Now showing 1 - 10 of 27
  • Publication
    Effects of extraction method on the prebiotic potential of Ascophylum nodosum extracts
    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.
  • Publication
    Exploring ultrasound-assisted extraction to recover high valuable polysaccharides from brown macroalgae and its related antioxidant activities
    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).
  • Publication
    Effect of seasons on the proximate composition of Laminaria hyperborea from Irish Atlantic coast
    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.
  • Publication
    In vitro effects of seaweed extracts on intestinal commensals and pathogens of weaned piglets
    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.
  • Publication
    Ultrasonic extraction
    Found in seaweed, fucoidans have many beneficial properties, but extracting them from the plant has proved difficult. UCD and TEAGASC researchers looked at one promising technology.
  • Publication
    Mycotoxin binder increases growth performance, nutrient digestibility and digestive health of finisher pigs offered wheat based diets grown under different agronomical conditions
    The objective of this study was to investigate the effect of a wheat-based diet, exhibiting different levels of mycotoxin contamination and the presence of a mycotoxin binder on growth performance, nutrient digestibility and digestive health in finisher pigs. Sixty-four pigs (38.7 kg (SD 3.48 kg)) were assigned to one of four dietary treatments: (T1) low quality wheat diet, (T2) low quality wheat diet containing 2 g/kg of a mycotoxin binder, (T3) high quality wheat diet, (T4) high quality wheat diet containing 2 g/kg of a mycotoxin binder. The inclusion of wheat was 500 g/kg. The mycotoxin binder used was a Hydrated Sodium-Calcium-Aluminum-Silicate, which also included calcium propionate and calcium formate. The low quality wheat grain had a higher level of zearalenone (233.02 vs. 33.36 μg/kg), aflatoxin (4.08 vs. 2.94 μg/kg) and ochratoxin (28.20 vs. 4.23 μg/kg). Pigs offered the low quality wheat diet had a lower average daily gain (ADG) (P < 0.05), average daily feed intake (ADFI) (P < 0.001) and had a reduced coefficient of apparent total tract digestibility (CATTD) (P < 0.05) of nitrogen (N) and gross energy (GE) compared with pigs offered the high quality wheat diets. The inclusion of a mycotoxin binder improved ADG and ADFI (P < 0.05) and also increased the CATTD of N and GE compared to diets without a mycotoxin binder. Pigs offered the low quality wheat diets had increased (P < 0.05) expression of tumour necrosis factor (TNF) in the duodenum and colon and of claudin 2 (CLDN2) (P < 0.001) in the duodenum, compared to pigs offered the high quality wheat diets. Pigs offered diets containing a mycotoxin binder had increased expression of ghrelin (GHRL) (P < 0.05) in the duodenum compared to pigs offered diets without a mycotoxin binder. There was a wheat × mycotoxin binder interaction on the expression of peptide transporter 1 gene (SLC15A1/PEPT1) and sodium-glucose linked transporter 1 gene (SLC5A1/SGLT1) (P < 0.05) in the duodenum. Pigs offered the low quality wheat with a mycotoxin binder had lower expression of SLC15A1/PEPT1 and SLC5A1/SGLT1 expression compared to the low quality wheat diet only. However, there was no response to mycotoxin binder supplementation with the high quality wheat diet. In conclusion, the low quality wheat reduced ADG, ADFI, nutrient digestibility and modified the gene expression of genes involved in intestinal nutrient transport and inflammation. The supplementation of a mycotoxin binder improved ADG, ADFI, nutrient digestibility and also improved digestive health through increases in nutrient transporter and tight junction gene expression.
      332Scopus© Citations 9
  • Publication
    Effect of dietary seaweed extracts, galactooligosaccharide and vitamin E supplementation on meat quality parameters in finisher pigs
    Fifty six pigs were assigned to 1 of 4 diets (n = 14) for 35 days pre-slaughter, to assess the effects on bacterial count, lipid peroxidation (LPO) and total antioxidant capacity (TAC) of fresh meat. The treatments were (T1) basal diet (BD), (T2) BD plus seaweed extract (SWE), (T3) BD plus vitamin E (Vit E) and (T4) BD plus galacto-oligosaccharides (GOS). At slaughter longissimus dorsi (LD) steaks were excised and stored in modified atmosphere packs for a 14 day period. The supplemented diets improved the TAC of LD steaks until day 11 of storage while SWE samples exhibited the highest TAC throughout. A reduction (P < 0.05) in the level of LPO was observed in LD steaks from SWE and Vit E supplementation. Compared to basal diet, SWE and GOS exhibited lower bacterial count throughout storage. These results demonstrate the potential for the incorporation of SWE into muscle foods via the diet.
