Now showing items 1-20 of 1672

    • Shelf-life extension of herring (Clupea harengus) using in-package atmospheric plasma technology

      Albertos, I.; Martin-Diana, A. B.; Cullen, Patrick J.; Tiwari, Brijesh; Shikha Ojha, K.; Bourke, Paula; Rico, D.; Regional Government of Castille and Leon, Spain; NUGAFU-PEP 2011/769 (Elsevier, 2017-09-17)
      Atmospheric cold plasma is a green and emerging technology, highly interesting to the food industry for its application. Dielectric Barrier Discharges (DBD) can generate atmospheric cold plasma inside sealed packages filled with air through the use of high voltages. This study investigated the use of a large gap DBD design to generate a plasma discharge within the headspace of packaged herring fillets, and its effects on microbiological and quality markers of the fish stored for 11 days at 4 °C. DBD plasma treatment conditions were 70 kV or 80 kV for 5 min treatment time. Results showed that the microbial load (total aerobic mesophilic, total aerobic psychrotrophics, Pseudomonas, lactic acid bacteria and Enterobacteriaceae) were significantly (p < 0.05) lower in the treated samples compared to the control samples. However, samples exposed to the lowest applied voltage better retained key quality factors (lower oxidation and less colour modification). DBD-treatment caused a reduction in trapped water in the myofibrillar network (T21), identified using low-field nuclear magnetic resonance of protons (1H LF NMR). The results indicate that in-package plasma treatment could be employed as an effective treatment for reducing spoilage bacteria in fish.
    • Effects of different freshness on the quality of cooked tuna steak

      Miao, Hanlin; Liu, Qin; Bao, Hairong; Wang, Xichang; Miao, Song; National High-tech Research & Development Program of China; #2012AA092302 (Elsevier, 2017-07-10)
      The variation in quality of yellowfin tuna (Thunnus albacares) steaks of different freshness after cooking were studied by analyzing K value, adenosine triphosphate (ATP)-related compounds content, histamine content, sensory quality, E-nose and E-tongue analysis. The results indicated that when the freshness of raw tuna steak decreased from sashimi grade to cooking grade, IMP content significantly decreased whereas HxR content significantly increased after cooking. With the decrease of freshness, K value of the 4th day sashimi-grade tuna and the 6th day cooking-grade tuna increased from 18% and 24% to 27% and 45% respectively after cooking. The higher histamine content in raw tuna steak, the more significantly increased histamine level of cooked tuna was observed. Raw tuna steaks with sashimi grade have significant variation from those with cooking grade in odor and taste by E-nose and E-tongue analysis after cooking The sensory evaluation showed that the freshness of tuna steak significantly influence the cooking quality (p < 0.05).
    • Comparison of photosynthetic performance of Fagus sylvatica seedlings under natural and artificial shading

      Sevillano, Ignacio; Short, Ian; Campion, Jerry; Grant, Olga M.; Grant, Jim; O’Reilly, Conor; Department of Agriculture, Food and the Marine; Teagasc Walsh Fellowship Programme (Elsevier, 2018-03-14)
      Commitment to sustainable forest management (alternatives to clearfelling) has led to a renewed interest in continuous cover forestry systems, which promote the control of light to produce stand benefits. Physiological performance of shade-tolerant European beech (Fagus sylvatica L.) in response to light availability was investigated in natural regeneration below the canopy in contrast to planted seedlings under artificial-shade conditions. Although beech seedlings had higher photosynthetic capacity with increasing light availability, they were able to maintain positive CO2 assimilation rates under low light levels in both field and controlled conditions. Leaves of seedlings under low light had the ability to use light more efficiently (higher PSII efficiency) than those in high light, which offer some physiological explanation for the ability of beech seedlings to grow under very low light conditions. Whilst caution is advised to interpret results from controlled to field studies, the overall general correspondence in the trend of the physiological response to light levels within beech grown below the canopy and under artificial-shade conditions suggests that it might be possible to extrapolate results from studies performed under artificial shade (nets) to field conditions. Hence, the use of nets may be an alternative way of assessing the potential physiological responses of seedlings to light availability.
    • Effect of finishing diet and duration on the sensory quality and volatile profile of lamb meat

