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Publication
Effect of dietary seaweed extracts, galactooligosaccharide and vitamin E supplementation on meat quality parameters in finisher pigs
2016-10, Rajauria, Gaurav, Draper, Jennifer, McDonnell, Mary, O'Doherty, John V.
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.
Publication
Effects of extraction method on the prebiotic potential of Ascophylum nodosum extracts
2018-06-28, Venardou, Brigkita, McDonnell, Mary, GarcĂa-Vaquero, Marco, Rajauria, Gaurav, O'Doherty, John V., Sweeney, Torres
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
In vitro effects of seaweed extracts on intestinal commensals and pathogens of weaned piglets
2018-06-21, Venardou, Brigkita, McDonnell, Mary, GarcĂa-Vaquero, Marco, Rajauria, Gaurav, O'Doherty, John V., Sweeney, Torres
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.