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O'Doherty, John V.
Preferred name
O'Doherty, John V.
Official Name
O'Doherty, John V.
Research Output
Now showing 1 - 10 of 21
- PublicationExploring ultrasound-assisted extraction to recover high valuable polysaccharides from brown macroalgae and its related antioxidant activities(2018-10-27)
; ; ; ; This study aimed to optimize the ultrasound-assisted extraction (UAE) parameters of temperature, time and amplitude on the yields of fucose and glucans and their antioxidant activities (FRAP and DPPH) of extracts from Laminaria digitata and to evaluate the application of these optimum UAE parameters in other brown macroalgae (L. hyperborea and Ascophyllum nodosum).44 - PublicationEffect of seasons on the proximate composition of Laminaria hyperborea from Irish Atlantic coast(2018-10-27)
; ; ; ; This study aimed to analyze the seasonal variation in the proximate composition of Laminaria hyperborea collected in 2016 and 2017, off the west coast of Ireland.52 - PublicationEffects of extraction method on the prebiotic potential of Ascophylum nodosum extracts(Microbiological Society, 2018-06-28)
; ; ; ; ; Seaweed-derived bioactive compounds exhibit various beneficial activities in humans and animals. A factor influencing their concentrations, and subsequent bioactivity, is the extraction method. Our aim was to evaluate the in vitro prebiotic potential of three differently-extracted Ascophylum nodosum samples. The samples were produced using either solid-liquid extraction with water (AN-W), or ethanol (AN-EtOH) as solvent or high pressure-assisted extraction with water as solvent (AN-HPW). All extracts were two-fold diluted from 2 mg/ml to 0.25 mg/ml. Lactobacillus plantarum (LP), L. reuteri (LR) and Bifidobacterium thermophilum (BT) were used at 106 -107 colony-forming unit(CFU)/ml. Each concentration of each extract and controls (0 mg/ml) were incubated for 18 h at 37 °C aerobically or anaerobically (BT). Final bacterial concentrations were determined by spread plating. All experiments were carried out in triplicate with technical replicates. All data were logarithmically transformed and analysed using PROC GLM (SAS 9.4). AN-HPW increased BT (≤0.9 LogCFU/ml, P<0.05) at all concentrations and LR and LP (0.2 LogCFU/ml, P<0.05) at 2 mg/ml and 1mg/ml, respectively. AN-W increased BT (≤0.6 LogCFU/ml, P<0.05) at 1-2mg/ml, but decreased both lactobacilli; LP ≤0.7 LogCFU/ml and LR ≤5.4 LogCFU/ml at all concentrations (P<0.05). AN-EtOH increased LP (≤0.7 LogCFU/ml, P<0.05), but reduced LR (≤5.7 LogCFU/ml, P<0.05) at all concentrations and BT (≤4 LogCFU/ml, P<0.05) at 1-2 mg/ml. In conclusion, the extraction method influenced the prebiotic potential of the A. nodosum extracts in vitro with AN-HPW being the most promising.56 - PublicationIn vitro effects of seaweed extracts on intestinal commensals and pathogens of weaned piglets(Microbiology Society, 2018-06-21)
; ; ; ; ; While the inclusion of certain seaweed extracts in weaner piglet diets leads to a beneficial gut microbial profile, the mode of action is not known. The aim of this study was to evaluate the prebiotic and antimicrobial potential of Laminaria digitata and Ascophylum nodosum extracts in vitro. Both extracts were two-fold diluted from 2 mg/ml to 0.25 mg/ml. The following strains were used at 106 -107 colonyforming unit(CFU)/ml concentrations: Lactobacillus plantarum, L. reuteri, Bifidobacterium thermophilum, Enterotoxigenic Escherichia coli O149 and Salmonella enterica ser Typhimurium PT12. Each concentration of each extract and controls (0 mg/ml) were incubated for 18 h at 37 °C aerobically or anaerobically (B. thermophilum). Final bacterial concentrations were determined by spread plating. All experiments were carried out with technical replicates on three independent occasions. All data were logarithmically transformed and analysed using the PROC GLM (SAS 9.4). The L. digitata extract increased B. thermophilum 0.7 LogCFU/ml at 0.25 mg/ml (P<0.05) and ≥1 LogCFU/ml from 0.5-2 mg/ml (P<0.05), with no effect on lactobacilli. The A. nodosum extract increased B. thermophilum up to 0.9 LogCFU/ml at all concentrations tested (P<0.05). Additionally, a 0.2 LogCFU/ml increase of L. reuteri and L. plantarum was observed at 2 mg/ml (P<0.05) and 1mg/ml (P<0.05), respectively. Both extracts displayed no antimicrobial activity against ETEC or S. Typhimurium. In conclusion, both extracts exhibited bifidogenic activity in vitro, with an additional slight increase of Lactobacillus spp. for A. nodosum, indicating a prebiotic potential.84 - PublicationEvaluation of Ultrasound, Microwave, Ultrasound–Microwave, Hydrothermal and High Pressure Assisted Extraction Technologies for the Recovery of Phytochemicals and Antioxidants from Brown Macroalgae(MDPI, 2021-05-27)