      Gkarane, Vasiliki; Brunton, Nigel; Allen, Paul; Gravador, Rufielyn S.; Claffey, Noel A.; Diskin, Michael G.; Fahey, Alan G.; Farmer, Linda J.; Moloney, Aidan P; Alcalde, Maria J.; et al. (Elsevier, 2018-08-02)
      Animal production factors can affect the sensory quality of lamb meat. The study investigated the effect of diet composition and duration of consumption on the proximate analysis, volatile profile and sensory quality of lamb meat. Ninety-nine male Texel × Scottish Blackface lambs were raised at pasture for 10 months before being assigned in groups of 11 to one of the following treatments: 100% Silage (S) for 36 (S36), 54 (S54) or 72 (S72) days; 50% Silage - 50% Concentrate (SC) for 36 (SC36), 54 (SC54) or 72 (SC72) days; 100% Concentrate (C) for 36 (C36) or 54 (C54) or 72 (C72) days. A trained sensory panel found Intensity of Lamb Aroma, Dry Aftertaste and Astringent Aftertaste to be higher in meat from lambs on the concentrate diet. Discriminant analysis showed that the volatile profile enabled discrimination of lamb based on dietary treatment but the volatile differences were insufficient to impact highly on sensory quality. Muscle from animals in the S54 group had higher Manure/Faecal Aroma and Woolly Aroma than the SC54 and C54 groups, possibly related to higher levels of indole and skatole. Further research is required to establish if these small differences would influence consumer acceptability.
    • Influence of stormflow and baseflow phosphorus pressures on stream ecology in agricultural catchments

      Shore, Mairead; Murphy, Sinead; Mellander, Per-Erik; Shortle, Ger; Melland, Alice R.; Crockford, Lucy; O'Flaherty, Vincent; Williams, Lauren; Morgan, Ger; Jordan, Philip; et al. (Elsevier, 2017-03-09)
      Stormflow and baseflow phosphorus (P) concentrations and loads in rivers may exert different ecological pressures during different seasons. These pressures and subsequent impacts are important to disentangle in order to target and monitor the effectiveness of mitigation measures. This study investigated the influence of stormflow and baseflow P pressures on stream ecology in six contrasting agricultural catchments. A five-year high resolution dataset was used consisting of stream discharge, P chemistry, macroinvertebrate and diatom ecology, supported with microbial source tracking and turbidity data. Total reactive P (TRP) loads delivered during baseflows were low (1–7% of annual loads), but TRP concentrations frequently exceeded the environmental quality standard (EQS) of 0.035 mg L− 1 during these flows (32–100% of the time in five catchments). A pilot microbial source tracking exercise in one catchment indicated that both human and ruminant faecal effluents were contributing to these baseflow P pressures but were diluted at higher flows. Seasonally, TRP concentrations tended to be highest during summer due to these baseflow P pressures and corresponded well with declines in diatom quality during this time (R2 = 0.79). Diatoms tended to recover by late spring when storm P pressures were most prevalent and there was a poor relationship between antecedent TRP concentrations and diatom quality in spring (R2 = 0.23). Seasonal variations were less apparent in the macroinvertebrate indices; however, there was a good relationship between antecedent TRP concentrations and macroinvertebrate quality during spring (R2 = 0.51) and summer (R2 = 0.52). Reducing summer point source discharges may be the quickest way to improve ecological river quality, particularly diatom quality in these and similar catchments. Aligning estimates of P sources with ecological impacts and identifying ecological signals which can be attributed to storm P pressures are important next steps for successful management of agricultural catchments at these scales.
    • Effect of suckler cow vaccination against glycoprotein E (gE)-negative bovine herpesvirus type 1 (BoHV-1) on passive immunity and physiological response to subsequent bovine respiratory disease vaccination of their progeny