      353Scopus© Citations 30
  • Publication
    Polysaccharides from macroalgae: Recent advances, innovative technologies and challenges in extraction and purification
    Polysaccharides obtained from macroalgae have promising prospects and could contribute greatly to the future of a marine based bio-economy. Specifically, laminarin and fucoidan from brown macroalgae have a wide variety of potential industrial applications including functional foods and nutraceuticals, due to their broad range of biological activities. These beneficial biological activities are related to the chemical composition and structure of the macroalgal polysaccharides. The molecular weight, monosaccharide composition and sulphate content of these polysaccharides could be influenced by both macroalgal biology (i.e. variations in polysaccharide composition due to macroalgae species and their biological cycle) and different extraction/purification techniques employed to obtain polysaccharide enriched products (i.e. de-sulphation or fragmentation of sulphated polysaccharides). This review focuses on the extraction and purification methods for the macroalgal polysaccharides laminarin and fucoidan used in the recent literature. The application of innovative extraction technologies (such as ultrasound, microwave and enzyme-assisted extractions), as well as new purification techniques (i.e. membrane separation), are also discussed together with the challenges concerning molecule structure-function relationship and macroalgal variability.
      2443Scopus© Citations 171
  • Publication
    Optimisation of Ultrasound Frequency, Extraction Time and Solvent for the Recovery of Polyphenols, Phlorotannins and Associated Antioxidant Activity from Brown Seaweeds
    This study investigates ultrasound assisted extraction (UAE) process parameters (time, frequency and solvent) to obtain high yields of phlorotannins, flavonoids, total phenolics and associated antioxidant activities from 11 brown seaweed species. Optimised UAE conditions (35 kHz, 30 min and 50% ethanol) significantly improved the extraction yield from 1.5-fold to 2.2-fold in all seaweeds investigated compared to solvent extraction. Using ultrasound, the highest recovery of total phenolics (TPC: 572.3 ± 3.2 mg gallic acid equivalent/g), total phlorotannins (TPhC: 476.3 ± 2.2 mg phloroglucinol equivalent/g) and total flavonoids (TFC: 281.0 ± 1.7 mg quercetin equivalent/g) was obtained from Fucus vesiculosus seaweed. While the lowest recovery of TPC (72.6 ± 2.9 mg GAE/g), TPhC (50.3 ± 2.0 mg PGE/g) and TFC (15.2 ± 3.3 mg QE/g) was obtained from Laminaria digitata seaweed. However, extracts from Fucus serratus obtained by UAE exhibited the strongest 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity (29.1 ± 0.25 mg trolox equivalent/g) and ferric reducing antioxidant power (FRAP) value (63.9 ± 0.74 mg trolox equivalent/g). UAE under optimised conditions was an effective, low-cost and eco-friendly technique to recover biologically active polyphenols from 11 brown seaweed species.
      103Scopus© Citations 56
  • Publication
    Cholecalciferol supplementation in heifer diets increases beef vitamin D concentration and improves beef tenderness
    This study investigated the effects of cholecalciferol (vitamin D₃) supplementation on beef vitamin D activity, beef tenderness and sensory attributes. Thirty heifers were randomly allocated to one of three finishing dietary treatments [(T1) basal diet + 0 IU vitamin D₃; (T2) basal diet + 2000 IU vitamin D₃; and (T3) basal diet + 4000 IU vitamin D₃] for a 30 day period pre-slaughter. Vitamin D₃ supplementation linearly increased serum 25-hydroxyvitamin D₃ (25-OH-D3) concentrations (R2 = 0.48), Longissimus thoracis (LT) total vitamin D activity (R2 = 0.78) as well as individually vitamin D₃ (R2 = 0.84) and 25-OH-D₃ (R2 = 0.75). The highest vitamin D₃ inclusion diet (T3) had a 42% increase (P < 0.001) in LT vitamin D activity compared to the intermediate diet (T2) and a 145% increase over the lowest level diet (T1). Vitamin D₃ supplementation decreased LT shear (P < 0.05) force values after 14 days chilling. Sensory parameters were not affected (P > 0.05). In conclusion, through short-term vitamin D₃ supplementation of cattle diets, beef vitamin D activity can successfully be enhanced
      310Scopus© Citations 17