; ; ; ; ; ; This study aims to explore novel extraction technologies (ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), ultrasound–microwave-assisted extraction (UMAE), hydrothermal-assisted extraction (HAE) and high-pressure-assisted extraction (HPAE)) and extraction time post-treatment (0 and 24 h) for the recovery of phytochemicals and associated antioxidant properties from Fucus vesiculosus and Pelvetia canaliculata. When using fixed extraction conditions (solvent: 50% ethanol; extraction time: 10 min; algae/solvent ratio: 1/10) for all the novel technologies, UAE generated extracts with the highest phytochemical contents from both macroalgae. The highest yields of compounds extracted from F. vesiculosus using UAE were: total phenolic content (445.0 ± 4.6 mg gallic acid equivalents/g), total phlorotannin content (362.9 ± 3.7 mg phloroglucinol equivalents/g), total flavonoid content (286.3 ± 7.8 mg quercetin equivalents/g) and total tannin content (189.1 ± 4.4 mg catechin equivalents/g). In the case of the antioxidant activities, the highest DPPH activities were achieved by UAE and UMAE from both macroalgae, while no clear pattern was recorded in the case of FRAP activities. The highest DPPH scavenging activities (112.5 ± 0.7 mg trolox equivalents/g) and FRAP activities (284.8 ± 2.2 mg trolox equivalents/g) were achieved from F. vesiculosus. Following the extraction treatment, an additional storage post-extraction (24 h) did not improve the yields of phytochemicals or antioxidant properties of the extracts.131Scopus© Citations 25 - PublicationPotential of a fucoidan-rich Ascophyllum nodosum extract to reduce Salmonella shedding and improve gastrointestinal health in weaned pigs naturally infected with Salmonella(Springer, 2022-04-04)
; ; ; ; ; ; ; ; ; Background. Dietary supplementation with a fucoidan-rich Ascophyllum nodosum extract (ANE), possessing an in vitro anti-Salmonella Typhimurium activity could be a promising on-farm strategy to control Salmonella infection in pigs. The objectives of this study were to: 1) evaluate the anti-S. Typhimurium activity of ANE (containing 46.6% fucoidan, 18.6% laminarin, 10.7% mannitol, 4.6% alginate) in vitro, and; 2) compare the effects of dietary supplementation with ANE and Zinc oxide (ZnO) on growth performance, Salmonella shedding and selected gut parameters in naturally infected pigs. This was established post-weaning (newly weaned pig experiment) and following regrouping of post-weaned pigs and experimental re-infection with S. Typhimurium (challenge experiment). Results. In the in vitro assay, increasing ANE concentrations led to a linear reduction in S. Typhimurium counts (P < 0.05). In the newly weaned pig experiment (12 replicates/treatment), high ANE supplementation increased gain to feed ratio, similar to ZnO supplementation, and reduced faecal Salmonella counts on d 21 compared to the low ANE and control groups (P < 0.05). The challenge experiment included thirty-six pigs from the previous experiment that remained on their original dietary treatments (control and high ANE groups with the latter being renamed to ANE group) apart from the ZnO group which transitioned onto a control diet on d 21 (ZnO-residual group). These dietary treatments had no effect on performance, faecal scores, Salmonella shedding or colonic and caecal Salmonella counts (P > 0.05). ANE supplementation decreased the Enterobacteriaceae counts compared to the control. Enterobacteriaceae counts were also reduced in the ZnO-residual group compared to the control (P < 0.05). ANE supplementation decreased the expression of interleukin 22 and transforming growth factor beta 1 in the ileum compared to the control (P < 0.05).220Scopus© Citations 4 - PublicationThe potential of cholecalciferol and 25-hydroxyvitamin D3 enriched diets in laying hens, to improve egg vitamin D content and antioxidant availability(Elsevier, 2017-12)
; ; ; ; ; Sixty Hy-line brown hens were randomly assigned to four barns (n = 4) to investigate the effects of cholecalciferol (vitamin D₃) versus 25-hydroxyvitamin D3 (25-OH-D₃) enriched diets on egg vitamin D concentration, antioxidant activity and egg quality parameters. Experimental design was a 4 × 4 Latin square consisting of 4 experimental treatments and 4 experimental periods. The treatments were (1) 1500 IU of vitamin D₃ (2) 3000 IU of vitamin D₃ (3) 1500 IU of vitamin D₃ and 37.5 μg of 25-OH-D₃ (4) 75 μg of 25-OH-D₃ per kg of feed. Hens offered 75 μg of 25-OH-D₃ had a higher (P < 0.05) total vitamin D egg yolk content (5.06 μg/egg), and antioxidant activity compared to other dietary treatments. The results demonstrates that the enrichment of hen diets with 25-OH-D₃ may be a useful approach and may contribute between 25 and 33% towards total vitamin D daily requirements while also improving antioxidant status of eggs. Industrial relevance: Vitamin D deficiency is now regarded as a major issue in northern Europe and has been described as a pandemic. A growing interest in vitamin D food fortification in northern Europe to satisfy the current dietary intake recommendations has been observed. The use of a bio-addition approach for increasing vitamin D intake through biofortification of livestock feeds attracts attention. Enrichment of the hen's diet with vitamin D may also supply additional benefits of increasing antioxidant activity. This increase in antioxidant activity may have the ability to increase food quality and extend the shelf life. This study explores the effect of vitamin D enriched diets fed to laying hens on vitamin D egg yolk content and antioxidant activity in the egg. These enriched diets could demonstrate that enrichment of hen diets with 25-hyroxvitamin D₃ may be a useful approach for tackling low vitamin D intakes and improving antioxidant capacity of eggs.Scopus© Citations 14 333 - PublicationVitamin D-biofortified beef: A comparison of cholecalciferol with synthetic versus UVB-mushroom-derived ergosterol as feed source(Elsevier, 2018-08-01)