      Earley, Bernadette; Tiernan, Katie; Duffy, Catherine; Dunn, Amanda; Waters, Sinead; Morrison, Steven; McGee, Mark; Department of Agriculture, Food and the Marine; 11/S/131 (Elsevier, 2018-01-10)
      The study objectives were: 1) to characterise the development of immunocompetence in beef suckler calves from birth to three months of age, and 2) to trace glycoprotein E (gE)-negative bovine herpesvirus type 1 (BoHV-1) antibodies from dam to calf and subsequent vaccination against pneumonia. Thirty multiparous beef suckler, spring-calving cows, consisting of two genotypes were involved; Limousin × Friesian (LF) and Charolais × Limousin (CL). Cows were immunised against the inactivated antigen strain of BoHV-1 (gE- (IBR marker vaccine) at day − 84 and received a booster at day − 56 relative to the expected calving date (d 0). Calves were immunised at 14 and 42 days of age against PI-3 virus, BRSV and Mannheimia (Pasteurella) haemolytica serotype A1 using a commercial vaccine administered subcutaneously. Additionally, calves were immunised against BoHV-1 at 42 days of age, using 1 dose of a live commercial vaccine administered intranasally. Blood samples were collected from all calves (n = 30) via jugular venipuncture at birth, prior to colostrum feeding (0 h), at 12 h (h), 24 h, 72 h and 168 h after the initial feeding of colostrum, and at d 7, 14, 28, 42, 56 and 84 post birth. The mean ratio of gE negative antibodies circulating in the blood of LF and CL dams pre-partum scored negative to gE ab (S/N ≥ 0.70). Antibody levels of BoHV-1 (wild type (wt)) peaked at 12 h post-birth in calves and declined thereafter, as the maternal antibodies decayed. There was no difference in BoHV-1 and BRSV antibody levels in calves post vaccination.
    • Phytosterol crystallisation within bulk and dispersed triacylglycerol matrices as influenced by oil droplet size and low molecular weight surfactant addition

      Zychowski, Lisa M.; Logan, Amy; Augustin, Mary Ann; Kelly, Alan L.; O'Mahony, James A.; Conn, Charlotte E.; Auty, Mark; Teagasc; Australian Research Council; 6412; et al. (Elsevier, 2018-04-12)
      Phytosterols can lower LDL-cholesterol and are frequently used by the functional food industry. However, little is known regarding how phytosterol crystallisation can be controlled, despite solubilised phytosterols having improved bioaccessibility. This study investigates phytosterol crystallisation in bulk milk fat and in model dairy emulsion systems at two average droplet sizes, 1.0 and 0.2 µm. The effect of lecithin and monoacylglycerol addition on phytosterol crystallisation for both emulsion and bulk systems was also evaluated. Results demonstrated that lecithin and monoacylglycerols enrichment into the bulk system minimised phytosterol crystallisation. However, in emulsions, phytosterol crystallisation was mainly influenced by decreasing the droplet size. Smaller emulsion droplets containing lecithin showed the greatest potential for decreasing phytosterol crystallisation and had improved physicochemical stability. This information can be employed by the functional food industry to minimise phytosterol crystallisation and possibly improve bioaccessibility.
    • Investigating the use of visible and near infrared spectroscopy to predict sensory and texture attributes of beef M. longissimus thoracis et lumborum

      Cafferky, Jamie; Sweeney, Torres; Allen, Paul; Sahar, Amna; Downey, Gerard; Cromie, A. R.; Hamill, Ruth M; Department of Agriculture, Food and the Marine; 11/SF/311 (Elsevier, 2019-08-16)
      The aim of this study was to calibrate chemometric models to predict beef M. longissimus thoracis et lumborum (LTL) sensory and textural values using visible-near infrared (VISNIR) spectroscopy. Spectra were collected on the cut surface of LTL steaks both on-line and off-line. Cooked LTL steaks were analysed by a trained beef sensory panel as well as undergoing WBSF analysis. The best coefficients of determination of cross validation (R2CV) in the current study were for textural traits (WBSF = 0.22; stringiness = 0.22; crumbly texture = 0.41: all 3 models calibrated using 48 h post-mortem spectra), and some sensory flavour traits (fatty mouthfeel = 0.23; fatty after-effect = 0.28: both calibrated using 49 h post-mortem spectra). The results of this experiment indicate that VISNIR spectroscopy has potential to predict a range of sensory traits (particularly textural traits) with an acceptable level of accuracy at specific post-mortem times.
    • Integration of high and low field 1H NMR to analyse the effects of bovine dietary regime on milk metabolomics and protein-bound moisture characterisation of the resulting mozzarella cheeses during ripening

