, <i>p</i> = 0.0892, were absorbed. Results indicate that thymol-β-d-glucopyranoside was absorbed 2.3 to 2.8 times less effectively than thymol, thus providing evidence that thymol-β-d-glucopyranoside may potentially be used as a feed additive to transport thymol to the piglet lower gut

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present