; ; ; ; ; This study investigates dietary fortification of heifer feeds with cholecalciferol and ergocalciferol sources and effects on beef total vitamin D activity, vitamer, respective 25-hydroxymetabolite contents, and meat quality. Thirty heifers were allocated to one of three dietary treatments [(1) basal diet + 4000 IU of vitamin D3 (Vit D3); (2) basal diet + 4000 IU of vitamin D2 (Vit D2); and (3) basal diet + 4000 IU of vitamin D2-enriched mushrooms (Mushroom D2)] for a 30 day pre-slaughter period. Supplementation of heifer diets with Vit D3 yielded higher (p < 0.001) Longissimus thoracis (LT) total vitamin D activity (by 38–56%; p < 0.05) and serum 25-OH-D concentration (by 20–36%; p < 0.05), compared to that from Vit D2 and Mushroom D2 supplemented animals. Irrespective of vitamin D source, carcass characteristics, sensory and meat quality parameter were unaffected (p > 0.05) by the dietary treatments. In conclusion, vitamin D3 biofortification of cattle diets is the most efficacious way to enhance total beef vitamin D activity.Scopus© Citations 21 288 - PublicationThe effects of mushroom powder and vitamin D2 enriched mushroom powder supplementation on the growth performance and health of newly weaned pigs(Wiley, 2022-05)
; ; ; ; ; ; ; ; A complete randomised block design experiment was conducted to examine the effects of mushroom powder (MP) and vitamin D2-enriched mushroom powder (MPD2) on growth performance, faecal scores, coefficient of apparent total tract digestibility (CATTD) of nutrients and selected microflora in weaned pigs up to day 35 post-weaning. One hundred and ninety-two weaned pigs (7.8kg [SD 1.08kg]) were blocked according to live weight, sex and litter of origin and randomly assigned to the following: (T1) control diet; (T2) control diet +MP; (T3) control diet + MPD2; and (T4) control diet +zinc oxide (ZnO) (n = 12 replicates/treatment). Mushroom powders were included at 2 g/kg of feed achieving a β-glucan content of 200ppm. ZnO was included at 3100 mg/kg feed and halved to 1550 mg/kg after 21 days. Vitamin D content was enhanced in MPD2 using synthetic UVB exposure to obtain a vitamin D2 level of 100 µg/kg of feed. Faecal samples were collected on day 14 for microbial and nutrient digestibility analysis. There was no difference (p > 0.05) in ADG, G:F, faecal scores, microbial populations and CATTD of nutrients in pigs supplemented with MP or MPD2 compared with the control diet. The supplementation of MP and MPD2 caused a reduction (p < 0.05) in feed intake compared with the control and ZnO diet throughout the 35-day experimental period. ZnO supplementation increased ADG and ADFI (p < 0.05) during the first period (D0-21) compared with pigs offered MP and MPD2. In conclusion, MP and MPD2 supplementation resulted in similar ADG, G:F, faecal scores compared with the control but were not comparable to ZnO, mainly due to a reduction in feed intake.70Scopus© Citations 5 - PublicationThe effect of 25‐hydroxyvitamin D3 and phytase inclusion on pig performance, bone parameters and pork quality in finisher pigs(Wiley, 2018-10)
; ; ; ; ; ; The objective of this study was to investigate the effects of supplementing both phytase and 25-hydroxyvitamin D3 (25-OH-D₃) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2 × 2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81 g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25-OH-D₃ (T3) and low P diet + phytase + 25-OH-D₃ (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI) (2.45 kg vs. 2.59 kg; p < 0.05) and lower feed conversion ratio (FCR) (2.74 kg/kg vs. 2.85 kg/kg; p < 0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p < 0.05) coefficient of apparent total tract digestibility (CATTD) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25-OH-D3 diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p < 0.05) bone DM, ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p < 0.05) between phytase and 25-OH-D3 on cook loss. Pigs offered 25-OH-D3 had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25-OH-D3 were offered in combination compared to the phytase only diet. Pigs offered 25-OH-D3 exhibited higher (p < 0.05) Warner Bratzler shear force values and lower (p < 0.05) pork lightness (L*) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25-OH-D3 on pig performance, bone parameters or pork quality.Scopus© Citations 17 508
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