      Boiani, Mattia; Sundekilde, Ulrik; Bateman, Lorraine M.; McCarthy, Daniel G.; Maguire, Anita R.; Gulati, Arunima; Guinee, Timothy P.; Fenelon, Mark A.; Hennessy, Deirdre; Fitzgerald, Richard J.; et al. (Elsevier, 2018-10-11)
      The influence of dairy cow feeding regime was investigated using 1H nuclear magnetic resonance (NMR). Two different NMR analytical systems were deployed: high field 1H NMR to investigate the influence on milk metabolomics and low field NMR to characterise proton relaxation linked to changes in the state of mozzarella cheese moisture during ripening. The metabolomics results showed that grass-based feeding increased the concentration of a biological marker that signifies near-organic milk production conditions. On the other hand, the investigation of cheese moisture distribution showed that grass-based diets reached final moisture partitioning in a shorter time, which implied the formation of a more compact protein structure in the cheese matrix. These results indicate that pasture-based dairying may be differentiated in terms of the provenance of milk produced along with the accrual of additional benefits during ripening of the resulting mozzarella cheeses.
    • Short communication: Multi-component interactions causing solidification during industrial-scale manufacture of pre-crystallized acid whey powders

      Drapala, Kamil P.; Murphy, Kevin M.; Ho, Quang Tri; Crowley, Shane V.; Mulcahy, Shane; McCarthy, Noel; O'Mahony, James A.; Technology Centres Programme; TC/2014/0016 (Elsevier, 2018-10-03)
      Acid whey (AW) is the liquid co-product arising from acid-induced precipitation of casein from skim milk. Further processing of AW is often challenging due to its high mineral content, which can promote aggregation of whey proteins, which contributes to high viscosity of the liquid concentrate during subsequent lactose crystallization and drying steps. This study focuses on mineral precipitation, protein aggregation, and lactose crystallization in liquid AW concentrates (∼55% total solids), and on the microstructure of the final powders from 2 independent industrial-scale trials. These AW concentrates were observed to solidify either during processing or during storage (24 h) of pre-crystallized concentrate. The more rapid solidification in the former was associated with a greater extent of lactose crystallization and a higher ash-to-protein ratio in that concentrate. Confocal laser scanning microscopy analysis indicated the presence of a loose network of protein aggregates (≤10 µm) and lactose crystals (100–300 µm) distributed throughout the solidified AW concentrate. Mineral-based precipitate was also evident, using scanning electron microscopy, at the surface of AW powder particles, indicating the formation of insoluble calcium phosphate during processing. These results provide new information on the composition- and process-dependent physicochemical changes that are useful in designing and optimizing processes for AW.
    • Efficacy of ultraviolet light (UV-C) and pulsed light (PL) for the microbiological decontamination of raw salmon (Salmo salar) and food contact surface materials

      Pedrós-Garrido, S.; Condón-Abanto, S.; Clemente, I.; Beltrán, J.A.; Lyng, James G.; Bolton, Declan J.; Brunton, Nigel; Whyte, P.; Department of Agriculture, Food and the Marine; 13F458 (Elsevier, 2018-10-03)
      The decontamination effect of two light-based technologies on salmon, polyethylene (PE) and stainless steel (SS) was evaluated. Optimization of treatment conditions for ultraviolet light (UV-C) and pulsed light (PL) was carried out on raw salmon, obtaining inactivation levels of 0.9 and 1.3 log CFU/g respectively. The effects of treatments on several microbial groups present in salmon were then evaluated. For both technologies, Pseudomonas spp. were found to be the most resistant group of microorganisms tested. Three different strains from within this group were isolated and speciated, including a P. fluorescens strain which was selected for subsequent studies. PE and SS surfaces were inoculated with a suspension of the P. fluorescens suspended in a ‘salmon juice’ solution, and treated with UV-C and PL at different doses (mJ/cm2). PE surfaces were effectively decontaminated a low doses for both technologies, with a reduction of >4 log cycles observed. Decontamination of SS was also effective when treated with PL, although at higher doses than for PE. When SS was treated with UV-C, the maximum reduction of P. fluorescens achieved was 2 log cycles, even at the highest dose.
    • Symposium review: Genomic investigations of flavor formation by dairy microbiota

      McAuliffe, Olivia; Kilcawley, Kieran N; Stefanovic, Ewelina; Teagasc Walsh Fellowship programme; Dairy Research Ireland; IRCSET; EU Marie Curie Actions Clarin Co-Fund (Elsevier, 2018-10-19)
      Flavor is one of the most important attributes of any fermented dairy product. Dairy consumers are known to be willing to experiment with different flavors; thus, many companies producing fermented dairy products have looked at culture manipulation as a tool for flavor diversification. The development of flavor is a complex process, originating from a combination of microbiological, biochemical, and technological aspects. A key driver of flavor is the enzymatic activities of the deliberately inoculated starter cultures, in addition to the environmental or “nonstarter” microbiota. The contribution of microbial metabolism to flavor development in fermented dairy products has been exploited for thousands of years, but the availability of the whole genome sequences of the bacteria and yeasts involved in the fermentation process and the possibilities now offered by next-generation sequencing and downstream “omics” technologies is stimulating a more knowledge-based approach to the selection of desirable cultures for flavor development. By linking genomic traits to phenotypic outputs, it is now possible to mine the metabolic diversity of starter cultures, analyze the metabolic routes to flavor compound formation, identify those strains with flavor-forming potential, and select them for possible commercial application. This approach also allows for the identification of species and strains not previously considered as potential flavor-formers, the blending of strains with complementary metabolic pathways, and the potential improvement of key technological characteristics in existing strains, strains that are at the core of the dairy industry. An in-depth knowledge of the metabolic pathways of individual strains and their interactions in mixed culture fermentations can allow starter blends to be custom-made to suit industry needs. Applying this knowledge to starter culture research programs is enabling research and development scientists to develop superior starters, expand flavor profiles, and potentially develop new products for future market expansion.
    • Evaluation of Vis-NIR hyperspectral imaging as a process analytical tool to classify brined pork samples and predict brining salt concentration

      Achata, Eva M.; Inguglia, Elena S.; Esquerre, Carlos; Tiwari, Brijesh; O'Donnell, Colm P.; Department of Agriculture, Food and the Marine; 13/FM/508 (Elsevier, 2018-10-20)
      Hyperspectral imaging in the visible and near infrared spectral range (450–1664 nm) coupled with chemometrics was investigated for classification of brined and non-brined pork loins and prediction of brining salt concentration employed. Hyperspectral images of control, water immersed and brined (5, 10 or 15% salt (w/v)) raw and cooked pork loins from 16 animals were acquired. Partial least squares (PLS) discriminative analysis models were developed to classify brined pork samples and PLS regression models were developed for prediction of brining salt concentration employed. The ensemble Monte Carlo variable selection method (EMCVS) was used to improve the performance of the models developed. Partial least squares (PLS) discriminative analysis models developed correctly classified brined and non-brined samples, the best classification model for raw samples (Sen = 100%, Spec = 100%, G = 1.00) used the 957–1664 nm spectral range, and the best classification model for cooked samples (Sen = 100%, Spec = 100%, G = 1.00) used the 450–960 nm spectral range. The best brining salt concentration prediction models developed for raw (RMSEp 1.9%, R2p 0.92) and cooked (RMSEp 2.6%, R2p 0.83) samples used the 957–1664 nm spectral range. This study demonstrates the high potential of hyperspectral imaging as a process analytical tool to classify brined and non-brined pork loins and predict brining salt concentration employed.
    • Preparation of modified whey protein isolate with gum acacia by ultrasound maillard reaction

      Chen, Weijun; Ma, Xiaobin; Wang, Wenjun; Lv, Ruiling; Guo, Mingming; Ding, Tian; Ye, Xingqian; Miao, Song; Liu, Donghong; National Key Research and Development Program of China; et al. (Elsevier, 2018-10-18)
      Effect of ultrasound treatment on whey protein isolate (WPI)-gum Acacia (GA) conjugation via Maillard reaction was investigated. And the physicochemical properties of the conjugates obtained by ultrasound treatment were compared with those obtained by classical heating. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, high-performance size exclusion chromatography and fourier transform infrared spectroscopy provided evidence on the formation of the Maillard type conjugation. Compared with classical heating, ultrasound treatment could accelerate the glycation reaction between WPI and GA. A degree of graft of 11.20% was reached by classical heating for 48 h, whereas only 20 min was required by ultrasound treatment. Structural analyses suggested that the conjugates obtained by ultrasound treatment had less α-helix content, higher surface hydrophobicity and fluorescence intensity than those obtained by classical heating. Significantly lower level of browning intensity and significantly higher (p < 0.05) level of solubility (under alkaline conditions), thermal stability, emulsifying activity and emulsifying stability were observed for the conjugates obtained by ultrasound treatment as compared with those obtained by classical heating.
    • Development of a scoring method to identify important areas of plant diversity in Ireland

      Walsh, Aidan; Sullivan, C. A.; Waldren, Stephen; Finn, John A.; Irish Research Council; Teagasc Walsh Fellowship Programme; PD/2011/2150; 2011012 (Elsevier, 2018-10-28)
      In the face of accelerating biodiversity loss it is more important than ever to identify important areas of biodiversity and target limited resources for conservation. We developed a method to identify areas of important plant diversity using known species’ distributions and evaluations of the species importance. We collated distribution records of vascular plants and developed a scoring method of spatial prioritisation to assign conservation value to the island of Ireland at the hectad scale (10 km × 10 km) and at the tetrad scale (2 km × 2 km) for two counties where sufficient data were available. Each plant species was assigned a species conservation value based on both its conservation status and distribution in Ireland. For each cell, the species conservation values within the cell were summed, thereby differentiating between areas of high and low conservation value across the landscape. Areas with high conservation value represent the most important areas for plant conservation. The protected area cover and the number of species present in these important areas were also examined by first defining threshold values using two different criteria. Species representation was high in the important areas; the identified important areas of plant diversity maintained high representation of species of conservation concern and achieved high species representation overall, requiring a low number of sites (<8%) to do so. The coincidence of protected areas and important areas for plant diversity was found to be low and while some important areas of plant diversity might benefit from the general protection afforded by these areas, our research highlights the need for conservation outside of protected areas.
    • Comparison of antioxidant activities of bovine whey proteins before and after simulated gastrointestinal digestion

      Corrochano, Alberto R.; Sariçay, Yunus; Arranz, Elena; Kelly, Philip M.; Buckin, Vitaly; Giblin, Linda; Department of Agriculture, Food and the Marine; Teagasc Walsh Fellowship Programme; 13 F 354-WheyGSH (Elsevier, 2018-10-24)
      Oxidative stress caused by free radicals has been implicated in several human disorders. Dietary antioxidants can help the body to counteract those reactive species and reduce oxidative stress. Antioxidant activity is one of the multiple health-promoting attributes assigned to bovine whey products. The present study investigated whether this activity was retained during upper gut transit using a static simulated in vitro gastrointestinal digestion (SGID) model. The capacity to scavenge free radicals and reduce ferric ion of whey protein isolate (WPI), individual whey proteins, and hydrolysates pre- and post-SGID were measured and compared using various antioxidant assays. In addition, the free AA released from individual protein fractions in physiological gut conditions were characterized. Our results indicated that the antioxidant activity of WPI after exposure to the harsh conditions of the upper gut significantly increased compared with intact WPI. From an antioxidant bioactivity viewpoint, this exposure negates the need for prior hydrolysis of WPI. The whey protein α-lactalbumin showed the highest antioxidant properties post-SGID (oxygen radical absorbance capacity = 1,825.94 ± 50.21 μmol of Trolox equivalents/g of powder) of the 4 major whey proteins tested with the release of the highest amount of the antioxidant AA tryptophan, 6.955 μmol of tryptophan/g of protein. Therefore, α-lactalbumin should be the preferred whey protein in food formulations to boost antioxidant defenses.
    • Comparison of the nutritional composition of experimental fermented milk:wheat bulgur blends and commercially available kishk and tarhana products

      O'Callaghan, Yvonne; Shevade, Ashwini V.; Guinee, Timothy P.; O'Connor, Tom P.; O'Brien, Nora M.; Department of Agriculture, Food and the Marine; 14/F/805 (Elsevier, 2018-11-05)
      Dried, fermented blends of dairy products and cereals, such as kishk and tarhana, are foodstuffs traditionally consumed in many regions as they possess good nutritional qualities and extended storage stability. This study examined the nutritional composition of kishk or tarhana type products and compared with experimental blends of fermented milk and wheat bulgur containing 60–80% milk. The blends with higher milk contents had levels of protein (18.9%) and fat (5.8%) at the concentrations specified in fortified blended foods as outlined by the World Food Program. Higher milk contents were also associated with higher contents of calcium (323.2 mg/100 g), phosphorus (335.3 mg/100 g), vitamin A (486.7 µg/100 g) and α-tocopherol (174.5 µg/100 g). The nutritional content of the experimental fermented milk:wheat bulgur blends compared favourably with that of the commercial samples. These blends may be suitable as base products, to be fortified with micronutrients, for the development of fortified blended foods (FBFs) for humanitarian distribution.
    • Modelling the changes in viscosity during thermal treatment of milk protein concentrate using kinetic data

      Ho, Quang Tri; Murphy, Kevin M.; Drapala, Kamil P.; Fenelon, Mark A.; O'Mahony, James A.; Tobin, John; McCarthy, Noel; Enterprise Ireland; TC/2014/0016 (Elsevier, 2018-10-24)
      This work aimed to model the effect of heat treatment on viscosity of milk protein concentrate (MPC) using kinetic data. MPC obtained after ultrafiltration was subjected to different time-temperature heat treatment combinations. Heat treatment at high temperature and short time (i.e., 100 or 120 °C×30 s) led to a significant increase in viscosity in MPC systems. Second-order reaction kinetic models proved a better fit than zero- or first-order models when fitted for viscosity response to heat treatment. A distinct deviation in the slope of the Arrhenius plot at 77.9 °C correlated to a significant increase in the rate of viscosity development at temperatures above this, confirming the transition of protein denaturation from the unfolding to the aggregation stage. This study demonstrated that heat-induced viscosity of MPC as a result of protein denaturation/aggregation can be successfully modelled in response to thermal treatment, providing useful new information in predicting the effect of thermal treatment on viscosity of MPC.
    • Using rejection thresholds to determine acceptability of novel bioactive compounds added to milk-based beverages

      Murray, Niamh M.; Jacquier, Jean Christophe; O'Sullivan, Michael; Hallihan, Áine; Murphy, Eoin; Feeney, Emma L.; O'Riordan, Dolores; Enterprise Ireland; TC2013001 (Elsevier, 2018-11-03)
      This study aimed to identify the amount of crude casein-hydrolysate (HMW) and a low molecular weight sub-fraction (LMW) thereof that could be incorporated into strawberry- and vanilla-flavoured beverages before the bitterness/taste became objectionable to panellists. The beverages were spiked with increasing amounts of hydrolysate and a 2-alternative forced choice (2-AFC) design was employed to determine rejection thresholds (RjT). Results showed a higher amount of HMW, than LMW, could be incorporated into the beverages before the taste became objectionable and the type of flavouring did not have a significant effect on RjT. Following the 2-AFC, panellists rated the bitterness of the hydrolysates (in water) on a general Labelled Magnitude Scale (gLMS). Results showed no significant differences between the bitterness perception of the HMW and LMW. However, there was considerable variation in the panellists’ perception of bitterness, suggesting possible evidence for segmentation. Using this rationale, each panel was segmented into two groups: those who rated the bitterness of the hydrolysate samples as ≤20 on the gLMS and, those who rated the bitterness as ≥75 on the gLMS, and RjT were examined within them. Although a trend was seen for those most sensitive to bitterness in water, to have a lower acceptance for the level in the beverages, the RjT of the segmented groups were not significantly different from each other. Evaluation of hydrolysates in water does therefore not appear to be suitable for predicting consumer acceptance of hydrolysates in food matrices; highlighting the importance of testing food ingredients in the final food product.
    • Artificial rearing affects piglets pre-weaning behaviour, welfare and growth performance

      Schmitt, Océane; O'Driscoll, Keelin; Boyle, Laura; Baxter, Emma M.; Department of Agriculture, Food and the Marine; 13S428 (Elsevier, 2018-11-02)
      One strategy adopted on farms to deal with managing large litters involves removing piglets from their mothers at seven days old to be reared in specialised accommodation with milk replacer. Effects on piglet behaviour, growth and some aspects of welfare were evaluated in this study by comparing 10 pairs of two litters (one sow-reared: SR, one artificially-reared: AR) selected at seven days-old at a similar weight. Piglet behaviour was recorded for 20 min following transfer of AR piglets to the artificial-rearing enclosure (D0) and for 20 min hourly between 09:00 h and 17:00 h (8 h) on D5 and D12. Hourly 5 min live observations were also undertaken. Qualitative Behavioural Assessment (QBA) was conducted on D14 to evaluate piglets’ emotional state. Survival and illness events were recorded until weaning. On D0, D1, D8 and D15 piglets were weighed and scored for tear staining, dirtiness of the face and severity of lesions on the snout, limbs, ear and tail. Survival and illness rates, as well as the rates of behaviours/min were analysed using GLMMs. Weights and QBA scores were analysed using GLM. Lesions, tear staining and dirtiness scores were averaged per litter and analysed using GLM. When AR piglets were transferred to the artificial-rearing enclosure, their behaviour was not different to SR piglets. Over the two observation days, AR piglets performed more belly-nosing (F1,76.53 = 42.25; P < 0.001), nursing-related displacements (F1,79 = 19.32, P < 0.001), visits to the milk cup (compared to nursing bouts; F1,73.8 = 38.42, P < 0.001), and oral manipulation of littermates’ ears (F1,91.95 = 12.79, P < 0.001) and tails (F1,58.54 = 15.63, P < 0.001) than SR piglets. However, SR piglets played alone (F1,88.99 = 8.29, P < 0.005) and explored their environment (F1,99.42 = 4.52, P < 0.05) more frequently than AR piglets. The QBA scores indicated a lower emotional state in AR piglets (t25.1=-3.25, P < 0.05). Survival rate and overall illness rate of piglets were similar between the treatments. AR piglets experienced a growth check following their transfer to the artificial-rearing enclosure and remained lighter than SR piglets through to weaning (6.53 ± 0.139 kg vs. 7.97 ± 0.168 kg, t256 = 9.79, P < 0.001). Overall, snout lesion scores were not different between the treatments, but AR piglets had lower limb (F1,10.1 = 5.89, P < 0.05) and ear (F1,14.5 = 24.89, P < 0.001) lesion scores and higher tail lesion scores (F1,34.5 = 15.54, P < 0.001). AR piglets were dirtier (F1,17.4 = 23.38, P < 0.001) but had lower tear staining scores (F1,19.1 = 68.40, P < 0.001) than SR piglets. In conclusion, artificial rearing impaired piglets’ behaviour, welfare and growth.